PlayStation®Mobile Development Cookbook

Table of Contents

PlayStation®Mobile Development Cookbook

Credits

About the Author

About the Reviewers

www.PacktPub.com

Support files, eBooks, discount offers and more

Why Subscribe?

Free Access for Packt account holders

Preface

A tour of the PlayStation Mobile SDK

PSM Studio IDE

Compiler and runtime

UIComposer

Other utilities

PlayStation Mobile certified devices

PlayStation Vita specifications

HTC Hero One X specifications

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Downloading the color images of this book

Errata

Piracy

Questions

1. Getting Started

Introduction

Accessing the PlayStation Mobile portal

Getting ready

How to do it...

How it works...

Installing the PlayStation Mobile SDK

Getting ready

How to do it...

How it works...

There's more...

See also

Creating a simple game loop

Getting ready

How to do it...

How it works...

There's more...

Loading, displaying, and translating a textured image

Getting ready

How to do it...

How it works...

There's more...

"Hello World" drawing text on an image

Getting ready

How to do it...

How it works...

There's more...

Deploying to PlayStation Mobile certified Android devices

Getting ready

How to do it...

There's more...

Deploying to a PlayStation Vita

Getting ready

How to do it...

There's more...

See also

Manipulating an image dynamically

Getting ready

How to do it...

How it works...

There's more...

Working with the filesystem

Getting ready

How to do it...

How it works...

There's more...

See also

Handling system events

Getting ready

How to do it...

How it works...

2. Controlling Your PlayStation Mobile Device

Introduction

Handling the controller's d-pad and buttons

Getting ready

How to do it...

How it works...

There's more...

See also

Using the Input2 wrapper class

Getting ready

How to do it...

How it works...

There's more...

See also

Using the analog joysticks

Getting ready

How to do it...

How it works...

There's more...

See also

Handling touch events

Getting ready

How to do it...

How it works...

There's more...

See also

Using the motion sensors

Getting ready

How to do it...

How it works...

There's more...

See also

Creating onscreen controls for devices without gamepads

Getting ready

How to do it…

How it works...

There's more...

See also

Configuring an Android application to use onscreen controls

Getting ready

How to do it…

How it works...

There's more...

See also

3. Graphics with GameEngine2D

Introduction

A game loop, GameEngine2D style

Getting ready

How to do it...

How it works...

There's more...

See also

Creating scenes

Getting ready

How to do it...

How it works...

There's more...

Adding a grid

See also

Adding a sprite to a scene

Getting ready

How to do it...

How it works...

There's more...

See also

Creating a sprite sheet

Getting ready

How to do it...

How it works...

There's more...

See also

Using a sprite sheet in code

Getting ready

How to do it...

How it works...

There's more...

See also

Batching a sprite with SpriteLists

Getting ready

How to do it...

How it works...

There's more...

See also

Manipulating a texture's pixels

Getting ready

How to do it...

How it works...

There's more...

See also

Creating a 2D particle system

Getting ready

How to do it...

How it works...

There's more...

See also

4. Performing Actions with GameEngine2D

Introduction

Handling updates with Scheduler

Getting ready

How to do it...

How it works...

There's more...

See also

Working with the ActionManager object

Getting ready

How to do it...

How it works...

There's more...

See also

Using predefined actions

Getting ready

How to do it...

How it works...

There's more...

See also

Transitioning between scenes

Getting ready

How to do it...

How it works...

There's more...

See also

Simple collision detection

Getting ready

How to do it...

How it works...

There's more...

See also

Playing background music

Getting ready

How to do it...

How it works...

There's more...

See also

Playing sound effects

Getting ready

How to do it...

How it works...

There's more...

See also

5. Working with Physics2D

Introduction

Creating a simple simulation with gravity

Getting ready

How to do it...

How it works...

There's more...

See also

Switching between dynamic and kinematic

Getting ready

How to do it...

How it works...

There's more...

See also

Creating a (physics!) joint

Getting ready

How to do it...

How it works...

There's more...

See also

Applying force and picking a physics scene object

Getting ready

How to do it...

How it works...

There's more...

See also

Querying if a collision occurred

Getting ready

How to do it...

How it works...

There's more...

See also

Rigid body collision shapes

Getting ready

How to do it...

How it works...

There's more...

Building and using an external library

Getting ready

How to do it...

How it works...

There's more...

6. Working with GUIs

Introduction

"Hello World" – HighLevel.UI style

Getting ready

How to do it...

How it works...

There's more...

See also

Using the UI library within a GameEngine2D application

Getting ready

How to do it...

How it works...

There's more...

See also

Creating and using hierarchies of widgets

Getting ready

How to do it...

How it works...

There's more...

Container widgets

Common widgets

Creating a UI visually using UIComposer

Getting ready

How to do it...

How it works...

There's more...

See also

Displaying a MessageBox dialog

Getting ready

How to do it...

How it works...

There's more...

See also

Handling touch gestures and using UI effects

Getting ready

How to do it...

How it works...

There's more...

See also

Handling language localization

Getting ready

How to do it...

There's more...

See also

7. Into the Third Dimension

Introduction

Creating a simple 3D scene

Getting ready

How to do it...

How it works...

There's more...

See also

Displaying a textured 3D object

Getting ready

How to do it...

How it works...

There's more...

See also

Implementing a simple camera system

Getting ready

How to do it...

How it works...

See also

A fragment (pixel) shader in action

Getting ready

How to do it...

How it works...

There's more...

See also

A vertex shader in action

Getting ready

How to do it...

How it works...

There's more...

See also

Adding lighting to your scene

Getting ready

How to do it...

How it works...

There's more...

See also

Using an offscreen frame buffer to take a screenshot

Getting ready

How to do it...

How it works...

There's more...

See Also

8. Working with the Model Library

Introduction

Importing a 3D model for use in PlayStation Mobile

Getting ready

How to do it...

How it works...

There's more...

See also

Loading and displaying a 3D model

Getting ready

How to do it...

How it works...

There's more...

See also

Using BasicProgram to perform texture and shader effects

Getting ready

How to do it...

How it works...

There's more...

See also

Controlling lighting using BasicProgram

Getting ready

How to do it...

How it works...

There's more...

See also

Animating a model

Getting ready

How to do it...

How it works...

There's more...

See also

Handling multiple animations

Getting ready

How to do it...

How it works...

There's more...

See also

Using bones to add a sword to our animated model

Getting ready

How to do it...

How it works...

There's more...

9. Finishing Touches

Introduction

Opening and loading a web browser

Getting ready

How to do it...

How it works...

There's more...

Socket-based client and server networking

Getting ready

How to do it...

How it works...

There's more...

See Also

Accessing (Twitter) data over the network using REST and HttpWebRequest

Getting ready

How to do it...

How it works...

There's more...

See also

Copying and pasting using Clipboard

Getting ready

How to do it...

How it works...

There's more...

Embedding and retrieving a resource from the application assembly

Getting ready

How to do it...

How it works...

There's more...

See also

Configuring your application using PublishingUtility

Getting ready

How to do it...

There's more…

See also

Creating downloadable content (DLC) for your application

Getting ready

How to do it...

How it works...

There's more...

See also

A. Publishing Your Application

Introduction

Process overview

Obtaining a developer license

Your publisher keys

Preparing your application for publication

Publishing your application

Index

PlayStation®Mobile Development Cookbook

PlayStation®Mobile Development Cookbook

Copyright © 2013 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

"PlayStation" is a registered trademark of Sony Computer Entertainment Inc.

"" is a trademark of the same company.

First published: March 2013

Production Reference: 1180313

Published by Packt Publishing Ltd.

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ISBN 978-1-84969-418-6

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Cover Image by Suresh Mogre (<suresh.mogre.99@gmail.com>)

Credits

Author

Michael Fleischauer

Reviewers

Neil Brown

Mehul Shukla

Acquisition Editor

Erol Staveley

Lead Technical Editor

Erol Staveley

Technical Editors

Sharvari Baet

Devdutt Kulkarni

Kirti Pujari

Project Coordinator

Anurag Banerjee

Proofreader

Lawrence A. Herman

Indexer

Rekha Nair

Graphics

Aditi Gajjar

Production Coordinator

Manu Joseph

Cover Work

Manu Joseph

About the Author

Michael Fleischauer has spent the last 16 years working as a programmer in a number of different industries from 3D tools creation to automotive and banking. Most recently he launched the internet start-up Flexamail. In his spare time he writes for and runs the game development site GameFromScratch.com, a popular destination for game development tutorials and news. Michael was recently made the first PlayStation Mobile MVP by Sony. Michael lives in Toronto, Canada with his wife and daughter.

I would like to thank my daughter Kailyn for sending me down this new career path and my wife Jenn for supporting me through it all. My thanks to my editor Erol Stavely and the entire team at Packt Publishing; this entire experience has been a pleasant one. Finally, I would like to thank Paul Holman, Mehul Shukla, and the entire PlayStation Mobile team at Sony; your ongoing support is greatly appreciated!

About the Reviewers

Neil Brown is Senior Team Leader in the SCEE R & D Developer Services team. Apart from providing technical support and performance advice, he coordinates support for all PlayStation platforms in the historic PAL regions, including PlayStation Mobile.

Neil has given technical talks at a number of games industry conferences around the world for SCE, speaking about PSM at Develop Brighton, Casual Connect in Kiev, and Nordic Game.

Neil has been in the games industry for almost 10 years, and has Masters degrees in Software Engineering, and Physics with Astrophysics.

Mehul Shukla is one of the PlayStation®Mobile specialists in the SCEE R & D Developer Services team. The Developer Services team provides front-line engineering support for all game developers, large or small, on all PlayStation platforms. On a daily basis, he provides technical support and performance advice for developers all over the globe on the PSM community forums.

Mehul has also given technical talks about PSM at a number of games industry conferences and academic events.

Mehul joined SCEE R & D straight from University and has a Master's degree in Games programming and a Bachelor's degree in Computer Systems Engineering.

I would like to thank Mike for his involvement in PlayStation®Mobile and his contribution to the developer community. Mike is one of the most valuable members of the PlayStation®Mobile community and has been actively involved in providing useful advice on our developer forums. We wish him all the best in the future.

Packt Publishing would also like to thank Paul Holman, Marijke Coopmans, and Sarah Thomson for their help and support throughout the development of this book.

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Preface

The PlayStation Mobile SDK presents an incredible opportunity for developers to easily and affordably create and sell applications for the PlayStation Vita, as well as a number of PlayStation certified devices. This represents the first time it has been possible to write applications for a console quality portable device without first having to spend several thousands of dollars on professional development kits.

It includes all of the tools you require to successfully create a game, including a complete Integrated Development Environment (IDE), a C#/Mono based compiler and runtime, as well as the tools and utilities required to create interfaces and import game assets. The SDK is suitable for a range of developers, from hobbyists to Indie game developers as well as AAA game studios. A number of large studios, including From Software, Gameloft, and Sega, have announced their support for PlayStation Mobile. To date, a number of titles have already shipped and are available in the online store.

A tour of the PlayStation Mobile SDK

We will now take a quick tour of what is included in the SDK; if you haven’t already, download it from the PlayStation Mobile Developer Portal at https://psm.playstation.net/. The SDK includes the components that we will discuss now.

PSM Studio IDE

The PSM Studio is a complete IDE derived from the popular open source MonoDevelop project. It includes a complete code editor, project management system, and integrated debugger. It contains most features you would expect of a modern IDE such as unit testing, code completion, and refactoring.

Compiler and runtime

PlayStation Mobile is built on top of the Mono compiler and virtual machine. In addition to the PlayStation provided libraries, it includes the following .NET libraries:

- System

- System.Core

- System.Runtime.Serialization

- System.ServiceModel

- System.ServiceModel.Web

- System.Web.Services

- System.Xml

- System.Xml.Linq

In addition to those standard .NET libraries, Sony has provided the following libraries:

- Sce.Pss.Core

- Sce.Pss.HighLevel.GameEngine2D

- Sce.Pss.HighLevel.Model

- Sce.Pss.HighLevel.Physic2D

- Sce.Pss.HighLevel.UI

You can also make use of any existing C# code that does not require native access. We will look at each of these libraries in more detail throughout the book.

UIComposer

The UIComposer enables you to visually create user interfaces. It includes a comprehensive set of widgets including buttons, text fields, progress bars, flip panels, scrolling areas, and more. Ultimately UIComposer is a code generator that will output a .cs file that makes use of partial classes to keep your application logic separate from system generated code. If you are familiar with WinForms, this will be instantly comfortable for you. It is a drag-and-drop environment, enabling you to build your user interfaces in a visual manner:

Other utilities

The SDK includes a number of utilities for importing your various assets for use in your game. There is a command line based model converter for importing your 3D model into PSM’s native MDX format. There are also tools for importing Flash animations, and graphical shaders, as well as a tool for creating on-screen controllers for Android devices. Finally, there is the PublishingUtility, which is used to prepare your application for deployment to the online store as well as for creating downloadable content. Assuming a default installation, all these tools and more are located in the folder C:\Program Files(x86)\SCE\PSM\tools. We will cover many of these tools in detail later in the book.

PlayStation Mobile certified devices

PlayStation Mobile can target the PlayStation Vita, as well as a growing number of PlayStation certified devices. Currently this includes a number of Xperia mobile phones, Sony Android tablets, and a series of HTC phones. You can see a full list of certified phones at http://www.playstation.com/psm/certified.html.

It is hard to believe the level of technology being packed into these devices. Let us now see the specifications for the PlayStation Vita and HTC One X phones, two supported devices.

PlayStation Vita specifications

The following are the system requirements for PlayStation Vita:

- ARM A9 Quad Core processor

- PowerVR SGX543MP4 Quad Core GPU

- 512 MB RAM and 128 MB Video RAM

- 5" 960x544 pixel multi-touch display

- GPS, two cameras, two touch sensors, gyroscope, dual analog sticks

HTC Hero One X specifications

The following are the system requirements for HTC Hero One X:

- ARM A9 Dual or Quad Core Processor (depending on region)

- NVidia Tegra3

- 1024 MB RAM with 16-32 GB of storage

- 4.7" 1280 x 720 pixel multi-touch display

- GPS, Gyroscope, G-Sensor, Proximity Sensor, two cameras

As you can see, PlayStation Mobile is running on some remarkably capable hardware. It’s hard to believe how far things have come when you consider the original PSP was running on a single CPU running at 333 MHz with only 32 MB RAM while the Gameboy DS was powered by a pair of CPUs running at 67 and 33.5 MHz, respectively, with a paltry 4 MB of RAM. This generation of handheld devices is sporting hardware comparable to what is found in the PlayStation 3 and Xbox 360!

What this book covers

Chapter 1, Getting Started, covers getting the PlayStation Mobile SDK up and running and deployed to various devices (a task of some complexity). It jumps right in, creating basic graphical applications and covers the details and restraints of working on the devices.

Chapter 2, Controlling Your PlayStation Mobile Device, covers all the various ways in which you can control PSM devices, from the traditional joystick to touch and motion controls. Additionally, since not all devices have the same capabilities, it covers creation and handling of on-screen controllers.

Chapter 3, Graphics with GameEngine 2D, covers the graphical aspects of working with GameEngine2D—a higher level 2D gaming engine similar in design to the popular Cocos2D. It covers all aspects of 2D graphics from scenes and sprites to special effects and performance optimizations with SpriteLists.

Chapter 4, Performing Actions with GameEngine 2D, covers the action side of using GameEngine2D. This involves updating game objects, scheduling events, and executing actions, both in-built actions such as MoveTo and MoveBy and also defining your own.

Chapter 5, Working with Physics2D, covers working with Physics2D, PSM SDK’s in-built 2D physics system for creating physics simulations. Physics2D is not the only option for physics, so it also looks at integrating the popular BEPU and FarSeer XNA physics engines into your PSM application.

Chapter 6, Working with GUIs, covers the UI system built into the PlayStation Mobile. This ranges from creating on-screen buttons and panels, handling clicks and hold events, to advanced touch gestures. Additionally, it covers using UIComposer to visually create and edit UIs.

Chapter 7, Into the Third Dimension, covers working in 3D, from creating a camera and using graphic primitives to using fragment and vertex shaders.

Chapter 8, Working with the Model Library, covers working with 3D objects, including creating and exporting them using a third party application, converting them using the SDK tools, and finally displaying and animating them in 3D.

Chapter 9, Finishing Touches covers the wealth of networking options available to PSM devices. Additionally, we cover the Publishing tool and preparing your application for deployment to the PlayStation Mobile App Store.

Appendix, Publishing Your Application, covers the process of compiling, signing, packaging, and deploying your finished application to the PlayStation App Store.

What you need for this book

In order to get the most out of this book, you need to have a Windows computer capable of running the PlayStation Mobile SDK. You will also need a copy of the PlayStation Suite SDK, which can be downloaded at http://psm.playstation.net/.

Most samples can be run using the included simulator, but to get the most out of the PlayStation Mobile SDK, you should have a hardware device to run on, such as a PlayStation Vita or a PlayStation certified Android device. Currently, it is free to use the simulator, but not to deploy to a device.

The PlayStation Mobile Studio has the following system requirements:

- One of the following operating systems:

- Microsoft® Windows® XP Service Pack 3 or later (32 bit version only)

- Microsoft® Windows® 7 Service Pack 1 (32 bit or 64 bit version) or later

- 3 GHz processor or greater

- At least 2 GB of free space on your hard disk

- At least 4 GB of RAM

- A graphics card that supports OpenGL 3.0 or higher

- A sound card compatible with DirectX 9.0

- 1 or more USB 2.0 compatible ports

Who this book is for

If you’ve got some prior experience with C# and want to create awesome projects for the PlayStation®Vita and PlayStation™ Certified devices then this book is for you.

Conventions

In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

A block of code is set as follows:

Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "clicking the Next button moves you to the next screen".

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.

Reader feedback

Feedback from our readers is always welcome. Let us know what you think about this book—what you liked or may have disliked. Reader feedback is important for us to develop titles that you really get the most out of.

To send us general feedback, simply send an e-mail to <feedback@packtpub.com>, and mention the book title through the subject of your message.

If there is a topic that you have expertise in and you are interested in either writing or contributing to a book, see our author guide on www.packtpub.com/authors.

Customer support

Now that you are the proud owner of a Packt book, we have a number of things to help you to get the most from your purchase.

Downloading the example code

You can download the example code files for all Packt books you have purchased from your account at http://www.packtpub.com. If you purchased this book elsewhere, you can visit http://www.packtpub.com/support and register to have the files e-mailed directly to you.

Downloading the color images of this book

We also provide you a PDF file that has color images of the screenshots/diagrams used in this book. The color images will help you better understand the changes in the output. You can download this file from http://www.packtpub.com/sites/default/files/downloads/4186OT_ColoredImages.pdf.

Errata

Although we have taken every care to ensure the accuracy of our content, mistakes do happen. If you find a mistake in one of our books—maybe a mistake in the text or the code—we would be grateful if you would report this to us. By doing so, you can save other readers from frustration and help us improve subsequent versions of this book. If you find any errata, please report them by visiting http://www.packtpub.com/support, selecting your book, clicking on the errata submission form link, and entering the details of your errata. Once your errata are verified, your submission will be accepted and the errata will be uploaded to our website, or added to any list of existing errata, under the Errata section of that title.

Piracy

Piracy of copyright material on the Internet is an ongoing problem across all media. At Packt, we take the protection of our copyright and licenses very seriously. If you come across any illegal copies of our works, in any form, on the Internet, please provide us with the location address or website name immediately so that we can pursue a remedy.

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We appreciate your help in protecting our authors, and our ability to bring you valuable content.

Questions

You can contact us at <questions@packtpub.com> if you are having a problem with any aspect of the book, and we will do our best to address it.

Chapter 1. Getting Started

In this chapter we will cover:

- Accessing the PlayStation Mobile portal

- Installing the PlayStation Mobile SDK

- Creating a simple game loop

- Loading, displaying, and translating a textured image

- "Hello World" drawing text on an image

- Deploying to PlayStation Mobile certified Android devices

- Deploying to a PlayStation Vita

- Manipulating an image dynamically

- Working with the filesystem

- Handling system events

Introduction

The PlayStation Mobile (PSM) SDK represents an exciting opportunity for game developers of all stripes, from hobbyists to indie and professional developers. It contains everything you need to quickly develop a game using the C# programming language. Perhaps more importantly, it provides a market for those games. If you are currently using XNA, you will feel right at home with the PSM SDK.

You may be wondering at this point, Why develop for PlayStation Mobile at all? Obviously, the easiest answer is, so you can develop for PlayStation Vita, which of itself will be enough for many people. Perhaps, though the most important reason is that it represents a group of dedicated gamers hungry for games. While there are a wealth of games available for Android, finding them on the App Store is a mess, while supporting the literally thousands of devices is a nightmare. With PlayStation Mobile, you have a common development environment, targeting powerful devices with a dedicated store catering to gamers.

We are now going to jump right in and get those tools up and running. Of course, we will also write some code and show how easy it is to get it running on your device. PlayStation Mobile allows you to target a number of different devices and we will cover the three major targets (the Simulator, PlayStation Vita, and Android). You do not need to have a device to follow along, although certain functionality will not be available on the Simulator.

One thing to keep in mind with the PlayStation Mobile SDK is that it is essentially two SDKs in one. There is a much lower level set of libraries for accessing graphics, audio, and input, as well as a higher-level layer build over the top of this layer, mostly with the complete source available. Of course, underneath this all there is the .NET framework. In this chapter, we are going to deal with the lower level graphics interface. If the code seems initially quite long or daunting for what seems like a simple task, don't worry! There is a much easier way that we will cover later in the book.

Accessing the PlayStation Mobile portal

This recipe looks at creating a PSM portal account. For this process it is mandatory to download and use the PSM SDK.

Getting ready

You need to have a Sony Entertainment Network (SEN) account to register with the PSM portal. This is the standard account you use to bring your PlayStation device online, so you may already have one. If not, create one at http://bit.ly/Yiglfk before continuing.

How to do it...

1. Open a web browser and log in to http://psm.playstation.net. Locate and click on the Register button.

2. Sign in using the SEN account.

3. Agree to the Terms and Conditions. You need to scroll to the bottom of the text before the Agree button is enabled. But, you always read the fine print anyways... don't you?

4. Finally select the e-mail address and language you want for the PlayStation Mobile portal. You can use the same e-mail you used for your SEN account. Click on Register.

5. An e-mail will be sent to the e-mail account you used to sign up. Locate the activation link and either click on it, or copy and paste into a browser window:

6. Your account is now completed, and you can log in to the PSM developer portal now.

How it works...

A PlayStation Mobile account is mandatory to download the PSM tools. Many of the links to the portal require you to be logged in before they will work. It is very important that you create and activate your account and log in to the portal before continuing on with the book! All future recipes assume you are logged in to the portal.

Installing the PlayStation Mobile SDK

This recipe demonstrates how to install the PlayStation Mobile SDK.

Getting ready

First you need to download the PlayStation Mobile SDK; you can download it from http://bit.ly/W8rhhx.

How to do it...

1. Locate the installation file you downloaded earlier and double-click to launch the installer. Say yes to any security related questions.

2. Take the default settings when prompting, making sure to install the runtimes and GTK# libraries.

3. The installer for the Vita drivers will now launch. There is no harm in installing them even if you do not have a Vita:

4. Installation is now complete; a browser window with the current release notes will open.

How it works...

The SDK is now installed on your machines. Assuming you used default directories, the SDK will be installed to C:\Program Files (x86)\SCE\PSM if you are running 64 bit Windows, or to C:\Program Files\SCE\PSM if you are running 32 bit Windows. Additionally all of the documentation and samples have been installed under the Public account, located in C:\Users\Public\Documents\PSM .

There's more...

There are a number of samples available in the samples directory and you should certainly take a moment to check them out. They range in complexity from simple Hello World applications, up to a full blown 3rd person 3D role playing game (RPG). They are, however, often documented in Japanese and often rely on other samples, making learning from them a frustrating experience at times, at least, for those of us who do not understand Japanese!

See also

- See the A Tour of the PlayStation Mobile SDK section in the Preface for a better understanding of what is included in the SDK you just installed

Creating a simple game loop

We are now going to create our first PSM SDK application, which is the main loop of your application. Actually all the code in this sample is going to be generated by PSM Studio for us.

Getting ready

From the start menu, locate and launch PSM Studio in the PlayStation Mobile folder.

How to do it...

1. In PSM Studio, select the File | New | Solution... menu.

2. In the resulting dialog box, in the left-hand panel expand C# and select PlayStation Suite, then in the right-hand panel, select PlayStation Suite Application. Fill in the Name field, which will automatically populate the Solution name field. Click on OK.

3. Your workspace and boilerplate code will now be created; hit the F5 key or select the Run | Start Debugging menu to run your code in the Simulator.

Not much to look at, but it's your first running PlayStation Mobile application! Now let's take a quick look at the code it generated:

using System;
using System.Collections.Generic;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;

namespace Ch1_Example1
{
public class AppMain{
private static GraphicsContext graphics;

public static void Main (string[] args){
Initialize ();

while (true) {
SystemEvents.CheckEvents ();
Update ();
Render ();
}
}

public static void Initialize (){
graphics = new GraphicsContext ();
}

public static void Update (){
var gamePadData = GamePad.GetData (0);
}

public static void Render ()
{
graphics.SetClearColor (0.0f, 0.0f, 0.0f, 0.0f);
graphics.Clear ();
graphics.SwapBuffers ();
}
}
}

Tip

Downloading the example code

You can download the example code files for all Packt Publishing books you have purchased from your account at http://www.packtpub.com. If you purchased this book elsewhere, you can visit http://www.packtpub.com/support and register to have the files e-mailed directly to you.

How it works...

This recipe shows us the very basic skeleton of an application. Essentially it loops forever, displaying a black screen.

private static GraphicsContext graphics;

The GraphicsContext variable represents the underlying OpenGL context. It is used to perform almost every graphically related action. Additionally, it contains the capabilities (resolution, pixel depth, and so on) of the underlying graphics device.

All C# based applications have a main function, and this one is no exception. Within Main() we call our Initialize() method, then loop forever, checking for events, updating, and finally rendering the frame. The Initialize() method simply creates a new GraphicsContext variable. The Update() method polls the first gamepad for updates (we will cover controls in more detail later).

Finally Render() uses our GraphicsContext variable to first clear the screen to black using an RGBA color value, then clears the screen and swaps the buffers, making it visible. Graphic operations in PSM SDK generally are drawn to a back buffer.

There's more...

The same process is used to create PlayStation Suite library projects, which will generate a DLL file. You can use almost any C# library that doesn't rely on native code (pInvoke or Unsafe); however, they need to be recompiled into a PSM compatible DLL format.

Color in the PSM SDK is normally represented as an RGBA value. The RGBA acronym stands for red, green, blue, and alpha. Each is an int variable type, with values ranging from 0 to 255 representing the strength of each primary color. Alpha represents the level of transparency, with 0 being completely transparent and 256 being opaque.

Loading, displaying, and translating a textured image

This recipe is going to create an application that loads a texture from an image file and displays it centered on the screen. This example is actually rather daunting, throwing quite a bit of information at a new developer. Don't worry if it seems overly complex for now; by the end of the book it will make more sense. If you feel overwhelmed, I recommend you continue the book and revisit this recipe later.

Getting ready

Following the instructions presented in the Creating a simple game loop recipe, create a new solution. I have named mine as Ch1_Example2.

How to do it...

1. First, we need to add an image file to our project to use as a texture. This can be done by right-clicking our project in the Solution panel and selecting Add | Add Files... from the menu, as shown in the following screenshot:

2. Now, we need to tell PSM Studio what to do with this file. Select our newly added image, right-click on it, and select Build Action | Content.

3. Now, enter the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;

namespace Ch1_Example2
{
public class AppMain
{
private static GraphicsContext _graphics;
private static Texture2D _texture;
private static VertexBuffer _vertexBuffer;
private static ShaderProgram _textureShaderProgram;
private static Matrix4 _localMatrix;
private static Matrix4 _projectionMatrix;
private static Matrix4 _viewMatrix;
private static float _viewportWidth;
private static float _viewportHeight;

public static void Main (string[] args){
Initialize ();

while (true) {
SystemEvents.CheckEvents ();
Update ();
Render ();
}
}

public static void Initialize (){
_graphics = new GraphicsContext ();
_viewportWidth = _graphics.GetFrameBuffer().Width;
_viewportHeight = _graphics.GetFrameBuffer().Height;

_texture = new Texture2D("/Application/FA-18H.png",false);
_vertexBuffer = new VertexBuffer(4,VertexFormat.Float3,VertexFormat.Float2);
_vertexBuffer.SetVertices(0,new float[] {
1,0,0,
_texture.Width,0,0,
_texture.Width,_texture.Height,0,
0,_texture.Height,0});

_vertexBuffer.SetVertices(1,new float[]{
0.0f,0.0f,
1.0f,0.0f,
1.0f,1.0f,
0.0f,1.0f});

_textureShaderProgram = new ShaderProgram("/Application/shaders/Texture.cgx");

_projectionMatrix = Matrix4.Ortho(
0,_viewportWidth,
0,_viewportHeight,
0.0f,32768.0f);

_viewMatrix = Matrix4.LookAt(
new Vector3(0,_viewportHeight,0),
new Vector3(0,_viewportHeight,1),
new Vector3(0,-1,0));

_localMatrix = Matrix4.Translation(new Vector3(-_texture.Width/2,-_texture.Height/2,0.0f))
* Matrix4.Translation(new Vector3(_viewportWidth/2,_viewportHeight/2,0.0f));
}

public static void Update (){
var gamePadData = GamePad.GetData (0);
}

public static void Render (){
_graphics.SetClearColor (0.0f, 0.0f, 0.0f, 0.0f);
_graphics.Clear ();

var worldViewProjection = _projectionMatrix * _viewMatrix * _localMatrix;
_textureShaderProgram.SetUniformValue(0,ref worldViewProjection);

_graphics.SetShaderProgram(_textureShaderProgram);
_graphics.SetVertexBuffer(0,_vertexBuffer);
_graphics.SetTexture(0,_texture);

_graphics.DrawArrays(DrawMode.TriangleFan,0,4);

_graphics.SwapBuffers ();
}
}
}

How it works...

Phew! That sure seemed like a lot of code to simply display a single image on screen, didn't it? The truth is, you did a lot more than just load and draw a texture. Let's jump in and look at exactly what we just created.

First, we declared the following variables, in addition to our existing GraphicsContext variable:

- _texture is our Texture2D object that is going to hold our textured image.

- _vertexBuffer is a VertexBuffer object that holds the 3D quad geometry we are going to map our texture on.

- _shaderProgram is a ShaderProgram variable, the texture shader needed to render our texture. The GraphicsContext variable requires at least one. Fortunately, a simple one with the extension .cgx was created for you already by PSM Studio when you created the project.

- _localMatrix, _projectionMatrix, and _viewMatrix are Matrix4 objects, representing the textured object's position.

- _viewportWidth and _viewportHeight contain the dimensions of our window.

The bulk of our activity is in the Initialize() method. Once again, we create a GraphicsContext variable, and then store the dimensions of the frame buffer in the _viewportHeight and _viewportWidth variables. Next, we create our Texture2D object, passing the constructor the filename and whether or not we want a mipmap generated.

Next, we create a _vertexBuffer object, which is going to be a fullscreen quad we can draw our texture on. We make two calls to SetVertices(). The first call is defining the x, y, and z float variables that make up the four vertices of the fullscreen quad. The second SetVertices function call is four x and y texture coordinates. Texture coordinates are represented with a value from 0 to 1.

Next, we create our _textureShaderProgram function using the default shader PSM Studio created for us. We will cover shaders in more detail later in this chapter.

Finally, we set up the _projectionMatrix, _viewMatrix, and _localMatrix objects. The projection matrix is an orthographical matrix that represents our screen. The view matrix represents the camera within the world, using Matrix4.LookAt. LookAt(), which requires 3 vectors, the first representing your eye's location in 3D space, the second, the 3D point you are looking at, and the third, the direction where "UP" is, in this case in the Y direction. Finally, the local matrix represents the position of texture, which we want to be centered in the middle of the screen.

Now, let's take a look at the Render() function, where our texture is going to be displayed to the screen. As before, we set the clear color to black and clear the buffer. Next, we generate our worldViewProjection matrix by multiplying our projection, view and local matrices together. We then bind our worldViewProjection matrix to our shader program and then set our shader program to the GraphicsContext variable. We also set our VertexBuffer object and Texture2D object to the GraphicsContext variable. The DrawArrays() call is what ties it all together, using our worldViewMatrix to transform our vertices from our VertexBuffer object and applying our texture map, rendering it all to the active buffer. Finally, we make that buffer visible, which draws it on screen.

Here is our program in action, rendering our sprite centered to the screen:

Again, if that seemed overly complex, don't panic! Most of this code only needs to be written once, and you have the option of not working at this low a level if you should choose!

There's more...

Build actions will be executed when your project is compiled, copying the content to the appropriate folder, performing whatever conversions are required. If you are used to XNA, this is similar to the functionality of the content pipeline, but not programmable.

Note

Why is there 3D in my 2D?

The bulk of this example was actually going through the process of faking a 2D environment using 3D. The reason is modern GPUs are optimized to work in 3D. If you look at the code to most modern 2D libraries, they are actually working in 3D. If you were to work with native 2D graphics libraries, your performance would be abysmal.

An explanation of 3D mathematics is beyond the scope of this book, but the Kahn Academy (see http://www.khanacademy.org/) is an excellent free resource with thousands of video tutorials.

Tip

The sprite I used for this example and throughout this book is from a wonderful free sprite library made available by GameDev.net user Prince Eugn. You can find more information and download the sprite pack at http://bit.ly/N7CPtE.

"Hello World" drawing text on an image

This recipe dynamically creates and displays a texture with text created using the imaging APIs.

Getting ready

This recipe builds on the code from the last recipe. Add the following using statement to the beginning of the program code:

using Sce.PlayStation.Core.Imaging

For the complete source code for this example, see Ch1_Example3.

How to do it...

1. In the Initialize() function, instead of loading a texture from the file, we will create one using the following code:

Image img = new Image(ImageMode.Rgba,new ImageSize(500,300),new ImageColor(0,0,0,0));
img.DrawText("Hello World",
new ImageColor(255,255,255,255),
new Font(FontAlias.System,96,FontStyle.Italic),
new ImagePosition(0,150));
_texture = new Texture2D(500,300,false,PixelFormat.Rgba);
_texture.SetPixels(0,img.ToBuffer());

2. Next, update the Render() method in the following code in which the bolded portions represent the changes:

public static void Render (){
_graphics.SetClearColor (0.0f, 0.0f, 0.0f, 0.0f);
_graphics.Clear ();

var worldViewProjection = _projectionMatrix * _viewMatrix * _localMatrix;
_textureShaderProgram.SetUniformValue(0,ref worldViewProjection);

_graphics.SetShaderProgram(_textureShaderProgram);
_graphics.SetVertexBuffer(0,_vertexBuffer);
_graphics.SetTexture(0,_texture);

_graphics.Enable(EnableMode.Blend);
_graphics.SetBlendFunc(BlendFuncMode.Add, BlendFuncFactor.SrcAlpha, BlendFuncFactor.OneMinusSrcAlpha);
_graphics.DrawArrays(DrawMode.TriangleFan,0,4);

_graphics.SwapBuffers ();
}

How it works...

Instead of loading a texture from an image file, we create an image dynamically. In the Image constructor, we pass the type of image we want created, the dimensions and the background color to fill it with.

Next, we draw on our newly created image using the DrawText() function, which takes as parameters the text to draw, the color to draw it in, the font to use (there is only one option, System) and the position to draw the text at. We then create a Texture2D object to hold our image. We pass its constructor the image dimensions, whether we want to generate a mipmap or not, as well as the pixel format to use. Finally, we assign the pixel data to our _texture object by calling SetPixel() function and passing in a byte array generated by calling ToBuffer() function on our image.

We had to make the change to the Render() method to support blending using the alpha channel, or background would not be properly visible through the transparent portions of the text. Run the code again without EnableMode.Blend enabled and your text will be illegible.

Now if we run our application, we will see the following screenshot:

There's more...

You can also load a font by name instead of using the built in system font. If you need precise control over your text positioning or size, be sure to check out the FontMetrics and CharMetrics classes in the documentation.

Deploying to PlayStation Mobile certified Android devices

This recipe covers deploying an application to an Android device. Running on an Android device requires a developer license that you can purchase in the PSM portal.

Getting ready

You need to have installed the PlayStation Mobile SDK to have access to required files. Of course you will also require a PlayStation Mobile compatible Android device. Make sure the Android ADB driver for your phone is installed on your computer; you can download a generic version from Google's Android development website if required.

How to do it...

1. Attach your Android phone by USB to your computer. It may install a driver at this point, let it.

2. Open a Command Prompt (Start | Run and type cmd.exe) and type "%SCE_PSM_SDK%/tools/update_psmdevassistant.bat" including the quotes. This will install the PSM Development Assistant on your device.

3. On your device, locate and run the PSM Development Assistant application.

4. On your computer, in the PlayStation Mobile folder in the Start menu, load Publishing Utility.

5. Now you need to create a Publisher Key; you will only have to do this once. First click the Key Management tab, then the Generate Publisher Key button. Name your key and then enter your login information for the PSM portal. A key will be generated for you.

6. Click on the Generate App Key Ring button. In the app.xml field locate the App.xml file of the project you want to run on your device and then click on OK. You will have to authenticate with your SEN ID again. If all goes well, your app will now be listed in the Registered App Key Ring list.

7. Now fire up your project in PSM Studio. Make sure that you have the PlayStation Mobile Development Assistant running on your device and your phone is connected by a USB connection. Set Android as your target using the Project | PlayStation Mobile Device Target menu item and select your phone device.

8. Run your application by pressing the F5 key or choosing Run or Debug from the menu and your application will be copied to your Android device and run.

There's more...

You need to make sure that USB debugging is enabled on your Android device. This varies from device to device, but is generally located in the Settings | Developer Options | USB debugging menu.

I ran into an error when trying to add my application to the key ring. To fix this, I recreated my Publisher Key. If you are working alone, this isn't a big process, but if you are part of a team, you will need to distribute the updated key.

Deploying to a PlayStation Vita

In this recipe, we will configure a PS Vita to be used with PSM Studio. Running on a PS Vita device requires a developer license, which you can purchase in the PSM portal.

Getting ready

You will need to have installed the PlayStation Mobile SDK to have the required Vita drivers installed. If you did not install the drivers as part of the install process, under a default install they are available at C:\Program Files (x86)\SCE\PSM\tools\vita\driver. Obviously you will need to have a PS Vita and a USB cable. You will need a project to run on your Vita; load either one of the examples we created earlier or one of the examples from the SDK.

How to do it...

1. Before you can run on your Vita, you need to install the Development Assistant from the PS Store. Load the PS Store application on your PS Vita device, and then click on the ... button in the bottom-right corner of the screen. Select Download List. Scroll down and select PlayStation Mobile Development Assistant and click on Download. The application will be downloaded and installed.

2. The PS Mobile Development application icon will now be available on your Vita. If you haven't already, connect your Vita to your PC using the USB cable. If prompted, allow it to install the driver.

3. On your Vita, run the PS Suite SDK application.

4. Make sure that your application has been added to the Registered App Key Ring list (see previous recipe for details).

5. Load up PSM Studio and load a solution to run on your Vita. Now open the Project | PlayStation Suite Device Target | PS Vita menu item. If your PS Vita doesn't show up, select Refresh Device List... and try again. The device will show as off, if the Development Assistant isn't running.

6. Run your application using either the F5 key or the Run | Start Debugging menu item.

There's more...

Be careful while connecting the USB cable to your Vita. For some unfathomable reason, you can easily put it in upside down! If you aren't getting a connection to your device, be sure to check if your cable is in upside down mode! I thought my Vita was broken the first time I encountered this, as I left it charging, or at least I thought I did. When I came back and it was completely dead, it took a few minutes of head-scratching until I figured out what was wrong.

See also

- The example locations can be found in the Installing the PlayStation Mobile SDK recipe

- See the Deploying to PlayStation Certified Android Devices recipe for details on managing App Keys using PublishingUtility

Manipulating an image dynamically

This recipe will demonstrate using the imaging SDK to resize and crop an image, and then saving that image to the gallery.

Getting ready

This recipe builds on the example created in the prior two recipes. The complete source code is available in Ch01_Example4.

How to do it...

In the Initialize() method, change the code as follows:

Image image = new Image(ImageMode.Rgba,new ImageSize(500,300),new ImageColor(0,0,0,0));
Image resizedImage, croppedImage;
image.DrawText("Hello World",
new ImageColor(255,255,255,255),
new Font(FontAlias.System,96,FontStyle.Italic),
new ImagePosition(0,150));
croppedImage = image.Crop (new ImageRect(0,0,250,300));
resizedImage = croppedImage.Resize(new ImageSize(500,300));
_texture = new Texture2D(resizedImage.Size.Width,resizedImage.Size.Height,false,PixelFormat.Rgba);
_texture.SetPixels(0,resizedImage.ToBuffer());
resizedImage.Export("My Images","HalfOfHelloWorld.png");
image.Dispose();
resizedImage.Dispose();
croppedImage.Dispose();

How it works...

First, we dynamically generate our image just like we did in the previous recipe. We then crop that image to half its width, by calling the Crop() function and providing an ImageRect variable half the size of the image. Crop returns a new image (it is not destructive to the source image) that we store in croppedImage. We then resize that image back to the original size by calling the Resize() function on croppedImage, with the original size specified as an ImageSize object. Like Crop(), Resize() is not destructive and returns a new image that we store in resizedImage. We then copy the pixels from resizedImage into our texture using SetPixels().

Next, we call Export(), which saves our cropped and resized image in a folder called My Images as a file named HalfOfHelloWorld.png on your device. Finally, we call Dispose() on all three images, to free up the memory they consumed.

Now if you run your code, instead of "Hello World", you simply get "Hello".

There's more...

When run on the simulator, export will save the image to your My Pictures folder. Be sure to call Dispose(), or wrap within a using statement all objects that implement IDisposable, or you will quickly run out of memory. Most resources like images and textures require disposal.

Working with the filesystem

This recipe illustrates the various ways you can access the filesystem.

Getting ready

The complete code for this example is available in Ch1_Example5. This example adds the following two new using statements:

- using System.Linq;

- using System.IO;

How to do it...

Create a new solution and enter the following code replacing the Main() function:

public static void Main (string[] args){
const string DATA = "This is some data";

byte[] persistentData = PersistentMemory.Read();

byte[] restoredData = persistentData.Take(DATA.Length * 2).ToArray();
string restoredString = System.Text.Encoding.Unicode.GetString(restoredData);

byte[] stringAsBytes = System.Text.Encoding.Unicode.GetBytes(DATA);

for(int i = 0; i < stringAsBytes.Length; i++)
persistentData[i] = stringAsBytes[i];
PersistentMemory.Write (persistentData);

using(FileStream fs = File.Open("/Documents/Demo.txt",FileMode.OpenOrCreate)){
if(fs.Length == 0)
fs.Write(stringAsBytes,0,stringAsBytes.Length);
else{
byte[] fileContents = new byte[fs.Length];
fs.Read(fileContents,0,(int)fs.Length);
}

}
}

How it works...

The first part of this sample demonstrates using the PersistentMemory class. It is a statically available class, so you cannot allocate one. Instead you access it using PersistentMemory.Read(). This returns a byte array that you can now modify. We read some data using the LINQ extension Take() method. We multiplied the size by 2 because the string is stored as UNICODE, which requires 2 bytes per character. We then convert those bytes into a Unicode string. Next, we convert our DATA string into a byte array, then write it to persistentData byte by byte in a for loop. Finally we commit our changes to persistentMemory by calling PersistentMemory.Write(), passing in our updated persisitentMemory byte array.

The next part of the recipe demonstrates traditional file access using the standard .NET libraries, in this case File and FileStream. We open a text file in the /Documents folder named Demo.txt, creating it if it doesn't exist. If the file doesn't exist, we write our byte array stringAsBytes to the file. Otherwise, we read the file contents into a new byte array fileContents.

The first time you run this example, PersistentMemory.Read() will contain gibberish, as nothing has been written to it yet. On the second run, it will start with the bytes composing your DATA string.

There's more...

Persistent storage is limited to 64 KB in space. It is meant for quickly storing information, such as configuration settings. It is physically stored on the filesystem in the /save directory in a file named pm.dat.

There are three primary locations for storing files:

- /Application: This is where your application files reside, as well as files added with the "Content" build action. These files are read only.

- /Documents: This is where you put files that require read and write access.

- /Temp: This is where you put temporary files, that can be read and written. These files will be erased when your program exits.

The PlayStation Mobile SDK limits directory structures to at most 5 levels deep, including the filename. Therefore, /documents/1/2/3/myfile.txt is permitted, but /documents/1/2/3/4/myfile.txt is not.

Note

The PersistentMemory classes was deprecated in the 1.0 release of PSM SDK and should no longer be used. Use traditional .NET file methods instead.

See also

- See the Loading, displaying, and translating a textured image recipe for details about how to add files to your app's folders using build actions

Handling system events

This recipe covers handling the OnRestored system event.

Getting ready

The complete code for this example is available in Ch01_Example06.

How to do it...

Replace Main() with the following code:

public class AppMain
{
static bool _done = false;
public static void Main (string[] args){

SystemEvents.OnRestored += HandleSystemEventsOnRestored;
while(!_done)  {
SystemEvents.CheckEvents();
// Loop until application minimized then restored.
}
}

static void HandleSystemEventsOnRestored (object sender, RestoredEventArgs e)
{
Console.WriteLine ("System restored, ok to shut down");
_done = true;
}
}

How it works...

This code starts by wiring an OnRestored event handler to global class SystemEvents. We then loop until the _done bool is set to true. Within our loop we poll SystemEvents.CheckEvents() to see if any events have occurred. If an OnRestored event occurs, our event handler will be fired.

Our event handler HandeSystemEventsOnRestored() simply writes out a message to the console, then sets the _done bool to true, causing our loop to end, and our program to exit.

Run this example, then minimize the simulator or change applications on your device. When you refocus the application, it will fire the OnRestored event, causing your program to exit.

Chapter 2. Controlling Your PlayStation Mobile Device

In this chapter we will cover:

- Handling the controller's d-pad and buttons

- Using the Input2 wrapper class

- Using the analog joysticks

- Handling touch events

- Using the motion sensors

- Creating onscreen controls for devices without gamepads

- Configuring an Android application to use onscreen controls

Introduction

In this chapter, we are going to look at the various ways you can control your PlayStation Mobile device. The PlayStation Vita includes touch sensors, a full d-pad, two analog sticks, motion sensors, and more. It has to stay compatible with other devices, so features such as the rear touch panel are not supported. Not all devices support all of the PS Vita's features; in fact, most do not. This is especially true regarding physical joystick support. Fortunately, Sony has provided a tool for making onscreen controls, which we will cover shortly. The onscreen controls are built directly into the PSM virtual machine; you simply configure the screen layout the way you wish to see it appear.

There are, however, some limitations, especially when it comes to what you can do in the simulator. For some of these recipes, you will require an actual physical device to test them. I will point out at the beginning of each recipe if there are special requirements.

You may also notice, examples in this chapter make use of the GameEngine2D framework. This is done to cut down the length of example source listings. As you may have seen from the recipes in Chapter 1, Getting Started, without using the framework, accomplishing some rather simple tasks can take a fair bit of code. Do not worry; we will cover GameEngine2D in greater detail in future recipes.

Handling the controller's d-pad and buttons

In this recipe, we will look at how to read the device's gamepad's d-pad and button states. The code remains the same regardless of whether it is a physical device or if the controls are emulated.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.GameEngine2D and Sce.PlayStation.GameEngine2D.Base. The complete source for this example can be found in Ch2_Example1.

How to do it...

In the AppMain.cs file of your newly created project, enter the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch2_Example1
{
public class AppMain
{
public static void Main (string[] args)
{
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();
Label label = new Label();
label.Position = new Vector2(0,Director.Instance.GL.Context.GetViewport().Height/2);

scene.AddChild(label);
Director.Instance.RunWithScene(scene,true);
bool quitApp = false;

while(!quitApp)
{
Director.Instance.Update();
string currentStatus = "You are currently pressing:\n";
var pressedButtons = GamePad.GetData(0).ButtonsDown;

if((pressedButtons & GamePadButtons.Up) == GamePadButtons.Up){
currentStatus += "Up button";
}
if((pressedButtons & GamePadButtons.Left) == GamePadButtons.Left){
currentStatus += "Left button";
}
if((pressedButtons & GamePadButtons.Right) == GamePadButtons.Right){
currentStatus += "Right button";
}
if((pressedButtons & GamePadButtons.Down) == GamePadButtons.Down){
currentStatus += "Down button";
}
if((pressedButtons & GamePadButtons.Cross) == GamePadButtons.Cross){
currentStatus += "Cross button";
}

if((GamePad.GetData(0).ButtonsPrev & GamePadButtons.Cross) == GamePadButtons.Cross){
quitApp = true;
}
label.Text = currentStatus;
Director.Instance.Render();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
}
}
}
}

How it works...

The initial code is all about setting up the GameEngine2D classes, which we will cover in detail later in the book. Essentially we just set up our scene then create a new Label object, which we will use to display the current control status on the screen. We then start our scene running and loop until the bool quitApp is set to true.

In our loop, we have to make four required calls using the Director object, which again we will cover later in this chapter. It is the remainder of the loop that is the focus of this recipe.

With each iteration through the loop we clear out our label's text. We then get the current state of our game pad using the following call:

var pressedButtons = GamePad.GetData(0).ButtonsDown;

At this point pressedButtons contains a GamePadButtons enum representing all of the buttons that are currently down. Think of this like a bit field of Boolean values, with the corresponding bit for each button on if the button is currently pressed. Therefore, to test if a certain button is down, we perform a binary and (&) operation, testing it against the button value we want to check.

We check the status of the Up, Left, Right, Down, and Cross buttons and update our label if any of these buttons is currently down. As you can see, the d-pad is basically just a collection of four individual buttons that are either on or off. There are additional buttons to the ones demonstrated here, including the left and right shoulder buttons and the start button. You handle them in the exact same manner. An action very similar to assigning pressedButtons is performed when we make the following call:

if((GamePad.GetData(0).ButtonsPrev & GamePadButtons.Cross) == GamePadButtons.Cross)

This works almost identical to when we checked the down button state, but instead it returns an enum representing buttons that were previously down. So if that button was pressed the prior time you checked input, it will be set. In this case, if the user previously pressed the cross button, we set quitApp to true, causing our program to exit.

The remaining code simply updates the label's text with our updated button status and makes calls to Director that are required if you manually manage your GameEngine2D game loop.

There's more...

In addition to checking if a button is down using ButtonsDown, or if it was previously down using ButtonsPrev, there are also options for checking if a button was released this frame using ButtonsUp, as well as the general Buttons enum, which tells you the button's current status regardless of when it occurred.

The GamePadData struct that GetData() returns also contains a bool named Skip. This value is used to indicate if the input has already been handled elsewhere in code. This is useful as GamePad is globally available, so it is possible that you handle input already in a different part of your code. If so, you can set Skip to true, letting any code that calls GamePad.GetData() again before it is updated know that this input has already been handled elsewhere. The use of Skip is completely optional.

If you are working using the simulator, you may be wondering how exactly you press buttons that don't exist. The following table illustrates the key mappings when running the simulator:

Emulated button

Key to press

Left d-pad

Left arrow key

Right d-pad

Right arrow key

Up d-pad

Up arrow key

Down d-pad

Down arrow key

Square button

A

Triangle button

W

Circle button

D

Cross button

S

SELECT button

Z

START button

X

Left shoulder button

Q

Right shoulder button

E

Sadly, you cannot currently emulate analog sticks using the simulator, although an upcoming release intends to add Dual Shock support.

Note

There is currently a bug in PSM Studio that prevents code completion from working for recently added references. You can work around this problem however. After you add a new library reference, save your project and exit PSM Sutdio. Once you restart PSM Studio, code completion should work normally. You can also simply add an additional library reference, then immediately remove it, and code completion will then be working properly. This prevents you from having to restart Studio.

See also

- See the A game loop, GameEngine2D style recipe in Chapter 3, Graphics with GameEngine2D for more details on how the GameEngine2D portions of this sample work

Using the Input2 wrapper class

In the previous recipe, you may have found the bit masking process a little crude. Apparently so did Sony, as they provided a helper method in the GameEngine2D library named Input2 that makes dealing with input a bit smoother. In this recipe, we are going to demonstrate how that class works.

Getting ready

Open or duplicate the code you created in the previous recipe. Only the contents of the while loop are going to change in this recipe. The full code for this recipe is available at Ch2_Example2.

How to do it...

Open AppMain.cs and change the contents to the following code:

while(!quitApp)
{
Director.Instance.Update();
string currentStatus = "Your DPad is current pointing at: x=";

currentStatus += Input2.GamePad0.Dpad.X;
currentStatus += " y=";
currentStatus += Input2.GamePad0.Dpad.Y;
label.Text = currentStatus;
if(Input2.GamePad0.Cross.Press)
quitApp = true;

if(Input2.GamePad0.Circle.Release)
quitApp = true;

if(Input2.GamePad0.Square.Down)
quitApp = true;

if(Input2.GamePad0.Triangle.On)
quitApp = true;

Director.Instance.Render();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
}

Now if you run the app, you will see the following output:

Move the d-pad in different directions and the x and y location will be displayed. You can press any face button to quit.

How it works...

This code simply gets the status of the d-pad and quits if either the Cross button is pressed, the Circle button is released, the Square button is down, or the Triangle button is On. The rest of the code is the same boilerplate code you need to work with GameEngine2D. So what exactly is different here?

Well first off, the d-pad is no longer represented as four independent buttons. Instead it is represented as a normalized 2D vector indicating which direction it is pointing. Pressing the up and left arrow will give you a value of (-1,-1), pressing no buttons will give a value of (0,0), and pressing the down and right arrow will give you a value of (1,1). This allows you to treat the d-pad as a single entity instead of as four separate buttons.

Additionally, all of the various button states we saw in the earlier recipe are still there. Using Input2 they are instead represented at a series of bool values, making the code slightly less compact, but certainly more readable. Keep in mind; this is basically just a helper layer over the top of the standard input functionality. The Input2 helper class provides no new functionality or information, it is simply easier to use.

Finally GamePad.GetInput(0) has the equivalent shortcut reference Input2.GamePad0, because as of this point in time you will never have more than one controller.

There's more...

The Input2 helper class is a static global variable. It is available for use once you have referenced GameEngine2D.Base.

You can also call SetData() and override the values returned by GetData(). This can be useful when you want to programmatically set controls, such as during testing, remapping controls dynamically or driving a replay. You simply set a GamePadData structure to the values you want and pass it into SetData().

See also

- See the Handling the controller's d-pad and buttons recipe for the code this recipe is based on, as well as to see the way input is handled without the Input2 wrapper to help

Using the analog joysticks

In this recipe, we will demonstrate how to use the device's analog sticks, if they exist. If they do not exist, the onscreen controller will appear automatically.

Getting ready

In PSM Studio, create a new project and add a reference to Sce.PlayStation.GameEngine2D and Sce.PlayStation.GameEngine2D.Base. This recipe also requires you to add an image file to be displayed. I am bringing back our trusty F-18 graphic, but you can substitute whatever image you desire as long as it is in the proper format (.png, .bmp, or .jpg). The full code for this recipe is available at Ch2_Example3.

This example requires an actual device!

How to do it...

Open AppMain.cs and enter the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch2_Example3
{
public class AppMain
{
public static void Main (string[] args)
{
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();
TextureInfo ti = new TextureInfo("/Application/FA-18H.png");
SpriteUV sprite = new SpriteUV(ti);
sprite.Quad.S = ti.TextureSizef;
sprite.Position = new Vector2(
Director.Instance.GL.Context.GetViewport().Width/2 - sprite.Quad.Center.X,
Director.Instance.GL.Context.GetViewport().Height/2 - sprite.Quad.Center.Y);

scene.AddChild(sprite);
Director.Instance.RunWithScene(scene,true);
bool quitApp = false;

while(!quitApp)
{
Director.Instance.Update();

if(GamePad.GetData(0).AnalogLeftX < 0)
{
if(sprite.Position.X > 0)
sprite.Position = new Vector2(sprite.Position.X + 10 * GamePad.GetData(0).AnalogLeftX ,sprite.Position.Y);
}
if(GamePad.GetData(0).AnalogLeftX > 0)
{
if(sprite.Position.X < Director.Instance.GL.Context.GetViewport().Width - sprite.CalcSizeInPixels().X)
sprite.Position = new Vector2(sprite.Position.X + 10 * GamePad.GetData(0).AnalogLeftX ,sprite.Position.Y);
}
Director.Instance.Render();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
}
ti.Dispose();
Director.Terminate();
}
}
}

Here is the application running in the following output screen:

Move the left analog stick left and right to move the sprite; the amount you move the stick will determine the speed.

How it works...

Most of the initial code relates to GameEngine2D and will be covered in more detail in a later series of recipes. Basically, it sets up the Director singleton and Scene objects required for GE 2D, then loads our trusty FA-18H.png image into a TextureInfo object, which is then used to create our SpriteUV object, sprite. Next we size the sprite object to the same dimensions as its texture and then position it in the middle of the screen. Finally, we add our sprite to the scene and kick off our scene running with a call to Director.Instance.RunWithScene().

Note

What's the difference between a sprite and an image?

People often use the term sprite and image interchangeably, but this isn't completely accurate. A sprite is a collection of pixels that can be drawn on the screen or elsewhere, such as a player graphic or score information. A sprite is often loaded from an image, but can also be generated dynamically. Additionally, although a sprite can be loaded from an image, it is also possible to store a number of sprites within a single image. Therefore, a sprite is often an image, but doesn't have to be, while an image can contain multiple sprites.

It is the highlighted code within the while loop that we are most interested in. Just as in the previous recipe we read the Gamepad data using GamePad.GetData(0), this time we are interested in the x axis of the left-hand stick, stored in GamePad.GetData(0).AnalogLeftX. This value returns a float with a value ranging from -1.0 to 1.0. A value of -1.0 means the stick is being pressed all the way to the left, while a value of +1.0 indicates the stick is being held all the way to the right. A value of 0.0 means the stick isn't being pressed at all.

Each pass through the loop we check to see if the left stick is being held to the left; if it is, we check to make sure our sprite isn't already all the way to the left, and if it isn't, we move it further to the left with the following call:

sprite.Position = new Vector2(sprite.Position.X + 10 * GamePad.GetData(0).AnalogLeftX ,sprite.Position.Y);

This works by updating the position to a new vector based on the current position + 10 * pixels, the amount the stick is pressed to the left. So for example, if the stick is pressed halfway to the left, AnalogLeftX will be -0.5 resulting in a value of -5, moving our position 5 pixels to the left. If the stick was pressed all the way to the left, the values would have been -1.0 * 10 = -10, which would move the position 10 pixels left. Unlike the d-pad, which is either on or off, the analog stick allows us to have a gradual range of values.

We then perform the same test, this time checking if AnalogLeftX is greater than 0, meaning that the stick is being pressed to the right. In this case, we update the position to move to the right by a value ranging from 0 to 10.0 pixels, depending on how hard the stick is being pressed.

The remaining code is required when you manually manage a GameEngine2D loop. Finally, after our loop ends we behave like good citizens and clean up after ourselves, disposing of our TextureInfo object and calling Terminate on the static Director class.

There's more...

Although this recipe only utilized AnalogLeftX to read the left/right movement of the analog stick, there is also the value AnalogLeftY which holds vertical movement of the stick, with a value of -1.0 representing a stick being pushed up, while a value of 1.0 means the stick is being held fully down. Additionally, the values AnalogRightX and AnalogRightY exist and hold the values of the right analog stick.

The Input2 class also has a simplified representation for the two analog sticks. Instead of a pair of separate floats each, it represents the stick's over-all position using a single Vector2 each, with (-1.0,-1.0) meaning the stick was being pushed to the top-left position, (0.0,0.0) representing a still stick, and a value of (1.0,1.0) indicating the stick was being pushed to the bottom-right corner. Obviously those represent the maximum ranges in each direction.

Note

Often when dealing with analog controls, it is normal to set a dead zone. This treats values close to (0,0) as basically being zero. This keeps stationary controls from being overly twitchy to extremely small motions. The PlayStation Mobile SDK automatically applies a dead-zone to analog controls, so you do not need to.

See also

- See the Loading, displaying, and translating a textured image recipe in Chapter 1, Getting Started for the download location of the sprite graphic used in this recipe

- See the Using the Input2 wrapper class recipe for more details on using the Input2 helper class

Handling touch events

In this recipe we will look into how to deal with touch events.

Getting ready

In PSM Studio, create a new project and add a reference to Sce.PlayStation.GameEngine2D and Sce.PlayStation.GameEngine2D.Base. Then add an image file to your project (I will re-use the trusty F18) and make sure its Build Action is set to Content. The full code for this recipe is available as Ch2_Example4.

This example will run in the simulator; however, it does not currently support multitouch. To see multiple touches handled, you will need to run this code on an actual device.

How to do it...

Open AppMain.cs and enter the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch2_Example4
{
public class AppMain
{
public static void Main (string[] args)
{
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

TextureInfo ti = new TextureInfo("/Application/FA-18H.png");
SpriteUV [] sprites = new SpriteUV[6];
sprites[0] = new SpriteUV(ti);
sprites[1] = new SpriteUV(ti);
sprites[2] = new SpriteUV(ti);
sprites[3] = new SpriteUV(ti);
sprites[4] = new SpriteUV(ti);
sprites[5] = new SpriteUV(ti);
sprites[0].Quad.S = sprites[1].Quad.S = sprites[2].Quad.S = sprites[3].Quad.S = sprites[4].Quad.S
= sprites[5].Quad.S = ti.TextureSizef;

float screenWidth = Director.Instance.GL.Context.GetViewport().Width;
float screenHeight = Director.Instance.GL.Context.GetViewport().Height;

foreach(var sprite in sprites)
scene.AddChild(sprite);

Director.Instance.RunWithScene(scene,true);
bool quitApp = false;

while(!quitApp)
{
Director.Instance.Update();
foreach(SpriteUV sprite in sprites)
sprite.Visible = false;

var touches = Touch.GetData(0);
for(int i = 0; i < touches.Count;i++)
{
// Top Left: -.5, -.5
// Top Right: .5, -5
// Bottom Left: -.5, .5
// Bottom Right: .5, .5
sprites[i].Visible = true;
sprites[i].Position = new Vector2(
(touches[i].X + 0.5f) * screenWidth,
screenHeight - ((touches[i].Y + 0.5f) * screenHeight));
}
Director.Instance.Render();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
}
ti.Dispose();
Director.Terminate();
}
}
}

How it works...

This example starts off with boilerplate GameEngine2D initialization code. We then create our TextureInfo object to store our F18 texture fire. We then create an array of six SpriteUV objects, all reusing the same texture. Next we size all six sprites equal to their source texture's dimensions. For convenience later on, we store the screen width and height. Next up, we add all six sprites to our scene, then kick it off with a call to RunWithScene(). Now we get to the heart of demonstration within the while loop.

With each iteration of the loop, in addition to the standard four required Director function calls, we do the following:

1. Loop through each of our SpriteUV object's in the sprites array, making them invisible.

2. Get the current touch data with a call to Touch.GetData(0).

3. Loop through each of the touches in the list; for each location touched on the screen, we make a sprite visible at that position for this frame.

4. Finally we clean up after ourselves by disposing of our TextureInfo object and terminate our Director singleton.

Now if you run the application, wherever you touch the screen a sprite will appear as long as you are touching the screen. Move your finger and the sprites will move, remove your finger and the sprite will disappear. Here is the application running with six touches occurring:

There's more...

The following line of code most likely jumped out at you:

sprites[i].Position = new Vector2(
(touches[i].X + 0.5f) * screenWidth,
screenHeight - ((touches[i].Y + 0.5f) * screenHeight));

What exactly are we doing here? The touch data x and y value returned in TouchData are screen coordinates ranging in value from -0.5 to +0.5. Therefore, we simply add 0.5 to the coordinate to make it a value from 0.0 to 1.0, then multiply it by our screen dimensions to give actual screen pixel coordinates. We then set the sprite's position to be at the pixel location the user is currently touching. Why then return a value between -0.5 and +0.5 instead of returning a value ranging from 0.0 to 1.0? That's a very good question! I cannot think of a good reason.

Another important thing to be aware of is, different devices may support a different maximum number of simultaneous touches. The PlayStation Vita tracks a maximum of six touches. Each touch is also assigned an ID value; however, if you have a situation where two fingers touch multiple times, how this is handled is device dependent. Some devices might report this as 1, 2, 1, 2 while other devices will report 1, 2, 3, 4. All concurrent touches though will be assigned an individual ID. In addition to checking if a touch is down, TouchStatus also indicates up, move, and cancelled statuses.

Just as when dealing with gamepads, touch data is also provided by the Input2 wrapper class. It represents touch statuses as a series of bools, as well as returning the touch location as much more sensible Vector2 coordinates in normalized screen coordinates ranging from -1.0 to 1.0.

Currently, the PSM SDK does not provide programmatic access to the rear touchscreen.

Note

The preceding image was taken as a screenshot on my PS Vita. If you want to take a screenshot, you simply press and hold the PS button and Start button at the same time. The screen will flash and your screenshot will be saved. You can access it in the Gallery section of the Photo application. You may be asking, How exactly do you touch the screen in six different locations, while simultaneously holding the PS Button and Start button? The answer... with great difficulty!

See also

- See the Using the Input2 wrapper class recipe for more details on using the Input2 helper class

Using the motion sensors

In this recipe we will look into how to use the accelerometer and gyroscope.

Getting ready

Open PSM Studio and create a new project, adding references for GameEngine2D and GameEngine2D.Base. The complete code for this recipe is available at Ch2_Example5.

This example will not run in the simulator. Some Android based devices may not support the gyro, so AngularVelocity may not be available.

How to do it...

Open AppMain.cs and enter the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch2_Example5
{
public class AppMain
{
public static void Main (string[] args)
{
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

float screenWidth = Director.Instance.GL.Context.GetViewport().Width;
float screenHeight = Director.Instance.GL.Context.GetViewport().Height;

Label labelAcceleration = new Label();
labelAcceleration.Text = "Acceleration vector";
labelAcceleration.Position = new Vector2(0,450);
labelAcceleration.Scale = new Vector2(3,3);

Label labelAngularVelocity = new Label();
labelAngularVelocity.Text = "Angular Velocity vector";
labelAngularVelocity.Position = new Vector2(0,250);
labelAngularVelocity.Scale = new Vector2(3,3);

Label labelPosition = new Label();
labelPosition.Position = new Vector2(0,350);
labelPosition.Scale = new Vector2(3,3);

Label acceleration = new Label();
acceleration.Position = new Vector2(0,400);
acceleration.Scale = new Vector2(3,3);

Label angularVelocity = new Label();
angularVelocity.Position = new Vector2(0,200);
angularVelocity.Scale = new Vector2(3,3);
scene.AddChild(labelAcceleration);
scene.AddChild(acceleration);
scene.AddChild(labelPosition);
scene.AddChild(labelAngularVelocity);
scene.AddChild(angularVelocity);

Director.Instance.RunWithScene(scene,true);
bool quitApp = false;

while(!quitApp)
{
Director.Instance.Update();

var motionData = Motion.GetData(0);

acceleration.Text =
"X: " + motionData.Acceleration.X.ToString() +
"  Y: " + motionData.Acceleration.Y.ToString() +
"  Z: " + motionData.Acceleration.Z.ToString();

labelPosition.Text = "";
if(System.Math.Round(motionData.Acceleration.Z,1) == -1)
labelPosition.Text = "Facing up";
if(System.Math.Round(motionData.Acceleration.Z,1) == 1)
labelPosition.Text = "Facing down";
else if(System.Math.Round(motionData.Acceleration.Y,1) == -1)
labelPosition.Text = "Facing you";
angularVelocity.Text =
"X: " + motionData.AngularVelocity.X +
"  Y: " + motionData.AngularVelocity.Y +
"  Z: " + motionData.AngularVelocity.Z;

if(Input2.GamePad0.Cross.Down == true)
quitApp = true;
Director.Instance.Render();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
}
Director.Terminate();
}
}
}

Here is the application running:

As you move the device around, the values will update depending on the speed and position. Press the cross button to exit.

How it works...

The first half of this code is the boilerplate GameEngine2D code, which is probably becoming rather familiar at this point. Additionally, we create four text labels for displaying our motion data on screen, which we then add to our scene object and run using the Director function. The only somewhat confusing call in the mix, if you have read the prior recipes in this chapter, is most likely the Scale = new Vector2(3,3); function. This simply scales the label by a factor of 3, as the default is so small as to be almost unreadable, at least to my aging eyes.

As before, the bulk of the new functionality is within the while loop. Once again, we have the typical four Director method calls. What we are doing here is:

- Getting the motion data and storing it in a motionData variable with a call to the static global Motion.GetData() object.

- Assigning the acceleration label the X, Y, and Z acceleration values within the motionData variable.

- Clearing out the labelPosition label text, then assigning it the value "Facing up" if the z axis is -1, "Facing down" if the z axis is 1, or assigning the value "Facing you" if the y axis is equal to 1. All of these values are rounded off to the nearest decimal place.

- We then assign the X, Y, and Z values of AngularVelocity in motionData to the angularVelocity label.

- Finally, we check to see if the Cross button is down, if it is we exit the application.

Now when you run the code and it will constantly update with the values from the accelerator and internal gyro (if your device has one).

There's more...

The naming decisions are rather odd and a bit confusing when it comes to motion data. Acceleration is probably easier thought of as the direction your device is facing in 3D space, while AngularVelocity describes its motion along each axis.

When trying to make sense of direction coordinates, think of it this way. Relative to the screen of the device, if the device is facing up (as in, lying flat on a table with the screen facing the sky), it will have an acceleration value of approximately (0,0,-1). If you flip the device over to face down, it will have a value of (0,0,1). While if you pick up the device so that the screen faces you with the cable socket facing the ground, it will have a value of (0,1,0). Run this sample program to get an idea of other positional values, as well as to see the effect of moving the device on the AngularVelocity vector.

See also

- See the Using the Input2 wrapper class recipe for more details on using Input2 helper class

Creating onscreen controls for devices without gamepads

In this recipe, we will look at creating onscreen controls for devices that do not have physical controls. We are going to configure a control set that has a left hand analog stick, select, start, as well as the cross, and triangle buttons. We are going to layout controls for an example device, the Xperia Arc, which has a 4.2" 480 x 854 screen.

Getting ready

This recipe can be created on your computer, however you will require an Android device to test it, as onscreen controls cannot be run on the Vita or simulator.

To get started, locate and execute OscCustomizeTool.exe. It will be located in the Tools folder, under the PSM Studio install directory. On my machine, which was installed using defaults, this file was located at C:\Program Files (x86)\SCE\PSM\tools\OscCustomizeTool.

How to do it…

1. On the main screen, uncheck all buttons except the L Analog, Select/Start, Select, Start, Face Button, Cross, and Triangle buttons like this:

2. Switch over to the Single Screen tab, change the Face Button button's Height to 2, then select the Face Button sub-tab and resize Triangle and Cross to have a width and height of 1.

3. You can now optionally add a background image that will be displayed under your controls. Select Background | Load and select an image to be used as a background.

4. In the layout window, select the checkbox next to To View Mode (once checked, it will display To Edit Mode).

5. Now switch over to the sizing window, select a 16:9 aspect ratio, and drag the slider to 4.2 (the size is displayed in the title of the window).

6. Switch back to the layout window, which should now be resized to the dimensions matching an Xperia Arc phone and displaying the buttons you have selected. Switch back to Edit mode. Now drag the buttons around, where you want them to be displayed.

7. Return to the main window and select the menu File | Save; save the osc.cfg file for later use.

How it works...

The OscCustomizeTool ultimately produces the osc.cfg file, which is read by the device to create the onscreen controls. It is important that you do not change the resulting filename.

The layout window is for visualization purpose only and doesn't actually change the positioning of the controls. The same layout is used by devices of all size, so you simply modify the values to see how your control design will look on different sized screens.

There's more...

The following table represents the typical resolutions and aspect ratios of supported PlayStation Mobile Android devices:

Device name

Screen size (inches) and resolution

Aspect ratio

Xperia PLAY

4" 854 x 480

16:9

Xperia Arc

4.2" 854 x 480

16:9

Xperia S

4.2" 854 x 480

16:9

Xperia ion

4.5" 1280 x 720

16:9

Xperia acro

4.2" 854 x 480

16:9

Xperia acro HD

4.3" 1280 x 720

16:9

Sony Tablet S

9.4" 1280 x 800

16:10

Sony Tablet P

2 x 5.5" 1024 x 480

16:15

HTC One X

4.7" 1280 x 720

16:9

The value System Bar in the main window determines how much space is left for the Android controls. For some devices, such as many Android 4 tablets, a portion of space needs to be reserved for the system controls such as the back and home buttons.

The system will automatically provide an onscreen controller for you. You only need to go through this process if you want to provide something different than the default gamepad. There are limitations to how much you can modify the controls as well to keep things somewhat consistent. Items on the left-hand side of the screen cannot be moved to the right-hand side and vice versa.

See also

- See the Configuring an Android application to use onscreen controls recipe for details on how to actually deploy your control settings to a device

Configuring an Android application to use onscreen controls

In this recipe, we will look at configuring onscreen controls on an Android device.

Getting ready

You need to have run through the prior recipe, or generated the osc.cfg file, which needs to be named exactly that. Locate the application PublishingUtility.exe. On my default install, it is located at C:\Program Files (x86)\SCE\PSM\tools\PublishingUtility. You will also need a PSM project you want to add the controls to.

How to do it…

1. Load PublishingUtility.exe.

2. Locate the Gamepad section and, in the drop-down to the right, set it to true.

3. Click on the Save button and save the file as app.xml in the same file location as osc.cfg.

4. In the project you want to add onscreen controls to, add app.xml, allowing it to overwrite the default.

5. Also add the file osc.cfg, then right-click it in the Solution view and set its Build Action to Content.

You are now complete; when the project is run on an Android device the customized onscreen keyboard will be shown.

How it works...

PublishingUtility generates the app.xml file for you, just as the OscCustomizeTool generated the osc.cfg file. You could have edited the app.xml file manually instead of loading the publishing tool. One is created for you by default when you create a new project.

There's more...

As you probably noticed, PublishingUtility handles a lot more than just setting Android configuration settings. We will look at the utility in greater detail in a later chapter.

See also

- See the Creating onscreen controls for devices without gamepads recipe for details on how to generate the required osc.cfg file

Chapter 3. Graphics with GameEngine2D

In this chapter we will cover:

- A game loop, GameEngine2D style

- Creating scenes

- Adding a sprite to a scene

- Creating a sprite sheet

- Using a sprite sheet in code

- Batching a sprite with SpriteLists

- Manipulating a texture's pixels

- Creating a 2D particle system

Introduction

At its core, PlayStation Mobile is actually a fairly low level SDK, just a small step above OpenGL. As you may have seen in Chapter 1, Getting Started, this results in a rather large amount of code to create 2D graphics, as you are working in 3D. Fortunately, Sony has provided a 2D library for you, GameEngine2D.

If you have ever used the popular Cocos2D library, GameEngine2D will feel immediately familiar, as Cocos2D was the inspiration behind GameEngine. GameEngine2D makes it significantly easier to make a 2D game.

A game loop, GameEngine2D style

In this recipe, we are going to create a game loop using the GameEngine2D library. The game loop is essentially the heart of your game, where input is read, graphics are drawn, and the game is updated. The GameEngine2D library helps you by making all of these aspects easier.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.GameEngine2D. The complete source for this example can be found in Ch3_Example1.

How to do it...

1. In the AppMain.cs enter the following code:

using System;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch3_Example1
{
public class AppMain  {
public static void Main(){
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

var label = new Sce.PlayStation.HighLevel.GameEngine2D.Label();
label.Text = "Hello world";

scene.AddChild(label);
Director.Instance.RunWithScene(scene);
Director.Terminate();
}
}
}

2. Finally hit the F5 key to run our application:

How it works...

This is about the smallest amount of code you can write that actually still accomplishes something. This is the iconic "Hello World" example, implemented using the GameEngine2D library.

At the heart of the GameEngine2D library is the Director singleton, which needs to be initialized manually. Behind the scenes, the Director object manages the scenes, rendering and updating the Scheduler and ActionManager, two key subsystems we will cover shortly. The Director object needs to be initialized before you use any GameEngine2D objects.

Next, we create a scene object, then set the scene's camera to render using the fullscreen dimensions with the scene.Camera.SetViewFromViewport() call. We then create a Label object, set its text to "Hello World", then add the label to our scene. Next, we call the Director singleton using its Instance member, calling RunWithScene() and passing in our newly created scene, causing our game to start. Finally, we call the Terminate() method that will clean up everything once the scene has finished running.

Note

Why was "Hello World" printed in the bottom-left corner?

GameEngine2D is based on Cocos2D and Cocos2D sets the origin point (0,0) at the bottom-left corner, instead of the more traditional top left corner. Ultimately, Cocos2D most likely used the bottom-left corner as the origin point because this is the coordinate system that OpenGL uses. When you add a node to a scene without specifying a position, it will be added at the origin. Therefore, when we added our label to the scene, it was located at the bottom-left corner.

There's more...

At this point you may be wondering, How is this a game loop, there is no loop? which is a very good question. There is still a loop, but it is hidden deep inside the Director class. We will be covering this in a bit more detail, in a later chapter. You can, however, have more control over the process by implementing your own game loop manually. If you want to manually control the main game loop (which Sony recommends), pass in true as the second parameter in the RunWithScene call, like this:

Director.Instance.RunWithScene(scene,true);

Once you inform Director that you are going to manually handle the game loop, there are a series of calls you need to make in the proper order. The following is the minimum code required in a manually handled game loop:

Director.Instance.RunWithScene(scene,true);
while(true)
{
Director.Instance.Update();
Director.Instance.Render ();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
}
Director.Terminate();

Note

GameEngine2D source included

Sony has included the complete source code for GameEngine2D (as well as all of the other libraries in the Sce.PlayStation.HighLevel namespace) in the source subdirectory on your PlayStation Mobile SDK install. On my PC, installed using the defaults, this folder is located at C:\Program Files (x86)\SCE\PSM\source.

See also

- See the Creating a simple game loop recipe in Chapter 1, Getting Started for an example of a non-GameEngine2Dgame loop

Creating scenes

In this recipe, we are going to implement a derived scene object, MyScene.

Getting ready

Load up PlayStation Mobile Studio and create a new project or duplicate the code from the A game loop, GameEngine2D style recipe, as the AppMain.cs code is going to be virtually unchanged. The complete source for this example can be found in Ch3_Example2.

How to do it...

1. In the Solution pane of PlayStation Mobile Studio, right-click on your Project (Ch3_Example2) and select the menu Add | New File....

2. In the New File dialog box, select General on the left-hand side, Empty Class on the right, then at the bottom in the Name: field, enter MyScene.cs, and click on the New button.

3. In MyScene.cs, enter the following code:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch3_Example2
{
public class MyScene : Scene
{
private Label _labelTopLeft;
private Label _labelTopRight;
private Label _labelBottomLeft;
private Label _labelBottomRight;
float elapsedTime = 0;
public MyScene ()
{
this.Camera.SetViewFromViewport();
var width = Director.Instance.GL.Context.Screen.Width;
var height = Director.Instance.GL.Context.Screen.Height;

_labelTopLeft = new Label() { Text="Top Left", Position=new Vector2(5,height-20) };
_labelTopRight = new Label() { Text="Top Right", Position=new Vector2(width-100,height-20) };
_labelBottomLeft = new Label() { Text="Bottom Left", Position=new Vector2(5,5) };
_labelBottomRight = new Label() { Text="Bottom Right", Position=new Vector2(width-100,5) };

this.AddChild(_labelTopLeft);
this.AddChild(_labelTopRight);
this.AddChild(_labelBottomLeft);
this.AddChild(_labelBottomRight);

Scheduler.Instance.ScheduleUpdateForTarget(this,1,false);
}

public override void Update(float dt)
{
elapsedTime += dt;
base.Update(dt);
}

public override void Draw ()
{
var tenSecondsElapsed = (System.Math.Floor(elapsedTime/ 10))% 2;
if(tenSecondsElapsed ==0)
_labelBottomLeft.Color = _labelBottomRight.Color = _labelTopLeft.Color = _labelTopRight.Color = new Vector4(255,0,0,255);
else
_labelBottomLeft.Color = _labelBottomRight.Color = _labelTopLeft.Color = _labelTopRight.Color = new Vector4(0,255,0,255);
base.Draw ();
}
}
}

In AppMain.cs, replace Main() with (changed bolded):
public static void Main(){
Director.Initialize();
MyScene scene = new MyScene();
scene.Camera.SetViewFromViewport();

var label = new Sce.PlayStation.HighLevel.GameEngine2D.Label();
label.Text = "Screen Center";
label.Position = new Sce.PlayStation.Core.Vector2(
Director.Instance.GL.Context.Screen.Width/2-50,
Director.Instance.GL.Context.Screen.Height/2-10);

scene.AddChild(label);

Director.Instance.RunWithScene(scene);
Director.Terminate();
}

4. Run your application by hitting the F5 key:

This application draws a label in each of the four corners, then every 10 seconds switches between red and green text. It also displays "Hello World" in the center of the screen.

How it works...

The Main() function in AppMain.cs is only changed slightly from the prior recipe. The major change is, instead of using a generic Scene object, we are now creating an instance of our custom MyScene object. The only other change is that we have centered the "Hello World" label in the middle of the screen.

MyScene is derived from Sce.PlayStation.HighLevel.GameEngine2D.Scene. We declare five member variables, one Label for each corner of the screen as well as a float for recording the time that elapsed since creation. In the constructor, we set the scene to render to the dimensions of the screen. We then cache the screen width and height for later use.

Next, we allocate all four of the labels, positioning each one slightly offset from each screen corner with the appropriate text. We then add each of the labels to MyScene object's widget collection using AddChild(). We then register MyScene to receive updates by passing our MyScene object to Scheduler.Instance.ScheduleUpdateForTarget(). We will cover this process in more detail in the next chapter.

The Update() method is called once per frame and simply adds the time delta (since the last call to Update()). In the Draw() method (which also is called once per frame), we first check if 10 seconds have elapsed. If it has, we set each corner label to green, then every 10 seconds we toggle between red and green.

There's more...

As you can see, GameEngine2D makes it easy to move logic from the game loop into individual scenes. By overriding the Draw method, you can control rendering at the scene level.

Adding a grid

It's quite common when debugging to display a grid over your scene. This task is incredibly easy to accomplish in a Scene object. At the bottom of your constructor add the following code:

Director.Instance.DebugFlags = Director.Instance.DebugFlags | DebugFlags.DrawGrid;
this.DrawGridStep = 32.0f;

This will cause a grid to appear when your scene is drawn, like this:

DrawGridStep determines the spacing of your grid in pixels.

You generally have to inherit from a Node derived object (like Scene) if you want to implement a custom draw function. You can, however, register a custom Draw method that will be called by Director each frame using the AdHocDraw event of any object that inherits from Node. For example:

_labelBottomLeft.AdHocDraw += () => {
_labelBottomLeft.Color = new Vector4(255.0f,255.0f,255.0f,255.0f);
};

This registers an AdHocDraw function to the node _labelBottomLeft, in this case a lambda function that changes the label's color to white. This function will be called every frame until the event handler is removed. This technique is used quite often in the PlayStation Mobile SDK samples to simplify the code. It prevents you from having to create a custom Scene if you simply want to override its Draw method.

See also

- See the Handling updates with Scheduler recipe in Chapter 4, Performing Actions with GameEngine2D for details on how to handle updating using Scene classes

Adding a sprite to a scene

In this recipe, we are going to create a sprite and add it to a scene, rendering it centered on the screen .

Getting ready

Create a new project and add a reference to GameEngine2D. You are going to need to add an image file to use as a sprite; I will be reusing our trusty F18 graphic. The complete source for this example can be found in Ch3_Example3.

How to do it...

1. Open AppMain.cs and add the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch3_Example3
{
public class AppMain
{
public static void Main (string[] args)
{
Director.Initialize();

Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

TextureInfo ti = new TextureInfo("/Application/FA-18h.png");
SpriteUV sprite = new SpriteUV(ti);

sprite.Scale = ti.TextureSizef;
sprite.Pivot = new Vector2(0.5f,0.5f);
sprite.Position = new Vector2(
Director.Instance.GL.Context.Screen.Width/2,
Director.Instance.GL.Context.Screen.Height/2);

scene.AddChild(sprite);

Director.Instance.RunWithScene(scene);
}
}
}

2. Now run the code by hitting the F5 key and you will see the following output:

How it works...

This code begins by initializing Director, creating, and setting up a scene as usual. We then create a TextureInfo object, passing it the path of our texture image. We then create a SpriteUV using the TextureInfo object.

Next, we set our sprite's scale equal to its texture image size (in pixels). Then, we set its pivot point to the center of the sprite and position the sprite in the center of the screen. Finally, we add the sprite to our scene, then tell the Director method to run our scene, causing our sprite to be displayed.

There's more...

Pivot points are an important concept to understand. The pivot point is the position (within the sprite) that transformations are performed relative to. By default in GameEngine2D, the pivot point will be set to the bottom-left corner of the sprite. Therefore, if we translated (moved) the sprite to the top-right corner of the screen, it would be completely offscreen. If the pivot point was set to the middle of the sprite, the same transformation to the top-right corner of the screen would result in only the bottom-left corner of the sprite being visible, while the other three fourth of the sprite would be offscreen. When performing a rotation, the pivot point is the point the rotation is performed around.

The pivot point is a Vector2 value with valid values ranging from (0,0) to (1,1). A value of (0,0) being the bottom-left corner and the value (1,1) representing the top-right corner. The following diagram demonstrates various pivot point values and their relative positions within the sprite:

Another important concept to understand is how transformations are actually applied to a Sprite object in GameEngine2D. Behind the scenes, we are still dealing with 3D and our sprite is actually a four-sided polygon aligned to the camera. This polygon data is held by the Quad attribute in SpriteBase, which SpriteUV inherits from. This Quad value in turn holds the four vertices that make up the quad, as well as the key attributes T, R, and S, which represent the current translation, rotation, and scale respectively. You do not generally access the Quad property directly; instead you use the higher-level properties such as Rotate and Scale inherited from the Node base class.

See also

- See the Loading, displaying, and translating a textured image recipe in Chapter 1, Getting Started for details on how to add an image resource to your project

Creating a sprite sheet

In this recipe, we are going to create a sprite sheet using the freely available TexturePacker application.

Getting ready

Head over to http://bit.ly/Nm0lUd and download TexturePacker. It is available for Window, Mac OS, and Ubuntu. This recipe uses the Windows version. The sprites used in this example can be downloaded from http://bit.ly/T3odB5. Run through the install and then run TexturePackerGUI. When prompted, select Use Essential to enable the basic free version.

We are going to create a 256 x 128 sprite sheet using these seven individual 64 x 64 pixel frames of animation, as shown in the following diagram:

How to do it...

1. Select Edit | Add Sprites, as shown in the following screenshot:

2. In the resulting dialog box, Ctrl + left-click to select our seven sprites in order and then click on Open.

3. By default, it will load the sprites to fit as tightly in the sprite sheet as possible. If we want to pack in a grid four sprites widely instead, in the Texture Settings panel under the Layout section, set Algorithm to Basic, Border padding to 0, Shape Padding to 0, and Sort by to Name. In the Geometry section set Fixed width to 256, and Fixed height to 128, as shown in the following screenshot:

4. In the Output section of the Texture Settings panel, specify a path and filename to save your sprite sheet to in the Texture file field, and then click on the Publish button at the top of the screen:

5. Your sprite sheet will be created in the location you specified in the previous step. It should now look something like the following screenshot:

How it works...

TexturePacker simply takes a sequence of independent image files and packs them together into a single image. When working with GPU hardware, power of 2 sizes (64 x 64, 128 x 128, 1024 x 1024, and so on) generally perform the best. In fact, some hardware actually requires textures to have width and height values that are a power of 2.

So why pack all of your textures together into a single texture? In a word, speed. Copying a single large file, either from the disk or in the memory, is almost always faster than copying a series of small files.

TexturePacker also generates a datafile describing the sprite data and its positioning within the texture; the format this file is generated in is determined by the selection you choose under Data Format. In this case, we will not be using this file. If you want to pack as many files as possible within a texture sheet or want to store multiple different animation sequences in a single sheet, this datafile becomes critical for locating your sprites within the texture.

There's more...

TexturePacker is by no means the only option when it comes to generating sprite sheets. You can manually arrange your sprites into a single file using any image editor, such as Photoshop, Paint.NET, or GIMP. As well, there are a number of competing sprite creation tools, such as Sprite Sheet Packer (http://spritesheetpacker.codeplex.com/) and Zwoptex (http://bit.ly/NUtIA1).

See also

- See the Loading, displaying, and translating a textured image recipe in Chapter 1, Getting Started for information on the sprites used in this recipe

- See the Using a sprite sheet in code recipe for an example of how to make use of a sprite sheet with the PlayStation Mobile SDK

Using a sprite sheet in code

In this recipe we are going to look at playing an animation sequence using the sprite sheet we just created in the prior recipe.

Getting ready

This recipe assumes you have completed the Creating a sprite sheet recipe or have a sprite sheet acquired from another source. Make sure your sprite sheet is composed of sprites of an identical size. In this example, our sheet is 2 rows of 4 columns of sprites, with the bottom-right sprite being empty, for a total of seven sprites.

Create a new project, and then add a reference to GameEngine2D.

How to do it...

1. In AppMain.cs replace the existing code with the following code:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.HighLevel.GameEngine2D;
namespace Ch3_Example4
{
public class AppMain
{
public static void Main (string[] args)
{
Director.Initialize();
SpritesheetScene scene = new SpritesheetScene();
Director.Instance.RunWithScene(scene);
}
}
}

2. Now add a new file of type Empty Class named SpritesheetScene.cs to your project. Enter the following code:

using System;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;
namespace Ch3_Example4
{
public class SpritesheetScene : Scene
{
private SpriteTile _currentSprite;
private Texture2D _texture;
private TextureInfo _ti;

private float elapsedTime = 0.0f;

public SpritesheetScene ()
{
_texture = new Texture2D("/Application/SpriteSheet.png",false);
_ti = new TextureInfo(_texture,new Vector2i(4,2));
_currentSprite = new SpriteTile(_ti,new Vector2i(0,1));
_currentSprite.Pivot = new Vector2(0.5f,0.5f);
_currentSprite.Position = new Vector2(0.0f,0.0f);
_currentSprite.Scale = new Vector2(3.0f,3.0f);
this.AddChild(_currentSprite);

Scheduler.Instance.ScheduleUpdateForTarget(this,1,false);
}

public override void Update (float dt)
{
elapsedTime += dt;
if(elapsedTime > 0.5f)
{
Vector2i currentTile = _currentSprite.TileIndex2D;
if(currentTile.Y == 1)
{
if(currentTile.X < 3)
currentTile.X ++;
else
currentTile = new Vector2i(0,0);
}
else
{
if(currentTile.X < 2)
currentTile.X++;
else
currentTile = new Vector2i(0,1);
}
_currentSprite.TileIndex2D = currentTile;
elapsedTime = 0.0f;
}
}
}
}

3. Hit F5 to run your application and you should see the following output:

A jet sprite will display centered to the screen, then every half a second it will advance to the next frame until it runs out of animations, at which point it will start over again.

How it works...

The code in AppMain.cs should be familiar at this point. It simply initializes the Director singleton, creates an instance of our SpritesheetScene class, and then the Director method runs with the newly created scene.

SpritesheetScene is where the bulk of our activity occurs. We start off by declaring four private member variables, a SpriteTile object to represent the currently displayed sprite within the sprite sheet, a Texture2D object to store the actual image in memory, a TextureInfo object to store texture details such as UV coordinates and number of sprites, and finally a float variable to keep a running total of time that has elapsed.

In our constructor we load _texture with a call to Texture2D specifying our texture's file location and the fact we do not want a mipmap generated. We then create our TextureInfo object, _ti by passing in our newly generated texture as well as a Vector2i specifying the number of sprites comprising our sprite sheet. It is very important to note that this value is NOT zero based.

We then create a SpriteTile object, _currentSprite passing in _ti, as well as specifying the indices of the sprite within the sprite sheet we want the SpriteTile object to point at. In this case, this value is zero based. When we specify (0,1) we are pointing at the top-left sprite in our sprite sheet, keeping in mind that GameEngine2D coordinates start at the bottom-left corner while our image file starts at the top-left. Next, we set the pivot point of the sprite to its center, its position to the middle of the screen, and then scale it up three times in size just to make it a bit more visible. Finally, we add our sprite to the scene and then schedule our scene to receive updates. We will cover the updating process in more detail in the next chapter.

In the update method, we increment the _elapsedTime variable by value of dt, which is the amount of time that has occurred since the last time update was called. We then check if the elapsed time is greater than .5 (half a second). If half a second has elapsed, we then advance the sprite one tile to the right in the animation sequence. If advancing would cause us to exceed the sprites available, we instead roll over to the beginning of the next now. Keep in mind that on the bottom row (currentTile.Y == 0) we check against currentTile.X, if it is less than 2 instead of 3, because the bottom-right sprite in our sprite sheet is empty. Once we have performed the calculation, we update the sprite that _currentSprite is pointing at by updating TileIndex2D. We then reset _elapsedTime to zero to begin the half-second countdown all over again.

There's more...

This whole process probably looked a bit more complicated than it actually is. Essentially you create a sprite sheet by passing in a Vector2i variable to your TextureInfo object, letting it know the texture it represents is actually a sprite sheet, containing however many rows and columns you specified in the vector. A SpriteTile object points at a single sprite within the sheet. When you create the SpriteTile object you can specify a Vector2i variable, which sets the offset from which the SpriteTile object will get its sprite. This value can later be updated using the value TileIndex2D. Think of the sprite sheet as a grid of sprites, and TileIndex2D as coordinates for an individual cell within that grid.

It is important to understand how tile indexing works. A sprite sheet requires all the images to be of the same width and height for a reason. When you tell a TextureInfo object that it holds a sprite sheet, it creates texture coordinates based on the dimensions you pass in. Say for example you pass in (5,5) to a TextureInfo object that contains a 160 x 160 texture; it will effectively hold 25 sprites with a 32 x 32 texture, in 5 rows, 5 columns wide. Using TileIndex2D to access the sprites, the values (0,0) to (4,0) will represent the bottom row of sprites in the image, (0,1) to (4,1) will represent the next row up, while (4,4) would represent the top-right 32 x 32 pixel tile within the sprite sheet. You can also access the individual sprites using TileIndex1D. In this case 0 represents the bottom-left sprite within the sprite sheet, 5 would represent the sprite directly above it, while 24 would represent the top-right sprite.

One of the major advantages to using a sprite sheet is the SpriteTile class. This class is a lot lighter than the SpriteUV class, as all of the sprites within a SpriteTile class have the same UV data. This means it will load quicker and use less memory and CPU than a comparable SpriteUV class.

See also

- See the Creating a sprite sheet recipe for instructions on how to create a sprite sheet

Batching a sprite with SpriteLists

In this recipe we are going to look at the benefits of using SpriteLists to accelerate 2D rendering of similar objects.

Getting ready

Create a new project and add a reference to GameEngine2D. Add a sprite to your project. I am going to reuse our trusty FA-18H sprite from prior recipes. You can download the complete source at Ch3_Example5.

How to do it...

1. In AppMain.cs enter the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;
namespace Ch3_Example5
{
public class AppMain
{
public static void Main (string[] args)
{
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();
Texture2D texture = new Texture2D("/Application/FA-18H.png",false);
TextureInfo ti = new TextureInfo(texture);
List<SpriteUV> sprites = new List<SpriteUV>();

Random random = new Random();

SpriteList spriteList = new SpriteList(ti);
for(int i = 0;i< 1000;i++)
{
SpriteUV sprite = new SpriteUV(ti);
sprite.Pivot = new Vector2(0.5f,0.5f);
sprite.Position = new Vector2(
random.Next(0,Director.Instance.GL.Context.Screen.Width),
random.Next(0,Director.Instance.GL.Context.Screen.Height));
sprite.Scale = sprite.TextureInfo.TileSizeInPixelsf;

sprite.Schedule( (dt) => {
if(sprite.Position.Y < Director.Instance.GL.Context.Screen.Height)
{
sprite.Position = new Vector2(sprite.Position.X,sprite.Position.Y + 1);
}
else
{
sprite.Position = new Vector2(sprite.Position.X,0.0f);
}
});
spriteList.AddChild(sprite);
}

scene.AddChild (spriteList);
scene.AddChild(new FPS());
Director.Instance.RunWithScene(scene);
}
}
}

2. Run the code by hitting F5 and you will see the following output:

3. Now uncomment the line spriteList.AddChild(sprite); and remove the comment before the line //scene.AddChild(sprite);. Run it again to see the following output:

Running in the simulator on my laptop, the sprite list version runs at least three times faster. This is especially impressive as the simulator has a fixed frame rate cap of 60 fps.

How it works...

We start off with the standard initialization code, setting up Director, our scene, and creating our Texture and TextureInfo objects. We then declare a SpriteList object. Next we create a list of SpriteUV objects, then loop 1,000 times creating a new sprite, setting it up, and positioning it randomly within the screen. We then schedule a lambda function for each sprite that will be called during the update phase, something we will cover in more detail in the next chapter. Finally, we either add the newly created sprite to the SpriteList (or to the scene normally if we uncomment the line scene.AddChild(sprite);).

Now that we have created 1,000 sprites and added them to SpriteList, we add SpriteList to our scene. We also add a new FPS (Frames Per Second) widget to the scene to display the current frame rate. Finally, we tell the Director singleton to run using scene.

The simple act of adding our sprites to the SpriteList, which is then added to the scene, instead of adding the sprites to the scene directly, resulted in a massive increase in speed.

There's more...

SpriteList manages this massive increase in speed by grouping all of the sprites together in a single batch. If you are coming from an XNA background, SpriteList is PlayStation Mobile's equivalent of the SpriteBatch class, and it has similar restrictions.

SpriteList gains this massive increase in speed by drawing all of the sprites using the exact same settings. This removes a lot of rendering overhead and setup from the process but imposes some serious restrictions. First, you can only add SpriteUV or SpriteTile derived objects to the SpriteList class. Second, all of the objects in a SpriteList class need to have the same TextureInfo object. The most common real world scenario for using SpriteList is to organize your game sprites into a number of different sprite sheets, then having one SpriteList per sprite sheet. You can have as many SpriteList objects in your scene as you want; however, you will benefit less and less the fewer the number of sprites in a SpriteList. If your sprite is only going to have a few instances on screen at once, do not use a SpriteList object.

We also made use of a simple widget I wrote called FPS. This is a simple SpriteUV derived object that creates an image with the current frame rate. Here is the code for FPS.cs:

using System;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Imaging;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch3_Example5
{
public class FPS : SpriteUV
{
TextureInfo _ti;

public FPS ()
{
Texture2D texture = new Texture2D(150,100,false,
PixelFormat.Rgba);
_ti = new TextureInfo(texture);

this.TextureInfo = _ti;
this.Quad.S = new Sce.PlayStation.Core.Vector2(150,100);
Scheduler.Instance.ScheduleUpdateForTarget(this,1,false);
}

public override void Update (float dt)
{
_ti.Dispose();
Image img = new Image(ImageMode.Rgba, new ImageSize(150,100),
new ImageColor(255,255,255,0));
img.DrawText("FPS:" + (1/dt).ToString(),
new ImageColor(255,255,255,255),
new Font(FontAlias.System,32,FontStyle.Bold),
new ImagePosition(0,0));

Texture2D texture = new Texture2D(150,100,false,
PixelFormat.Rgba);
texture.SetPixels(0,img.ToBuffer(),PixelFormat.Rgba);
img.Dispose();
_ti = new TextureInfo(texture);
this.TextureInfo  = _ti;

base.Update (dt);
}
~FPS(){
_ti.Dispose();
}
}
}

Simply add FPS.cs to your project, create a new FPS, and add it to your scene, and it will automatically update with the current frame rate.

For performance reasons, it is incredibly important to batch together calls with similar properties (same shader, render settings, texture, and so on), not just on PSM, but in game programming in general. Removing the setup overhead between common rendering calls can make a huge difference, the difference between a good frame rate and a game that struggles when drawing to the screen.

See also

- See the Using a sprite sheet in code recipe for more details on using SpriteTile and sprite sheets

Manipulating a texture's pixels

In this recipe, we are going to modify a sprite by working with its pixel data directly. We are going to perform two actions on the image. First we are going to increase the transparency of every solid pixel in the image. Then we are going to surround the image with a red rectangle, as you might put around a selected character sprite or button.

Getting ready

Create a new solution, add a reference to GameEngine2D, and add a sprite object. Once again I am going to use FA-18H.png. The source for this project is available as Ch03_Example6.

How to do it...

1. In AppMain.cs replace the existing code with the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Imaging;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch03_Example5
{
public class AppMain
{
public static void Main (string[] args)
{
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

Image image = new Image("Application/FA-18H.png");
image.Decode();
var buffer = image.ToBuffer();

int totalBytes = image.Size.Width * image.Size.Height * 4;

for(int i = 0; i < totalBytes;i+=4)
if(buffer[i+3] != (byte)0)
buffer[i+3] = (byte)32;

for(int i = 0; i < totalBytes; i+=4)
{
if(i < image.Size.Width * 4 * 3 ||
i >= (totalBytes - (image.Size.Width * 4 * 3)) ||
(i % (image.Size.Width * 4)) < 12 ||
(i % (image.Size.Width * 4)) >= (image.Size.Width * 4) - 12
)
{
buffer[i] = (byte)255;
buffer[i+3] = (byte)255;
}
}

Texture2D texture = new Texture2D(image.Size.Width,
image.Size.Height,
false,
PixelFormat.Rgba);
texture.SetPixels(0,buffer);
TextureInfo ti = new TextureInfo(texture);

SpriteUV sprite = new SpriteUV(ti);
sprite.Scale = ti.TextureSizef;
sprite.Pivot = new Vector2(0.5f,0.5f);

sprite.Position = new Vector2(
Director.Instance.GL.Context.Screen.Width/2,
Director.Instance.GL.Context.Screen.Height/2);
scene.AddChild(sprite);

Director.Instance.GL.Context.SetClearColor(new Vector4(255,255,255,255));
Director.Instance.RunWithScene(scene);
}
}
}

2. Run your scene by hitting F5 and you will see the following output:

How it works...

After the standard Director and Scene initialization, instead of loading an image directly into a Texture2D object, we instead create an Image object, located in the Sce.PlayStation.Core.Imaging namespace. We create an image by passing it a file path as usual, then decode the image from its native (often compressed) format using a call to image.Decode();.

At this point we get the image data by calling ToBuffer(), which returns a byte array we store as buffer. This buffer is going to be composed of 4 byte pairs representing each pixel, one byte for each color (red, green, blue), plus one byte for the alpha channel (transparency).

The first four bytes in the buffer are the top-left pixel in the image, while the last four bytes represent the bottom-right corner pixel of the image. We can therefore calculate the total size of our byte buffer with the following code:

int totalBytes = image.Size.Width * image.Size.Height * 4;

First, we loop through all of the pixels in the image and if the alpha channel isn't 0 (meaning it isn't completely transparent already), we reduce (or increase) its alpha channel to 12.5 percent (32/256), making it almost completely transparent. Remember, each pixel is represented by four bytes, so buffer[0] is the red pixel, buffer[1] is the green pixel, buffer[2] is the blue pixel, and buffer[3] is the alpha channel. This is why we increment the index by four at a time each iteration through the loop, causing i to point to the next pixel grouping in the buffer.

Next, we want to draw a red 3 pixel border around the outside edge of the sprite. We do this by checking our location in the array. We can tell our position by calculating our offset within the byte array. Each "line" of image data will be image width X 4 bytes per pixel bytes long, so a 100 x 100 image would be composed of 100 x 400 byte lines. If we are in the first three lines, the last three lines, or within 12 bytes (3 pixels) of either the left or right side of the image, we set the red byte to full (256). The end result is a red rectangle 3 pixels thick around the edge of our image.

Now, that we have modified our image buffer, we create a Texture2D object using the image dimensions, then copy in the pixel data using SetPixels(). The first parameter represents the image layer and will always be 0, unless you are using mipmapping. We then create TextureInfo and SpriteUV objects, center them to the screen, tell the Director object to clear to white each frame it draws, then finally start our scene running.

There's more...

It is important to note that this entire recipe assumes you are using a RGBA pixel format image, which is the default. If you use a different pixel format, all of the calculations need to be updated! The PlayStation Mobile SDK supports a number of different pixel formats, but RGBA is the norm, as it is the default in most graphic applications.

Many of you will be tempted to work directly with pixels; there is something primal about working directly with your image data! I highly recommend against this! Modern CPUs do not really work at the pixel level anymore, so direct pixel level manipulations are a rather expensive action. Try to keep any direct pixel operations done on a frame by frame basis to an absolute minimum.

See also

- See the "Hello World" drawing text on an image and Manipulating an image dynamically recipes in Chapter 1, Getting Started for more details on using the imaging classes

Creating a 2D particle system

In this recipe, we are going to create an extremely simple pinwheel particle system.

Getting ready

Create a new solution, and add a reference to GameEngine2D. You will also need a small graphic to use as your particle; I created a small 32 x 32 pixel image that was mostly transparent. Create an image and add it to your project. The source for this project is available as Ch03_Example7.

How to do it...

1. In AppMain.cs replace the existing code with the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch3_Example7
{
public class AppMain
{
public static void Main (string[] args)
{
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

var particles = new Particles(2000);
var pinwheel = particles.ParticleSystem;
pinwheel.TextureInfo = new TextureInfo(new Texture2D("Application/WaterDrop.png",false));

pinwheel.Emit.Position = new Vector2(
Director.Instance.GL.Context.Screen.Width/2,
Director.Instance.GL.Context.Screen.Height/2);
pinwheel.Emit.LifeSpan = 5.0f;
pinwheel.Emit.Velocity = new Vector2(0.0f,650.0f);
pinwheel.Emit.WaitTime = 0.005f;
pinwheel.Emit.ScaleStart = 26.0f;
pinwheel.Emit.ScaleEnd= 6.0f;
pinwheel.Emit.ColorEnd = new Vector4(0.0f,0.0f,0.0f,0.0f);

pinwheel.Simulation.Gravity = 300.0f;
pinwheel.Simulation.Fade = 0.0f;
float rotate = 0.0f;
particles.Schedule((dt) => {
pinwheel.Emit.Velocity = pinwheel.Emit.Velocity.Rotate (
Sce.PlayStation.HighLevel.GameEngine2D.Base.Math.Deg2Rad(rotate+=1.0f*dt));
});

scene.AddChild(particles);
Director.Instance.RunWithScene(scene);
}
}
}

2. Run your scene with F5 and you will see the following output:

How it works...

We start off with the standard Director and Scene initialization code. We then create a Particles object, passing it 2000, which represents the maximum particle count that the system will support. The Particles class is just a simple wrapper around a ParticleSystem object, enabling the Particles object to be used as a node within a scene. The actual heavy lifting is done in the ParticleSystem attribute, so we take a reference for convenience in the variable pinwheel.

First, we create a TextureInfo object that will be used for each particle. The TextureInfo object contains a Texture2D object, which in turn loads the image we created, in this case WaterDrop.png. This image is going to be the visual basis of every rendered particle.

Now that we have an image for our particle system to draw each particle with, we configure the particle emitter. This is done using the Emit attribute. We set the LifeSpan of each particle to 5, causing the particles to live for 5 seconds. We then set the Velocity to (0.0f, 650.0f), which causes the particles to shoot straight up and out to a distance of 650 pixels (minus the effect of gravity). Next, we set the WaitTime to 0.005, which is the time in seconds to wait before creating each particle, resulting in a nearly constant stream of particles. Then, we set the ScaleStart and ScaleEnd values. These values represent the size of the particles when they are emitted; then the values will scale down, resulting in each particle shrinking over its 5 second lifespan. Finally, we set the ColorEnd variable to a transparent black, causing particles to fade to black at the end of their lifespans.

Next, we set up the simulation parts of the particle system. In this case we tell it to apply Gravity at a rate of 300 pixels per second. The axis that gravity is applied on can also be specified (using GravityDefault), but in this case we will take the default. Finally, we tell the particles not to Fade, as we do this already (and smoother) using the ColorEnd attribute of the Emit class. We then schedule a simple update lambda to be called each frame during the scheduler's update phase (we will cover this in more detail in the next chapter). Each update we apply a crude rotation to the emitter, causing the pinwheel effect as the emitter rotates each frame. Finally, we add the Particles object to our scene and start it running.

There's more...

Due to space constraints, this recipe only brushes on the very basics of what ParticleSystem is capable of. There are a few dozen other settings we haven't mentioned here. In addition, you can apply a shader to each particle, resulting in just about any effect you can imagine. Particles can be used to represent explosions, fire, water effects, and so on.

See also

- The PlayStation Mobile SDK example Feature Catalog in the \sample\GameEngine2D folder demonstrates a fire/smoke effect using a compound particle system

Chapter 4. Performing Actions with GameEngine2D

In this chapter we will cover:

- Handling updates with Scheduler

- Working with the ActionManager object

- Using predefined actions

- Transitioning between scenes

- Simple collision detection

- Playing background music

- Playing sound effects

Introduction

In this chapter, we are going to explore the various ways you can control program execution using GameEngine2D. This involves the use of two critical subsystems, ActionManager and Scheduler. We are going to look at how you can make use of both these systems. We are also going to look at how you play sound effects and background music, as well as see how to add a graphical transition between scenes.

Handling updates with Scheduler

In this recipe we are going to demonstrate three different ways you can update a node derived object: handling the update directly in the game loop, inheriting from a node derived class, and overriding the Update method or passing a delegate in to a Node's Schedule property.

Getting ready

Load up PSM Studio and create a new project. Add a reference to Sce.PlayStation.GameEngine2D. We also need a sample sprite to work with; I will again be using our trusty F18 sprite, but feel free to substitute any reasonably sized graphic of your own. The complete source for this example can be found in Ch4_Example1.

How to do it...

1. Add the sprite to the project and set its Build Action to Content.

2. Open AppMain.cs and replace the existing code with the following code:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch4_Example1
{
public class AppMain{
public static void Main (string[] args){
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

SpriteUV jetSprite1 = new SpriteUV(new TextureInfo("/Application/FA-18h.png"));
jetSprite1.Scale = jetSprite1.TextureInfo.TextureSizef.Multiply(new Vector2(0.5f,0.5f));
jetSprite1.Position = new Vector2(0,550 - jetSprite1.Scale.Y);

SpriteUV jetSprite2 = new JetSpriteWithUpdate();
SpriteUV jetSprite3 = new SpriteUV(new TextureInfo("/Application/FA-18h.png"));

jetSprite3.Scale = jetSprite3.TextureInfo.TextureSizef.Multiply(new Vector2(0.5f,0.5f));
jetSprite3.Position = new Vector2(0,150 - jetSprite3.Scale.Y);

jetSprite3.Schedule((dt) => {
if(jetSprite3.Position.X > Director.Instance.GL.Context.GetViewport().Width)
jetSprite3.Position = new Vector2(0,150 - jetSprite3.Scale.Y);
else
jetSprite3.Position = new Vector2(jetSprite3.Position.X + 1,150 - jetSprite3.Scale.Y);
});
scene.AddChild(jetSprite1);
scene.AddChild(jetSprite2);
scene.AddChild(jetSprite3);
Director.Instance.RunWithScene(scene,true);

bool done=false;
while(!done){
Director.Instance.Update();

if(jetSprite1.Position.X > Director.Instance.GL.Context.GetViewport().Width)
jetSprite1.Position = new Vector2(0,550 - jetSprite1.Scale.Y);
else
jetSprite1.Position = new Vector2(jetSprite1.Position.X + 1,550 - jetSprite1.Scale.Y);

Director.Instance.Render();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
}
}
}
}

3. Create a new CS file named JetSpriteWithUpdate.cs and enter the following code:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch4_Example1
{
public class JetSpriteWithUpdate : SpriteUV
{
public JetSpriteWithUpdate ()
{
this.TextureInfo = new TextureInfo("/Application/FA-18H.png");
this.Scale = this.TextureInfo.TextureSizef.Multiply(new Vector2(0.5f,0.5f));
this.Position = new Vector2(0,350 - this.Scale.Y);
this.ScheduleUpdate(0);
}

public override void Update (float dt)
{
if(this.Position.X > Director.Instance.GL.Context.GetViewport().Width)
this.Position = new Vector2(0,350 - this.Scale.Y);
else
this.Position = new Vector2(this.Position.X + 1,350 - this.Scale.Y);
}

~JetSpriteWithUpdate()
{
this.TextureInfo.Dispose();
}
}
}

4. Press F5 to run and you will see the following output:

What you should see is three individual jet sprites, all being updated identically each frame by a completely different method.

How it works...

This code starts off with typical boilerplate code. We initialize our Director object, create a new scene, and then set the size of the camera to match the viewport. Next, we create three different instances of the same F18 sprite, each positioned evenly across the left-hand side of the screen. The first sprite, jetSprite1, we are going to update the traditional way, in the game loop. The second sprite is a custom class derived from SpriteUV, which we will look at in a second.

The final sprite is controlled using its Schedule member. In this case, we are simply passing a lambda function that is going to move the sprite left to right, until it moves beyond the edge of the screen, then it is going to repeat the process all over again. The function takes a single parameter, dt, which is a float variable containing the elapsed time since the last call in seconds.

Now take a look at the JetSpriteWithUpdate class. This class inherits from SpriteUV; in the constructor we simply perform all of the tasks we did on the standalone sprites, load the sprite, scale, and position it. Finally, we call ScheduleUpdate(), which registers the sprite's Update method with the global Scheduler object. The logic in the Update method is identical to that we used for the other sprites. Finally, we declare a destructor, because TextureInfo is an IDisposable resource and needs to be disposed off manually.

Back in AppMain.cs, we add all three sprites to our scene, then kick the scene off with a call to RunWithScene(). We pass in the value true because we want to manage our game loop manually.

As you may recall from the previous chapter, if you manually handle a game loop, there are four Director methods that need to be called. We perform an infinite while loop, calling Update(), Render(), SwapBuffers(), and PostSwap(). In between Update() and Render(), we manually update jetSprite1, using the same logic again.

There's more...

The call by Director to Update() is very important, as behind the scenes this is what tells the Scheduler object to update, which in turn causes all of the objects and functions registered with Scheduler to get updated. If you remove this call from the game loop, no updating will occur.

In addition to Schedule(), Node has a method named ScheduleInterval(), which takes an additional parameter interval, which tells the scheduler how often (in seconds) to call the scheduled function. There is also a method named ScheduleUpdate(), which performs the exact same process as Schedule, but instead passes the Node's Update method instead of a user defined function, as we saw in JetSpriteWithUpdate.

Scheduler itself is a singleton object that we have not used directly in this recipe. Scheduler can be accessed the same way as the Director singleton using the Instance property, although Scheduler does not require initialization. It exposes members for adding and removing scheduled updates, although you have very little reason to utilize it directly.

As mentioned earlier, you can perform updates on any Node derived object. The following is the class hierarchy of classes derived from node. You can schedule updates on any of these classes:

See also

- See the A game loop, GameEngine2D style recipe in Chapter 3, Graphics with GameEngine2D for more details on the game loop process

Working with the ActionManager object

In this recipe, we are going to look at using the ActionManager singleton to perform actions on nodes. We will create our own action, OrbitTarget, which enables our moon sprite to orbit our earth sprite.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.GameEngine2D. We also need to add a pair of sprites to the project, one representing the moon, the other the earth. The complete source and images for this example can be found in Ch4_Example2.

How to do it...

1. Open AppMain.cs and replace the existing code with the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;

using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch4_Example2
{
public class AppMain{
public static void Main (string[] args){
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();
var screenSize = Director.Instance.GL.Context.GetViewport();
SpriteUV earth = new SpriteUV(new TextureInfo("/Application/earth.png"));
earth.Scale = earth.TextureInfo.TextureSizef;
earth.Pivot = new Vector2(0.5f,0.5f);
earth.Position = new Vector2(
screenSize.Width/2,
screenSize.Height/2);

SpriteUV moon = new SpriteUV(new TextureInfo("/Application/moon.png"));
moon.Scale = moon.TextureInfo.TextureSizef;
moon.Pivot = new Vector2(0.5f,0.5f);
moon.Position = new Vector2(
screenSize.Width/2,
screenSize.Height - moon.Scale.Y/2);

scene.AddChild(earth);
scene.AddChild(moon);

OrbitTarget orbit = new OrbitTarget(earth, 180.0f);
ActionManager.Instance.AddAction(orbit,moon);
orbit.Run();
Director.Instance.RunWithScene(scene);
}
}
}

2. Create a new file, OrbitTarget.cs, and enter this code:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;
namespace Ch4_Example2
{
public class OrbitTarget : ActionBase
{
Node _nodeToOrbit = null;
float _currentAngle = 0.0f;
float _degreesPerSecond;

public OrbitTarget (Node nodeToOrbit, float degreesPerSeconds)
{
_nodeToOrbit = nodeToOrbit;
_degreesPerSecond = degreesPerSeconds;
}

public override void Update (float dt)
{
_currentAngle+= dt*  Sce.PlayStation.HighLevel.GameEngine2D.Base.Math.Deg2Rad(_degreesPerSecond);

var distance = this.Target.Position.Distance(this._nodeToOrbit.Position);

var newAngleX = (float)System.Math.Cos(_currentAngle);
var newAngleY = (float)System.Math.Sin(_currentAngle);

var targetPos = new Vector2(
_nodeToOrbit.Position.X + (distance  * newAngleX),
_nodeToOrbit.Position.Y + (distance  * newAngleY)
);
this.Target.Position = targetPos;
}
}
}

3. Now hit F5 to run your application and you should see the following output:

The moon will rotate around the earth at a fixed orbit of half a complete rotation per second.

How it works...

First, we initialize our Director object, create a new scene and size its camera to match the viewport dimensions. We then create a SpriteUV object for our earth and moon sprites and set each one's scale, pivot, and position values. We want the earth sprite positioned in the middle of the screen, while the moon sprite is going to start at the top center of the screen. We then add both sprites to our scene.

Next, we create an instance of our OrbitTarget class, passing in the object we want to orbit (the earth sprite), as well as the amount in degrees that we want to orbit by each second. We then register our action with a call to the ActionManager singleton's AddAction() method, passing both the action we want to perform as well as the node to perform the action on. We then tell our action to run and finally run the scene.

In OrbitTarget.cs we declare a new class OrbitTarget, derived from ActionBase. It has three member variables: _nodeToOrbit is the Node object passed in via the constructor and is the object that we want to orbit around, _currentAngle stores the current rotation (relative to the orbited node), and _degreesPerSecond is the speed to orbit, also passed in to the constructor. In the constructor, we simply store the target node and degrees per second value.

The bulk of the logic is in the Update() method, which is going to be called each frame (after the action has been Run()). It is passed to the float dt, which is the elapsed time in seconds since the last time Update() was called.

In Update we increment the _currentAngle value by the degrees per second converted to radians, multiplied by the elapsed time. By calculating by the elapsed time, you are essentially splitting your movement up over fractions of a second, so that after a second elapses you should have moved by the desired amount.

The formula for rotating one object around another object is X = distance + Cos(angle), Y = distance + Sin(angle), plus the coordinates of the object to orbit. This code performs that calculation. We then update our position to the newly rotated value.

There's more...

An action's target property is the node the action is applied to. This value is passed as the second parameter when calling ActionManager.Instance.AddAction().

ActionManager, such as the Scheduler, is called each frame during the Director.Update() phase of the game loop. You should use Scheduler to schedule objects to receive updates, while you should use ActionManager to actually perform the actions. In real production code, the previous recipe using the Scheduler object would actually be better performed using actions.

As you can see from the recipe, if you do not manually manage the game loop, the default game loop will automatically call the Director object's Update() method. You can therefore move all game logic into individual scene Update methods, and handle moving even more game logic into reusable activity classes. Actions make it extremely easy to write reusable game logic. Actions can only be applied to classes derived from the Node class (which includes Scene and SpriteUV).

In addition to ActionBase, custom actions can inherit from the following classes:

- ActionWithDuration

- ActionTweenGeneric<T>

- ActionTweenGenericVector2

- ActionTweenGenericVector2Rotation

- ActionTweenGenericVector2Scale

- ActionTweenGenericVector4

See also

- See the Using predefined actions recipe for examples of using GameEngine2D's built in action classes

Using predefined actions

In this recipe, we are going to demonstrate the use of a number of the built-in actions available in GameEngine2D.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.GameEngine2D. We are going to re-use the earth sprite from the previous recipe, but you can substitute any other image. The complete source and images for this example can be found in Ch4_Example3.

How to do it...

1. Open AppMain.cs and replace the existing code with the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;

using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch4_Example3
{
public class AppMain
{
public static void Main (string[] args)
{
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

SpriteUV earth1 = new SpriteUV(new TextureInfo("/Application/earth.png"));
earth1.Scale = earth1.TextureInfo.TextureSizef;
earth1.Position = new Vector2(0,250);

Sequence sequence = new Sequence();
sequence.Add(new DelayTime(3.0f));

sequence.Add(new MoveTo(
new Vector2(Director.Instance.GL.Context.GetViewport().Width,
250),10.0f));

sequence.Add (new MoveBy(new Vector2(
-Director.Instance.GL.Context.GetViewport().Width/2 - earth1.Scale.X/2,0)
,5.0f));

var origColor = earth1.Color;
sequence.Add (new TintTo(new Vector4(0.0f,0.0f,0.0f,0.0f),10.0f));
sequence.Add (new TintTo(origColor,10.0f));

var origSize = earth1.Scale;
sequence.Add (new ScaleTo(new Vector2(3.0f,3.0f),10.0f));
sequence.Add (new CallFunc(()=>{
earth1.Scale = origSize;
earth1.Position = new Vector2(0,250);
}));
RepeatForever repeater = new RepeatForever();
repeater.InnerAction = sequence;
ActionManager.Instance.AddAction(repeater,earth1);
repeater.Run();
scene.AddChild(earth1);
Director.Instance.RunWithScene(scene);
}
}
}

2. Now run the code by hitting F5 and you should see the following output:

The following sequence of actions should occur:

- Waits for 3 seconds

- Moves the earth to the far right-hand side of the screen

- Moves back to the center of the screen

- Fades over 10 seconds to nothingness

- Fades back to original color over a period of 10 seconds

- Shrinks in 10 seconds to a size of 3 x 3 pixels

- Resized it back to its original size

- Reset position to the starting point and start the process over again

How it works...

We start off with the typical code, initializing the director, creating, and setting up a scene. We then load, size, and position a SpriteUV object with our earth graphic.

Next, we create a series of actions. The first is a Sequence action, which is used to hold a series of actions to be executed in the order they are added. The first action we add to the sequence is a DelayTime action, which simply waits for 3 seconds. Next, we add a MoveTo action, which moves the targeted node to the specified coordinate (the far right-hand side of the screen) over the specified period of time, in this case 10 seconds.

Next, we add a MoveBy action, which instead of moving to a specific coordinate, moves relative to a certain amount. In this case, we want to move by half the screen width minus half the sprite width, which will result in it being centered on the screen. This action will also take 10 seconds.

Next, we take a copy of the current sprite color, then apply a TintTo action, passing in a Vector4 object holding the target red, green, blue, and alpha values we wish to TintTo (in this case, black and transparent), and once again let it take 10 seconds. Next we TintTo back to the original color, causing our sprite to slowly reappear.

Then, we copy the sprites size, and scale it down to 3 x 3 pixels using the ScaleTo function. After 10 seconds, the sprite will have been completely shrunken; we then restore it to its previous size using the CallFunc action, which simply calls the passed in function, in this case a simple lambda that resizes and positions the sprite.

We then create one more action, a RepeatForever action, which simply causes the passed in action to repeat forever. We then set the action to be repeated using the InnerAction property. Finally, we call ActionManager and register our container action (repeater) and bind it to the earth node with a call to AddAction(). This call is how the individual actions know what node to apply their action against. As you can see, when you are dealing with a hierarchy of actions like a Sequence or RepeatForever action (or in this case a RepeatForever action containing a Sequence action), you only add the outermost action to the ActionManager singleton.

Finally, we tell the repeater action to start running, add our earth sprite to the scene, and then start the scene running with a call to RunWithScene(). It is of critical importance that you add an action to the ActionManager before calling Run() or you will generate an exception.

There's more...

The GameEngine2D library provides the following actions:

- MoveBy

- MoveTo

- SkewBy

- SkewTo

- RotateBy

- RotateTo

- ScaleBy

- ScaleTo

- TintBy

- TintTo

- DelayTime

- CallFunc

- Repeat

- RepeatForver

- Sequence

See also

- See the Working with the ActionManager object recipe for details on creating your own action classes

Transitioning between scenes

In this recipe, we are going to demonstrate the various graphical transitions you can perform when switching between scenes.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.GameEngine2D. The complete source for this example can be found in Ch4_Example4.

How to do it...

1. Open AppMain.cs and replace the existing code with the following code:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Imaging;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch4_Example4
{
public class ExampleScene : Scene
{
String _text;
TextureInfo _ti;
Texture2D _texture;

public ExampleScene (string text, ImageColor textColor, int textSize)
{
_text = text;
var screenSize = Director.Instance.GL.Context.GetViewport();
var textImage = new Image(ImageMode.Rgba,
new ImageSize(screenSize.Width,screenSize.Height),
new ImageColor(0,0,0,0));
textImage.Decode();

Font font = new Font(FontAlias.System,textSize,FontStyle.Regular);

textImage.DrawText(text,
textColor,
new Font(FontAlias.System,textSize,FontStyle.Regular),
new ImagePosition(
(screenSize.Width - font.GetTextWidth(text))/2,
screenSize.Height/2 - textSize/2));

_texture = new Texture2D(screenSize.Width,screenSize.Height, false, PixelFormat.Rgba);
_texture.SetPixels(0,textImage.ToBuffer());
textImage.Dispose();

_ti = new TextureInfo(_texture);

SpriteUV sprite = new SpriteUV(_ti);
sprite.Pivot = new Vector2(0.5f,0.5f);
sprite.Position = new Vector2(screenSize.Width/2,screenSize.Height/2);
sprite.Scale = _ti.TextureSizef;
this.Camera.SetViewFromViewport();
this.AddChild(sprite);

this.RegisterDisposeOnExitRecursive();
}

public override void OnEnter ()
{
DelayTime delay = new DelayTime(3);
CallFunc callFunc = new CallFunc(()=> {
switch(_text)
{
case "Scene1":
Director.Instance.ReplaceScene(
new TransitionCrossFade(
new ExampleScene("Scene2",new ImageColor(0,255,0,255),220))
{ Duration=3.0f }
);
break;

case "Scene2":
Director.Instance.ReplaceScene(
new TransitionDirectionalFade(
new ExampleScene("Scene3",new ImageColor(0,0,255,255),220))
{ Duration=3.0f, Direction=Sce.PlayStation.HighLevel.GameEngine2D.Base.Math._10 }
);
break;
case "Scene3":
Director.Instance.ReplaceScene(

new TransitionSolidFade(
new ExampleScene("Scene4",new ImageColor(255,255,255,255),220))
{ Duration=3.0f }
);
break;

case "Scene4":
Director.Instance.ReplaceScene(
new TransitionCrossFade(
new ExampleScene("Scene1",new ImageColor(255,0,0,255),220))
{
Tween = (x) => Sce.PlayStation.HighLevel.GameEngine2D.Base.Math.PowEaseOut(x,2.0f)
}
);
break;
default:
break;
}
});
Sequence seq = new Sequence();
seq.Add(delay);
seq.Add (callFunc);
ActionManager.Instance.AddAction(seq,this);
seq.Run ();
}

~ExampleScene()
{
_ti.Dispose();
_texture.Dispose();
}
}
}

2. Now run the code by hitting F5 and you should see the following output:

The text Scene1 will be displayed, then transition to Scene2 then Scene3 each in different colors, each change using a different graphical transition effect.

How it works...

AppMain.cs contains a minimal amount of code. First, we initialize the Director object, and create a new scene of our custom class ExampleScene. The ExampleScene class takes a few parameters: the text to display, the color to display the text in as well as the font size to use. Finally, we start the scene with a call to RunWithScene().

The ExampleScene class starts off by declaring some member variables, the text to display on screen, the Texture2D object to draw the texture on, and TextureInfo to hold our texture details. Next, we store the passed in text and the screen dimensions. We then create a new clear black Image the same size as the screen. We then draw the text centered to the image, taking into account the width of the string. We then allocate the Texture2D and copy the image pixel data into it using SetPixels(). We are now done with the image, so we call Dispose() on it. Next, we create a SpriteUV object from our newly created texture, scale and then position it centered. Then, we add the sprite to the scene using AddChild(). Finally, we tell the scene that we want it to be disposed when OnExit events occur with a call to RegisterDisposeOnExitRecursive().

The OnEnter() method is called when the scene is run (after the RunWithScene() call). We create a pair of actions, one is a time delay of 3 seconds and the other is a CallFunc action. In the function, we have a switch to the currently displayed text. If the current text is Scene1, we replace our scene with a new ExampleScene using a TransitionCrossFade, setting the text to Scene2. If the value is Scene2, we instead transition using a TransitionDirectionalFade object. If it is Scene3, we use TransitionSolid fade and finally in the event of Scene4 we use a TransitionCrossFade, but this time instead of passing a Duration value, we pass in a Tween function that will control the fade.

We then create a Sequence action, add our delay and CallFunc actions to the sequence, and register it with ActionManager with a call to AddAction. Finally, we Run() the sequence.

Essentially the scene loads up and draws its text on screen in the specified color, then waits 3 seconds and begins transitioning the scene to a new scene with different text of a different color, using one of three different transition effects.

There's more...

The call to RegisterDisposeOnExitRecursive() was absolutely critical to keeping memory usage under control. Once you've called this method, when OnExit occurs, it causes the scene to call Dispose on each of its child nodes, then on itself. If you do not call this method when changing scenes, you can quickly run out of memory. There is another version, RegisterDisposeOnExit, but it will only dispose of the single value you pass as a parameter. If you are planning to reactivate the scene immediately (such as after showing a menu), you won't necessarily want to call this method.

You may have never encountered the word tween before now. It is a common expression in animation and is short hand for in between. It is a function that handles the transition between two states. In this recipe, we used a tween to control the rate that a fade transition occurred.

See also

- See the "Hello World" drawing text on an image recipe in Chapter 1, Getting Started for more details on text rendering

Simple collision detection

In this recipe we are going to demonstrate the basic collision detection facilities provided by the Bounds2 class.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.GameEngine2D. You also need an image file; I am reusing our earth sprite from earlier recipes. The complete source for this example can be found in Ch4_Example5.

How to do it...

1. Open AppMain.cs and replace the existing code with the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;

namespace Ch4_Example5
{
public class AppMain{
public static void Main (string[] args){
Director.Initialize();

Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

SpriteUV world1 = new SpriteUV(new TextureInfo("/Application/earth.png"));
SpriteUV world2 = new SpriteUV(new TextureInfo("/Application/earth.png"));
world1.Scale = world2.Scale = world1.TextureInfo.TextureSizef;
world1.Pivot = world2.Pivot = new Vector2(0.5f,0.5f);
world1.Position = new Vector2(0,Director.Instance.GL.Context.GetViewport().Height/2);
world2.Position = new Vector2(Director.Instance.GL.Context.GetViewport().Width,
Director.Instance.GL.Context.GetViewport().Height/2);

scene.AddChild(world1);
scene.AddChild(world2);

world1.Schedule((dt)=>{
world1.Position = new Vector2(world1.Position.X+1,world1.Position.Y);
},0);
World2.Schedule((dt)=>{
world2.Position = new Vector2(world2.Position.X-1,world2.Position.Y);

Bounds2 w1bounds = new Bounds2();
Bounds2 w2bounds = new Bounds2();
world1.GetContentWorldBounds(ref w1bounds);
world2.GetContentWorldBounds(ref w2bounds);
if(w1bounds.Overlaps(w2bounds))
{
world1.Position = new Vector2(0,Director.Instance.GL.Context.GetViewport().Height/2);
world2.Position = new Vector2(Director.Instance.GL.Context.GetViewport().Width,
Director.Instance.GL.Context.GetViewport().Height/2);
}
},0);
Director.Instance.RunWithScene(scene);
}
}
}

2. Now hit F5 to run the application and you should see the following output:

The two earth sprites will move towards the center of the screen until they collide, then they reset back to their original position and start the process all over again.

How it works...

We initialize the Director object, create, and configure a scene. We then create two SpriteUV object's using the same earth.png image; we position one on the left-center portion of the screen, and the other on the right-center portion of the screen. We then add both sprites to the scene.

We schedule an update routine on the first sprite, world1, to increase the x position by 1 per update. We then schedule world2 to decrease its x position by 1 each update. Additionally, it will check for a collision each frame. First it creates a pair of Bounds2 objects, w1bounds and w2bounds. It then gets the current bounding box of each sprite by calling GetContentWorldBounds(), with the results stored in w1bounds/w2bounds. We then check to see if w1bounds overlaps with w2bounds, and if it does we reset both sprites back to their starting positions.

Finally, we start the scene running with a call to RunWithScene().

There's more...

In addition to bounding boxes, you can also use a sphere (Sphere2), plane (Plane2), and convex polygon (ConvexPoly2). In addition to checking for overlaps, you can also use Bounds2 to check if a point is inside the bounds, get the intersection between two bounds (returned as another bounds), and more. There is also a complete 2D physics system if you require more complex collision behavior, which we will cover in a later chapter.

You may be wondering where the pixel level collision detection is, often referred to as pixel perfect collision detection. Short answer, there isn't any. If you loaded all your textures from an Image class, it would be possible to store the alpha values of every pixel. There, is however, no way to access the image data of any class other than Image. This is due to performance; direct pixel access is quite slow.

See also

- See the Querying if a collision occurred and Rigid body collision shapes recipes in Chapter 5, Working with Physics2D for more details on handling collisions using the physics system

- See the Manipulating a texture's pixels recipe in Chapter 3, Graphics with GameEngine2D for details on directly accessing the alpha channel, if you want to implement pixel level collision detection

Playing background music

In this recipe we are going to illustrate how to add background music to your game.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.GameEngine2D. This example also requires a pair of MP3 files; I used two public domain classical music scores. The complete source for this example can be found in Ch4_Example6.

How to do it...

1. Add the two MP3 files to your project; set their Build Action to Content.

2. Open AppMain.cs and replace the existing code with the following code:

using System;
using System.Collections.Generic;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.Core.Audio;
using Sce.PlayStation.HighLevel.GameEngine2D;

namespace Ch4_Example6
{
public class AppMain{

private static Dictionary<string,Bgm> _songs;
private static BgmPlayer _bgmPlayer;

private static void PlaySong(string filename){
if(_bgmPlayer != null){
if(_bgmPlayer.Status == BgmStatus.Playing)
_bgmPlayer.Stop();
_bgmPlayer.Dispose();
}
if(!_songs.ContainsKey(filename))
_songs.Add(filename,new Bgm(filename));

_bgmPlayer = _songs[filename].CreatePlayer();
_bgmPlayer.Play();
}

public static void Main (string[] args){
Director.Initialize();
Scene scene = new Scene();
_songs = new Dictionary<string, Bgm>();

CallFunc playSong1 = new CallFunc(
()=>  PlaySong ("/Application/Bach_Fugue.mp3")
);

CallFunc playSong2 = new CallFunc(
()=>  PlaySong ("/Application/RideOfTheValkyries.mp3")
);
Sequence seq = new Sequence();
seq.Add(playSong1);
seq.Add (new DelayTime(30));
seq.Add(playSong2);

ActionManager.Instance.AddAction(seq,scene);
seq.Run();

Director.Instance.RunWithScene(scene);

}
}
}

3. Hit the F5 key to run the application. A window will open and Bach's Fugue in G Minor will start playing. Thirty seconds later it will be replaced by Wagner's Ride of the Valkyries.

How it works...

We start by declaring a pair of member variables, a dictionary of Bgm (Bgm = Background music) files, indexed by their filenames, and a BgmPlayer. We then create a function PlaySong() that plays an opened file and plays the MP3 file passed in. First, it checks to see if _bgmPlayer has been allocated, if it has, we check to see if it is playing and, if it is, we stop playback with a call to _bgmPlayer.Stop(). We then dispose off this player.

Next we check to see if there is an entry in our dictionary already for a song by this name; if there isn't, we create a new Bgm object and add it to our dictionary. Next, we get the Bgm file from the dictionary and create a new BgmPlayer by calling CreatePlayer(). Finally, we play the song with a call to Play().

In the main function, we initialize the Director object, create a scene, and allocate our _songs dictionary. We then create a pair of CallFunc actions, the first to call PlaySong() to play the Bach piece, the second to call PlaySong() to play the Wagner piece. Next, we declare a sequence, and add our two function actions to it, with a 30 second DelayTime action in between. Next, we register our Sequence action and associate it with the scene. Then, we run the sequence and then start the scene running.

There's more...

Bgm only supports MP3 files with the following specifications:

- Codec: MPEG Layer3

- Num channels: 1/2

- Sampling rate: 44100/48000 Hz

- Bitrate: 128 to 320 kbps

If you need to convert your audio to MP3, I highly recommend you to check out the freely available open source application Audacity, which you can download from http://bit.ly/NRDuky. Audacity is available for Windows, Linux, and MacOS, and is capable of an amazing number of audio processing and conversion tasks.

In addition to playing and stopping a song, you can also pause, resume, change the volume, loop, and change position and playback rate using the BgmPlayer class. There are no events to determine when a song is finished, so you will need to poll the current song's status if you want, when it is done.

See also

- See the Using predefined actions recipe for details on the Sequence and CallFunc actions

Playing sound effects

In this recipe we are going to play back some WAV sound effects.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.GameEngine2D. You will need a pair of WAV files to play as sound effects. The complete source for this example can be found in Ch4_Example7.

How to do it...

1. Add the two WAV files to your project and set their Build Action to Content.

2. Open AppMain.cs and replace the existing code with the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.Core.Audio;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;
namespace Ch4_Example7
{
public class AppMain
{
private static Sound _machinegunSound;
private static Sound _explosionSound;
private static SoundPlayer _soundPlayerMachinegun;
private static SoundPlayer _soundPlayerExplosion;

public static void Main (string[] args)  {
Director.Initialize();
Director.Instance.RunWithScene(new Scene(),true);

_machinegunSound = new Sound("Application/machinegun.wav");
_explosionSound = new Sound("Application/explosion.wav");

_soundPlayerMachinegun = _machinegunSound.CreatePlayer();
_soundPlayerExplosion = _explosionSound.CreatePlayer();

bool quit = false;

while(!quit)
{
Director.Instance.Update();

if(Input2.GamePad0.Cross.Down)
quit = true;

if(Input2.GamePad0.Up.Down)
{
_soundPlayerMachinegun.Play();
}

if(Input2.GamePad0.Down.Down)
{
_soundPlayerExplosion.Play();
}

Director.Instance.Render();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
}
_machinegunSound.Dispose();
_explosionSound.Dispose();
_soundPlayerMachinegun.Dispose();
_soundPlayerExplosion.Dispose();
}
}
}

3. Now hit F5 to run the application. Press the up arrow to play a machine gun sound effect, and press the down arrow to play an explosion sound. Finally, press the X button (S in the simulator) to exit.

How it works...

We start off by initializing the Director object (getting used to this yet?), and start running with RunWithScene(), passing in a new Scene and true, indicating that we will manually manage the event loop this time.

We then load each of our sound effect files by passing each file path to the Sound constructor. For each Sound we then create a SoundPlayer by calling CreatePlayer().

We then loop until the bool quit is true. Since we are manually handling the loop, there are four mandatory functions we need to call. Additionally, after the Update() call, we check to see if the Cross (X) button is down, in which case we set quit to true, exiting the loop. If Up is down (ok, that felt weird) we play our machine gun sound by calling its Play() method. We perform the same action on _soundPlayerExplosion if the down key is down.

We then call the remaining mandatory methods for the game loop. Finally, both SoundPlayer and Sound are IDisposable, so we call the Dispose() method on each object.

There's more...

Like Bgm, sound effects are played by first creating a Sound object and passing a WAV file to it, then creating a player from it. A player will only allow playback of a single instance of a sound effect at a time, so if you call play again, it will simply start the sound effect over. If you want to play multiple copies of the same sound effect at once, you are going to need to create multiple players. You can of course have multiple SoundPlayer functions playing at once.

The SoundPlayer class includes properties for controlling the volume, panning, looping, and playback rate. You can also check the status (playing or stopped) of a sound effect. Like Bgm, you need to poll if you want to determine when a sound effect has finished playing.

SoundPlayer supports WAV file playback with the following specifications:

- Num channels: 1/2

- Sampling rate: 22050/44100 Hz

- Sampling bit depth: 16 bit only

- * Linear PCM only

Note

The sound effects used in this recipe were downloaded from http://FreeSound.org, a gigantic archive of free sound files. You do need to sign up before you can download any sounds. If you are looking for sound files, it is an excellent place to start.

Sony also provides a number of royalty free sound effects available in the SFX Asset Library. They can be downloaded on the PSM Developer Portal. Once you have logged in to the portal they are available for download at https://psm.playstation.net/static/general/dev/en/sdk_assets.html. This link will not work until you log in.

See also

- See the A game loop, GameEngine2D style recipe in Chapter 3, Graphics with GameEngine2D for more details on manually handling the game loop

Chapter 5. Working with Physics2D

In this chapter we will cover:

- Creating a simple simulation with gravity

- Switching between dynamic and kinematic

- Creating a (physics!) joint

- Applying force and picking a physics scene object

- Querying if a collision occurred

- Rigid body collision shapes

- Building and using an external library

Introduction

Physics is an integral part of many modern games, including many 2D games. The massive success of Angry Birds and similar titles really brought physics to the masses. Fortunately, Sony included a 2D library in the PlayStation Mobile SDK, Physics2D. In this chapter, we are going to look at a number of ways this library can be used.

Creating a simple simulation with gravity

In this recipe, we are going to configure a simple physics scene consisting of a single rigid body (a sphere) and the effects of gravity on it.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add references to Sce.PlayStation.HighLevel.GameEngine2D and Sce.PlayStation.HighLevel.Physics2D. We also need to add a circular sprite; I used a picture of the earth aptly named earth.png. The complete source and all images used can be found in Ch5_Example1.

How to do it...

1. Add the earth sprite to your project, and set its Build Action to Content.

2. Open up the AppMain.cs file and replace the existing code with the following code:

using System;
usingSce.PlayStation.Core;
usingSce.PlayStation.Core.Graphics;
usingSce.PlayStation.Core.Input;

using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;
using Sce.PlayStation.HighLevel.Physics2D;

namespace Ch5_Example1 {
public class AppMain {

private static TextureInfo _ti;
private static Texture2D _texture;

public static void Main (string[] args)  {
Director.Initialize();

Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

_texture = new Texture2D("/Application/earth.png",false);
_ti = new TextureInfo(_texture);

SpriteUV sprite = new SpriteUV(_ti);
sprite.Scale = _ti.TextureSizef;
sprite.Pivot = new Vector2(0.5f,0.5f);
sprite.Position = new Vector2(
Director.Instance.GL.Context.GetViewport().Width/2,
Director.Instance.GL.Context.GetViewport().Height - sprite.Scale.Y/2);

scene.AddChild(sprite);

PhysicsScenephysicsScene = new PhysicsScene();
physicsScene.InitScene();
physicsScene.sceneName = "Test";
physicsScene.NumBody = 1;
physicsScene.NumShape = 1;

physicsScene.sceneShapes[0] = new PhysicsShape(sprite.Scale.Y/2.0f);
physicsScene.sceneBodies[0] = new PhysicsBody(physicsScene.sceneShapes[0],1.0f);
physicsScene.sceneBodies[0].position = sprite.Position;
physicsScene.sceneBodies[0].rotation = 0;
physicsScene.sceneBodies[0].shapeIndex = 0;

physicsScene.gravity = new Vector2(0,-98.0f);

Director.Instance.RunWithScene(scene, true);

bool done = false;
while(!done){
Director.Instance.Update();

Vector2 touchPosition = Input2.Touch.GetData(0)[0].Pos;
Vector2 diffPosition = new Vector2();            physicsScene.Simulate(-1,ref touchPosition, ref diffPosition);

sprite.Position = physicsScene.SceneBodies[0].Position;

Director.Instance.Render();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
if(sprite.Position.Y + sprite.Scale.Y/2 < 0)
done=true;
}

physicsScene.ReleaseScene();
_ti.Dispose();
_texture.Dispose();
}
}
}

How it works...

This code starts off initializing the Director singleton, creating a new scene, and setting the camera. It then creates a new SpriteUV object to hold our earth.png texture. We then position the texture at the top-middle of the screen and finally add it to the scene.

Next, we create the PhysicsScene object, which is completely unrelated to GameEngine2D's Scene class. Start off by initializing the scene with a call to InitScene and name it by setting the property SceneName (the name has no importance). We then tell our scene how many PhysicsBody and PhysicsShape objects it is going to contain.

We then declare our shape in the array physicsScene.SceneShapes. In the PhysicsShape constructor, we pass a single parameter, which is the radius of the sphere's rigid body that is half the width of our sprite

Next, we declare our PhysicsBody constructor in the array physicsScene.sceneBodies. We pass in the PhysicsShape constructor we just created, as well as the default mass to use in the simulation. We then set our PhysicsBody position to match our earth sprite, set the rotation to 0 and the shapeIndex to 0. The shape index is the location of the PhysicsShape this PhysicsBody is going to occupy in the sceneShapes array. It is possible for multiple PhysicsBody objects to use the same shape.

Now we set the scene gravity to (0.0,-98.0f), which results in the earth being pulled down by an acceleration starting at 98 pixels per second. Finally we start the scene running with a call to Director.RunWithScene, passing false in addition to the scene, indicating we will be manually handling the event loop.

In the event loop, we call the Director object's Update method, then declare a pair of Vector2 objects, touchPosition and diffPosition, which the Simulate scene requires, although they serve no purpose in this example. After calling Simulate, we then synchronize the sprite's position to match the newly updated SceneBody object's position. We then call the required Render, SwapBuffer, and PostSwap methods. We then check to see if the sprite has passed to the bottom of the screen. If it has, we toggle our done flag to true, which exits the game loop. Finally, we clean up before the program exits.

Now press F5 to run your game and you will see the following output:

The earth sprite will appear at the top-middle of the screen and then gravity will pull it to the bottom, which will cause the program to exit.

There's more...

It is important to realize what a physics engine does and does not do. A physics engine runs a physical simulation on a series of physics bodies (shapes, joints), using factors such as mass, force, gravity, and more, to determine movement in a (often) realistic manner. You define the objects in your physics scene, the properties of the scene itself, and then update it each frame with a call to PhysicsScene.Simulate, which causes the simulation to advance in time calculating how all of its bodies interact and move. These movements, however, are not displayed in your GameEngine2D scene. It is your responsibility to take the updated position data from the physics simulation and update your game's graphics accordingly.

In this particular recipe, we made one physics unit equal to one pixel, which is why setting gravity to (0,-98) resulted in the earth moving starting at 98 pixels per second (and increasing as it falls). In a more complex scene, this is not the ideal approach to take, as it quickly makes your physics engine numbers meaningless. Internally, the Physics2D engine treats 1.0 mass as 1 kg, while 1 unit in Physics2D is a meter. We will deal with mapping between Physics2D units and GameEngine2D pixels in a later recipe.

Note

PhsyicsScene contains three very important pre-allocated arrays, SceneBodies, SceneShapes, and SceneJoints. The SceneBodies array contains 250 items, while SceneShapes and SceneJoints are both 100 items each. These represent the maximum number of rigid bodies, shapes, and joints you can have in a single PhysicsScene array. You use the values NumBody, NumShape, and NumJoint to tell Physics2D how many of each you use. It is very important you set each of these values correctly, or a crash will occur.

If you are asking yourself, Why did Sony choose to use pre-allocated arrays instead of just lists?, that is a very good question! It's much better question than my answer; I have no idea.

See also

- See the Adding a sprite to a scene recipe in Chapter 3, Graphics with GameEngine2D for more information on drawing sprites with GameEngine2D

Switching between dynamic and kinematic

In this recipe, we are going to demonstrate toggling a physics body between dynamic and kinematic. We are also going to illustrate the effect of the coefficient of restitution on the physics scene.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.HighLevel.GameEngine2D and Sce.PlayStation.HighLevel.Physics2D. I will again be using our earth.png sprite; add this image or a similar one to your scene and set its Build Type to Content. The complete source and all images used can be found in Ch5_Example2.

How to do it...

1. Open AppMain.cs and edit it as follows:

using System;
usingSystem.Collections.Generic;

usingSce.PlayStation.Core;
usingSce.PlayStation.Core.Environment;
usingSce.PlayStation.Core.Graphics;
usingSce.PlayStation.Core.Input;

using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;
using Sce.PlayStation.HighLevel.Physics2D;

namespace Ch5_Example2
{
public class AppMain
{

private static TextureInfo _ti;
private static Texture2D _texture;

public static void Main (string[] args)
{
Director.Initialize();

Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

_texture = new Texture2D("/Application/earth.png",false);
_ti = new TextureInfo(_texture);

SpriteUV sprite = new SpriteUV(_ti);

sprite.Scale = _ti.TextureSizef;
sprite.Pivot = new Vector2(0.5f,0.5f);
sprite.Position = new Vector2(
Director.Instance.GL.Context.GetViewport().Width/2,
Director.Instance.GL.Context.GetViewport().Height - sprite.Scale.Y/2);

scene.AddChild(sprite);

PhysicsScenephysicsScene = new PhysicsScene();
physicsScene.InitScene();
physicsScene.SceneName = "Demo scene";
physicsScene.NumBody = 2;
physicsScene.NumShape = 2;
physicsScene.SceneMax = new Vector2(1000.0f,5000.0f);
physicsScene.RestitutionCoeff = 1.0f;

physicsScene.SceneShapes[0] = new PhysicsShape(sprite.Scale.Y/2.0f);
physicsScene.SceneBodies[0] = new PhysicsBody(physicsScene.sceneShapes[0],100.0f);
physicsScene.SceneBodies[0].Position = sprite.Position;
physicsScene.SceneBodies[0].Rotation = 0;
physicsScene.SceneBodies[0].ShapeIndex = 0;
physicsScene.SceneBodies[0].ColFriction = 0.01f;
physicsScene.SceneBodies[0].SetBodyKinematic();

physicsScene.SceneShapes[1] = new PhysicsShape(new Vector2(
Director.Instance.GL.Context.GetViewport().Width,
1.0f));

physicsScene.SceneBodies[1] = new PhysicsBody(physicsScene.SceneShapes[0],PhysicsUtility.FltMax);
physicsScene.SceneBodies[1].position = new Vector2(0,0);
physicsScene.SceneBodies[1].shapeIndex = 1;

physicsScene.SceneBodies[1].SetBodyStatic();

physicsScene.Gravity = new Vector2(0.0f,-98.0f);

Director.Instance.RunWithScene(scene, true);

bool done = false;
while(!done)
{
Director.Instance.Update();
System.Diagnostics.Debug.WriteLine(physicsScene.sceneBodies[0].Position.Y);

if(Input2.GamePad0.Down.Down == true)
physicsScene.sceneBodies[0].BackToDynamic();
if(Input2.GamePad0.Up.Down == true)
physicsScene.sceneBodies[0].SetBodyKinematic();
if(Input2.GamePad0.Left.Press == true)
physicsScene.RestitutionCoeff = physicsScene.RestitutionCoeff -0.1f;
if(Input2.GamePad0.Right.Press == true)
physicsScene.RestitutionCoeff = physicsScene.RestitutionCoeff +0.1f;
if(Input2.GamePad0.Cross.Down == true)
done = true;

if(physicsScene.CheckOutOfBound(physicsScene.SceneBodies[0]))
done = true;

Vector2 touchPosition = Input2.Touch.GetData(0)[0].Pos;
Vector2 diffPosition = new Vector2();
physicsScene.Simulate(-1,ref touchPosition, ref diffPosition);

sprite.Position = physicsScene.SceneBodies[0].Position;
if(sprite.Position.Y + sprite.Scale.Y/2 < 0 ||
(System.Math.Floor (sprite.Position.Y) == 0 + sprite.Scale.Y/2 )
&&physicsScene.SceneBodies[0].Velocity.Y< 1.0f)
done=true;

Director.Instance.Render();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();

}

physicsScene.ReleaseScene();
_ti.Dispose();
_texture.Dispose();
}
}
}

2. Hit the F5 key to run your application and you should see the following output:

The earth sprite will appear at the top of the screen. Pressing the down arrow will toggle the object to dynamic, causing gravity to take effect and the earth to start falling. Pressing up arrow again will toggle back to kinematic. Pressing the left arrow will decrease the coefficient of restitution while pressing the right arrow will increase it. The higher the value, the more the earth will bounce. When it hits the bottom of the screen, it will bounce up as determined by the coefficient amount. Once it comes to a complete stop, or you press X, the game will exit.

How it works...

We start off with the usual initialization code, initialize the Director object, set and configure the scene, load our earth sprite, position it at the top-middle of the screen, and finally add it to the scene.

The PhysicsScene setup is very similar to the prior recipe. This time we have two PhysicsShape objects and two PhysicsBody objects in our scene array, so we set NumBody and NumShape accordingly. SceneMax is the outer boundary for physics objects (once reached, the scene will stop processing it). Since we are allowing our earth to bounce a substantial amount offscreen, we greatly increase the SceneMax object's Y value. By default, SceneMax is normally set to (1000,1000) while SceneMin is (-1000,-1000). Finally, we set the scene's RestitutionCoeff to 1.0f.

Next, we create a PhysicsShape and PhysicsBody to represent our earth sprite, set to a radius half the sprite's width. Using this newly created shape, we create a new PhysicsBody object, giving it a mass of 100.0f. We match the rigid body position to the sprite position, set Rotation to 0, ShapeIndex to 0 (matching the value we passed in the constructor), its ColFriction to 0.01f (meaning virtually no friction on collision), and initially set the body to kinematic by calling the function SetBodyKinematic.

Next, we create another PhysicsShape object; this one is box shaped. We pass the width and height of the box in to the PhysicsShape constructor. We are creating a 1 pixel high box across the bottom of the screen for the earth to bounce off. In the PhysicsBody constructor we pass in the newly created PhysicsShape object, as well as the value PhysicsUtility.FltMax for mass. PhysicsUtility.FltMax is the highest value mass can go up to and can effectively be considered to be infinity. Finally, since this body is completely stationary, we set it to static with the call SetBodyStatic.

We then set the gravity to -98.0f in the Y direction and run our GameEngine2D scene using RunWithScene, passing true, indicating we will be manually handling our event loop.

In the event loop, we call the mandatory Update method. We print out the earth's physics body location to the debug window since it can spend a lot of time offscreen. You can see this value in the Application Output window in Studio and is a handy way to debug offscreen physics objects.

Next we check the gamepad status. If the user presses the down arrow on the d-pad, we switch the earth to Dynamic. If the user presses the up arrow, the earth is set to Kinematic. If the left d-pad is pressed, we decrease the RestitutionCoeff by 0.1f, while pressing the right one increases it by 0.1f. Finally, pressing X will exit the application.

Next, we check to see if the earth has managed to bounce out of bounds (a Y value greater than 5000) with a call to CheckOutOfBound and exit if it has. Next, we create two (unused) Vector2 values required by Simulate and then call Simulate, which causes the physics scene to update and advance in time. Then we update the GameEngine2D sprite's position to match the physics body location.

Then we check to make sure that the earth hasn't somehow gone off the bottom of the screen and that the velocity hasn't dropped below 1.0f. You can't check for 0, since in a physics simulation values will almost never be pure zero. If the earth has stopped moving, we exit the application. We then call the mandatory Render, SwapBuffers, and PostSwap calls. Once the game loop ends, we clean up before exiting.

There's more...

The RestitutionCoeff variable holds the restitution of coefficient, which represents the ratio of speeds before and after a collision. A value of 1.0f, all other values being equal, means that the rigid body will bounce out with the same force it came in at. A value of 0.0f will mean no bounce at all, while a value greater than 1.0f will cause a much greater amount of recoil. In the real world, however, this value would never exceed 1.0f, so if you want a realistic simulation, never set this value higher than 1. Unlike other physics engines, in Physics2D the restitution coefficient is set at the scene level instead of the body level. By default in our example with the value of 1.0f, the earth will bounce back to pretty much where it started.

You may have noticed when we switched the object from Dynamic to Kinematic it no longer fell. When it is kinematic, external forces (collisions, gravity, air friction, and so on) will have no effect on the movement of the body. Only direct influences, such as velocity, will affect its movement. A static body is even less affected by the physics simulation and basically only exists for other bodies to interact with. It is, however, much lighter weight and easier for the simulation to process, so if you have an object that is stationary, you should set it to static.

In addition to setting a rigid body to kinematic or static to save on processing power in the physics simulation, you can also put inactive (offscreen, invisible, and so on) bodies to sleep. Simply set the sleep property to true and the physics engine will skip it during the Simulate process.

See also

- See the Handling the controller's d-pad and buttons recipe in Chapter 2, Controlling Your PlayStation Mobile Device for more details on using the d-pad

Creating a (physics!) joint

In this recipe, we are going to look at simulating a joint to create a pendulum style effect, swinging one physics body around another.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.HighLevel.GameEngine2D and Sce.PlayStation.HighLevel.Physics2D. We will be re-using our earth sprite from the earlier recipe, this time reduced in size by 50 percent and named, appropriately enough, earthSmall.png. Add this image or a similar one to your scene and set its Build Type to Content. The complete source and all images used can be found in Ch5_Example3.

How to do it...

1. Open AppMain.cs and change the code to the following:

using System;
usingSce.PlayStation.Core;
usingSce.PlayStation.Core.Graphics;
usingSce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;
using Sce.PlayStation.HighLevel.Physics2D;

namespace Ch5_Example3 {
public class AppMain {

private static TextureInfo _ti;
private static Texture2D _texture;

public static void Main (string[] args) {
Director.Initialize();

Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

_texture = new Texture2D("/Application/earthSmall.png",false);
_ti = new TextureInfo(_texture);

SpriteUV sprite = new SpriteUV(_ti);
sprite.Scale = _ti.TextureSizef;
sprite.Pivot = new Vector2(0.5f,0.5f);
sprite.Position = new Vector2(
Director.Instance.GL.Context.GetViewport().Width/2,
Director.Instance.GL.Context.GetViewport().Height - sprite.Scale.Y/2);

SpriteUV sprite2 = new SpriteUV(_ti);
sprite2.Scale = _ti.TextureSizef;
sprite2.Pivot = new Vector2(0.5f,0.5f);
sprite2.Position = new Vector2(
0 + sprite2.Scale.X/2,
Director.Instance.GL.Context.GetViewport().Height - sprite2.Scale.Y/2);
scene.AddChild(sprite);
scene.AddChild(sprite2);

scene.AdHocDraw += () => {
Director.Instance.DrawHelpers.DrawLineSegment(sprite.Position,sprite2.Position);
};

PhysicsScenephysicsScene = new PhysicsScene();
physicsScene.InitScene();
physicsScene.SceneName = "Demo scene";
physicsScene.NumBody = 2;
physicsScene.NumShape = 1;
physicsScene.NumJoint = 1;

physicsScene.SceneShapes[0] = new PhysicsShape(sprite.Scale.Y/2.0f);
physicsScene.SceneBodies[0] = new PhysicsBody(physicsScene.sceneShapes[0],100.0f);
physicsScene.SceneBodies[0].Position = sprite.Position;
physicsScene.SceneBodies[0].Rotation = 0;
physicsScene.SceneBodies[0].ShapeIndex = 0;
physicsScene.SceneBodies[0].SetBodyStatic();

physicsScene.SceneBodies[1] = new PhysicsBody(physicsScene.sceneShapes[0],100.0f);
physicsScene.SceneBodies[1].Position = sprite2.Position;
physicsScene.SceneBodies[1].Rotation = 0;
physicsScene.SceneBodies[1].ShapeIndex = 0;

physicsScene.SceneJoints[0] = new PhysicsJoint(physicsScene.SceneBodies[0],
physicsScene.SceneBodies[1],
sprite.Position,
0,1);
physicsScene.SceneJoints[0].AngleLim =0;

physicsScene.Gravity = new Vector2 (0.0f, -98.0f);
Director.Instance.RunWithScene(scene, true);

bool done = false;
while(!done) {
Director.Instance.Update();

if(Input2.GamePad0.Cross.Down == true)
done = true;
Vector2 touchPosition = Input2.Touch.GetData(0)[0].Pos;
Vector2 diffPosition = new Vector2();
physicsScene.Simulate(-1,ref touchPosition, ref diffPosition);

sprite.Position = physicsScene.SceneBodies[0].Position;
sprite2.Position = physicsScene.SceneBodies[1].Position;

Director.Instance.Render();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();

}

physicsScene.ReleaseScene();
_ti.Dispose();
_texture.Dispose();
}
}
}

2. Hit the F5 key to run your application and you should see the following output:

One small earth sprite located in the top-left corner of the screen will swing in an arc around another earth sprite locate at the top-center of the screen. The joint connecting them will be drawn using a purple line. Once it completes its arc, it will then proceed to return in the other direction and loop until the user hits the X button or S key to exit.

How it works...

This code starts off with initialization code nearly identical to that of the last few recipes. We create and configure our scene, load our earthSmall.png texture into a pair of SpriteUV objects, and position one at the top-center of the screen and the other at the top-left corner of the screen. We then add both sprites to the scene. Next we register an AdHocDraw method to draw a line between the two sprites, representing the joint.

Next we set up the physics scene; it will contain one PhysicsShape, two PhysicsBody objects, and one PhysicsJoint, so we set NumBody, NumShape, and NumJoint accordingly. We configure a spherical shape for our two earths, and then create a PhysicsBody for each one. The center one is not going to be moving at all, so we create it as static with the call SetBodyStatic.

Next, we create a PhysicsJoint in the SceneJoints array. The PhysicsJoint constructor takes the two rigid bodies the joint is going to connect, the joint's pivot point (our centered earth sprite's position), then the index in the SceneBodies array of the two PhysicsBodies the joint hinges. Yes, like with ShapeIndex, these two indexes seem redundant to me as well. Next, we set the joint's angle limit to 0 using the AngleLim property. A value of 0 puts no limitations on the rotation of the joint.

Next, we set the scene's gravity to -98.0f on the y axis, which is what is responsible for the motion in our scene. Finally, we tell the GameEngine2D scene to start running with a call to Director.Instance.RunWithScene. In our game loop, we call the various required methods, update the physics simulation, and then update the position of our sprites (somewhat redundantly in the case of the centered sprite, since it is static). Finally, we exit if the user presses the X button or S key in the Simulator.

There's more...

Joints can be constrained to a single axis, creating a joint that only moves in a single direction. For example, to simulate the movement of a sliding door, you could constrain movement to the x axis only with the following code:

sceneJoints[index].axis1Lim = new Vector2(1.0f, 0.0f);
sceneJoints[index].axis2Lim = new Vector2(0.0f, 0.0f);

To allow this joint to move along both axes again, you would set axis2Lim to (0.0f,1.0f).

See also

- See the Creating scenes recipe in Chapter 3, Graphics with GameEngine2D for more details about using AdHocDraw

Applying force and picking a physics scene object

In this recipe, we are going to cover two separate concepts at once. First, we are going to look at how to apply force to a rigid body. Then we are going to look at how to handle selecting objects within the physics scene by clicking/touching.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.HighLevel.GameEngine2D and Sce.PlayStation.HighLevel.Physics2D. Once again we will be making use of our small earth sprite, earthSmall.png. The complete source and all images used can be found in Ch5_Example4.

How to do it...

1. Open AppMain.cs and enter the following code:

using System;
usingSce.PlayStation.Core;
usingSce.PlayStation.Core.Graphics;
usingSce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;
using Sce.PlayStation.HighLevel.Physics2D;

namespace Ch5_Example4
{
public class AppMain
{

private static TextureInfo _ti;
private static Texture2D _texture;

privateconst float PtoM = 50.0f;
static float _screenWidth;
static float _screenHeight;

static Vector2 GetClickPos(Vector2 point) {
// Convert from NDC ( -1 to 1 ) to normalized coordinates ( 0 to 1 )
varnewx = (_screenWidth/2 + (point.X * _screenWidth/2))/_screenWidth;
varnewy = (_screenHeight/2 + (point.Y * _screenHeight/2))/_screenHeight;

// Convert from normalized to screen coordinates at a ratio of Pixels to Meters
// PtoM = 50 means 50 pixels to a meter
return new Vector2((newx * _screenWidth) / PtoM, (newy * _screenHeight) / PtoM);
}

public static void Main (string[] args) {
Director.Initialize();

Scene scene = new Scene();
scene.Camera.SetViewFromViewport();
_screenWidth = Director.Instance.GL.Context.GetViewport().Width;
_screenHeight = Director.Instance.GL.Context.GetViewport().Height;
_texture = new Texture2D("/Application/earthSmall.png",false);
_ti = new TextureInfo(_texture);

SpriteUV sprite = new SpriteUV(_ti);
sprite.Scale = _ti.TextureSizef;
sprite.Pivot = new Vector2(0.5f,0.5f);
sprite.Position = new Vector2(
_screenWidth/2,
_screenHeight/2);

scene.AddChild(sprite);

PhysicsScenephysicsScene = new PhysicsScene();
physicsScene.InitScene();
physicsScene.SceneName = "Demo scene";
physicsScene.NumBody = 1;
physicsScene.NumShape = 1;
physicsScene.SceneMin = new Vector2(
0.0f - (sprite.Scale.X/2)/PtoM,
0.0f - (sprite.Scale.Y/2)/PtoM);

physicsScene.SceneMax = new Vector2(
(_screenWidth + sprite.Scale.X/2)/PtoM,
(_screenHeight + sprite.Scale.Y/2)/PtoM);

physicsScene.Gravity = new Vector2(0.0f,0.0f);

physicsScene.SceneShapes[0] = new PhysicsShape((sprite.Scale.Y/2.0f)/PtoM);
physicsScene.SceneBodies[0] = new PhysicsBody(physicsScene.sceneShapes[0],10.0f);
physicsScene.SceneBodies[0].Position = sprite.Position/PtoM;

physicsScene.SceneBodies[0].Rotation = 0;
physicsScene.SceneBodies[0].ShapeIndex = 0;

Director.Instance.RunWithScene(scene, true);

bool done = false;
Vector2 touchPosition = new Vector2();
Vector2 diffPosition = new Vector2();

while(!done) {
Director.Instance.Update();

if(Input2.GamePad0.Cross.Down == true)
done = true;

varsceneBody = physicsScene.SceneBodies[0];
if(Input2.GamePad0.Right.Press == true)
sceneBody.Force = sceneBody.Force.Add(new Vector2(40.0f,0.0f));
if(Input2.GamePad0.Left.Press == true)
sceneBody.Force = sceneBody.Force.Subtract(new Vector2(40.0f,0.0f));
if(Input2.GamePad0.Up.Press == true)
sceneBody.Force = sceneBody.Force.Add(new Vector2(0.0f,40.0f));
if(Input2.GamePad0.Down.Press == true)
sceneBody.Force = sceneBody.Force.Subtract(new Vector2(0.0f,40.0f));

if(physicsScene.CheckOutOfBound(sceneBody))
done = true;

touchPosition =  GetClickPos(Input2.Touch00.Pos);
vartouchIndex = -1;
if(Input2.Touch00.Press)
{
touchIndex = physicsScene.CheckPicking(ref touchPosition,refdiffPosition,true);
if(touchIndex != -1)
done = true;
}

physicsScene.Simulate(-1,ref touchPosition, ref diffPosition);
sprite.Position = physicsScene.SceneBodies[0].Position * PtoM;

Director.Instance.Render();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
}

physicsScene.ReleaseScene();
_ti.Dispose();
_texture.Dispose();
}
}
}

2. Press F5 to run the application and you will see the following output:

3. Press the d-pad or arrow key in any direction and force in that direction will be applied. Each time you press in a single direction more force will be applied and the earth sprite will move faster. Adding force in the opposite direction will decrease speed and eventually reverse the direction of travel.

4. Hitting the X button or S key will exit the application.

5. Finally, if you click on the earth or leave the screen, the application will exit.

How it works...

In addition to our usual Texture2D and TextureInfo member variables, we declare _screenWidth and _screenHeight to cut down a bit on code length. We are also defining a constant float value, PtoM. This stands for Pixels To Meters and is used to map from screen space to physics space. This will be explained in more detail shortly.

Next, we define a function GetClickPos, which will translate a click into a physics scene coordinate. This looks rather confusing because there are three sets of conversions going on here. First our touch coordinate, passed in as a point, is in a normalized device coordinate format, which ranges in value from (-1,-1) to (1,1). To translate that coordinate to normalized coordinates (0,0) to (1,1), you multiply the x value by half the screen width + half the screen width divided by the screen width. The same process is now repeated for the y coordinate. We then translate this coordinate into GameEngine2D coordinates by multiplying x by the screen width and y by the screen height. We finally convert it to Physics2D coordinate space by dividing it by our PtoM ratio.

Within the main function, the code is very similar to the prior recipes. We create and configure the scene, cache the dimensions for convenience, load our texture into a SpriteUV that we center to the screen, and then add the sprite to the scene.

Next, we setup our PhysicsScene. It contains a single PhysicsShape object and a single PhysicsBody object, the collision sphere around our sprite. The only major difference from previous recipes is that we modify all values by converting pixels to meters. Next, we turn gravity off by setting it to a Vector2 variable with a value of (0.0,0.0). Then, we set the boundaries for our physics simulation. We want enough room for our screen, plus half of the width of our earth sprite, since the earth sprite has the pivot set to its middle. Once again, this value needs to be converted to Physics2D coordinates. Next, we construct our PhysicsShape and PhysicsBody values, giving it a mass of 10 kg, a very light planet. Feel free to update this value, but if you do, you are going to have to add a lot more force later on! After running the scene we declare a pair of Vector2 values, touchPosition and diffPosition, which we are actually going to use in this recipe.

In our game loop, in addition to the four required method calls, we check the status of the gamepad. If the user hits the X button (or S key) we exit the application. If the user hits left, we subtract 40 force along the x axis, while if the user presses down we subtract 40 force along the y axis. If the user presses right or up we instead increase the force by 40. All of these values are cumulative, so pushing left twice will move faster, while pushing left and then right will cancel movement out completely. We then check if our rigid body has left the simulation boundaries with a call to CheckOutOfBounds, and exit if it has.

Next, we handle user touches (or clicks on the simulator). We pass the value of Input2.Touch00.Pos in to the GetClickPos function we defined earlier, which translates it to Physics2D compatible coordinates. We then check to see if an actual touch has occurred, and if one has, we check to see if there is something in the simulation at that location. This is done with the call CheckPicking, which takes as parameters the touch location, a Vector2 variable that will hold the distance between the center of the rigid body and the touch position, and a bool indicating how thorough we want the click testing to be. If there is nothing at the touched location, CheckPicking will return -1. Otherwise, it will return the index of the body (within the SceneBodies array) of the object that was selected. If the user successfully touched the earth, we exit the application.

Next, we update the simulation with a call to Simulate. Once the simulation has updated, we update our sprite's position to match its corresponding rigid body position. This time we need to map from physics coordinates to screen coordinates, so we multiply our coordinates by PtoM.

There's more...

Up until this recipe, we have paid no attention to the actual units we were using; we simply treated one unit in the physics simulation to equal one pixel in the game. There is nothing wrong with this, but it can lead to some remarkably odd values. In this recipe, we convert from pixels to physics units and vice versa. Physics2D is set up so that 1 unit of measurement = 1 meter, while 1 unit of weight = 1 kg and 1 unit of force = 1 Newton. When you start using real world units, the simulation becomes much easier to understand. In this case we are going to translate at a rate of 50 to 1, in that 50 pixels = 1 meter. This value was chosen arbitrarily; feel free to change it.

You may at this point be wondering about the values you pass in to simulate. The first is the index of the item the user clicked (within the SceneBodies array), while clickPosition and diffPosition allow you to specify two points used to apply velocity to the rigid body specified by the clickIndex variable. So basically it allows you to apply motion to the item touched and, frankly, I think it was bad design.

Earlier we mentioned that force was applied as Newtons. Therefore, when we subtract 40 force, we are actually subtracting 40 Newtons. One Newton is equivalent to the force of earth's gravity acting on an object weighing about 100 gms, which is approximately the weight of an apple. Had Newton been hit on the head with say, an anvil, a Newton would be a much different unit of measure!

See also

- See the Using the Input2 wrapper class recipe in Chapter 2, Controlling Your PlayStation Mobile Device for more information on Input2 and coordinate conversion

Querying if a collision occurred

In this recipe, we are going to demonstrate how to check for a collision between rigid bodies.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.HighLevel.GameEngine2D and Sce.PlayStation.HighLevel.Physics2D. This time we will be using our full-sized earth sprite earth.png. The complete source and all images used can be found in Ch5_Example5.

How to do it...

1. Replace the existing code in AppMain.cs with the following code:

using System;
usingSce.PlayStation.Core;
usingSce.PlayStation.Core.Graphics;
usingSce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;
using Sce.PlayStation.HighLevel.Physics2D;

namespace Ch5_Example5 {
public class AppMain {

private static Texture2D _texture;
private static TextureInfo _ti;
privateconst float PtoM = 50.0f;

public static void Main (string[] args) {
Director.Initialize();

Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

_texture = new Texture2D("/Application/earth.png",false);
_ti = new TextureInfo(_texture);

SpriteUV sprite = new SpriteUV(_ti);
sprite.Scale = _ti.TextureSizef;
sprite.Pivot = new Vector2(0.5f,0.5f);
sprite.Position = new Vector2(
sprite.Scale.X/2,
Director.Instance.GL.Context.GetViewport().Height/2);

SpriteUV sprite2 = new SpriteUV(_ti);
sprite2.Scale = _ti.TextureSizef;
sprite2.Pivot = new Vector2(0.5f,0.5f);
sprite2.Position = new Vector2(
Director.Instance.GL.Context.GetViewport().Width - sprite.Scale.X/2,
Director.Instance.GL.Context.GetViewport().Height/2);

scene.AddChild(sprite);
scene.AddChild(sprite2);

PhysicsScenephysicsScene = new PhysicsScene();
physicsScene.InitScene();
physicsScene.SceneName = "Demo scene";
physicsScene.NumBody = 2;
physicsScene.NumShape = 1;
physicsScene.Gravity = new Vector2(0.0f,0.0f);

physicsScene.SceneShapes[0] = new PhysicsShape((sprite.Scale.Y/2.0f)/PtoM);

physicsScene.SceneBodies[0] = new PhysicsBody(physicsScene.sceneShapes[0],1.0f);
physicsScene.SceneBodies[0].Position = sprite.Position/PtoM;
physicsScene.SceneBodies[0].Rotation = 0;
physicsScene.SceneBodies[0].ShapeIndex = 0;

physicsScene.SceneBodies[1] = new PhysicsBody(physicsScene.sceneShapes[0],1.0f);
physicsScene.SceneBodies[1].Position = sprite2.Position/PtoM;
physicsScene.SceneBodies[1].Rotation = 0;
physicsScene.SceneBodies[1].ShapeIndex = 0;

physicsScene.SceneBodies[0].Force = new Vector2(200.0f,0);
physicsScene.SceneBodies[1].Force = new Vector2(-200.0f,0);

Director.Instance.RunWithScene(scene, true);

Vector2 touchPosition = new Vector2();
Vector2 touchDiff = new Vector2();

bool quit = false;
while(!quit)
{
Director.Instance.Update();
if(Input2.GamePad0.Cross.Press)
quit = true;

physicsScene.Simulate(-1,ref touchPosition,reftouchDiff);
sprite.Position = physicsScene.SceneBodies[0].Position * PtoM;
sprite2.Position = physicsScene.SceneBodies[1].Position * PtoM;

if(physicsScene.QueryContact(0,1))
{
physicsScene.SceneBodies[0].Position = new Vector2(
sprite.Scale.X/2,
Director.Instance.GL.Context.GetViewport().Height/2) /PtoM;
physicsScene.SceneBodies[0].Force = new Vector2(200.0f,0);

physicsScene.SceneBodies[1].Position = new Vector2(
Director.Instance.GL.Context.GetViewport().Width - sprite.Scale.X/2,
Director.Instance.GL.Context.GetViewport().Height/2) /PtoM;
physicsScene.SceneBodies[1].Force = new Vector2(-200.0f,0);
}
Director.Instance.Render();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
}
_ti.Dispose();
_texture.Dispose();
Director.Terminate();
}
}
}

2. Now press F5 to run your application and you should see the following output:

Two earth sprites will start centered, one on the left and the other on the right-hand side of the screen. They will both travel towards the screen's middle until a collision occurs, at which point they will be reset to their starting positions and the process will begin again. Pressing the X button or S key will exit the application.

How it works...

Almost all of the code is repeated from previous recipes. We create our scene, load, and position the two sprites at each side of the screen, vertically centered, then add them both to the scene. We then configure the physics scene to contain two rigid bodies and one shape. Like the prior recipe, we will be converting to physics coordinates using a ratio of 50 pixels to a meter. We then add a force of 200N to each body, sending them on a collision course at the middle of the screen.

In our game loop, in addition to the mandatory function calls, we update the physics simulation with a call to Simulate, and then update each sprite's position accordingly. We then check to see if a collision occurred. This is done with the QueryContact method. You pass QueryContact the index of the two bodies with the SceneBodies array that you want to check for a collision between. If a collision occurs, QueryContact returns true, otherwise it returns false. In the event a collision occurs, we re-center our two sprites and reset their force values (the collision will have greatly reduced the force of each).

There's more...

In addition to setting a rigid body to kinematic, dynamic, or static, you can also set it to be a trigger by calling SetBodyTrigger. If a body is a trigger, it will not participate in the physics simulation, but it can receive collisions. You can use the method QueryContactTrigger to check if a body collided with the trigger. You pass QueryContactTrigger the index of the trigger itself, and an array of body indexes to check for collisions.

See also

- See the Switching between dynamic and kinematic recipe for more details on the effects of each setting

Rigid body collision shapes

In this recipe, we are going to look at the three different shapes a rigid body can have, the sphere, box, and convex hull.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.HighLevel.GameEngine2D and Sce.PlayStation.HighLevel.Physics2D. We are going to re-use our small earth sprite, earthSmall.png, once again, as well as our trusty FA-18H.png sprite to provide a slightly more complex shape. The complete source and all images used can be found in Ch5_Example6.

How to do it...

1. Open AppMain.cs and replace the existing code with the following code:

using System;
usingSce.PlayStation.Core;
usingSce.PlayStation.Core.Graphics;
usingSce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;
using Sce.PlayStation.HighLevel.Physics2D;

namespace Ch5_Example6 {
public class AppMain {
private static Texture2D _textureJet;
private static TextureInfo _tiJet;

private static Texture2D _textureEarth;
private static TextureInfo _tiEarth;

privateconst float PtoM = 50.0f;

public static void Main (string[] args) {
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

SpriteUVjet,earth;
_textureJet = new Texture2D("/Application/FA-18H.png",false);
_tiJet = new TextureInfo(_textureJet);
jet = new SpriteUV(_tiJet);
jet.Position = new Vector2(Director.Instance.GL.Context.GetViewport().Width/2,
Director.Instance.GL.Context.GetViewport().Height/2);
jet.Pivot = new Vector2(0.5f,0.5f);
jet.Scale = _tiJet.TextureSizef;

_textureEarth = new Texture2D("/Application/earthSmall.png",false);
_tiEarth = new TextureInfo(_textureEarth);
earth = new SpriteUV(_tiEarth);
earth.Position = new Vector2(Director.Instance.GL.Context.GetViewport().Width/2,
Director.Instance.GL.Context.GetViewport().Height);
earth.Pivot = new Vector2(0.5f,0.5f);
earth.Scale = _tiEarth.TextureSizef;

scene.AddChild(jet);
scene.AddChild(earth);

PhysicsSceneps = new PhysicsScene();
ps.InitScene();
ps.SceneName = "Demo Scene";
ps.NumBody = 3;
ps.NumShape = 3;

Vector2[] points = new Vector2[9];

Vector2 center = new Vector2(jet.Scale.X/2,jet.Scale.Y/2);
points[0] = new Vector2(0.0f,center.Y) / PtoM;
points[1] = new Vector2(50.0f, 30.0f) / PtoM;
points[2] = new Vector2(center.X - 10.0f,10.0f) / PtoM;
points[3] = new Vector2(center.X - 10.0f, - 30.0f) / PtoM;
points[4] = new Vector2(30.0f,-center.Y + 30.0f) / PtoM;
points[5] = new Vector2(-30.0f,-center.Y + 30.0f) / PtoM;
points[6] = new Vector2(-center.X + 10.0f,-30.0f) / PtoM;
points[7] = new Vector2(-center.X + 10.0f,10.0f) / PtoM;
points[8] = new Vector2(-50.0f, 30.0f) / PtoM;
//Jet
ps.SceneShapes[0] = new PhysicsShape(points,9);
ps.SceneBodies[0] = new PhysicsBody(ps.SceneShapes[0],2.0f);
ps.SceneBodies[0].ShapeIndex = 0;
ps.SceneBodies[0].Position = new Vector2(Director.Instance.GL.Context.GetViewport().Width/2,
Director.Instance.GL.Context.GetViewport().Height/2) / PtoM;

//Earth
ps.SceneShapes[1] = new PhysicsShape(earth.Scale.X/2 / PtoM);
ps.SceneBodies[1] = new PhysicsBody(ps.SceneShapes[1],1.0f);
ps.SceneBodies[1].ShapeIndex = 1;
ps.SceneBodies[1].Position = new Vector2(Director.Instance.GL.Context.GetViewport().Width/2,
Director.Instance.GL.Context.GetViewport().Height) / PtoM;

//Ground
ps.SceneShapes[2] = new PhysicsShape(
new Vector2(Director.Instance.GL.Context.GetViewport().Width,1.0f) / PtoM);
ps.SceneBodies[2] = new PhysicsBody(ps.SceneShapes[1],PhysicsUtility.FltMax);
ps.SceneBodies[2].Position = new Vector2(0.0f,0.0f);
ps.SceneBodies[2].ShapeIndex = 2;

scene.AdHocDraw += () => {
//Cannot use DrawConvexPolygon because each point needs to be converted back to pixel space
Director.Instance.DrawHelpers.SetColor(new Vector4(255.0f,0.0f,0.0f,255.0f));
for(inti=1; i< 10; i++){
Vector2 p1,p2;
//Convert to screen coordinates and rotate to match physics object
if(i == 9) {
p1 = ps.SceneShapes[0].vertList[8];
p2 = ps.SceneShapes[0].vertList[0];
}
else {
p1 = ps.SceneShapes[0].vertList[i-1];
p2 = ps.SceneShapes[0].vertList[i];
}
p1 = p1.Rotate(ps.sceneBodies[0].Rotation);
p1 = p1  *PtoM + jet.Position;

p2 = p2.Rotate(ps.SceneBodies[0].Rotation);
p2 = p2 * PtoM + jet.Position;

Director.Instance.DrawHelpers.DrawLineSegment(p1,p2);
}

Director.Instance.DrawHelpers.SetColor(new Vector4(0.0f,255.0f,0.0f,255.0f));
var bounds = new Bounds2(ps.SceneBodies[0].AabbMin*PtoM,ps.SceneBodies[0].AabbMax*PtoM);
Director.Instance.DrawHelpers.DrawBounds2(bounds);

var bounds2 = new Bounds2(ps.SceneBodies[1].AabbMin*PtoM,ps.SceneBodies[1].AabbMax*PtoM);
Director.Instance.DrawHelpers.DrawBounds2(bounds2);
};

Director.Instance.RunWithScene(scene,true);

Vector2 touchPosition = new Vector2();
Vector2 touchDiff = new Vector2();

bool quit = false;
while(!quit) {
if(Input2.GamePad0.Cross.Press)
quit = true;

Director.Instance.Update();
ps.Simulate(-1,ref touchPosition,reftouchDiff);

jet.Position = ps.sceneBodies[0].Position * PtoM;
jet.Rotation = new Vector2((float)System.Math.Cos(ps.SceneBodies[0].Rotation),
(float)System.Math.Sin (ps.SceneBodies[0].Rotation));

earth.Position = ps.sceneBodies[1].Position * PtoM;
earth.Rotation = new Vector2((float)System.Math.Cos(ps.SceneBodies[1].Rotation),
(float)System.Math.Sin (ps.SceneBodies[1].Rotation));
Director.Instance.Render ();
Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
}

_tiJet.Dispose();
_textureJet.Dispose();
_tiEarth.Dispose();
_textureEarth.Dispose();

Director.Terminate();
}
}
}

2. Press F5 to run the application and you should see the following output:

The F18 sprite will fall from the sky due to gravity, followed shortly by a small earth sprite. The two bodies will then collide and respond accordingly. The bounding box of each sprite is drawn in green, while the exact boundaries of the F18 sprite are drawn in red. As you can see, the bounding box shrinks as the sprite rotates.

How it works...

The scene starts off typically, loading and positioning both of our sprites, and adding them to the scene. We then create a PhysicsScene constructor containing three PhysicsBody objects with three PhysicsShape objects. We start off creating the first shape, which is going to be made up of a series of Vector2 objects composing the hull around our sprite. We construct these points at the scene origin, with positioning relative to the center of our sprite, like this:

Once again, we are using the 50 pixels to 1 meter ratio, so we divide each Vector2 by PtoM to adjust it. We then construct our jet's PhysicsShape by passing the Vertex2 array and array length in to the PhysicsShape constructor. This creates a polygon around the hull that will be used for collision detections. We also create a sphere physics body for our earth object and a box rigid body for the ground at the bottom of the screen.

Next, we register an AdHocDraw method to draw the lines composing the polygon around the jet. First we set the current drawing color to red. Then we start at the second item, and draw from the previous Vector2 in the array to the current item, unless it is the last item, in which case we draw from the final Vector2 back to the first one, closing off the shape. As part of the Simulate process, the SceneBody controlling the jet will be rotated in addition to being moved, so we need to apply this rotation to each Vector2 in the array.

We then need to translate each line from Physics2D coordinates relative to the origin to screen coordinates relative to the sprite's position. Finally, we draw the line on the screen using the helper method DrawLineSegment.

Once we have drawn the bounding polygon, we switch the color to green. We get the bounding box around our jet and earth bodies using the AabbMin and AabbMax values (Aabb = Axis Aligned Bounding Box). Then draw these bounds using the DrawHelper object's method DrawBounds2.

Within the game loop, we check for the user pressing X, in which case we exit the application. Otherwise we update the simulation, and then update the jet Position and Rotation, as well as the earth's Position and Rotation. Then we call the mandatory functions required if you manually manage your game loop. Finally, before the program exits, we clean up after ourselves.

There's more...

The DrawHelpers object contains a method named DrawConvexPoly2 that could have drawn our shape in a single call. However, we needed to translate each line segment to use our screen coordinates, so we instead choose to draw the outline as a series of line segments. It should be noted that DrawHelpers is not meant for production code and has not been optimized.

Building and using an external library

In this recipe, we will examine the process of building and using an external library.

Getting ready

Load up PlayStation Mobile Studio. Open a solution you wish to add a library to, or create a new workspace.

How to do it...

1. Right-click on the solution at the top of the Solution panel tree. In the context menu select Add | Add New Project.

2. In the resulting dialog box, on the left-hand side, expand C# and select PlayStation Mobile. On the right-hand side, select PlayStation Mobile Library Project. Select a location for your library, give it a name, and then click on OK.

3. In the Solution panel, your library should now be added. Now add code and resources from the library you wish to import.

4. Now, we will add the library to your existing project. Right-click your application's References folder in the Solution panel and select Edit References….

5. In the resulting dialog box, select the Projects tab. Simply check the checkbox to the left of your library name and then press OK.

How it works...

There are two major limitations of external libraries you can use with PlayStation Mobile. First, they need to be compatible with the subset of the .NET runtime included with PlayStation Mobile. Generally, this shouldn't prove to be a big problem. Second, they need to include no unsafe or native code. Generally, if the library is simply a wrapper around a native DLL such as Box2D, it will not work with PlayStation Mobile.

There's more...

In addition to the included Physics2D engine, there are a few third party physics engines that will work with PlayStation Mobile Studio. The first is the BEPU physics engine (http://bit.ly/QbjQV9), while the second is the FarSeer physics engine (http://bit.ly/NY3U9T), both of which are fully open source and hosted on CodePlex.

There is also a port of the popular MonoGame library (http://bit.ly/QD43hh), a library designed to make porting of XNA games to various platforms (iOS, Android, Linux, Mac, and now PlayStation Mobiles) easier.

Chapter 6. Working with GUIs

In this chapter we will cover:

- "Hello World" – HighLevel.UI style

- Using the UI library within a GameEngine2D application

- Creating and using hierarchies of widgets

- Creating a UI visually using UIComposer

- Displaying a MessageBox dialog

- Handling touch gestures and using UI effects

- Handling language localization

Introduction

In this chapter we are going to learn about the HighLevel.UI toolkit as well as UIComposer, a visual UI building tool. When combined together they enable you to create rich user interfaces for your game or application with relative ease. The UI library ships with a rather extensive set of premade controls; we will take a closer look at a few of them.

"Hello World" – HighLevel.UI style

In this recipe we are going to create a simple "Hello World" application, implemented using a Panel and a Label widget from the HighLevel.UI library.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.HighLevel.UI. You can download this complete project as Ch6_Example1.

How to do it...

Edit the AppMain.cs file to match the following:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.UI;

namespace Ch6_Example1
{
public class AppMain {
public static void Main() {
GraphicsContext graphics = new GraphicsContext();
UISystem.Initialize(graphics);

var scene = new Sce.PlayStation.HighLevel.UI.Scene();
var panel = new Sce.PlayStation.HighLevel.UI.Panel();
panel.Width = graphics.Screen.Width;
panel.Height = graphics.Screen.Height;

var label = new Sce.PlayStation.HighLevel.UI.Label();
label.HorizontalAlignment = HorizontalAlignment.Center;
label.VerticalAlignment = VerticalAlignment.Middle;
label.SetPosition (
graphics.Screen.Width/2 - label.Width/2,
graphics.Screen.Height/2 - label.Height/2
);
label.Text = "Hello world";

panel.AddChildLast(label);
scene.RootWidget.AddChildLast(panel);

UISystem.SetScene(scene);
graphics.SetViewport(0,0,graphics.Screen.Width,graphics.Screen.Height);
graphics.SetClearColor(new Vector4(0,0,0,255));

bool done = false;
while(!done)  {
graphics.Clear ();
var touches = Touch.GetData(0);
if(touches.Count > 0 && touches[0].Status == TouchStatus.Down)
done = true;
UISystem.Update (touches);
UISystem.Render ();

graphics.SwapBuffers();
}
}
}
}

Press F5 to run the code and you should see the following:

This is the iconic "Hello World" application; the text Hello world will be displayed, centered on your screen.

How it works...

This example doesn't make use of the GameEngine2D framework, so we start off creating a new GraphicsContext. Next we initialize the UISystem singleton (similar in function to the Director singleton) passing in our newly created graphics context (we will see how this process works with a GameEngine2D scene in an upcoming recipe). Next we create a Scene and a Panel, which will contain our label control. We then set the panel's dimensions to match the full extents of the screen.

Next we create a Label object, which will display our string on screen. We set the label to be displayed in the center by setting its HorizontalAlignment and VerticalAlignment to Center and Middle, respectively. This causes the text to be centered within the Label control itself, but we still need to center the label to the panel, which we do using SetPosition. Finally, we set our label's text with the Text property.

Now we add the label to the panel by passing it as a parameter to AddChildLast. Next we add the panel itself to the UI Scene by calling AddChild on scene's RootWidget, making the panel the root-level widget in the tree of UI controls. We will look at this hierarchy of controls in greater detail later. We then set our scene as the active Scene by calling UISystem.SetScene.

Finally, before our game loop begins, we configure our viewport to the same dimensions as the screen and set the clear color to black.

In our game loop, we start by clearing the screen with a call to Clear. We then get the current touch state, and if a touch has occurred we set our done flag, telling the application to exit. Next we update UISystem with the current touch data by calling Update, and then display the UI with a call to Render. Finally, we draw the updated screen with a call to graphics.SwapBuffers().

There's more...

It is important to realize that a UI Scene class has nothing in common with the Physics and GameEngine2D Scene classes and cannot be interchanged in any way. They all simply share a somewhat common design and naming convention, but that is where the similarities end.

In addition to passing touch data in to UISystem when you call the Update method, you can also add gamepad support. In this case, you also pass in the gamepad data, as follows:

UISystem.Update(Touch.GetData(0),GamePad.GetData(0));

You are required to pass in the touch information when calling UISystem's Update, but gamepad data is completely optional. When interacting with gamepad, pressing any button will set focus on the control; then pressing a button again will be effectively the same as touching it.

Note

Just like the Physics and GameEngine2D libraries, the UI library is provided with full source code. If you installed everything to default locations, the full source code should be available at C:\Program Files (x86)\SCE\PSM\source\UI.

There is one very important point you should be aware of. All of the classes in the UI library are not thread safe. All members of UISystem and all created widgets should be created in the main thread!

See also

- See the Creating a simple game loop recipe in Chapter 1, Getting Started, for more information on GraphicsContext and the basics of the game loop

- See the Creating and using hierarchies of widgets recipe for a list of available widget controls

Using the UI library within a GameEngine2D application

In this recipe we will look at integrating the UI library with a GameEngine2D project. In the process we will demonstrate adding and handling a Button widget.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.HighLevel.UI and Sce.PlayStation.HighLevel.GameEngine2D. Additionally, we will be drawing a 960 x 544 (the Vita's native resolution) SpriteUV using the image beach.png; of course you can substitute your own. The entire project including images is available in Ch6_Example2.

How to do it...

Open AppMain.cs and change the existing code to the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;
using Sce.PlayStation.HighLevel.UI;

namespace Ch6_Example2
{
public class AppMain {

public static void Main (string[] args)  {
Director.Initialize();
UISystem.Initialize(Director.Instance.GL.Context);

var scene = new Sce.PlayStation.HighLevel.GameEngine2D.Scene();
scene.Camera.SetViewFromViewport();
Texture2D texture = new Texture2D("/Application/beach.png",false);
TextureInfo ti = new TextureInfo(texture);
SpriteUV background = new SpriteUV(ti);
background.Scale = ti.TextureSizef;
scene.AddChild(background);

var uiScene = new Sce.PlayStation.HighLevel.UI.Scene();
Panel panel = new Panel();
panel.Width = Director.Instance.GL.Context.GetViewport().Width;
panel.Height = Director.Instance.GL.Context.GetViewport().Height;

bool quit = false;

Button button = new Button();
button.Name = "button1";
button.Text = "Push me to quit";
button.Width = 300;
button.Height = 100;
button.PivotType = PivotType.MiddleCenter;
button.SetPosition(panel.Width/2,panel.Height/2);
button.TouchEventReceived += (sender, e) => {
quit = true;
};

panel.AddChildLast(button);
uiScene.RootWidget.AddChildFirst(panel);
UISystem.SetScene(uiScene);
Director.Instance.RunWithScene(scene,true);

while(!quit){
Director.Instance.Update();
Director.Instance.Render();

UISystem.Update(Touch.GetData(0));
UISystem.Render();

Director.Instance.GL.Context.SwapBuffers();
Director.Instance.PostSwap();
}

texture.Dispose();
ti.Dispose();
Director.Terminate();
UISystem.Terminate();
}
}
}

Hit F5 to run the application and you should see the following screenshot:

In addition to a background of a beautiful Jamaican beach, a button labeled Push me to quit will be centered on the screen. Predictably enough, if you click on the button, the application will quit.

How it works...

This recipe starts off initializing both the GameEngine2D Director singleton, as well as the UISystem singleton. UISystem is initialized by passing in the GL context from within the Director singleton. Then it creates a (GameEngine2D) Scene, configures the camera, creates a Texture2D and a TextureInfo, which are used to create a SpriteUV object, which is scaled and added to the scene. If you have read the last couple of chapters already, this code should all be intimately familiar at this point.

Next we create a UI Scene, aptly named uiScene. Again, this Scene class has absolutely nothing in common with other Scene classes and cannot be interchanged; in fact, you may need to fully resolve the namespace to distinguish between the two classes. We then create a Panel object to hold our controls and size it to the full dimensions of the device. We also declare a bool object named quit to control program execution.

Then we declare a new Button widget. We set its name (ID) to button1 and its displayed Text to Push me to quit. Next we set the button width and height and set the pivot point to the middle of the button using PivotType. PivotType is similar to GameEngine2D Node's Pivot, except instead of taking the x and y coordinates, it takes a PivotType enum. Next we set the button position to the center of the panel and then register a TouchEventReceived handler, which is a simple function that sets the quit flag to true.

Next we add the button to the panel using AddChildLast and then add the panel to uiScene by adding it to RootWidget, this time using AddChildFirst (when there is only one widget, there is no functional difference between AddChildLast and AddChildFirst). Finally, we set uiScene as the active Scene by calling UISystem.SetScene() and start the (GameEngine2D) scene running with a call to Director.RunWithScene(), passing in our scene and false, indicating we will manually handle the event loop.

In the event loop we make the mandatory Update, Render, SwapBuffers, and PostSwap calls. Additionally, after the Director singleton has been updated and drawn, we call UISystem.Update() and UISystem.Render(). After our event loop, we do some cleanup, including calling Terminate on both of our singletons.

There's more...

It is critically important that UISystem.Render() is called after Director.Instance.Render(). UISystem uses the GL context you passed in when you called UISystem.Initialize() to perform all of its drawing. This context is shared between the Director and UISystem objects and if you do not call UISystem object's Render after Director object's Render, the UI will be overdrawn by the GameEngine2D render process!

See also

- See Chapter 3, Graphics with GameEngine2D, for more details on drawing graphics using GameEngine2D

Creating and using hierarchies of widgets

This recipe looks at the relationship between widgets. We are going to build a scrollable panel that contains another panel that is filled with an array of buttons and then demonstrate how they respond as a single unit.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.HighLevel.UI. The project is available in Ch6_Example3.

How to do it...

Open AppMain.cs and edit the code to match the following:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.UI;

namespace Ch6_Example3
{
public class AppMain {
public static void Main() {
GraphicsContext graphics = new GraphicsContext();
UISystem.Initialize(graphics);

var scene = new Sce.PlayStation.HighLevel.UI.Scene();
var scrollPanel = new Sce.PlayStation.HighLevel.UI.ScrollPanel();

scrollPanel.SetPosition(0,0);
scrollPanel.Width = graphics.Screen.Width/2;
scrollPanel.Height = graphics.Screen.Height;
scrollPanel.VerticalScroll = true;
scrollPanel.HorizontalScroll = false;
scrollPanel.ScrollBarVisibility= ScrollBarVisibility.ScrollableVisible;
scrollPanel.PanelWidth = graphics.Screen.Width/2;
scrollPanel.PanelHeight = 100*10;

var panel = new Sce.PlayStation.HighLevel.UI.Panel();
panel.Width = graphics.Screen.Width/2;
panel.Height = 100*10;
panel.Clip = true;

for(int i = 0; i < 10; i++)  {
Button button = new Button()
{ X=0,Y=100*i, Width = 300, Height=100, Name = "button"+i, Text="Button #"+i };

button.ButtonAction += (sender, e) => {
if(scrollPanel.X ==0) scrollPanel.X = graphics.Screen.Width/2;
else scrollPanel.X = 0;
};
panel.AddChildLast(button);
}
scrollPanel.AddChildFirst(panel);
scene.RootWidget.AddChildLast(scrollPanel);

UISystem.SetScene(scene);
graphics.SetViewport(0,0,graphics.Screen.Width,graphics.Screen.Height);
graphics.SetClearColor(new Vector4(0,0,0,255));

while(true)  {
graphics.Clear();

UISystem.Update(Touch.GetData(0));
UISystem.Render();

graphics.SwapBuffers();
}
}
}
}

Press the F5 key to run your application:

An array of 10 buttons will be drawn on the left-hand side of the screen. Touch and drag to scroll the screen. Tapping a button will cause the entire collection of buttons, the containing panel, and the scroll bars all to move to the other side of the screen. Stop the application using the menu Run | Stop or by hitting Shift + F5 in PlayStation Mobile Studio.

How it works...

This recipe also doesn't make use of the GameEngine2D library, so we have to create a GraphicsContext, then initialize the UISystem singleton. Next we create a UI Scene object.

The first widget we create is ScrollPanel, which is a special panel that scrolls its contents if they exceed the size of the panel. We set its width to be half the screen size and the height to be full screen, and enable vertical scrolling but not horizontal. We also set the scroll bars to be visible by setting ScrollBarVisibility to ScrollBarVisibility.ScrollableVisible. We then set PanelWidth to half the screen size and set PanelHeight to 1000, large enough to accommodate 10 100-pixel high buttons. PanelHeight/PanelWidth represents the dimensions of the panel ScrollPanel contains.

Speaking of which, we create the inner panel next, which is a standard Panel object. It predictably enough uses the same dimensions as the ones we just used for PanelHeight and PanelWidth. We set Clip to true, clipping the nonvisible portions of the widget.

Next we loop 10 times, creating 10 separate Button widgets, all with the same values except the y position, which we increment by 100 pixels with each iteration of the loop. For each button we define the same lambda function for ButtonAction. This function simply moves scrollPanel between the left- and right-hand side of the application each time a button is pressed. Finally at the end of each loop iteration the newly created Button is added to the panel.

We then add panel to scrollPanel by calling AddChildFirst, then add scrollPanel to the scene's RootWidget. With all the controls created and displayed we set our UI scene active with a call to SetScene, configure the viewport and clear color, and then loop forever, clearing the screen, updating and rendering the UI, and displaying it to the user.

There's more...

The position of a child widget is relative to the widget that contains it. All UI coordinates are relative to the upper-left corner of the screen for RootWidget, and the upper-left corner of the container for child widgets. Therefore the origin (0, 0) is at the upper-left corner of the screen, instead of the lower-left as used in GameEngine2D.

There are two kinds of controls in UI library, common widgets and container widgets. Container widgets are widgets that can contain other widgets, such as Panel and Dialog. Common widgets are your various UI components including Button and Label. A container widget is still a widget and has all of the same abilities, but the reverse is not true.

The following sections show the available UI controls in the PlayStation Mobile UI library.

Container widgets

The following are the container widgets:

- Dialog

- MessageDialog

- GridListPanel

- ListPanel

- LiveScrollPanel

- Panel

- ListPanelItem

- LiveJumpPanel

- LiveSpringPanel

- UIAnimationPlayer

- RootWidget

- ScrollPanel

Common widgets

The following are the common widgets:

- AnimationImageBox

- BusyIndicator

- Button

- CheckBox

- ContainerWidget

- DatePicker

- EditableText

- ImageBox

- Label

- LiveFlipPanel

- LiveListPanel

- LiveSphere

- PagePanel

- PopupList

- ProgressBar

- ScrollBar

- Slider

- TimePicker

RootWidget is a special widget that represents the root of the widget tree. Each UI scene has RootWidget and it forms the base of all widget hierarchies. Beyond the one defined in scene, RootWidget classes are never declared. ContainerWidget is the parent class of all container widgets and is not used directly.

Creating a UI visually using UIComposer

This recipe is going to use the UIComposer application to create a simple user interface.

Getting ready

Load up UIComposer; there should be a Start Menu entry in the PlayStation Mobile folder. If you installed with default settings, it should also be available at C:\Program Files (x86)\SCE\PSM\tools\UIComposer if your OS is 64 bit, or C:\Program Files\SCE\PSM\tools\UIComposer if your OS is 32 bit.

How to do it...

To create a UI visually using UIComposer perform the following steps:

1. Select File | Create New Project.

2. In the Create New Project dialog box, fill in the Project Name and File Path fields with whatever values you like (remember the location). Click on OK when finished:

3. In the NewLayoutWindow dialog box, set Class to Layout to Scene, Class Name to Demo, and for Size select 960x544 (the PlayStation Vita's resolution), then click on OK:

4. You should now have an editable surface you can drag, where you can essentially draw the UI. From the WidgetList area, locate the Panel Widgets section and drag a Panel widget over to the design surface.

5. Now set the properties of the Panel widget using the Property tab. Variable Name is the actual C# name that this widget will be assigned. Drag and position the panel in design surface to take up the full screen, or set the dimensions from the Property tab. Set x and y to 0, w to 960, and h to 544, as shown in the following screenshot:

6. Drag a Button widget to the to the design surface, then center it by clicking on the Align Vertical Center In Container and Align Horizontal Center in Container toolbar buttons (on the left-hand side of the screen). In the Text property, change it from Button to Click Me. Drag a Label widget above the button; you will notice that snapping lines will appear to help you position it relative to other controls. The end results should look something like the following screenshot:

7. Select the menu File | Build. A dialog should appear titled Code Generating Progress with a list of generated files. You can optionally save your project for editing it later with the menu File | Save Project.
The files you just generated can now be used for importing into any existing project.

8. Open a solution in PlayStation Mobile Studio and be sure to add the UI library as a reference. Then import the files we just generated. Simply right-click on the project in the Solution panel and select Add | Add Files…, navigate to and select Demo.cs, Demo.Composer.cs, and UIStringTable.cs and click on Open. You will be prompted, as shown in the following screenshot:

9. If you want to be able to make further changes to the design in UIComposer, select Add a Link to the file. Otherwise you can select Copy the file to the directory or Move the file to the directory.
Now that these files have been included in your project, making use of this class is trivial. The following code loads the UI we just created:

public static void Main (string[] args)
{
var graphics = new GraphicsContext ();
DemoScene.Demo demo = new DemoScene.Demo();

UISystem.Initialize(graphics);
UISystem.SetScene(demo);

graphics.SetClearColor (0.0f, 0.0f, 0.0f, 0.0f);
while (true) {
graphics.Clear ();
UISystem.Update(Touch.GetData(0));
UISystem.Render();
graphics.SwapBuffers ();
}
}

Then if you run this code, you will see the following screenshot:

The code doesn't actually do anything, but it does demonstrate the UI in action.

How it works...

UIComposer is essentially a code generator, writing the UI code for you. Thanks to the use of partial classes, you can implement logic in the ClassName.cs file, such as your ButtonEvent handlers, and leave generated code alone in the ClassName.Composer.cs file. This allows you to make future edits in UIComposer, without overwriting the customizations you make. It is still the programmer's responsibility to actually wire the UI up to… well, do stuff.

There's more...

In addition to creating complete Scene objects, UIComposer, it can also be used to create the Panel, Dialog, and ListPanelItem derived classes.

UIComposer has the ability to create layouts for both portrait and landscape modes. Use the menu item View | Canvas Orientation | Landscape and View | Canvas Orientation | Portrait to toggle between the two modes. The generated code will then handle initializing the widgets for the selected layout and provide a mechanism for switching between them.

See also

- See the Creating and using hierarchies of widgets recipe for a complete list of available widgets

Displaying a MessageBox dialog

This short recipe is going to demonstrate displaying a message box dialog with an OK or Cancel prompt and show how to handle the user's response.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.HighLevel.UI. The entire project is available in Ch6_Example4. Copy the game's existing code from an earlier recipe in this chapter, as we are only going to cover the specifics of creating and interacting with the dialog in this recipe.

How to do it...

Add the following code during the update process to create and display MessageDialog:

var gamePadData = GamePad.GetData (0);
if((gamePadData.Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
{
var dialog = MessageDialog.CreateAndShow(MessageDialogStyle.OkCancel,"User Prompts",
"Are you sure you wish to continue?");
dialog.ButtonPressed += (sender, e) => {
if(dialog.Result == DialogResult.Ok)
System.Diagnostics.Debug.WriteLine("Continuing");
else
System.Diagnostics.Debug.WriteLine("The user pressed cancel");
};
}

In your main loop, make sure you update UISystem with the following code:

UISystem.Update (Touch.GetData(0));
UISystem.Render();

Now hit F5 to run your application, then press the X button (or S in the simulator) and you should see the following screenshot:

Depending on which button you choose, a different message will be written to the debug console in Studio.

How it works...

We start off by retrieving the gamepad state, then check to see if the X button has been pressed. If it has, we create and display a message box using the static method MessageDialog.CreateAndShow, passing the value MessageDialogStyle.OkCancel indicating that we want the OK and Cancel buttons displayed. We also pass in the message box title and message text. Then we define a method to be called when the user clicks on a button, which checks the Result property to determine which button the user clicked. In either case, we print a message to the debug console using System.Diagnostics.Debug.WriteLine(), an easy way to output debug information.

There's more...

You can create a dialog class that is much more sophisticated than MessageDialog by deriving a class from Dialog. Dialog is one of the supported types generated by UIComposer, so you can use that tool to visually build more complex dialog boxes.

See also

- See the Creating a UI visually using UIComposer recipe for more details on using UIComposer, which can be used to create a custom dialog class

Handling touch gestures and using UI effects

In this recipe we are going to look at handling touch gestures such as double tapping and swiping. Additionally, in response to certain gestures, we are going to apply a couple of the built-in UI special effects.

Getting ready

Load up PlayStation Mobile Studio and create a new project. Add a reference to Sce.PlayStation.HighLevel.UI. We are going to be re-using our FA-18h.png image, but feel free to substitute any appropriate image. The entire project including images is available in Ch6_Example4.

How to do it...

Open AppMain.cs and replace Main with the following code:

public static void Main (string[] args)  {
var graphics = new GraphicsContext ();
UISystem.Initialize(graphics);
graphics.SetClearColor (0.0f, 0.0f, 0.0f, 0.0f);

Panel panel = new Panel();
panel.Width = graphics.Screen.Width;
panel.Height = graphics.Screen.Height;

ImageBox imageBox = new ImageBox();
imageBox.Image = new ImageAsset("/Application/FA-18h.png");
imageBox.Width = imageBox.Image.Width;
imageBox.Height = imageBox.Image.Height;
imageBox.PivotType = PivotType.MiddleCenter;
imageBox.SetPosition(panel.Width/2,panel.Height/2);
panel.AddChildLast(imageBox);
FlickGestureDetector flickDetector = new FlickGestureDetector();
flickDetector.Direction = FlickDirection.Horizontal;
flickDetector.FlickDetected += delegate(object sender, FlickEventArgs e) {
System.Diagnostics.Debug.WriteLine("Flick");
if(e.Speed.X <0)
new MoveEffect(imageBox,2000.0f,0,imageBox.Y,MoveEffectInterpolator.Elastic).Start();
else
new MoveEffect(imageBox,2000.0f,graphics.Screen.Width,imageBox.Y,MoveEffectInterpolator.Elastic).Start ();
};

DoubleTapGestureDetector doubleTapDetector = new DoubleTapGestureDetector();
doubleTapDetector.DoubleTapDetected += delegate(object sender, DoubleTapEventArgs e) {
new BunjeeJumpEffect(imageBox,1.0f).Start();
};

DragGestureDetector dragDetector = new DragGestureDetector();
dragDetector.DragDetected += delegate(object sender, DragEventArgs e) {
imageBox.SetPosition(e.WorldPosition.X,e.WorldPosition.Y);
};

imageBox.AddGestureDetector(flickDetector);
imageBox.AddGestureDetector(doubleTapDetector);
imageBox.AddGestureDetector(dragDetector);

var scene = new Scene();
scene.RootWidget.AddChildFirst(panel);
UISystem.SetScene(scene);

while(true) {
graphics.Clear();
UISystem.Update(Touch.GetData(0));
UISystem.Render();
graphics.SwapBuffers();
}
}

Hit F5 to run your code and you should see the following screenshot:

The F18 sprite will be centered on the screen. Touch and drag to move the sprite around the screen, touch and "flick" left or right to throw the sprite to either side of the screen, or double tap it to apply a bungee jump style animation.

How it works...

This code starts off as usual, creating GraphicsContext and initializing UISystem. Next we create a full screen Panel to hold our widget, and then create an ImageBox widget. The image within ImageBox is ImageAsset, which we create by providing the image file location. We then set the ImageBox size to match the source image, and set its PivotType to MiddleCenter, making translations happen relative to the middle of ImageBox. Then we position the image in the middle of the panel and finally add it to the panel.

Now we declare a series of gesture detectors, starting with FlickDetector. We configure it to check for only horizontal movement and then register a delegate that will be called when a flick is detected. If a flick occurs, we check to see what the speed is. If it is moving in a negative x direction, this means it was flicked to the left, so we create MoveEffect. MoveEffect is targeted at imageBox and has a duration of 2000 milliseconds, a destination of the middle-left side of the screen and an elastic style interpolation effect. In the event the user flicks right, we perform the same action, but instead target the middle-right side of the screen.

Next we register DoubleTapGestureDetector and create a delegate to be called when a double tap occurs. In the event of a double tap we perform BungieJumpEffect on ImageBox, with an elasticity of 1.0 (valid values are 0.0f to 1.0f), and immediately run the effect with a call to Start.

Then we register DragGestureDetector. Just like the others, it is handled with a delegate, which simply updates the ImageBox location with a call to SetPosition and passing in the drag location passed in as part of DragEventArg. The end result is that, as the touch location changes, ImageBox will be moved to that position.

We then have to wire all of the various gesture detectors to our widget. This is accomplished by calling the ImageBox widget's AddGestureDetector for each of the detectors we created. The remaining code is now the familiar infinite event loop.

There's more...

In addition to DoubleTapGestureDetector, DragGestureDetector, and FlickGestureDetector, there are also more detectors. LongPressGestureDetector is used to detect a tap and hold action. PinchGestureDetector is for detecting a two finger touch and drag, either inward or outward. Finally, there is TapGestureDetector for detecting a single tap gesture.

There are also a ton of built-in animation effects in addition to MoveEffect and BunjeeEffect . The following is a complete list of UI effect objects:

- BunjeeJumpEffect

- DelayedExecutor

- FadeInEffect

- FadeOutEffect

- FlipBoardEffect

- JumpFlipEffect

- MoveEffect

- SlideInEffect

- SlideOutEffect

- TiltDropEffect

- UIMotion

- ZoomEffect

See also

- See the Loading, displaying, and translating a textured image recipe from Chapter 1, Getting Started for details on how to add an image resource to your project and set its build action

Handling language localization

In this recipe we look at how to support multiple languages in your user interface using UIComposer.

Getting ready

Load up UIComposer, either load the UI project we made earlier or create a new one. Be sure to add at least one widget with a Text property, such as a Label widget.

How to do it...

To handle language localization perform the following steps:

1. In UIComposer; select the menu Window | Language Table Window to enable the text editing functionality. You may need to click on the Reload button for the table to render properly. It should look like the following screenshot:

2. Right-click on the empty space to the right of English and select Add Column; a dialog box will appear. Enter the language name you want to support; in this example I am going to use French. Then click on OK and the column will be added.

3. In the designer, select your label. In the dialog area, click on a Label widget. In the Property window, set Text to @LABEL_TEXT@, as shown in the following screenshot:

4. Then back in the Language Table window add an entry to LABEL_TEXT; in the English column enter Hello World and in the French column enter Bonjour tout le monde. Then click on the Apply to layout button:

The design surface should now be updated to show your modified text. You can toggle between active languages by clicking on the language column in the Language Table window.

5. Build your UI project using either the menu File | Build or by hitting F5. In addition to the two files representing your UI, a third file UIStringTable.cs will be generated, such as the following one:

namespace DemoScene
{
public static class UIStringTable
{
static string[] currentTable;
static UILanguage currentLanguageId;
static UILanguage defaultLanguageId;
static string[][] textTable;

public static string Get(UIStringID id)
{
return currentTable[(int)id];
}

public static UILanguage UILanguage
{
get { return currentLanguageId; }
set
{
if (currentLanguageId != value)
{
currentLanguageId = value;
currentTable = textTable[(int)currentLanguageId];
}
}
}

static UIStringTable()
{
textTable = new string[][]
{
new string[]
{
"Hello World",
},
new string[]
{
"Bonjour tout le monde",
},
};
defaultLanguageId = UILanguage.English;
currentLanguageId = defaultLanguageId;
currentTable = textTable[(int)currentLanguageId];
}
}

public enum UIStringID : int
{
LABEL_TEXT = 0,
}

public enum UILanguage : int
{
English = 0,
French = 1,
}
}

The generated UI classes will automatically make use of this class. You can then change languages by setting the currentLanguageId property in your applications code.

There's more...

You can also save the language table to import from a CSV (comma separated values) file. This enables you to create and maintain your translations in a program other than UIComposer, such as Microsoft Excel. Strings can be any valid Unicode value.

See also

- See the Creating a UI visually using UIComposer recipe for more information on using UIComposer

Chapter 7. Into the Third Dimension

In this chapter, we will cover the following:

- Creating a simple 3D scene

- Displaying a texture 3D object

- Implementing a simple camera system

- A fragment (pixel) shader in action

- A vertex shader in action

- Adding lighting to your scene

- Using an offscreen frame buffer to take a screenshot

Introduction

In this chapter, we are going to learn about creating 3D graphics using the Sce.PlayStation.Core.Graphics library. The graphics library included with PlayStation Mobile is a fairly thin layer on top of OpenGL ES, so if you have done some prior OpenGL programming, this chapter should be immediately comfortable. Additionally, PlayStation Mobile makes heavy use of the Cg shader programming language, which we will also be covering.

Creating a simple 3D scene

In this recipe we are going to create about the simplest 3D scene possible, a single red triangle centered on the screen.

Getting ready

Load PlayStation Mobile Studio and create a new project. You can download the complete project as Ch7_Example1

How to do it...

1. Change AppMain.cs to match the following code:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;

namespace Ch7_Example1
{
public class AppMain {
public static void Main (string[] args){
var graphics = new GraphicsContext ();
graphics.SetClearColor (255.0f, 255.0f, 255.0f, 255.0f);

var projectionMatrix = Matrix4.Perspective(FMath.Radians(45.0f),graphics.Screen.AspectRatio,1.0f,100000.0f);

var viewMatrix = Matrix4.LookAt(new Vector3(0.0f,1.0f,-3.0f),
new Vector3(0.0f,0.0f,0.0f),
Vector3.UnitY);

var shaderProgram = new ShaderProgram("/Application/shaders/simple.cgx");
var vertexBuffer = new VertexBuffer(3,VertexFormat.Float3);

shaderProgram.SetUniformBinding(0,"WorldViewProj");
shaderProgram.SetAttributeBinding(0,"a_Position");
float[] positions = {
0.0f, 1.0f, 0.0f,
-1.0f, -1.0f, 0.0f,
1.0f, -1.0f, 0.0f,
};

vertexBuffer.SetVertices(0,positions);

bool done = false;
while(!done) {
graphics.Clear ();

if((GamePad.GetData(0).Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
done = true;

var viewProjection = projectionMatrix * viewMatrix;
shaderProgram.SetUniformValue(0, ref viewProjection);
graphics.SetShaderProgram(shaderProgram);
graphics.SetVertexBuffer(0,vertexBuffer);
graphics.DrawArrays(DrawMode.TriangleStrip,0,3);

graphics.SwapBuffers ();
}

graphics.Dispose();
shaderProgram.Dispose();
vertexBuffer.Dispose();
}
}
}

2. Next expand the shaders folder, open Simple.fcg, and edit it as follows:

void main( float4 out Color : COLOR,uniform float4 MaterialColor )
{
Color = float4(1,0,0,1);
}

3. Press F5 to run the code and you should see the output, as shown in the following screenshot:

A single red triangle will be displayed in the center of the screen. You can press the X button or the S key to exit.

How it works...

If you have already read Chapter 1, Getting Started; this recipe might look virtually identical to the Hello World application, as the process is basically the same. In fact it is a bit simpler.

We start off creating the GraphicsContext, which is an encapsulation of the underlying OpenGL context and is the heart of all graphic related activity. We then set the clear color to solid white. Next we create a pair of Matrix4 objects, the projectionMatrix and the viewMatrix. The projectionMatrix is responsible for converting the world from 3D view space to clip space, or in plainer less accurate language, to your screen. When creating the projection matrix you pass in the field of view (in radians), the screen's aspect ratio plus the near and far clip planes of the view frustrum.

The viewMatrix, on the other hand, represents your virtual eye within the 3D world. When creating the viewMatrix you pass in a trio of Vector3 objects, one representing the eye's location in 3D space, the next representing where the eye is looking. The third vector indicates where "Up" is; in this case we set the Y axis as the Up vector. The world (not used here), view, and projection matrices work together to transform the 3D scene to your devices screen. We cover this process in more detail later in this chapter.

Next we load the simple.cgx shader file, which PlayStation Mobile Studio automatically created for us. You may notice the file extension is different from the files in your script folder; don't worry, we will cover why this is shortly. Next we create a VertexBuffer, three items in length, containing Float3 objects. Then we bind to the shader values WorldViewProj and a_Position using the methods SetUniformBinding and SetAttributeBinding.Think of binding simply as setting a relationship between an application variable and a shader variable. We will cover both methods in more detail soon.

Now that our shader is loaded and properly bound, we need to create our triangle. We do this manually in an array of floats named positions, each value represents the x, y, or z coordinate making up each individual vertex. Therefore the first vertex of our triangle is (0.0f, 1.0f, 0.0f), the second is (-1.0f, -1.0f, 0.0f), and so on. We then load our vertices into the vertexBuffer by calling SetVertices(), the 0 representing the index of the buffer we want to load. As you will see later, you can load multiple buffers into a single VertexBuffer, in this case, we only have the one.

Next is the event loop. Each pass through the loop we clear the screen, then check to see if the user has pressed the X button and, if they have, toggle the done variable to true, which will end our loop the next pass through. Then we calculate the viewProjection matrix; this is a combination of the View and Projection matrixes and is calculated by simply multiplying them together. We then pass this calculated matrix in to our shader at the 0th index that we bound earlier to the shader variable "WorldViewProj".

Finally, we load our shader into the graphics context with a call to SetShaderProgram() load our VertexBuffer by calling SetVertexBuffer(), which again can accommodate multiple buffers; so we set it to the 0th position since we have only one. Next we draw the actual triangle to the screen with a call to DrawArrays, telling it to render the VertexBuffer as a triangle strip, starting at 0 and with a count of 3. Finally we display our rendered triangle onscreen by calling SwapBuffers().

In addition to the graphics object, ShaderProgram and VertexBuffer are both IDisposable, so to prevent leaking memory, we Dispose() of each before exiting.

There's more...

TriangleStrip is just one of the primitives that you can render; in addition to TriangleStrip, you can render the following primitive types with DrawArray():

- Points

- Lines

- LineStrip

- Triangles

- TriangleFan

TriangleStrip is the most commonly used type, as devices are generally optimized to render in triangle strips. A TriangleFan is similar to a TriangleStrip, except every triangle in the fan shares a single vertex.

The DrawArray call we made earlier is a very expensive operation in terms of overhead. Care should be taken to batch as many calls together in a single DrawArray call as possible. You can batch together graphics operations that have a great deal in common (same shader and rendering settings).

See also

- See the Loading, displaying and translating a textured image recipe in Chapter 1, Getting Started, for another recipe demonstrating creating and rendering a simple 3D scene.

Displaying a textured 3D object

In this recipe we are going to implement the "Hello World" equivalent of the 3D graphics world. We will be creating a fully textured 3D crate, the most famous textured cube known to mankind.

Getting ready

Load PlayStation Mobile Studio and create a new project. Additionally, you will need a create texture map. I downloaded this texture from the site www.OpenGameArt.org. You can download this particular texture at http://bit.ly/TuKCo. You can download the complete project including images as Ch7_Example2.

How to do it...

1. Open AppMain.cs and replace its contents with the following code:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;

namespace Ch7_Example2
{
public class AppMain {
public static VertexBuffer MakeCube() {
VertexBuffer vertexBuffer = new VertexBuffer(24, 36, VertexFormat.Float3, VertexFormat.Float2);

float[] positions = {
-0.5f,  0.5f, -0.5f, -0.5f,  0.5f,  0.5f, 0.5f,  0.5f, -0.5f, 0.5f,  0.5f,  0.5f, //top
0.5f, -0.5f, -0.5f, 0.5f, -0.5f,  0.5f, -0.5f, -0.5f, -0.5f, -0.5f, -0.5f,  0.5f,//bottom
-0.5f,  0.5f,  0.5f, -0.5f, -0.5f,  0.5f, 0.5f,  0.5f,  0.5f, 0.5f, -0.5f,  0.5f,//front
0.5f,  0.5f, -0.5f, 0.5f, -0.5f, -0.5f, -0.5f,  0.5f, -0.5f, -0.5f, -0.5f, -0.5f,//back
0.5f,  0.5f,  0.5f, 0.5f, -0.5f,  0.5f, 0.5f,  0.5f, -0.5f, 0.5f, -0.5f, -0.5f,//right
-0.5f,  0.5f, -0.5f, -0.5f, -0.5f, -0.5f, -0.5f,  0.5f,  0.5f, -0.5f, -0.5f,  0.5f//left
};
float[] texcoords = {
0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, //top
0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, //bottom
0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, //front
0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, //back
0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f, //right
0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 1.0f, 1.0f, 0.0f //left
};
ushort[] indices = {
0,  1,  2, 1,  3,  2,  //top
4,  5,  6, 5,  7,  6,  //bottom
8,  9, 10, 9, 11, 10,  //front
12, 13, 14, 13, 15, 14, //back
16, 17, 18, 17, 19, 18, //right
20, 21, 22, 21, 23, 22  //left
};
vertexBuffer.SetVertices(0, positions);
vertexBuffer.SetVertices(1, texcoords);
vertexBuffer.SetIndices(indices);

return vertexBuffer;
}

public static void Main (string[] args){
var graphics = new GraphicsContext ();
graphics.SetClearColor (255.0f, 255.0f, 255.0f, 0.0f);
var projectionMatrix = Matrix4.Perspective(FMath.Radians(45.0f),graphics.Screen.AspectRatio,1.0f,100000.0f);

var viewMatrix = Matrix4.LookAt(new Vector3(0.0f,1.0f,-3.0f),
new Vector3(0.0f,0.0f,0.0f),
Vector3.UnitY);
var vertexBuffer = MakeCube();
var texture = new Texture2D("/Application/crate.png",false);

var textureShader = new ShaderProgram("/Application/shaders/Texture.cgx");
textureShader.SetUniformBinding(0, "WorldViewProj");
textureShader.SetAttributeBinding(0, "a_Position");
textureShader.SetAttributeBinding(1, "a_TexCoord");

bool done = false;
while(!done) {
if((GamePad.GetData(0).Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
done = true;

graphics.Clear ();
var viewProjection = projectionMatrix * viewMatrix;
textureShader.SetUniformValue(0, ref viewProjection);

graphics.SetShaderProgram(textureShader);
graphics.SetVertexBuffer(0,vertexBuffer);
graphics.SetTexture(0,texture);

graphics.Enable(EnableMode.CullFace,true);
graphics.DrawArrays(DrawMode.Triangles,0,vertexBuffer.IndexCount);

graphics.SwapBuffers ();
}
textureShader.Dispose();
texture.Dispose();
graphics.Dispose();
}
}
}

2. Next we need to create a new shader in the shader folder.

3. Right-click on the shader folder in the Solution window and select Add | New File….

4. In the resulting dialog, on the left-hand side select PlayStation Mobile, then on the right-hand side select Empty Shader File. At the bottom in the Name field, call it Texture, then click on the New button.
This will create a pair of files, Texture.vcg and Texture.fcg.

5. Open Texture.vcg and edit it to match the following code:

void main(float4 in a_Position  : POSITION,
float2 in a_TexCoord  : TEXCOORD0,
float4 out v_Position : POSITION,
float2 out v_TexCoord : TEXCOORD0,
uniform float4x4 WorldViewProj
)
{
v_Position= mul( a_Position, WorldViewProj );
v_TexCoord  = a_TexCoord;
}

6. Then open Texture.fcg and edit it to match the following code snippet:

void main(
float2 in  v_TexCoord     : TEXCOORD0,
float4 out Color  : COLOR,
uniform sampler2D Texture0 : TEXUNIT0)
{
Color = tex2D(Texture0, v_TexCoord);
}

7. Now run the application and you should see the following output:

A fully textured 3D cube will appear centered on the screen. Press X or hit the S key to exit.

How it works...

We start off by defining a function named MakeCube(). We make it a function because we are going to be re-using this cube in future recipes. The first thing we do in the function is create a VertexBuffer. The first parameter for the VertexBuffer constructor is the number of vertices that will be in our buffer, and the second value is the number of indices. Next we pass in the format of each buffer we want to create; in our case we will be creating two. The first is of type VertexFormat.Float3 and holds vertex information. The second is of type VertexFormat.Float2 and holds 2D texture coordinates.

Now we populate the array of values that compose our cube. In our positions array, each value represents a coordinate composing our vertices. For example, the array starts with the values -0.5f, 0.5f, and -0.5f, which will result in the first vertex having an x value of -0.5f, a y value of 0.5f, and a z value of -0.5f. We then continue to define all of the other vertices composing our cube. The first 12 values comprise the 4 vertices that in turn make up the triangles forming the top of our cube. All of these coordinates are relative to the origin. We then repeat the process for the bottom, front, back, right, and left faces.

Next we define our texture coordinates or UV values. In this case, the buffer is a Vertex2 format, so the first value becomes (0,1), the second becomes (0,0), and so on. By setting the UV coordinates in order (clockwise or counterclockwise depending how the renderer is configured), we are telling OpenGL how to draw our texture on the face. By altering UV coordinates, you can rotate, skew, flip, and so on the texture on the face.

Finally we create our indices array. These values are offsets within the positions array and tell OpenGL how to draw our triangles. For example, the values (0,1,2) say that the triangle composing half of our top face is composed of the vertices at positions 0, 1, and 2 in the positions array. Therefore our first triangle is made up of the vertices (-0.5,0.5,-0.5),(-0.5,0.5,0.5), and (0.5,0.5,-0.5), while our second triangle is made using vertices 1,3, and 2, which are (-0.5,0.5,0.5), (0.5,0.5,0.5), and (0.5,0.5,-0.5). As you can see, these two triangles share a pair of vertices and together form the quad that make up the top of our cube.

When we created the VertexBuffer, in the constructor we told it to expect two arrays. Therefore our VertexBuffer is now expecting a pair of arrays, one that will be made of Vector3 objects and one that will be made of Vector2 objects. We pass these in using the method SetVertices() in the same order they were defined in the constructor. Finally, we set the indices array with a call to SetIndices() and return our newly created VertexBuffer.

In our Main function, we start off creating our GraphicsContext, and then set the clear color to solid white. We set up our projectionMatrix to use a 45 degree field of view and an aspect ratio matching our screen's, with a nearly infinite viewing frustum. Then we create our viewMatrix, which is our location and view direction within the 3D scene. We position our viewing angle slightly up (Y axis) and back (Z axis) so that we will see our cube at a slight angle (otherwise it would look remarkably like a rectangle!). Since we are drawing our cube about the origin, we set that location as our view target.

Next we actually make our VertexBuffer by calling MakeCube and loading the crate.png into a Texture2D object. Then we load or Texture.cgx shader and bind theWorldViewProj script value and the a_Position and a_TexCoord attributes. Don't worry if this process is a bit confusing for now; we cover it in more detail in an upcoming recipe.

Now we start our event loop, looping until the user hits the X button or S key. With each pass through the loop, we clear the screen then create our viewProjection matrix by multiplying the projection and view matrixes together. We then load our shader, buffer, and texture in to the graphics context with calls to SetShaderProgram, SetVertexBuffer, and SetTexture respectively. We then enable culling, so that polygons further back in the scene will not draw over closer polygons (comment out this line to see the effect in action). Then we render the whole thing by calling DrawArrays(). Finally we display all our hard work on screen with a call to SwapBuffers(). After the event loop we perform some cleanup before exiting.

There's more...

When texture mapping with PlayStation Mobile, to be compatible across devices, the following features are not available:

- Repeating non power of two textures

- Compressed textures

- Vertex textures

- Depth textures

- 3D textures

- Rendering to half float textures

- Rendering to luminance alpha textures

Graphics, textures, and shaders also have the following limits:

- MaxTextureSize 2048

- MaxCubeMapTextureSize 2048

- MaxRenderbufferSize 2048

- MaxVertexUniformVectors 128

- MaxFragmentUniformVectors 64

- MaxVertexAttribs 8

- MaxVaryingVectors 8

- MaxTextureImageUnits 8

- MaxAliasedLineWidth 8

- MaxAliasedPointSize 128

If these limitations seem confusing to you, do not worry, you generally will not run into most of them.

See also

- See the A fragment pixel shader in action and A vertex shader in action for more details on how shaders work and for more details on how a cgx file is generated

Implementing a simple camera system

In this recipe, we are going to create a simple camera that can be panned, rotated, and zomed in and out.

Getting ready

Load PlayStation Mobile Studio and create a new project. This recipe is going to build heavily on the code from the prior recipe, Creating a 3D scene. You may wish to duplicate the project; if you do not, be sure to copy AppMain.cs, crate.png, texture.vcg, and texture.fcg over to your new project. You can download the complete project as Ch7_Example3.

How to do it...

1. Add a new file, Camera.cs and enter the following code:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.Core.Graphics;

namespace Ch7_Example3
{
public class Camera
{
private Matrix4 _projection;
private Matrix4 _view;
private Matrix4 _world;
private float _FOV;
private float _aspectRatio;
private Vector3 _position;
private Vector3 _target;

public Camera (float fov, float aspectRatio, Vector3 position, Vector3 target)
{
_FOV = FMath.Radians(fov);
_aspectRatio = aspectRatio;
_position = position;
_target = target;
_world = Matrix4.Translation(new Vector3(0.0f,0.0f,0.0f));
}

public Matrix4 GetMatrix()
{
HandleInput();
_projection = Matrix4.Perspective(_FOV,_aspectRatio,1.0f, 10000.0f);
_view = Matrix4.LookAt(_position,_target,Vector3.UnitY);

return _projection * _view * _world;
}

public void SetTarget(Vector3 target)
{
_target = target;
}

public void SetPosition(Vector3 position)
{
_position = position;
}

private void HandleInput()
{
// Panning with dpad
if((GamePad.GetData(0).Buttons & GamePadButtons.Up) == GamePadButtons.Up)
_world = _world * Matrix4.Translation(new Vector3(0.0f,-0.1f,0.0f));
if((GamePad.GetData(0).Buttons & GamePadButtons.Down) == GamePadButtons.Down)
_world = _world * Matrix4.Translation(new Vector3(0.0f,0.1f,0.0f));
if((GamePad.GetData(0).Buttons & GamePadButtons.Left) == GamePadButtons.Left)
_world = _world * Matrix4.Translation(new Vector3(-0.1f,0.0f,0.0f));
if((GamePad.GetData(0).Buttons & GamePadButtons.Right) == GamePadButtons.Right)
_world = _world * Matrix4.Translation(new Vector3(0.1f,0.0f,0.0f));

// Zooming with shoulder buttons ( Q/E )
if((GamePad.GetData(0).Buttons & GamePadButtons.R) == GamePadButtons.R)
_world = _world * Matrix4.Translation(new Vector3(0.0f,0.0f,-0.1f));
if((GamePad.GetData(0).Buttons & GamePadButtons.L) == GamePadButtons.L)
_world = _world * Matrix4.Translation(new Vector3(0.0f,0.0f,0.1f));
_view = Matrix4.LookAt(_position,_target,Vector3.UnitY);

// Rotate left right using on screen touch.
var touch = Touch.GetData (0);
if(touch.Count > 0)
{
if(touch[0].X < -0.1f)
_world = _world * Matrix4.RotationY(FMath.Radians(1.0f));
if(touch[0].X > 0.1f)
_world = _world * Matrix4.RotationY(-FMath.Radians(1.0f));
}
}
}
}

2. Open AppMain.cs and edit the Main function to look similar to the following (changes highlighted):

public static void Main (string[] args){
var graphics = new GraphicsContext ();
graphics.SetClearColor (255.0f, 255.0f, 255.0f, 0.0f);

Camera camera = new Camera(45.0f,graphics.Screen.AspectRatio,new Vector3(0.0f,1.0f,-3.0f),new Vector3(0.0f,0.0f,0.0f));

var vertexBuffer = MakeCube();
var texture = new Texture2D("/Application/crate.png",false);
var textureShader = new ShaderProgram("/Application/shaders/Texture.cgx");
textureShader.SetUniformBinding(0, "WorldViewProj");
textureShader.SetAttributeBinding(0, "a_Position");
textureShader.SetAttributeBinding(1, "a_TexCoord");
var done = false;
while(!done) {
if((GamePad.GetData(0).Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
done = true;
graphics.Clear ();

var viewWorldProjection = camera.GetMatrix();
textureShader.SetUniformValue(0, ref viewWorldProjection);

graphics.SetShaderProgram(textureShader);
graphics.SetVertexBuffer(0,vertexBuffer);
graphics.SetTexture(0,texture);

graphics.Enable(EnableMode.CullFace,true);
graphics.DrawArrays(DrawMode.Triangles,0,vertexBuffer.IndexCount);

graphics.SwapBuffers ();
}
textureShader.Dispose();
vertexBuffer.Dispose();
graphics.Dispose();
}

3. Press F5 to run your application and you should see output similar to the following screenshot:

Once again, a cube will be drawn centered on the screen. Now, however, you have control over the camera. You can zoom the camera in and out using the shoulder buttons (or Q and E keys), pan the camera using the d-pad, and rotate it by touching the left-hand side or right-hand side of the screen. Press the X button or the S key to exit.

How it works...

The bulk of our new changes take place in the new Camera.cs class. The class itself is relatively simple; we are creating a wrapper around the construction of the WorldViewProjection matrix, which is a combination of world, view, and projection matrixes. As mentioned earlier, the View matrix is your eye's position and target within the 3D world. The Projection matrix is what translates the world from 3D to clip space, or in other words, what is going to be displayed on your screen. The World matrix represents movement within the world. When you translate or rotate your position in the 3D world, it is done with the World matrix.

Our Camera class constructor takes the field of view, aspect ratio, initial eye position, and target. We also set up the World matrix with a basically empty translation. GetMatrix() is the function that is called externally and is responsible for building each of the matrixes and combining them together. The actual logic used to construct the projection and view matrixes is exactly the same as prior recipes, just moved into an external class. Before building the resulting matrix, we call HandleInput() to see if the user has moved the camera.

HandleInput is fairly straightforward. If the user presses the d-pad, we move the camera in the corresponding direction. This is accomplished by multiplying the World matrix by a new Translation matrix in the appropriate direction along the X or Y axis. We then perform the same action if the user presses one of the shoulder buttons; this time instead we want to zoom the camera in and out. This is accomplished by creating a translation on the Z axis. Finally we check to see if the user tapped either the left-hand side or right-hand side of the screen, and if they have we rotate the screen accordingly. This is accomplished using RotateY, which creates a matrix that performs a rotation around the Y axis, and then multiply this matrix by our World matrix. The rotation is in radians, so we convert using the FMath.Radians()utility function. You may be wondering why I didn't make use of the analog sticks to control the camera. The simple answer is they aren't supported using the simulator so to make it easier to follow along for people that don't have a PS Vita device. I tended not to use them in the recipes.

Back in AppMain.cs, the only major changes is we no longer build each matrix by hand; instead we create and use the Camera object. Additionally, once each game loop, we get the updated matrix with a call to GetMatrix(), effectively updating the location in the world.

See also

- This recipe represents a relatively primitive camera class. www.OpenGL.org has some more detailed information on dealing with some of the more complex camera issues, such as framing a target. Although the examples are in C, the information translates almost perfectly. The link is http://bit.ly/U9EY0J.

A fragment (pixel) shader in action

In this recipe we create a simple fragment shader that will allow you to cycle the color on our textured cube.

Getting ready

Load PlayStation Mobile Studio and create a new project. Once again, this recipe's code will build off the code from the prior recipe, so simply copying that project is the easiest way to start. If you decide to create a new project, be sure to copy the crate.png texture over, as well as the code from AppMain.cs. The complete project is available as Ch7_Example4.

How to do it...

1. Add AppMain.cs and, assuming you copied the code from the prior recipe, change Main to match the following (changes are highlighted):

public static void Main (string[] args){
var graphics = new GraphicsContext ();
graphics.SetClearColor (0.0f, 0.0f, 0.0f, 0.0f);

Camera camera = new Camera(45.0f,graphics.Screen.AspectRatio,new Vector3(0.0f,1.0f,-3.0f),new Vector3(0.0f,0.0f,0.0f));

var vertexBuffer = MakeCube();
var texture = new Texture2D("/Application/crate.png",false);

var textureShader = new ShaderProgram("/Application/shaders/Texture.cgx");
textureShader.SetUniformBinding(0, "WorldViewProj");

textureShader.SetAttributeBinding(0, "a_Position");
textureShader.SetAttributeBinding(1, "a_TexCoord");

Vector4 colorMask = new Vector4(1,1,0,0);
float alpha = 1.0f;

bool done = false;
while(!done) {
graphics.Clear ();

var viewWorldProjection = camera.GetMatrix();
textureShader.SetUniformValue(0, ref viewWorldProjection);

if((GamePad.GetData(0).Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
done = true;

if((GamePad.GetData(0).Buttons & GamePadButtons.Triangle) == GamePadButtons.Triangle){
colorMask = new Vector4(0,1,1,0);
}
else if((GamePad.GetData(0).Buttons & GamePadButtons.Circle) == GamePadButtons.Circle){
colorMask = new Vector4(1,0,1,0);
}
else if((GamePad.GetData(0).Buttons & GamePadButtons.Square) == GamePadButtons.Square){
colorMask = new Vector4(1,1,0,0);
}
textureShader.SetUniformValue(textureShader.FindUniform("ColorMask"),ref colorMask);

if((GamePad.GetData(0).Buttons & GamePadButtons.Select) == GamePadButtons.Select){
if(alpha < 1.0f) alpha += 0.01f;
}
if((GamePad.GetData(0).Buttons & GamePadButtons.Start) == GamePadButtons.Start){
if(alpha > 0.0f) alpha -= 0.01f;
}
textureShader.SetUniformValue(textureShader.FindUniform("Alpha"),alpha);

graphics.Enable(EnableMode.Blend);
graphics.SetBlendFunc(new BlendFunc(BlendFuncMode.Add,BlendFuncFactor.SrcAlpha,BlendFuncFactor.OneMinusSrcAlpha));

graphics.SetShaderProgram(textureShader);
graphics.SetVertexBuffer(0,vertexBuffer);
graphics.SetTexture(0,texture);

graphics.Enable(EnableMode.CullFace,true);
graphics.DrawArrays(DrawMode.Triangles,0,vertexBuffer.IndexCount);

graphics.SwapBuffers ();
}
vertexBuffer.Dispose();
textureShader.Dispose();
graphics.Dispose();
}
Now open Texture.fcg and edit to match:
void main(
float2 in  v_TexCoord     : TEXCOORD0,
float4 out Color  : COLOR,
uniform sampler2D Texture0 : TEXUNIT0,
uniform float4 ColorMask,
uniform float Alpha)
{
float4 texelColor = tex2D(Texture0, v_TexCoord);
Color = texelColor - ColorMask;
Color.a = Alpha;
}

2. Now run the application and you will see the output similar to the following screenshot:

It is our trusty cube again, once again centered on the screen, although you can now move the camera around using the same controls as the prior recipe. Now if you press the Triangle, Circle, or Square buttons, the color of the texture will change between red, blue, and green. Additionally, Select and Start will increase and decrease the alpha value, causing the cube to become more or less transparent. Once again, the X button will exit the application.

How it works...

The code in AppMain.cs is virtually unchanged from the prior recipe. The majority of the changes revolve around two new variables, colorMask, which is a Vector4 representing the colors we don't want in our texture, and alpha, a float value representing the target alpha channel value of our texture. In our game loop, we update the colorMask and alpha values based on the user's actions. The following are the most important lines:

textureShader.SetUniformValue(textureShader.FindUniform("ColorMask"),ref colorMask);

and

textureShader.SetUniformValue(textureShader.FindUniform("Alpha"),alpha);

These two calls are what binds our C# based variables to a variable within the shader. The first call, for example, looks in the shader for a variable named ColorMask and sets its value to ColorMask.

If you look at Texture.fcg you will see in the main function declaration that we defined the parameters uniformfloat4 ColorMask and uniform float Alpha; these two variables get populated by these SetUniformValue calls.

The shader itself is really simple. tex2D is a Cg function that performs a texture lookup at a given position. Essentially it gives us the pixel in exture0 at the v_TexCoord location, which is the UV coordinate of the fragment currently being processed. In simpler English, tex2D returns the color of the pixel of this particular fragment within the texture map. We then take that color and subtract our ColorMask from it, so for example if our ColorMask is (0,1,1,0), we will remove all the green and blue from the resulting color and set that as our out Color. We also set the colors alpha channel based on the Alpha value we bound earlier.

There's more...

A top-level view of how rendering occurs might help you understand the shader process. It all starts with the shader program, vertex buffers, texture coordinates, and so on being passed in to the graphics device. Then this information is sent off to a vertex shader, which can then transform that vertex, do lighting calculations and more (we will see this process shortly). The vertex shader is executed once for every vertex and a number of different values can be output from this process (these are the out attributes we saw in the shader earlier). Next the results are transformed, culled, and clipped to the screen, discarding anything that is not visible, then rasterized, which is the process of converting from vector graphics to pixel graphics, something that can be drawn to the screen.

The results of this process are fragments, which you can think of as "prospective pixels," and the fragment are passed in to the fragment shader. This is why they are called fragment shaders instead of pixel shaders, although people commonly refer to them using either expression. Once again, the fragment shader is executed once for each fragment. A fragment shader, unlike a vertex shader, can only return a single attribute, which is the RGBA color of the individual pixel. In the end, this is the value that will be displayed on the screen. It sounds like a horribly complex process, but the GPUs have dedicated hardware for performing exactly such operations, millions upon millions of times per second. That description also glossed over about a million tiny details, but that is the gist of how the process occurs.

So if you think back to Texture.fcg, think of it as a miniature program that gets run for each potential pixel to be displayed on your screen. Each fragment (pixel to be) can be passed a great deal of information in the form of uniform values and attributes, but at the end of the day can only make one decision: What color is this pixel going to be?

Note

The PlayStation Mobile SDK makes use of a technology called Cg, which is a specialized programming language created by NVIDIA in collaboration with Microsoft. It has a C like syntax, and applications are run through the Cg compiler, creating a native DirectX or OpenGL shader as a result. In PlayStation Mobile Studio, the compilation process is handled for you during the build process if you set an asset's build action to shader program. This configuration is done automatically when you create a new shader. This process takes fragment shader (.fcg) and vertex shader (.vcg) files and creates the .cgx file you use when creating a ShaderProgram.

See also

- This chapter only covers the very basic details of the Cg programming language. More information and additional tools can be found on nVidia's developer site located at http://bit.ly/U9XwxX. Also see the next recipe, A vertex shader in action, for more information on shders in PlayStation Mobile.

A vertex shader in action

In this recipe, we create a simple vertex shader that will allow us to move each individual vertex in the cube along its normal.

Getting ready

Load PlayStation Mobile Studio and create a new project. This example again builds heavily on the code from the previous tutorials, so the easiest thing would be to just duplicate or edit the prior recipe's project. The complete project is available as Ch7_Example5.

How to do it...

1. Edit AppMain.cs; I will assume that you are working from the prior recipes source code. For this recipe we are going to also require normal information for our textured cube, so we have to make a small alteration to MakeCube(). When we construct our VertexBuffer, we need to inform it of the additional normal array; this is done by adding an additional type to the constructor as follows:

VertexBuffer vertexBuffer = new VertexBuffer(24, 36, VertexFormat.Float3, VertexFormat.Float2,VertexFormat.Float3);

2. Now we create the new array of Float3 values. The positions array create the following new array:

float[] normals = {
0.0f,  1.0f, 0.0f, 0.0f,  1.0f,  0.0f, 0.0f,  1.0f, 0.0f, 0.0f,  1.0f,  0.0f, //top
0.0f,  -1.0f, 0.0f, 0.0f,  -1.0f,  0.0f, 0.0f,  -1.0f, 0.0f, 0.0f,  -1.0f,  0.0f, //top
0.0f,  0.0f, 1.0f, 0.0f,  0.0f,  1.0f, 0.0f,  0.0f, 1.0f, 0.0f,  0.0f,  1.0f, //front
0.0f,  0.0f, -1.0f, 0.0f,  0.0f,  -1.0f, 0.0f,  0.0f, -1.0f, 0.0f,  0.0f,  -1.0f, //back
1.0f,  0.0f, 0.0f, 1.0f,  0.0f,  0.0f, 1.0f,  0.0f, 0.0f, 1.0f,  0.0f,  0.0f, //right
-1.0f,  0.0f, 0.0f, -1.0f,  0.0f,  0.0f, -1.0f,  0.0f, 0.0f, -1.0f,  0.0f,  0.0f //left
};

3. We now want to make sure our normals are added to the VertexBuffer with the following code:

vertexBuffer.SetVertices(0, positions);
vertexBuffer.SetVertices(1, texcoords);
vertexBuffer.SetVertices(2,normals);
vertexBuffer.SetIndices(indices);

4. In our Main, we now need to bind our additional normal attribute, which is accomplished by doing the following:

textureShader.SetAttributeBinding(0, "a_Position");
textureShader.SetAttributeBinding(1, "a_TexCoord");
textureShader.SetAttributeBinding(2, "a_Normal");
float magnitude = 0.0f;

5. We also declared the magnitude float value, which is going to control how far along its normal a vertex can be moved. Finally, in our event loop, after we get the camera matrix, we add the following code:

if((GamePad.GetData(0).Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
quit = true;

if((GamePad.GetData(0).Buttons & GamePadButtons.Square) == GamePadButtons.Square){
if(magnitude < 0.5f) magnitude += 0.01f;
}
if((GamePad.GetData(0).Buttons & GamePadButtons.Circle) == GamePadButtons.Circle){
if(magnitude > 0f) magnitude -= 0.01f;
}
textureShader.SetUniformValue(textureShader.FindUniform("Magnitude"),magnitude);

6. Last, we enter the following code for our vertex shader Texture.vcg:

void main(float4 in a_Position  : POSITION,
float2 in a_TexCoord  : TEXCOORD0,
float3 in a_Normal : NORMAL,
float4 out v_Position : POSITION,
float2 out v_TexCoord : TEXCOORD0,
uniform float4x4 WorldViewProj,
uniform float Magnitude
)
{
v_Position= mul( a_Position, WorldViewProj );
v_TexCoord  = a_TexCoord;
v_Position += mul(float4(a_Normal,1),WorldViewProj) * Magnitude;
}

7. Run the application and you should see output similar to the following screenshot:

Each time you press the Square button (A key), the faces of the mesh will explode outward along the faces' normal until they hit the maximum magnitude. The Circle Button (D key) will move the faces in the opposite direction.

You may notice that the initial box appears odd. To make backfaces (the generally not visible part of a polygon) visible, we turned face culling off. This odd rendering is the direct result.

How it works...

Our changes start off with the addition of normal information to our vertex buffer. This starts by telling the VertexBuffer constructor to expect another array, this one composed of Vector3 objects. We then create our normals array by hand. Think of a normal as the direction each vertex is facing. For example, the four vertices that compose the top face of our crate all should face up, which using our coordinate system is positive Y. If you look at the first four sets of the three floats in our normals array, they are all being assigned the value of (0,1,0). This process is then repeated for every other vertex in the buffer. Given that our box is aligned around the origin, the math itself is pretty straightforward; if the cube wasn't aligned so nicely, the vertices composing our faces certainly wouldn't be so consistent! Now that our vertexBuffer knows to expect an additional array, and we've constructed our array, we simply assign it using the SetVertices() method, this time passing in the index value of 2.

Our main is almost identical to the previous recipe, although this time we are binding the variable magnitude to the uniform shader value Magnitude. We also needed to set an attribute binding, which we perform with the call SetAttributeBinding(2, "a_Normal"), which is simply saying set the attribute a_Normal to the buffer at index position 2. The remaining changes are just some input code, so if the user hits the Square button we increment the magnitude by 0.01f, while if the user hits the Circle button, we decrement it by 0.01f. All the remaining logic is performed in the vertex shader.

Looking at our Texture.vcg vertex shader, you will notice that there is one in attribute for each of the arrays we bound with SetAttributeBinding() calls, a_Position, a_TexCoord, and a_Normal. We also have a pair of out values, v_Position and v_TexCoord, which are the ultimate results of running this vertex shader. v_Position holds the transformed position of this particular vertex, keeping in mind that this shader is run once for each vertex. v_TexCoord holds the 2D texture coordinate that we passed in; we simply pass this value through. We also have a pair of uniform variables, one for the WorldViewProjection matrix and the other for the magnitude to move by. In pretty much every vertex shader you will want to apply the WorldViewProjection matrix against each vertex, causing each one to be properly transformed. The name uniform might seem a bit scary, but it really just means that it is a constant, in that its value will stay uniform.

Additionally, in this particular shader, we want to translate each vertex along its normal by the Magnitude amount. This is handled by transforming the vertex's normal by the WorldViewProj matrix and multiplying the result by the magnitude. We then add this calculated value to the v_Position float4, which moves the vertex in its normal direction by the amount specified by magnitude. Like tex2D, mul is a function built in to the Cg programming language.

There's more...

Unlike a fragment shader, which can only output a single value, COLOR, you can output multiple values from a vertex shader. You may have noticed that in both vertex and pixel shaders each parameter ended with a value such as POSITION or TEXCOORD0. These are called semantics and I will let NVIDIA explain them:

Semantics are, in a sense, the glue that binds a Cg program to the rest of the graphics pipelie. The semantics POSITION and COLOR indicate the hardware resource that the respective member feeds when the Cg program returns its output structure.

Essentially, it is through semantics that we tie a Cg script value back to the actual graphics hardware. There are a number of restrictions on what semantics can be used with each part of the process in PlayStation Mobile. These limits are as follows:

- Semantics that can be used as input for vertex shaders:

- POSITION

- NORMAL

- TEXCOORD0-7

- COLOR0-1

- DIFFUSE

- SPECULAR

- TANGENT

- BINORMAL

- BLENDWEIGHT

- BLENDINDICES

- FOGCOORD

- POINTSIZE

- Semantics that can be used as output for vertex shaders:

- POSITION (HPOS)

- TEXCOORD0-7 (TEX0-7)

- COLOR0-1 (COL0-1)

- FOGC (FOG)

- PSIZE (PSIZ)

- Semantics that can be used as input for fragment shaders:

- TEXCOORD0-7 (TEX0-7)

- COLOR0-1 (COL0-1)

- FOGC (FOG)

- POINTCOORD

- WPOS (There is currently a bug with WPOS that causes it to render upside down on the PS Vita.)

- FACE

- Semantics that can be usd as output for fragment shaders:

- COLOR

Note

Up until this point, we have combined all of our shaders into a single .cgx file by giving them the extensions .fcg and .vcg. If for some reason, you want your fragment and vertex shaders to be compiled into separate .cgx files, instead give them.fp.cg and .vp.cg extension, respectively.

The Cg programming language and DirectX's HLSL share a common root, so many HLSL shaders and tools will work with Cg, with a small bit of effort.

See also

- In addition to programming Cg shaders by hand, there is an editor available called FxComposer. It is a bit old now, but should still work; just be aware that PlayStation Mobile only supports a subset of Cg, so it isn't guaranteed your shader will work unchanged. You can download FxComposer at http://bit.ly/TgWwbw.

Adding lighting to your scene

If you take a look through the PlayStation Mobile documentation, you may notice there is no functionality in the SDK for lighting. How then do you add lights to your scene? Well, shaders of course! In this recipe we are going to do exactly that.

Getting ready

Load PlayStation Mobile Studio and create a new project. Once again, we will use the prior recipe as a base for this recipe. The complete project is available as Ch7_Example6.

How to do it...

1. Using AppMain.cs from Example5, edit Main to match the following (the new code is highlighted):

Vector3 lightPosition = new Vector3(0.0f,10.0f,-3.0f);
textureShader.SetUniformValue(textureShader.FindUniform("vecLightPos"),ref lightPosition);
Vector4 ambientLightColor = new Vector4(0.05f,0.05f,0.05f,1.0f);

bool done = false;
while(!done) {

2. Then further down, edit the event loop to match the following code snippet:

while(!done) {
graphics.Clear ();

var viewWorldProjection = camera.GetMatrix();
textureShader.SetUniformValue(0, ref viewWorldProjection);

if((GamePad.GetData(0).Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
done = true;

if((GamePad.GetData(0).Buttons & GamePadButtons.Square) == GamePadButtons.Square)
ambientLightColor = new Vector4(ambientLightColor.R+0.05f,ambientLightColor.G,ambientLightColor.B,ambientLightColor.A);
else if((GamePad.GetData(0).Buttons & GamePadButtons.Circle) == GamePadButtons.Circle)
ambientLightColor = new Vector4(ambientLightColor.R-0.05f,ambientLightColor.G,ambientLightColor.B,ambientLightColor.A);
textureShader.SetUniformValue(textureShader.FindUniform("ambLightColor"),ref ambientLightColor);

graphics.Enable(EnableMode.Blend);
graphics.SetBlendFunc(new BlendFunc(BlendFuncMode.Add,BlendFuncFactor.SrcAlpha,BlendFuncFactor.OneMinusSrcAlpha));

graphics.SetShaderProgram(textureShader);
graphics.SetVertexBuffer(0,vertexBuffer);
graphics.SetTexture(0,texture);

graphics.Enable(EnableMode.CullFace,true);
graphics.DrawArrays(DrawMode.Triangles,0,vertexBuffer.IndexCount);

graphics.SwapBuffers ();
}

3. Next, edit Texture.fcg to match the following code snippet:

void main(
float2 in  v_TexCoord     : TEXCOORD0,
float3 in v_Light  : TEXCOORD1,
float3 in v_Normal  : TEXCOORD2,
float4 out Color  : COLOR,
uniform sampler2D Texture0 : TEXUNIT0,
uniform float4 ambLightColor
)
{
float4 diffuse = tex2D ( Texture0, v_TexCoord );
Color = ambLightColor + diffuse * saturate(dot(v_Light, v_Normal));
}

And Texture.vcg as follows:

void main(float4 in a_Position  : POSITION,
float2 in a_TexCoord  : TEXCOORD0,
float3 in a_Normal  : NORMAL,
float4 out v_Position : POSITION,
float2 out v_TexCoord : TEXCOORD0,
float3 out v_Light : TEXCOORD1,
float3 out v_Normal : TEXCOORD2,

uniformfloat3 vecLightPos,
uniform float4x4 WorldViewProj
)
{
v_Position= mul( a_Position, WorldViewProj );
v_TexCoord  = a_TexCoord;
v_Light = normalize(vecLightPos);
v_Normal = a_Normal;
}

4. Now, if you run your application you will see output similar to the following screenshot:

It's our trusty textured crate, this time softly lit by a light source above it. Pressing the Square button (the A key) will add some ambient red lighting, while pressing Circle (the D key) will reduce it. Once again the X button (the S Key) will exit.

How it works...

The code within AppMain.cs should all be remarkably familiar by now. This time we are setting a Vector4 color value as a uniform binding that will control the level of ambient light, and starting off with a neutral grey color. We also create and bind a Vector3 value to hold our light's position in the world. In our event loop, we check for the appropriate button presses and increase or decrease the red component of the light accordingly. The majority of the work is done in the shaders in this recipe.

First in the vertex shader, we transform the vertex and pass through the texture coordinates as normal. This time we are also passing through the normal information. Finally, we are passing out our light direction in the v_Light value.

In our fragment shader we get the starting texel color using the Tex2D function and store it as diffuse. We then calculate our final pixel color by adding the diffuse value to the ambient light value and multiplying that value by the saturated value of the dot product of the light vector and the vertex's normal. Saturate is another built-in Cg function and it sounds much more complex than it really is. Saturate simply makes sure the result is a value between 0 and 1.

There's more...

This example only touches on the basics of the lighting effects that you can create with Cg shaders. Surfaces can be given properties, such as reflectivity; additional light sources can be added, and so on. Check the link in the See Also section for some more examples of what you can accomplish creating your lighting using shaders.

See also

The mathematics behind various lighting models is far beyond the scope of this book. There is a very good article on Gamasutra, Implementing Lighting Models with HLSL, which can be re-implemented fairly easily in Cg. This article is available at http://bit.ly/XvdeT5.

Using an offscreen frame buffer to take a screenshot

PlayStation Mobile has the ability to render to a user defined offscreen frame buffer. This can be useful for a number of reasons: rendering to a texture, doing post processing before displaying, or, as we will see in this recipe, taking a screenshot.

Getting ready

Load PlayStation Mobile Studio and create a new project. This time we are going to be reusing the code we created way back at the start of the chapter during Creating a Simple 3D scene. The complete project is available as Ch7_Example7.

How to do it...

1. Using AppMain.cs from the earlier recipe, add the following code to the main loop:

if((GamePad.GetData(0).Buttons & GamePadButtons.Start) == GamePadButtons.Start){
var frameBuffer = new FrameBuffer();
var screenshotTexture = new Texture2D(
graphics.Screen.Width,
graphics.Screen.Height,
false,
PixelFormat.Rgba,
PixelBufferOption.Renderable);
frameBuffer.SetColorTarget(screenshotTexture,0);
frameBuffer.SetDepthTarget(null);
graphics.SetFrameBuffer(frameBuffer);

var viewProjection = projectionMatrix * viewMatrix;
shaderProgram.SetUniformValue(0, ref viewProjection);

graphics.SetShaderProgram(shaderProgram);
graphics.SetVertexBuffer(0,vertexBuffer);
graphics.DrawArrays(DrawMode.TriangleStrip,0,3);
graphics.SwapBuffers();

var bytes = new byte[graphics.Screen.Width * graphics.Screen.Height * 4];
graphics.ReadPixels(bytes,PixelFormat.Rgba,0,0,graphics.Screen.Width,graphics.Screen.Height);

var image = new Image(ImageMode.Rgba,new ImageSize(graphics.Screen.Width,graphics.Screen.Height),bytes);
image.Export("ScreenShots","demo.jpg");
image.Dispose();

frameBuffer.Dispose();
screenshotTexture.Dispose();
graphics.SetFrameBuffer(null);
}
else {
var viewProjection = projectionMatrix * viewMatrix;
shaderProgram.SetUniformValue(0, ref viewProjection);
graphics.SetShaderProgram(shaderProgram);
graphics.SetVertexBuffer(0,vertexBuffer);
graphics.DrawArrays(DrawMode.TriangleStrip,0,3);

graphics.SwapBuffers ();
}

2. Running your application, you will see the output similar to the following screenshot:

It's the red triangle again! This time though, if you press the Start button, a screenshot is taken and added to your gallery.

How it works...

In our game loop, we check to see if the user has pressed the Start button. If he or she has not, we render as normal in a rather crude else block. If Start has been pressed, we create a new FrameBuffer. Next we create a Texture2D with the same dimensions as the screen. The key thing to notice is the last parameter, PixelBufferOption.Renderable, which allows this texture to be written to.

We then set this newly created texture as the rendering target with a call to SetColorTarget(). We won't be using a depth target, so we set it to null with a call to SetDepthTarget. Next we set our newly created FrameBuffer as the active frame buffer by calling graphics.SetFrameBuffer(). From this point on, all graphics routines will draw to our offscreen buffer instead of the back buffer for display on screen.

The next few lines of code are exactly the same, setting up the view matrix, setting our shader, and buffer, and rendering the vertexBuffer. After we call SwapBuffers, our FrameBuffer should now contain a capture of the screen. Then it's time to save it as an image.

First we create a byte array large enough to hold the screen, which is 4 bytes per pixel, multiplied by the width and height. We then read the pixels in to our buffer using graphics.ReadPixels. We then create an image of the same dimensions and color depth from this byte buffer. Now that our image is created, we export it, then dispose of it. The FrameBuffer class is also an IDisposable class, so it needs to be disposed of as well. Finally we set the frame buffer to null in a call to SetFrameBuffer(); this sets rendering back to normal.

There's more...

This recipe was mostly for fun and demonstration purposes. The Vita and most Android devices already have built-in screen capture abilities. To take a screenshot using your PlayStation Vita, simply hold the PS button and the Start button at the same time. Additionally the ReadPixels method used in the example is a very expensive operation and should be avoided if possible.

See Also

- See the Manipulating an image dynamically recipe in Chapter 1, Getting Started, for more information on working with the Image class

Chapter 8. Working with the Model Library

In this chapter we will cover:

- Importing a 3D model for use in PlayStation Mobile

- Loading and displaying a 3D model

- Using BasicProgram to perform texture and shader effects

- Controlling lighting using BasicProgram

- Animating a model

- Handling multiple animations

- Using bones to add a sword to our animated model

Introduction

In the previous chapter we covered working in 3D using PlayStation Mobile. However, we only made use of the simplest primitives, a triangle and a simple textured cube. In a real game you are going to want to make use of more complex shapes, animated and textured models exported from a 3D graphical application such as 3D Studio Max, Maya, or Blender. Fortunately, PlayStation Mobile provides tools for importing such models, as well as a library for loading and displaying them, Sce.PlayStation.HighLevel.Model. In addition to handling 3D models, it also provides classes to simplify the use of textures, lights, and shaders.

Importing a 3D model for use in PlayStation Mobile

In this recipe we explore the process of importing a 3D model to the PlayStation Mobile format using the ModelConverter application.

Getting ready

In your favorite 3D modeling application, export your model in one of the formats that PlayStation Mobile supports. Make sure the textures are in the same location and are compatible with the Texture2D supported types. If you have no prior modeling, I have made available a simple textured cube .Blend file exported to .x format that you can use. It is available as Ch8_Example1.

How to do it...

To import a 3D model for use in PlayStation Mobile perform the following step:

1. Open Windows Explorer and navigate to the location where ModelConverter.exe is located. If you choose the default install and are running a 64-bit copy of Windows, the program will be located at C:\Program Files (x86)\SCE\PSM\tools\ModelConverter.

2. Open another Explorer window and navigate to where your 3D model is saved.

3. Now drag the model files you want to convert and drop them on ModelConverter.exe. Hold the Control key down if you want to specify any command line arguments (see the following screenshot). You can drag and convert multiple files at once. If you held down the Control key, you will see something like the following screenshot (otherwise you will see nothing):

4. Your file should now be converted, and there will be a new file of the same name with the .mdx extension in the same folder.

5. You can now test how your model will look in PlayStation Mobile by using the utility ModelViewer.exe. It is located in the same folder as ModelConverter.exe; simply drag the newly generated .mdx file and drop it on the ModelViewer icon and you should see the following screenshot:

You can rotate the scene using the arrow keys and zoom the camera in and out using the Z and X keys.

Note that the ModelViewer application requires that the DirectX9 redistributable be installed on your computer.

How it works...

For performance reasons, PlayStation Mobile Studio converts files into its own native format, .mdx. Additionally, for debugging reasons you can also export to an ASCII (text) encoded format, .mds. To encode a file as text, hold the Control key when dropping the file on ModelConverter.exe and when prompted for more options? enter -S, as shown in the following screenshot:

Of course, if you prefer, ModelConverter can be used completely from the command line. Using ModelConverter from the command line will display additional information about the model conversion process. It supports the following parameters:

- -o <filename>: specify output filename

- -s <scale>: Scale geometry size

- -t <scale>: Scale animation speed

- -S: Output in text format

- -N: Do not optimize

- -models: Merge models into one file

- -motions: Merge motions into one file

There's more...

ModelConverter supports the following file formats:

- FBX

- XSI

- COLLADA

- X

- MDX/MDS

If you want to support the XSI format, you need to install Autodesk Crosswalk 2013, available at http://autode.sk/UepCmI.

Note

Model conversion from almost any 3D application is a finicky process. One tip when exporting your model is to immediately re-import it in to your 3D application to see if any problems were introduced. Some formats certainly work better than others; for example, with Blender, I find that the archaic .x format actually produces the best results, but it also is the most restricted. The COLLADA support, however, is awful, although the Blender community is actively working to improve it.

There are a number of different applications you can use to create content and export in the preceding formats. Autodesk has a series of products including 3D Studio Max, Maya, and Softimage, each of which has a several thousand dollar price tag. There are also free options such as Blender or the Wings3D modeler. You can see a fairly comprehensive list of 3D applications at http://bit.ly/SsMD90.

See also

- See API Overview | HighLevel.Model Overview in the PlayStation Mobile documentation for more details on using ModelConverter as well as limitations of each supported file format

Loading and displaying a 3D model

This recipe demonstrates adding a 3D model to your project as well as the code required to load and display it on screen.

Getting ready

If you haven't already, load PlayStation Mobile Studio and create a new project. This example and many that follow are going to make use of a fully textured and animated model that is shipped with the PlayStation Mobile SDK, walker.mdx. This is because a great deal of small issues can be introduced when exporting a model from various 3D programs, so it is best to start with a model we know. If you choose the default install, the model file will be available at C:\Users\Public\Documents\PSM\sample\Model\BasicModelSample\walker.mdx.

Add the model file to your project, and then be sure to set its Build Action to Content. You also need to add a reference to the library, Sce.PlayStation.HighLevel.Model. The code for this example is available as Ch8_Example2.

How to do it...

Open AppMain.cs and enter the following code:

using System;
using System.Collections.Generic;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.Model;

namespace Ch8_Example2
{
public class AppMain {
public static void Main (string[] args) {
var graphics = new GraphicsContext ();
graphics.SetClearColor (255.0f, 255.0f, 255.0f, 0.0f);

var model = new BasicModel("/Application/walker.mdx",0);

Matrix4 view = Matrix4.LookAt( new Vector3(0.0f,0.0f,25.0f),
new Vector3(0.0f,0.0f,0.0f),
Vector3.UnitY);
Matrix4 proj = Matrix4.Perspective(FMath.Radians(45),graphics.Screen.AspectRatio,1,10000f);
Matrix4 world = Matrix4.Translation(-model.BoundingSphere.Xyz);

model.SetWorldMatrix(ref world);
Vector3 ambient = new Vector3(1.0f,1.0f,1.0f);
BasicParameters parameters = new BasicParameters();

parameters.SetProjectionMatrix(ref proj);
parameters.SetViewMatrix(ref view);
parameters.SetLightAmbient(ref ambient);

var program = new BasicProgram(parameters);

bool done = false;
while(!done) {
graphics.Clear ();
var gamepad = GamePad.GetData(0);
if((gamepad.Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
done = true;
if((gamepad.Buttons & GamePaadButtons.Left) == GamePadButtons.Left)
world *= Matrix4.RotationY(FMath.Radians(1));
if((gamepad.Buttons & GamePadButtons.Right) == GamePadButtons.Right)
world *= Matrix4.RotationY(-FMath.Radians(1));

model.SetWorldMatrix(ref world);

graphics.Enable( EnableMode.CullFace ) ;
graphics.SetCullFace( CullFaceMode.Back, CullFaceDirection.Ccw ) ;
graphics.Enable( EnableMode.DepthTest ) ;
graphics.SetDepthFunc( DepthFuncMode.LEqual, true ) ;

model.Update();
model.Draw(graphics,program);
graphics.SwapBuffers ();
}
model.Dispose();
program.Dispose();
graphics.Dispose();
}
}
}

Press F5 to run your application and you should see the following screenshot:

The model, a man in mid-step, should be drawn on the center of the screen. You can use left and right on the d-pad or the arrow keys to rotate the camera. Press the X button (or the S key) to exit.

How it works...

The first thing we do is create the required GraphicsContext and set the clear color to white. We then load our model file, which is a BasicModel. We simply pass the filename in to the constructor. The second parameter represents the index of the model within the .mdx file, in case there are multiple models in a single .mdx file. Next we set up the view, projection, and world matrices, all of which were described in the previous chapter. We will load the model at the origin and position our camera away 25 units along the z axis. The only change in the process of creating the matrices compared to prior recipes is the following line of code:

Matrix4 world = Matrix4.Translation(-model.BoundingSphere.Xyz);

This is because our model is positioned about the origin, in that its feet are located at (0,0,0), meaning we will only see half of the model on screen. Therefore we translate our world matrix by the model's BoundingSphere, causing it to be centered on the screen. The bounding sphere is the smallest sphere that can contain the entire contents of the model. In addition to using it to determine the model's dimensions, the bounding sphere is also used to perform collision detection.

Next we set the model's location in the 3D world with a call to SetWorldMatrix. Then we create a light, a BasicParameters object, configure its view and projection matrices, and pass in our ambient light. Finally, we create a new BasicProgram using our newly created BasicParamters object. We will cover this process in more detail in the next chapter.

Now we start our game loop. First we clear the back buffer, and then poll the state of the gamepad. We toggle our done flag if the user presses the X button, and rotate the world matrix left or right 1 degree each time the d-pad is pressed in either direction. We then update the model's world matrix, in case we rotated the view.

Next we enable culling by calling Enable( EnableMode.CullFace ). In the call to SetCullFace(), we specify that we want backfaces culled, and that polygons are drawn counterclockwise, which the graphics context uses to determine which direction a polygon is facing. Backface culling basically just removes all polygons that aren't facing the camera, speeding up the rendering process. Next we enable depth testing, again using the Enable function. Depth testing will remove all polygons not within the viewing frustum, which we set when we created the projection matrix. In this simple example, it doesn't have any real effect on performance, but in a larger scene it certainly will!

Next we call the model's Update() method. Update() simply applies the model's world matrix to all child bones. It is very important that you call Update() for each frame if your model contains any bones, or it will be drawn mangled and not animate properly. Now we tell our model to call Draw(), passing in GraphicsContext and BasicProgram to use them during the rendering process. Like Update(), Draw() needs to be called once per frame or your model will not be rendered. Finally we present the back buffer to the screen, making our frame visible with a call to SwapBuffers().

After our loop, we clean up our IDisposable items. It is important to note that BasicModel needs to be disposed off, or it will leak resources.

There's more...

Just like all of the other high-level namespace libraries, the full source code of the Model library is available. If you choose the default install, the source code should be located at C:\Program Files (x86)\SCE\PSM\source\Model or C:\Program Files \SCE\PSM\source\Model if you have a 32-bit version of Windows. If you need to debug into the Model source code, you can include this project in your solution instead of adding the library as a reference.

Note

Bones?

Bones are a fundamental part of 3D animation. An animated model is generally composed of a mesh (the polygon data) and a series of bones that manipulate the mesh. For example, a leg mesh might contain three bones, one for the upper leg, one for below the knee, and one for the foot. If you rotate the foot bone, it will then rotate all of the vertices in the mesh that are assigned to that bone, therefore rotating the foot. When you call Update() on BasicModel, it updates the position of every bone it contains in world space. The coordinates of each bone are relative to the model itself. It is through movement of these bones that animation can occur.

See also

- Refer to the Creating a simple 3D scene recipe in Chapter 7, Into the Third Dimension, for more details on working in 3D

Using BasicProgram to perform texture and shader effects

In Chapter 7, Into the Third Dimension, we applied a number of visual effects on a cube using vertex and fragment shaders. The Model library provides the BasicProgram class to simplify this process. In this example, we are going to load a 3D crate model and show how to alter its transparency, change its color, and even swap textures completely using BasicProgram.

Getting ready

Load PlayStation Mobile Studio, create a new project, and add a reference to Sce.PlayStation.HighLevel.Model. Instead of building the cube from scratch like we did in Chapter 7, Into the Third Dimension, we are going to load it as a model. You can either create your own textured box, or download a working example from http://bit.ly/PtMj9w. The ZIP includes a .mdx file of a textured cube, as well as a second texture for the cube. Download and extract the archive, and add box.mdx and crateNeon.png to your project, setting Build Action to Content for both of them. You can get the files and complete source code as Ch8_Example3.

How to do it...

Open AppMain.cs and replace Main with the following function:

public static void Main (string[] args) {
var graphics = new GraphicsContext ();
graphics.SetClearColor (255.0f, 255.0f, 255.0f, 0.0f);

var model = new BasicModel("/Application/box.mdx",0);

Matrix4 view = Matrix4.LookAt( new Vector3(0.0f,0.0f,25.0f),
new Vector3(0.0f,0.0f,0.0f),
Vector3.UnitY);
Matrix4 proj = Matrix4.Perspective(FMath.Radians(45),graphics.Screen.AspectRatio,1,10000f);
Matrix4 world = Matrix4.Translation(-model.BoundingSphere.Xyz) * Matrix4.Scale (3f,3f,3f);

model.SetWorldMatrix(ref world);

Vector3 ambient = new Vector3(1.0f,1.0f,1.0f);
BasicParameters parameters = new BasicParameters();

parameters.SetProjectionMatrix(ref proj);
parameters.SetViewMatrix(ref view);
parameters.SetLightAmbient(ref ambient);

var program = new BasicProgram(parameters);

BasicTexture texture1 = model.Textures[0];
BasicTexture texture2 = new BasicTexture();
texture2.FileName = "/Application/crateNeon.png";
texture2.Texture = new Texture2D("/Application/crateNeon.png",false);

bool done = false;
float opacity = 1f;
Vector3 ambientColor = new Vector3(1,1,1);

while(!done) {
graphics.Clear ();
var gamepad = GamePad.GetData(0);
if((gamepad.Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
done = true;
if((gamepad.Buttons & GamePadButtons.Left) == GamePadButtons.Left)
world *= Matrix4.RotationY(FMath.Radians(1));
if((gamepad.Buttons & GamePadButtons.Right) == GamePadButtons.Right)
world *= Matrix4.RotationY(-FMath.Radians(1));

if((gamepad.ButtonsUp & GamePadButtons.Circle) == GamePadButtons.Circle) {
if(model.Textures[0].FileName == "/Application/crateNeon.png")
model.Textures[0] = texture1;
else
model.Textures[0] = texture2;
}
if((gamepad.Buttons & GamePadButtons.Up) == GamePadButtons.Up) {
if(opacity < 1f) opacity+= 0.01f;
}
if((gamepad.Buttons & GamePadButtons.Down) == GamePadButtons.Down) {
if(opacity > 0f) opacity-= 0.01f;
}
if((gamepad.ButtonsUp & GamePadButtons.Triangle) == GamePadButtons.Triangle) {
Random rand = new Random();

ambientColor = new Vector3(rand.Next(0,255)/255f,rand.Next(0,255)/255f,rand.Next(0,255)/255f);
}
model.SetWorldMatrix(ref world);
model.Materials[0].Ambient = ambientColor;
model.Materials[0].Opacity = opacity;

graphics.Enable(EnableMode.Blend);
graphics.SetBlendFunc(BlendFuncMode.Add, BlendFuncFactor.SrcAlpha, BlendFuncFactor.OneMinusSrcAlpha);
graphics.Enable(EnableMode.CullFace);
graphics.SetCullFace(CullFaceMode.Back, CullFaceDirection.Ccw);
graphics.Enable(EnableMode.DepthTest);
graphics.SetDepthFunc(DepthFuncMode.LEqual, true);

model.Update();
model.Draw(graphics,program);

graphics.SwapBuffers ();
}
model.Dispose();
program.Dispose();
graphics.Dispose();
}

Hit F5 to run the application and you will see the following screenshot:

A cube will be centered on the screen. Press left or right on the d-pad to rotate the cube and press the X button to exit. Press the triangle button to randomize the cube's color, press up or down on the d-pad to increase or decrease the opacity, or press the circle button to toggle between the normal and neon textures.

How it works...

This recipe basically starts off with initialization code identical to the previous recipe, except the clear color is now white and we are loading a different .mdx file into our BasicModel. After creating our various view matrices, we create a BasicParamaters object and use it to create a BasicProgram. A BasicProgram is a preconfigured and substantially easier to use ShaderProgram, coupled with a prewritten vertex and fragment shader. After creating our program, we take a reference to our model's existing texture called texture1, as well as declaring a new BasicTexture, texture2. We then assign texture2 a filename and load that file into the Texture member of texture2. We then declare our exit flag done, as well as declare a variable to hold the texture's opacity and a Vector to hold the texture's color.

In our game loop, we clear the screen then check the gamepad for input. If the user presses the X button, we set the done flag and cause the application to exit. Once again, pressing left and right on the d-pad causes the scene to rotate. We then check to see if the circle button has been pressed and released, and if it has, we swap the active texture on the model to either texture1 or texture2. Next we check to see if the user pressed up or down on the d-pad, and if so we increase or decrease the opacity value. Lastly we check to see if the user pressed the triangle button, and if he/she has we assign ambientColor a random red/green/blue value. This color value is a floating point value between 0 and 1, while the Random object returns an int value, so we simply request a random value between 0 and 255 and divide that value by 255, giving us a value in the proper range of 0 to 1.

Now we update the model's world matrix, and set the texture's Ambient and Opacity values. All of the remaining code is identical to the prior recipe except for the fact that we add an Enable() call to enable the Blend mode. If you have transparent or translucent objects in your scene, you need to enable blending. See the link in the See also section of this recipe for more details on how blending works in OpenGL.

There's more...

If you have more than one BasicProgram, or simply do not want to pass it in to the model's Draw() method, the model class has a method named BindPrograms() that you can pass BasicProgramContainer in to. BasicProgramContainer is a simple data type that holds a collection of key/value pairs of BasicPrograms. When creating BasicProgramContainer, you can pass in a BasicParameters value to the constructor and those parameters will be shared between all contained BasicPrograms. If you do not want to share a BasicParamters value, simply pass in null. The following is an example:

var param = new BasicParameters();
var container = new BasicProgramContainer(param);
var progam = new BasicProgram();
container.Add("program1",prog);
model.BindPrograms(container);

As mentioned earlier, BasicProgram is a wrapper around the vertex and fragment shader functionality. Behind the scenes BasicProgram is populating a vertex and fragment shader for you. If you want to extend the functionality of these shaders or BasicProgram, you will need to build the Model library yourself. Assuming a default install, the shaders used by Model are located at C:\Program Files (x86)\SCE\PSM\source\Model\shaders, in a pair of files named Basic.fcg and Basic.vcg

See also

- See a fragment (pixel) shader in action and a vertex shader in action for an example of performing the same process without the help of the Model library. Additionally, see http://bit.ly/X9hni7 (OpenGL site: Transparency, Translucency, and Blending) for more details on GL blending and blending functions.

Controlling lighting using BasicProgram

In this recipe we will look at how the Model library simplifies the process of adding lighting to our scene.

Getting ready

In Studio create a new project and add a reference to the Sce.PlayStation.HighLevel.Model library. Also add walker.mdx and set its Build Action to Content. The project can be downloaded as Ch8_Example4.

How to do it...

Open AppMain.cs and enter the following in place of the Main function:

public static void Main (string[] args) {
var graphics = new GraphicsContext ();
graphics.SetClearColor (0.0f, 0.0f, 0.0f, 0.0f);

var model = new BasicModel("/Application/walker.mdx",0);

Matrix4 view = Matrix4.LookAt( new Vector3(0.0f,0.0f,25.0f),
new Vector3(0.0f,0.0f,0.0f),
Vector3.UnitY);
Matrix4 proj = Matrix4.Perspective(FMath.Radians(45),graphics.Screen.AspectRatio,1,10000f);
Matrix4 world = Matrix4.Translation(-model.BoundingSphere.Xyz);
model.SetWorldMatrix(ref world);
var program = new BasicProgram();

bool done = false;
bool light1On, light2On, light3On, fogOn, ambientOn;
light1On = light2On = light3On = fogOn = ambientOn = false;
Vector3 light1Diffuse, light2Diffuse, light3Diffuse, fogColor, ambient;
Vector3 light1Direction, light2Direction, light3Direction;

while(!done) {
BasicParameters parameters = program.Parameters;
parameters.Enable(BasicEnableMode.Fog,true);
parameters.Enable(BasicEnableMode.Lighting,true);
graphics.Clear();

var gamepad = GamePad.GetData(0);
if((gamepad.Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
done = true;
if((gamepad.Buttons & GamePadButtons.Left) == GamePadButtons.Left)
world *= Matrix4.RotationY(FMath.Radians(1));
if((gamepad.Buttons & GamePadButtons.Right) == GamePadButtons.Right)
world *= Matrix4.RotationY(-FMath.Radians(1));

if((gamepad.ButtonsUp & GamePadButtons.Triangle) == GamePadButtons.Triangle)
light1On = !light1On;
if((gamepad.ButtonsUp & GamePadButtons.Circle) == GamePadButtons.Circle)
light2On = !light2On;
if((gamepad.ButtonsUp & GamePadButtons.Square) == GamePadButtons.Square)
light3On = !light3On;
if((gamepad.ButtonsUp & GamePadButtons.Start) == GamePadButtons.Start)
fogOn = !fogOn;
if((gamepad.ButtonsUp & GamePadButtons.Select) == GamePadButtons.Select)
ambientOn = !ambientOn;
light1Direction = new Vector3(0f,-3f,0f);
if(light1On)
light1Diffuse = new Vector3(1f,0f,0f);
else
light1Diffuse = new Vector3(0f,0f,0f);

light2Direction = new Vector3(-3f,0f,0f);
if(light2On)
light2Diffuse = new Vector3(1f,1f,0f);
else
light2Diffuse = new Vector3(0f,0f,0f);

light3Direction = new Vector3(3f,0f,0f);
if(light3On)
light3Diffuse = new Vector3(0f,0f,1f);
else
light3Diffuse = new Vector3(0f,0f,0f);
if(fogOn)
fogColor = new Vector3(1.0f,0.4f,0.3f);
else
fogColor = new Vector3(0f,0f,0f);

if(ambientOn)
ambient = new Vector3(1f,1f,1f);
else
ambient = new Vector3(0f,0f,0f);

model.SetWorldMatrix(ref world);

parameters.SetProjectionMatrix(ref proj);
parameters.SetViewMatrix(ref view);
parameters.SetLightAmbient(ref ambient);
parameters.SetLightCount(3);

parameters.SetLightDirection(0,ref light1Direction);
parameters.SetLightDiffuse(0,ref light1Diffuse);
parameters.SetLightDirection(1,ref light2Direction);
parameters.SetLightDiffuse(1,ref light2Diffuse);
parameters.SetLightDirection(2,ref light3Direction);
parameters.SetLightDiffuse(2,ref light3Diffuse);
parameters.SetFogColor(ref fogColor);
parameters.SetFogRange(0f,100f);
graphics.Enable(EnableMode.Blend);
graphics.SetBlendFunc(BlendFuncMode.Add, BlendFuncFactor.SrcAlpha, BlendFuncFactor.OneMinusSrcAlpha);
graphics.Enable(EnableMode.CullFace);
graphics.SetCullFace(CullFaceMode.Back, CullFaceDirection.Ccw);
graphics.Enable(EnableMode.DepthTest);
graphics.SetDepthFunc(DepthFuncMode.LEqual, true);

model.Update();
model.Draw(graphics,program);

graphics.SwapBuffers ();
}
model.Dispose();
program.Dispose();
graphics.Dispose();
}

Run the application and you should see the following screenshot:

Initially the screen will be completely dark, until you turn on some lights. Once again, press left and right on the d-pad to rotate the scene and click on X to exit. Hitting the triangle button turns on a directional light from above the character, hitting the square button turns on a light on the left-hand side, while hitting circle turns on a light on the right-hand side. Hitting the Select button toggles the ambient lighting, while the Start button turns fog on and off.

How it works...

This recipe starts off virtually identically to prior recipes in this chapter. We create the graphics context, set our clear color to black, load the model, and then create and configure our three matrices. This time we create BasicProgram without specifying parameters, as those are going to change each pass through the loop. We then create a bool to control when our application is done and one bool for each configurable item in the scene. We then create a Vector3 to hold the color of each of our three diffuse lights, the fog, and the ambient lighting. Then we create Vector3 objects to hold the direction of each of the diffuse lights.

In our game loop, we take a reference to the program's Parameters value; then enable fog and lighting. We then check the state of the gamepad and toggle features on or off depending on which buttons are pressed. Then for each light, we set the direction (light1 is aiming down the y axis, light2 is aiming left along the x axis, and light3 is aiming right along the x axis), then depending on whether the light is on or off, we set its color. If a light is off, we set the color to (0,0,0). If the light is on, we set it to a particular color (light1 is red, light2 is green, and light3 is blue). We then perform a similar process for the ambient light and fog, minus the positioning.

We need to tell the program how many lights are in the scene, which we accomplish with the SetLightCount method. Then for each diffuse light, we call SetLightDirection() and SetLightDiffuse(). The first parameter is the index of the light, while the second parameter is the direction and color, respectively. Next we pass our fog color in by calling SetFogColor, and set the near and far depth ranges of the fog with a call to SetFogRange(). All of the remaining code is identical to the prior recipe.

There's more...

When discussing lighting, we've seen a few words over and over such as ambient, specular, and diffuse. An ambient light is a directionless light; it is the general pervasive light in a scene. Diffuse and specular lights, however, both have a direction—think of a spot light or laser beam. The difference between diffuse and specular lights is how the light is reflected from a surface. Diffuse light scatters equally in all directions after hitting a surface, while a specular light tends to reflect in a specific direction. For a general directional light, such as a lamp or spot light, it is generally a diffuse light you want. You can also make a model emit its own light by setting the Emission property. BasicProgram supports up to three lights (via SetLightCount), in addition to a single ambient light. If you want to use more lights, you will need to extend the shader yourself.

There is one major limitation to the current lighting solution provided by BasicProgram. You currently cannot give a light a position, only a direction. By increasing the magnitude of the light's direction vector you can increase the intensity of the light—for example a light with the direction (0,-5,0) will cast a light down the y axis that is much more intense than a light with a direction of (0,-1,0)—but you cannot set the light's source position, making localized direct lights such as a lamp impossible to implement. Adding support in a Cg shader for additional lights or a spotlight wouldn't be too difficult; see the link in the See also section of this recipe for an example of creating a spotlight using Cg.

See also

- See the Adding lighting to your scene recipe in Chapter 7, Into the Third Dimension, for an example of using vertex and fragment shaders to perform lighting. Also see http://bit.ly/RAUb7t (NVIDIA Cg Tutorial: Lighting) for more details on lighting in Cg shaders, as well as an example shader for implementing a spot light.

Animating a model

This recipe will show how easy it is to animate a model using the HighLevel.Model library.

Getting ready

Create a new project, add Walker.mdx, and set the Build Action to Content. The code and all materials for this recipe are available as Ch8_Example5.

How to do it...

Edit AppMain.cs and edit Main to match the following (changes highlighted):

public static void Main (string[] args) {
var graphics = new GraphicsContext();
graphics.SetClearColor (0.0f, 0.0f, 0.0f, 0.0f);

var model = new BasicModel("/Application/walker.mdx",0);

Matrix4 view = Matrix4.LookAt( new Vector3(0.0f,0.0f,25.0f),
new Vector3(0.0f,0.0f,0.0f),
Vector3.UnitY);
Matrix4 proj = Matrix4.Perspective(FMath.Radians(45),graphics.Screen.AspectRatio,1,10000f);
Matrix4 world = Matrix4.Translation(-model.BoundingSphere.Xyz) * Matrix4.RotationY(FMath.Radians(90f));

model.SetWorldMatrix(ref world);

BasicParameters parameters = new BasicParameters();
parameters.SetProjectionMatrix(ref proj);
parameters.SetViewMatrix(ref view);
var ambient = new Vector3(1f,1f,1f);
parameters.SetLightAmbient(ref ambient);

var program = new BasicProgram(parameters);
bool done = false;

System.Diagnostics.Stopwatch stopWatch = new System.Diagnostics.Stopwatch();
stopWatch.Start();

long previousTicks = 0;
while(!done) {
float delta = (stopWatch.ElapsedTicks - previousTicks) / (float)System.Diagnostics.Stopwatch.Frequency;
previousTicks = stopWatch.ElapsedTicks;
graphics.Clear();

var gamepad = GamePad.GetData(0);
if((gamepad.Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
done = true;

model.SetWorldMatrix(ref world);
graphics.Enable( EnableMode.CullFace );
graphics.SetCullFace( CullFaceMode.Back, CullFaceDirection.Ccw );
graphics.Enable( EnableMode.DepthTest );
graphics.SetDepthFunc( DepthFuncMode.LEqual, true );

model.Update();
model.Animate(delta);
model.Draw(graphics,program);

graphics.SwapBuffers ();
}
model.Dispose();
program.Dispose();
graphics.Dispose();
}

Hit F5 to run the application and you should see the following screenshot:

A side view of the walker mesh will be drawn centered on the screen; this time it will live up to its name and walk! You can still rotate the camera using the d-pad and exit the application by pressing the X button.

How it works...

Since this recipe is so similar to the prior recipe, I will only address the highlighted changes. The first difference is that we apply an additional 90-degree rotation to our world matrix; this is simply for us to see a slightly more pleasing side view of our walker by default. Then right before our event loop we create a StopWatch object and start it running. We then declare a long object that will hold the tick count of the previous pass through the game loop.

In the game loop we calculate how much time has occurred since the last pass through the loop. We obtain this value by subtracting the current ElapsedTicks from the elapsed ticks from the previous pass through the loop, then divide this value by the StopWatch Frequency. The frequency is the resolution that the timer is running at, and is a value representing the number of "ticks" in a second. At this point, our delta value holds the number of seconds that occurred since the last loop occurred.

The only remaining difference is that after we call Update() and before we call Draw() (this order is very important!), we call Animate(), passing it the amount of time in seconds to advance the animation by. This will cause the animation to advance consistently regardless of the speed of the underlying hardware.

There's more...

Passing a negative value to Animate() will play the animation in reverse. As you will see shortly, you can have multiple animations in the same model.

See also

- See the Handling multiple animations recipe for details on how you deal with more than one animation in a single .mdx file

Handling multiple animations

This recipe illustrates how to handle multiple animations in a single model.

Getting ready

This recipe requires an MDX file with multiple animations, which unfortunately walker.mdx does not have and none of the other examples provided with the SDK will work, for reasons explained next. Therefore I acquired a fully rigged model from the Internet and created my own simple animations using Blender. The model itself is from OpenGameArt and can be downloaded from http://bit.ly/QeoPGP. The MDX file I generated is included along with all of the source code as Ch8_Example6.

Create a new project, add the preceding .mdx file to the project, and set its Build Action to Content. You also need to add a reference to Sce.PlayStation.HighLevel.Model.

How to do it...

Open AppMain.cs and replace the Main function with the following (once again, changes are bolded):

public static void Main (string[] args) {
var graphics = new GraphicsContext ();
graphics.SetClearColor (0.0f, 0.0f, 0.0f, 0.0f);
var model = new BasicModel("/Application/fgc_skeleton.mdx",0);
Matrix4 view = Matrix4.LookAt( new Vector3(0.0f,0.0f,60.0f),
new Vector3(0.0f,0.0f,0.0f),
Vector3.UnitY);
Matrix4 proj = Matrix4.Perspective(FMath.Radians(45),graphics.Screen.AspectRatio,1,10000f);
Matrix4 world = Matrix4.Translation(0,-20f,0) * Matrix4.RotationY(FMath.Radians(45f));

model.SetWorldMatrix(ref world);

Vector3 ambient = new Vector3(0.3f,0.3f,0.3f);
BasicParameters parameters = new BasicParameters();

parameters.SetProjectionMatrix(ref proj);
parameters.SetViewMatrix(ref view);
parameters.SetLightAmbient(ref ambient);

var program = new BasicProgram(parameters);

model.SetCurrentMotion(0);

var frameRate = 30f;
bool done = false;
Vector3 ambientColor = new Vector3(1,1,1);
while(!done) {
graphics.Clear ();
var gamepad = GamePad.GetData(0);
if((gamepad.Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
done = true;
if((gamepad.Buttons & GamePadButtons.Left) == GamePadButtons.Left)
world *= Matrix4.RotationY(FMath.Radians(1));

if((gamepad.Buttons & GamePadButtons.Right) == GamePadButtons.Right)
world *= Matrix4.RotationY(-FMath.Radians(1));
if((gamepad.Buttons & GamePadButtons.R) == GamePadButtons.R) {
frameRate += 1f;
model.Motions[model.CurrentMotion].FrameRate = frameRate;
}

if((gamepad.Buttons & GamePadButtons.L) == GamePadButtons.L) {
frameRate -= 1f;
model.Motions[model.CurrentMotion].FrameRate = frameRate;
}

if((gamepad.ButtonsUp & GamePadButtons.Up) == GamePadButtons.Up) {
model.SetCurrentMotion(0,1f);
}
if((gamepad.ButtonsUp & GamePadButtons.Down) == GamePadButtons.Down) {
model.SetCurrentMotion(1,1f);
}

model.SetWorldMatrix(ref world);

graphics.Enable(EnableMode.Blend);
graphics.SetBlendFunc(BlendFuncMode.Add, BlendFuncFactor.SrcAlpha, BlendFuncFactor.OneMinusSrcAlpha);
graphics.Enable(EnableMode.CullFace);
graphics.SetCullFace(CullFaceMode.Back, CullFaceDirection.Ccw);
graphics.Enable(EnableMode.DepthTest);
graphics.SetDepthFunc(DepthFuncMode.LEqual, true);

model.Update();
model.Animate(0.01f);
model.Draw(graphics,program);

graphics.SwapBuffers ();
}
model.Dispose();
program.Dispose();
graphics.Dispose();
}

Run the application and hopefully you will see the following:

A shrugging skeleton will be drawn on the center of the screen. Pressing up and down on the d-pad will toggle between the two available animations, shrug and lean. Pressing the right bumper (E key) will increase the animation speed, while pressing the left bumper (Q key) will decrease it. Once again, rotate the scene to the left and right and press the X button to exit.

How it works...

Once again, this recipe shares a great deal of common code with recipes we covered previously, so we will only cover the changes. The first obvious change is that we load our model from the fgc_skeleton.mdx file. We make a few changes to the view and world matrices to better accommodate the dimensions of our skeleton. We set the model playing its first animation by calling SetCurrentMotion(), passing the index of the animation to play. We then declare a variable to hold our frameRate, which is the rate we want the animation to play back at.

In our game loop, we check to see if the right or left bumper is pressed, and if so we increase or decrease frameRate by 1, depending on which was selected. We then update the FrameRate property of the current animation to our newly updated frameRate value. As you can see, the model contains an array named Motions containing all of its animations, as well as a CurrentMotion property holding the index of the currently playing motion. You can completely stop an animation by setting FrameRate to 0. Each Motion contains more information, including the starting frame, ending frame, and current frame, as well as the FrameRepeat property, which will determine if an animation will loop when completed.

If the user presses up on the d-pad, we set Motion 0 as the active motion, while if the user presses down, we set Motion 1 as the active motion. This is accomplished by calling SetCurrentMotion(). The first parameter is the index of Motion set to active, while the second value is the number of seconds to delay before transitioning. It will default to 0 if you do not provide a value. Once again we update our animation by calling Animate(). This time, to simplify the recipe, I pass in a value of a tenth a second. This is not ideal, as the animation will advance at different rates on different hardware.

There's more...

Note

When setting out to write this chapter I had a bit of a challenge. The walker.mdx file only has a single animation. Therefore I considered co-opting one of the MDX files from the various demos included with the SDK, such as the hero model from the RPG demo. That is when I discovered that these MDX files are not compatible with the MDX files required by the Model library. In fact, only a single sample and none of the demos make use of the Model library.

Getting multiple animations out of Blender proved to be somewhat of a trick. I managed to create an MDX file with multiple animations using Action Editor in the DopeSheet menu to create each animation, but once imported they never worked correctly and only a single animation played using the ModelViewer. I did, however, manage to get multiple animations to work using the following process:

1. In Blender, model each animation in a separate .Blend file.

2. Export each file as an Autodesk FBX. When exporting, select only the Armature and Mesh tabs; make sure that Include Animation and Optimize Keyframes are checked, and Include Default Take is not. Your export setting should look like the following screenshot:

3. Perform the preceding process for each of your animations. In Windows Explorer, while keeping the Ctrl key pressed, select all of the FBX files and drag them onto ModelConverter.exe.

4. When prompted for params, enter -motions.

This is the process used to create the animations in this recipe and will result in a single MDX file with multiple animations that will work with PlayStation Mobile.

When working on this chapter, I had a bit of a battle getting my animations work properly. While debugging I discovered that the ModelViewer should be your new best friend. Also, when importing an external file into Studio over and over, you will save a great deal of time adding it as a link instead of adding the file directly to the project.

The following screenshot shows ModelViewer:

ModelViewer is a simple utility that is located in the same directory as ModelConverter. You can use it to preview how your MDX file will look once imported into your application. Simply drag-and-drop the MDX file on ModelViewer.exe to load your model. The Z and X keys zoom your camera in and out, while the arrow keys rotate the project. Pressing a number key from 1 through 5 will toggle the application between different modes, as follows:

- View Mode

- Animation

- State Switches (up and down arrows to navigate, left and right to toggle)

- Information

- Help

ModelViewer is invaluable for troubleshooting model importing and rendering problems.

See also

- See the Animating a model recipe for details on how to properly advance the time step passed to the Animate function

Using bones to add a sword to our animated model

One very common action to perform in 3D games is to dynamically add weapons and details to a mesh. This recipe shows the process of loading a sword and binding it to the walker model's wrist.

Getting ready

Create a new project, add the walker.mdx model, and set its Build Action to Content. Be sure to add a reference to the Sce.PlayStation.HighLevel.Model library. I modeled an extremely simple sword mesh in Blender and exported it to MDX as sword.mdx. Add it to your project and again set its Build Action to Content. It is available with the source code as Ch8_Example7.

How to do it...

Once again this code shares a great deal with earlier recipes. Open AppMain.cs and change Main to match the following code (bolded area represents changes):

public static void Main (string[] args) {
var graphics = new GraphicsContext ();
graphics.SetClearColor (0.0f, 0.0f, 0.0f, 0.0f);

var model = new BasicModel("/Application/walker.mdx",0);
var sword = new BasicModel("/Application/sword.mdx",0);

Matrix4 view = Matrix4.LookAt( new Vector3(0.0f,0.0f,25.0f),
new Vector3(0.0f,0.0f,0.0f),
Vector3.UnitY);
Matrix4 proj = Matrix4.Perspective(FMath.Radians(45),graphics.Screen.AspectRatio,1,10000f);
Matrix4 world = Matrix4.Translation(-model.BoundingSphere.Xyz);

model.SetWorldMatrix(ref world);

Vector3 ambient = new Vector3(1.0f,1.0f,1.0f);
BasicParameters parameters = new BasicParameters();

parameters.SetProjectionMatrix(ref proj);
parameters.SetViewMatrix(ref view);
parameters.SetLightAmbient(ref ambient);

var program = new BasicProgram(parameters);

bool done = false;
Vector3 ambientColor = new Vector3(1,1,1);
while(!done) {
graphics.Clear ();
var gamepad = GamePad.GetData(0);
if((gamepad.Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
done = true;
if((gamepad.Buttons & GamePadButtons.Left) == GamePadButtons.Left)
world *= Matrix4.RotationY(FMath.Radians(1));

if((gamepad.Buttons & GamePadButtons.Right) == GamePadButtons.Right)
world *= Matrix4.RotationY(-FMath.Radians(1));

model.SetWorldMatrix(ref world);

graphics.Enable(EnableMode.Blend);
graphics.SetBlendFunc(BlendFuncMode.Add, BlendFuncFactor.SrcAlpha, BlendFuncFactor.OneMinusSrcAlpha);
graphics.Enable(EnableMode.CullFace);
graphics.SetCullFace(CullFaceMode.Back, CullFaceDirection.Ccw);
graphics.Enable(EnableMode.DepthTest);
graphics.SetDepthFunc(DepthFuncMode.LEqual, true);

model.Update();
model.Animate(0.01f);

sword.Update();

model.Draw(graphics,program);
sword.SetWorldMatrix(ref swordMatrix);
sword.Draw(graphics,program);
var swordMatrix = model.Bones[24].WorldMatrix;
graphics.SwapBuffers ();
}
model.Dispose();
program.Dispose();
graphics.Dispose();
}

Hit F5 to run and you should see the following screenshot:

Our now familiar walker model will be animated on screen. Now, however, he is holding a sword that will animate with him! Use left and right on the d-pad to rotate the screen and hit X to exit the app.

How it works...

We start off loading an additional model, sword.mdx. In our game loop, just like with our model, we need to call Update() and Draw() for our sword. Since the sword model is not animated, we do not need to call the Animate() method. We can use the same program and graphics context for both models. The biggest change here is that we find the wrist bone (which happens to be the 24th bone, but we could have also found it by its name) within the model's Bones array, and set our sword's world matrix to be the same as the wrist bone. This means that as the wrist moves, so will the sword.

There's more...

Each bone contains a fair amount of information. In addition to the world matrix and name, each bone also has a bounding sphere, the index in the Bones array of its parent, translation and scaling vectors, a rotation quaternion, as well as an array of the parts it modifies.

In addition to an array of Bones and Motions, BasicModel contains a number of other arrays: Textures, which contains the textures applied to the model; Programs, which contains the BasicPrograms attached to the model; Materials, which contains the material attributes of the model (such as shininess, emission, opacity, and so on); and Parts, which actually contains the vertex information. Oddly, the model's Motion data include Fcurves, but has no functionality for blending animations.

Chapter 9. Finishing Touches

In this chapter we will cover:

- Opening and loading a web browser

- Socket-based client and server networking

- Accessing (Twitter) data over the network using REST and HttpWebRequest

- Copying and pasting using Clipboard

- Embedding and retrieving a resource from the application assembly

- Configuring your application using PublishingUtility

- Creating downloadable content (DLC) for your application

Introduction

In this chapter we are going to cover the best of the rest. We will be covering a fairly wide range of topics, from networking and copy and paste to preparing your application for deployment.

Opening and loading a web browser

This recipe is by far the book's shortest and simplest recipe. We are going to illustrate how to open the device's web browser and load a web page.

Getting ready

Open PlayStation Mobile Studio and create a new project. You can download the full sources as Ch9_Example1.

How to do it...

Open AppMain.cs and replace the code with the following:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;

namespace Ch9_Example1 {
public class AppMain {
public static void Main (string[] args)  {
var action = Shell.Action.BrowserAction(@"http://www.gamefromscratch.com");
Shell.Execute(ref action);
}
}
}

Run the application and you should see the following screenshot:

A web browser will open on the user's device and load the world's greatest website!

How it works...

The Shell class is located in the Sce.PlayStation.Core.Environment namespace. As of right now BrowserAction is the only available action. As I said earlier, this is a very short recipe.

There's more...

BrowserAction will open the Vita browser if run on PlayStation Vita. In the simulator, it will open the default browser on your PC. On Android it will create a browser intent, prompting you which browser you wish to open.

Socket-based client and server networking

This recipe demonstrates socket-based networking between PlayStation Mobile devices. It is a little bit different from prior recipes in that there are two code examples in a single recipe, the client and the server. The client simply sends a message to the server; the server receives and displays any incoming messages on screen.

Getting ready

Open two copies of PlayStation Mobile Studio and in each one create a new project. We are going to make use of the UI classes, so you need to add a reference to Sce.PlayStation.HighLevel.UI in each project. They are available as Ch9_Example2 and Ch9_Example2b.

How to do it...

First we will create our simple server. Open AppMain.cs in the first project and enter the following code:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.UI;
using System.Net;
using System.Net.Sockets;

namespace Ch9_Example2 {
public class AppMain {

private static Socket socket;
private static Label results;

private static void Main(string [] args) {
var graphics = new GraphicsContext();
UISystem.Initialize(graphics);

var scene = new Scene();
results = new Label() { Text = "Waiting for connection on IP ",
Width = graphics.Screen.Width, Height = graphics.Screen.Height};
var panel = new Panel() { Width=graphics.Screen.Width, Height=graphics.Screen.Height };
panel.AddChildFirst(results);
scene.RootWidget.AddChildFirst(panel);
UISystem.SetScene(scene);

IPHostEntry ipHostInfo = Dns.GetHostEntry(Dns.GetHostName());
IPAddress ipAddress = ipHostInfo.AddressList[0];

results.Text += ipAddress.ToString() + " on PORT 9210";

IPEndPoint ipEndPoint = new IPEndPoint(IPAddress.Any,9210);
socket = new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);
socket.Bind(ipEndPoint);
socket.Listen(10);

socket.BeginAccept(new AsyncCallback(IncomingSocket),null);
bool quit = false;
while(!quit) {
if((GamePad.GetData(0).Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
quit = true;
graphics.Clear();
UISystem.Update(Touch.GetData(0));
UISystem.Render();
graphics.SwapBuffers();
}
if(socket.Connected)
socket.Disconnect(false);
socket.Close();
}

private static void IncomingSocket(IAsyncResult asyncResult)
{
using(var incomingSocket = socket.EndAccept(asyncResult)){
var data = new byte[1024];
var bytesReceived = incomingSocket.Receive(data);
results.Text += "\n" + System.Text.Encoding.ASCII.GetString(data,0,bytesReceived);

}
socket.BeginAccept(new AsyncCallback(IncomingSocket),null);
}
}
}

This code comprises our extremely primitive server.

Now in the other project, replace the code in AppMain.cs with the following code:

using System;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.UI;
using System.Net;
using System.Net.Sockets;

namespace Ch9_Example2b {

public class AppMain {

private static Socket socket;
private static EditableText textIpAddress;
private static EditableText textMessage;

private static void Main(string [] args) {
var graphics = new GraphicsContext();
UISystem.Initialize(graphics);
var scene = new Scene();
textIpAddress = new EditableText() { Width= graphics.Screen.Width, Height = 32, DefaultText= "Enter IP Address" };
textMessage = new EditableText() { Y=40, Width= graphics.Screen.Width, Height = 32, DefaultText= "Message to send" };
var buttonGo = new Button() { Y=80, Width=300, Height=32, Text="Go" };

buttonGo.ButtonAction += HandleButtonGoButtonAction;
var panel = new Panel() { Width=graphics.Screen.Width, Height=graphics.Screen.Height };

panel.AddChildFirst(buttonGo);
panel.AddChildFirst(textMessage);
panel.AddChildFirst(textIpAddress);

scene.RootWidget.AddChildFirst(panel);

UISystem.SetScene(scene);

bool quit = false;
while(!quit) {
if((GamePad.GetData(0).Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
quit = true;
graphics.Clear();
UISystem.Update(Touch.GetData(0));
UISystem.Render();
graphics.SwapBuffers();
}
}

static void HandleButtonGoButtonAction (object sender, TouchEventArgs e)
{
using(Socket socket = new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp)){
socket.Connect(new IPEndPoint(IPAddress.Parse(textIpAddress.Text),9210));
socket.Send(System.Text.ASCIIEncoding.ASCII.GetBytes(textMessage.Text));
socket.Close();
}
}
}
}

Now run the first application (your server) and make note of the IP address. Run the other application (leaving the first application running) and enter this IP address, as well as a message, and click on Go, like this:

Now if you look back at your server window you should see the following:

As you can see, communicating between devices is relatively simple. The server can actually serve requests from a number of different devices and handle a number of concurrent requests. Click on the X button on either application to exit.

How it works...

Let's start off looking at our server code. We start off creating our GUI by creating a GraphicsContext, which is used to initialize the UISystem singleton, creating a scene and populating it with a panel containing a full screen label for displaying our text. We set the panel as the scene's RootWidget, then set the scene running with a call to SetScene.

Next we get IP information about the machine by getting the host name with a call to Dns.GetHostName() and in turn passing that value to Dns.GetHostEntry(), which returns IPHostEntry. Because a machine can have multiple IP addresses, especially because of IPv4 and IPv6, IPHostEntry has an array of IPAddress values, but we are only interested in the first one. Please note that although the vast majority of the time the first address returned will be the IPv4 address, it is not safe to assume so! Now that we have our machine's IP address, we display it on the Label text, as well as the port number, 9210.

Next we create an IPEndPoint; the values we pass as parameters are the IP addresses and port that we will accept connections on. We pass IPAddress.Any and 9210, meaning we will accept connections from any IP address that comes in on port 9210. Next we create our Socket. When creating a Socket there are a ton of available connection options and protocols—literally thousands of possible combinations. AddressFamily.InterNetwork is a very long way of saying we are using IPv4; this is going to be a streaming socket using the TCP protocol. Next we call Bind(), which associates the socket with the IpEndPoint. You need to perform a Bind operation before you can call Listen on a port. Speaking of Listen(), that's exactly what we do next, call Listen on the socket, which will listen for network activity. The value 10 is the maximum length of the queue for incoming socket requests and is a value I chose pretty much at random. Finally, when calling BeginAccept we register an AsyncCallback function, IncomingSocket, which will be called each time a socket connection is established.

Next is our Main loop; we check to see if the user hit the X button, in which case we exit the program. We also call all the required functions, clearing the screen, updating the UI, and rendering the UI to screen. Finally, after our event loop exits, we disconnect and close our Socket. Until a socket is closed, you cannot connect to it again, so be sure to call Close() once complete.

Finally, we have the IncomingSocket function, which is called each time BeginAccept is called. We then call EndAccept on the socket, passing in the IAsyncResult value that was passed to our function. EndAccept returns the actual data that was sent over the socket, which we copy to a byte[] buffer by calling Receive(). We then convert this buffer to a string and display it by appending it to our Label text. We then call BeginAccept again, preparing it for the next incoming socket to repeat the entire process all over again.

This handles our basic server code. Now let's take a quick look at what we did in the client code. This code starts off by creating a very simple GUI containing an EditableText widget for IP address entry and another for entering the message to send. We also create a Button labeled Go and call the function HandleButtonGoButtonAction when the button is clicked. The remaining code simply adds the controls to the scene, sets the scene active with a call to UISystem.SetScene(), and then creates an identical loop to the one we used for the server.

In the HandleButtonGoButtonAction function, we create a Socket in the same way we did on the server. A client, however, does not need to call Bind() for the socket before using it. We connect to our server using socket.Connect, creating an IPEndPoint, from an IPAddress that was created by parsing the text the user entered. Of course, there is no error handling code here, but in a production environment you would obviously improve this code a great deal. Once connected, sending data is as simple as sending a byte[] array in a call to socket.Send(). We simply convert the message the user typed in to a byte[] array and send it. Finally, we close the socket. If you forgot to close it, the next call to HandleButtonGoButtonAction would fail. You will notice that Socket is wrapped in a using block; this is because Socket is an IDisposable object and will leak resources if not disposed of properly.

There's more...

In both of these examples, we are using System.Net.Socket, which is part of .NET Framework, so the same code will run on Windows, Mac, and so on, minus of course the UI-specific parts. Networking is a gigantic subject, one worthy of its own book, so we can only show the simplest of examples here. Sockets also aren't your only option; you can also make use of the higher level UdpClient and TcpClient classes, which abstract away a lot of the low-level details. There are also options such as UdpListener and TcpListener for implementing servers. Unless you have a good reason not to, you are better served working at a higher level of abstraction when possible.

Note

Why port 9210?

Absolutely no good reason. I simply picked it because as far as I know it is not a port that is commonly used. A port can be any value from 1 to 65,536, although most of the lower numbers are commonly used for other tasks, such as Port 21 for e-mail, or port 80 for HTTP traffic. I used to always use port 4242 for my random port usage, but it turns out programmers really like this number for some odd reason…

See Also

- Refer to Chapter 6, Working with GUIs, for more details on working with the UI library. See http://bit.ly/SKWx2b for more details on System.Net.Socket usage.

Accessing (Twitter) data over the network using REST and HttpWebRequest

You will often want to access data from the Internet, for a variety of different reasons. REST is an incredibly popular format that web services use to expose information online. This recipe illustrates how to use the HttpWebRequest class to access one such web service, Twitter.

Getting ready

Open PlayStation Mobile Studio and create a new project. You also need to add references to Sce.PlayStation.HighLevel.UI, System.Xml, and System.Xml.Linq. You can download the full source code as Ch9_Example3.

How to do it...

Open AppMain.cs and replace the code there with the following code:

using System;
using System.Collections.Generic;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.UI;
using System.IO;
using System.Net;
using System.Linq;
using System.Xml.Linq;

namespace Ch9_Example3 {
public class Tweet {
public string TweetText;
public string ProfileImage;
public string Name;
}

public class AppMain {
private static List<Tweet> tweets = new List<Tweet>();

private static void Main(string [] args) {
var graphics = new GraphicsContext();
UISystem.Initialize(graphics);
var scene = new Scene();
var results = new Label() { Text = "",
Width = graphics.Screen.Width, Height = graphics.Screen.Height};

var panel = new Panel() { Width=graphics.Screen.Width, Height=graphics.Screen.Height };

panel.AddChildFirst(results);
scene.RootWidget.AddChildFirst(panel);
UISystem.SetScene(scene);

var request = HttpWebRequest.Create(@"http://api.twitter.com/1/statuses/user_timeline.xml?id=gamefromscratch");
request.ContentType = "application/xml";
request.Method = "GET";
request.Timeout = 30000;

using (HttpWebResponse response = request.GetResponse() as HttpWebResponse) {
if (response.StatusCode != HttpStatusCode.OK)
Console.Out.WriteLine("Error fetching data. Server returned status code: {0}", response.StatusCode);
else {
using (StreamReader reader = new StreamReader(response.GetResponseStream())) {
var content = reader.ReadToEnd();
if (string.IsNullOrWhiteSpace(content)) {
System.Diagnostics.Debug.WriteLine("Twitter returned no tweets");
}
else {
XDocument doc = XDocument.Parse(content);
tweets = (from e in doc.Root.Descendants("status")
select new Tweet {
Name= "GameFromScratch",
ProfileImage = e.Element("user").Element("profile_image_url").Value,
TweetText = e.Element("text").Value,
}).ToList();
foreach (var tweet in tweets) {
results.Text += tweet.TweetText + "\n";
}

}
}
}
}

bool quit = false;
while(!quit) {
if((GamePad.GetData(0).Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
quit = true;
graphics.Clear();
UISystem.Update(Touch.GetData(0));
UISystem.Render();
graphics.SwapBuffers();
}
}
}
}

Run the application and you should see the following screenshot:

Assuming you have a working network connection, you should now see a text dump of a certain person's Twitter feed. Once again, you can exit the application by pressing the X button.

How it works...

Twitter returns a great deal of data, but we are only interested in a portion of it, so we create the Tweet class to hold just the information we care about. Next we declare a List of Tweet objects.

In Main we start off with the typical initialization code. In this example we are making use of UISystem, so we need to initialize the singleton, and create a scene, a panel, and a full screen label named results to hold our text output. We add the label to the panel, add the panel to the scene, and then set the scene active with a call to UISystem.SetScene().

Now we create our HttpWebRequest object, passing it the URL http://api.twitter.com/1/statuses/user_timeline.xml?id=gamefromscratch. This is the web service URL you use to request the latest status updates for Twitter user gamefromscratch (I wonder who that is?). See the See also section of this recipe for a link with more details about the various URLs Twitter supports. We specify that we expect the results to be XML by specifying the ContentType as "application/html", that the request will be a GET request (as opposed to a POST request) and finally that we want this request to wait for at least 30 seconds before timing out.

Next, we actually make our request by calling GetResponse(). As you can see it is wrapped in a using block; this is because HttpWebResponse is an IDisposable object, so we don't want to leak resources. First, we check the StatusCode and print out an error to the console if we get a response other than OK. Otherwise, we read the results using GetResponseStream() using StreamReader (which is also an IDisposable object). We read the entire buffer using ReadToEnd() and verify that it isn't empty.

At this point we should have a valid XML document in memory, which we read using XDocument.Parse() and extract the appropriate values to populate our tweet list. We then loop through the tweet list and print the tweets to our label results. The remaining code is the standard application loop and should be completely familiar at this point.

There's more...

Twitter is just one of many services you can access using HttpWebRequest and HttpWebRequest is just one of the ways you can use to access information over the Web. The PlayStation Mobile SDK also includes the ServiceModel assemblies, which allow you to access SOAP-based web services. SOAP-based web services are becoming increasingly less common as REST services grow in popularity.

Also be aware that the Twitter API we used is incredibly limited. It is only able to access publically available information and is read-only. Additionally, it has a limited rate of 150 requests per hour. You can, however, register your application with Twitter to have the rate limits raised and to be able to access additional information and functionality, such as publishing a tweet. This process requires authenticating, which is far too complex to go into more detail here.

Note

REST?

REST stands for Representational State Transfer and is a software design architecture style, most commonly implemented over HTTP, providing what are commonly referred to as RESTful services. In a grossly simplified description, you generally access a REST service by creating a specially formed URL and making an HTTP request. No information about the client session state is stored on the server, so each request must then contain all information the request requires. The lack of server-side session state makes it much easier to scale up such services. This lack of session state, though, is a double-edged sword, making authentication, for example, a much more complex issue than with traditional web services.

See also

- See http://bit.ly/Q6uoWL for more details on the Twitter developer program if you wish to add Twitter functionality to your application

- Refer to Chapter 6, Working with GUIs, for more details on using UISystem and the PlayStation Mobile UI system

Copying and pasting using Clipboard

PlayStation Mobile provides a simple Clipboard class to provide copy and paste functions. This recipe shows how to add basic copy and paste support to your application.

Getting ready

Open PlayStation Mobile Studio and create a new project. We are going to make use of the UI system for this recipe, so be sure to add a reference to Sce.PlayStation.HighLevel.UI. The full project is available as Ch9_Example4.

How to do it...

Open AppMain.cs and replace the code there with the following code:

using System;
using System.Collections.Generic;
using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.UI;

namespace Ch9_Example4 {

public class AppMain {

private static void Main(string [] args){

var graphics = new GraphicsContext();
UISystem.Initialize(graphics);
var scene = new Scene();

var textCopied = new EditableText() { Width= graphics.Screen.Width, Height = 32, DefaultText= "Type text here to be copied" };
var textPasted = new EditableText() { Y=40, Width= graphics.Screen.Width, Height = 32, DefaultText= "Text will be pasted here" };
var buttonCopy = new Button() { Y=80, Width=300, Height=32, Text="Copy" };
var buttonPaste = new Button() { X=340, Y=80, Width=300, Height=32, Text="Paste" };
buttonCopy.ButtonAction += (sender, e) => {
Clipboard.SetText(textCopied.Text);
};
buttonPaste.ButtonAction += (sender, e) => {
textPasted.Text = Clipboard.GetText();
};
var panel = new Panel() { Width=graphics.Screen.Width, Height=graphics.Screen.Height };

panel.AddChildFirst(buttonCopy);
panel.AddChildFirst(buttonPaste);
panel.AddChildFirst(textCopied);
panel.AddChildFirst(textPasted);

scene.RootWidget.AddChildFirst(panel);

UISystem.SetScene(scene);

bool quit = false;
while(!quit) {
if((GamePad.GetData(0).Buttons & GamePadButtons.Cross) == GamePadButtons.Cross)
quit = true;
graphics.Clear();
UISystem.Update(Touch.GetData(0));
UISystem.Render();
graphics.SwapBuffers();
}
}
}
}

Run this application and you should see the following screenshot:

Two text fields and two buttons appear on screen. Enter text in one field and click on Copy, then on Paste, and the other field should be populated with the text you just entered. Once again, you can click on X to exit.

How it works...

This recipe starts off by initializing the GraphicsContext and UISystem as usual. We create a UI Scene, two EditableText fields, one for entering the text to copy, the other to receive the text when pasted. We also create a pair of Button objects for the Copy and Paste buttons. We then register a handler for when the Copy button is pressed, inside which we copy the text to the clipboard using the Clipboard.SetText method, passing the Text value of the textCopied EditableText field as the text to be copied. We then register a handler for the Paste button's click action, where we assign the text from the clipboard to the Text value of textPasted. The text is retrieved from the clipboard using the Clipboard.GetText() method.

The remaining code in this recipe should be completely familiar at this point; we add all of our UI elements to a Panel object and set the panel as the root element of the scene, which we then make active. Otherwise it's a standard event loop that continues until the user clicks on the X button.

There's more...

The Clipboard object only handles copying and pasting of text data. The Clipboard object is declared in the Sce.PlayStation.Core.Environment library.

Embedding and retrieving a resource from the application assembly

It is possible to store data directly in the application assembly, instead of as a separate file. This recipe demonstrates how to store and retrieve an image resource from the application assembly.

Getting ready

Open PlayStation Mobile Studio and create a new application. You will need to include the Sce.PlayStation.HighLevel.GameEngine2D library reference. For the image file, I will be re-using our trusty FA-18H sprite, although you of course can use whatever image you wish. You can download this complete recipe as Ch9_Example5.

How to do it...

In your newly created solution, add the image file to your project. Right-click on the image file and select Build Action | EmbeddedResource.

Now open AppMain.cs and replace the code there with the following code:

using System;
using System.Collections.Generic;

using Sce.PlayStation.Core;
using Sce.PlayStation.Core.Environment;
using Sce.PlayStation.Core.Graphics;
using Sce.PlayStation.Core.Input;
using Sce.PlayStation.HighLevel.GameEngine2D;
using Sce.PlayStation.HighLevel.GameEngine2D.Base;
using System.Reflection;
using System.IO;

namespace Ch9_Example5 {
public class AppMain {
public static void Main(string[] args)  {
Director.Initialize();
Scene scene = new Scene();
scene.Camera.SetViewFromViewport();

Assembly resourceAssembly = Assembly.GetExecutingAssembly();
if (resourceAssembly.GetManifestResourceInfo("Ch9_Example5.FA-18H.png") == null) {
throw new FileNotFoundException("File not found.");
}

Stream fileStream = resourceAssembly.GetManifestResourceStream("Ch9_Example5.FA-18H.png");
Byte[] dataBuffer = new Byte[fileStream.Length];

fileStream.Read(dataBuffer, 0, dataBuffer.Length);

Texture2D t = new Texture2D(dataBuffer,false);
TextureInfo ti = new TextureInfo(t);
SpriteUV sprite = new SpriteUV(ti);
sprite.Scale = ti.TextureSizef;
fileStream.Close();
fileStream.Dispose();

scene.AddChild(sprite);
Director.Instance.RunWithScene(scene);
}
}
}

Run the application and you should see the following:

Your image will be loaded and displayed on screen, positioned in the lower-left corner.

How it works...

To keep the code shorter, we are making use of the GameEngine2D library. We start by initializing the Director singleton, creating and calibrating a Scene object. Next we get a reference to our running application Assembly by calling Assembly.GetExecutingAssembly(). Next we check to make sure our embedded image exists within the assembly by calling GetManifestResourceInfo() passing in the filename prefixed with the application name Ch9_Example5.FA-18H.png. If the file isn't found we throw a FileNotFoundException.

Assuming the file is found, we retrieve a Stream using GetManifestResourceStream(), again passing in the filename prefixed with the application name. Next we create a byte[] array big enough to hold the stream contents, then read the stream into our array. We then use this array to create a Texture2D object, then use that object to create a TextureInfo, which in turn we create a SpriteUV with. Now we close and dispose of our Stream, add our newly created sprite to the scene, and start things running.

There's more...

For the sake of brevity, this example (and others earlier in this book) don't completely clean up before the application exits, resulting in a very short-lived memory leak. Just be aware that, if you load a Texture2D in this manner, you are still responsible for disposing it off.

See also

- See Chapter 3, Graphics with GameEngine2D, for more details on working with the GameEngine2D library

Configuring your application using PublishingUtility

Once you have finished your application and are getting ready to publish it, there are a number of settings you can configure using PublishingUtility. This recipe takes a closer look at how you configure your application using this tool.

Getting ready

You will need to have an existing project to work through this recipe. Either use a prior recipe's project or create a new one.

How to do it...

To configure your application using PublishingUtility perform the following steps:

1. Open PublishingUtility; a shortcut should be available in the PlayStation Mobile folder of your Start Menu.

2. In PublishingUtility, select File | Load and browse to the app.xml file of the project you are working on, then click on Open.

3. With metadata selected on the left-hand side, a series of tabs will appear across the top of the window. Select the Common Property tab and enter the relevant information about your application. The primary and secondary genre are used to position your application within the store; the purpose of the settings in the Development section are described later on. Fill in a shorthand copyright message as well as provide a TXT file with your complete copyright details (this is mandatory, and will fail if you do not provide a file with a TXT extension). Fill the form out, such as the following example of a horror fitness game:

4. Now switch over to the Application Name tab and enter a long and short name for your application for each language area you support. Both names can be the same, although the short name is limited to 16 characters while the long name can be as long as 64 characters. The following is our game with values defined for American and British English, as well as French:

5. Next switch over to the Image tab. Here you need to provide at least a 512 x 512 image that will be used to create the applications icons. You can click on the Generate image from 512 button to have it automatically create resized versions as well. You can also specify a splash screen, the details of which are provided in the following screenshot:

6. Finally, we come to the Rating Check tab. This is where you can apply for various maturity ratings for your game (not applicable for most applications). The requirements for ratings vary from country to country. We will be ignoring the In-App Purchase tab for now:

7. Finally, click on Save and your app.xml file will be updated.

If you open app.xml, the code should look something like the following code snippet:

<?xml version="1.0" encoding="utf-8"?>
<application project_name="Ch9_Example6" version="1.00" runtime_version="1.00" sdk_version="1.00.00" default_locale="en-US">
<name>
<localized_item locale="en-US" value="Survival Fitness Horrorshow" />
<localized_item locale="en-GB" value="Ye Olde Survival Fitness HorrorShow" />
<localized_item locale="fr-FR" value="Les Survival Fitness Horrorshow" />
</name>
<short_name>
<localized_item locale="en-US" value="SurviveFitHorror" />
<localized_item locale="en-GB" value="SurviveFitHorror" />
<localized_item locale="fr-FR" value="SurviveFitHorror" />
</short_name>
<parental_control lock_level="2" />
<rating_list highest_age_limit="3" has_online_features="false">
<online_features chat="false" personal_info="false" user_location="false" exchange_content="false" />
<rating type="ESRB" value="3" age="3" code="" />
<rating type="PEGIEX" value="3" age="3" code="" />
</rating_list>
<images icon_128x128="..\..\..\GIMPProjects\SurvivalFitnessHorrorshow_128.png" icon_256x256="..\..\..\GIMPProjects\SurvivalFitnessHorrorshow_256.png" icon_512x512="..\..\..\GIMPProjects\SurvivalFitnessHorrorshow.png" splash_854x480="..\..\..\GIMPProjects\SurvivalFitnessHorrorshowSplash.png" />
<genre_list>
<genre value="Games:Fitness" />
<genre value="Games:Horror" />
</genre_list>
<developer>
<name value="" />
</developer>
<website href="http://www.gamefromscratch.com" />
<copyright author="(C) 2012 GameFromScratch.com" />
<runtime_config>
<memory managed_heap_size="32768" resource_heap_size="65536" />
</runtime_config>
<feature_list>
<feature value="GamePad" />
<feature value="Touch" />
<feature value="Motion" />
</feature_list>
</application>

There's more…

The end result of this entire operation is the generation or modification of your project's app.xml file. Many of the actions performed using PublishingUtility can be accomplished by hand editing the XML file. You can make changes in the XML file and they will persist if you reopen the file in the utility.

The GamePad, Touch, and Motion values can be used to toggle support for the gamepad, touch screen, and motion controls, respectively, on and off. If you turn GamePad on for a device that does not support a game pad, the onscreen controller will be displayed.

The Managed Heap and Resource Heap values control your application's memory allocation. The value is specified in kilobytes, with a maximum total value of 96 MB combined. The managed heap is the data your application will use to run; for example, if you allocate a byte[] array, this would consume space on the managed heap. Resource Heap on the other hand is the storage used by PlayStation Mobile when loading assets such as audio files and images.

When specifying your images, there are a few things to be aware of. You need to create only a single 512 x 512 image that can be used to generate the smaller icon sizes. The splash screen image needs to be 854 x 480 in size and 8 bits per pixel indexed in format. As of this writing, the tool will currently fail if there is a space in your file path for any of the images.

Note

Using a PNG image for creating a splash screen of 8 bits per pixel can prove to be a bit tricky. In the GIMP photo editor, create or load your image as usual, then select Image | Mode | Index…. Set 255 as the maximum number of colors. The one particular snag you can run into is that if you use less than 16 colors in your image, it will be saved as 4bpp or 2bpp. To prevent this, I added a new layer behind the image, so it isn't visible, and filled it with a multicolor gradient. This gets the image's color count over 16, resulting in an 8-bit image when saved.

See also

- See the Configuring an Android application to use onscreen controls recipe in Chapter 2, Controlling Your PlayStation Mobile Device, for more details on enabling the GamePad option

- See Appendix, Publishing Your Application, for details on publishing your application or generating keys using PublishingUtility

Creating downloadable content (DLC) for your application

The PlayStation Store supports adding downloadable content for your application. This recipe examines how you use PublishingUtility to create DLC items for use with your app.

Getting ready

Like the prior recipe, this one assumes you have an existing PSM project to work with.

How to do it...

To create DLC for your application perform the following steps:

1. Open PublishingUtility; a shortcut should be available in the PlayStation Mobile folder of your Start Menu.

2. Open the app.xml file of the application, you want to add downloadable content to.

3. Once open, select the In-App Purchase tab. To add a new item, enter a six-digit alpha-numeric code in the Product Label field. Check each language your DLC is going to be available in and click on the Add Product button.

4. An entry will appear for each item you have added, with one line displayed per language specified. In the right-hand side field enter the localized description of the item. If the item is consumable (used up on use) check the Consumable checkbox. It should look somewhat like the following screenshot:

5. Click on the Save button when done.

How it works...

Just as in the prior recipe, the end result of this process is the generation of the app.xml file. Here is the DLC specific output from the preceding example:

<purchase>
<product_list>
<product label="SWD001" type="normal">
<name>
<localized_item locale="en-US" value="Sword of awesomeness" />
<localized_item locale="en-GB" value="Sword of awesomeness" />
</name>
</product>
</product_list>
</purchase>

The product is actually created on the server when you publish your application. You can control DLC details using the PlayStation Mobile portal.

There's more...

There is some programming involved in actually showing the DLC items to the user for purchase. Essentially, the process involves creating and showing an InAppPurchaseDialog to the user. You get a list of purchasable items from the server by calling GetProductInfo(); those items are exactly what we created in this process. Next you use GetTicketInfo() to get ticket information from the server, which will hold the transaction details. The Purchase() method then attempts to make the actual purchase, while Consume() actually consumes the item if it's a usage-based consumable item.

See also

- The process of implementing DLC in code happens across multiple parts and doesn't lend itself to the recipe format as a result. Fortunately, there are a pair of samples you can work from: InAppPurchaseSample1 and InAppPurchaseSample2. Assuming you used a default install, they will be located at C:\Users\Public\Documents\PSM\sample\Services.

- See Appendix, Publishing Your Application, for more details on publishing to the PlayStation Mobile store and accessing the portal.

Appendix A. Publishing Your Application

Introduction

At this point in the book you should know everything you need to create the next big game. It's time to look at the process of publishing your application to the PlayStation store.

Process overview

The following graphic created by Sony details the application development process, from initial creation to getting paid for your hard work. The portions in blue are the parts that you, the developer, are responsible for:

We have covered the development and testing portions in detail already, earlier in the book. Now we will look at the other details of publishing your application to the store.

Obtaining a developer license

Once you have developed your application and are ready to publish it, you will need to obtain a developer license. As of the time of writing, this costs US $99 a year and is available at https://psm.playstation.net.

If you don't already have one, you need to register for a Sony Entertainment Network account (if you have a PlayStation online or have used any of Sony's forums, this is your SEN account). They are free to sign up for and are required if you want to participate in the PlayStation Mobile development forums.

Once you've logged in to the portal, fill in the application form for a developer license, which will be submitted to Sony. Once your application is approved, you will receive an e-mail indicating your acceptance as well as a link that will direct you to the form where you can pay the fee. PlayStation Mobile is now active on your SEN account.

Your publisher keys

Now that your account is activated and approved you can request your publisher keys. Keys are created using PublishingUtility, described earlier in Chapter 9, Finishing Touches. Load PublishingUtility and select Key Management. Then, click on the Generate Publisher Key button:

A dialog window will appear prompting you for the key name. Enter a value and click on OK:

Next, you will be prompted for your SEN ID and password. Enter these values and click on OK. You should soon see a dialog stating the keys were successfully created.

Preparing your application for publication

Before you can deploy your application, you need to configure a number of settings using the PSM Publishing Utility. Open the utility and in the menu select File | Load, then select your app.xml file.

Now select the Metadata tab; pretty much every category needs to be filled in.

The following screenshot shows a sample entry for the common properties:

Most of the values here we have already covered or are fairly self-explanatory. Clicking on an item will bring up a description of the values you should use.

Now we look at the Application Name tab:

These values simply represent the complete name and short name of your application on the PS Mobile Store. You simply specify the language code as well as the two values you wish to use.

Next up is the Image tab:

This part can be a bit tricky. You need to provide a 32 bit per pixel 512x512 resolution image that will be used for your store icon. You can have the tool automatically generate the smaller versions for you. You also need a splash screen that is 854x480 in size and 8 bits per pixel indexed. This last part can be a bit tricky to accomplish. I generated the image using GIMP. However, I had to create an invisible layer with more than 16 colors on it, or the GIMP would automatically reduce the image to 4 bits when saved. It is very important that this image be in the proper format or it will not work.

Finally, let's see the Rating Check tab:

On this page you submit your application to PEGI, ESRB, and the PSM age system. Each service is freely available; follow each link and fill in the resulting forms. In the end you will either be given or e-mailed a code. Once you have the codes, enter them into the corresponding form field.

Now that your application is configured, click on Save.

Publishing your application

Open your application in PSM Studio. Do a clean build. Then select the menu Project|Compose PSM Master Package. If prompted for credentials, log in. Assuming everything goes well, you should see the message shown in the following screenshot:

Next, you will be asked if you wish to submit the application to Sony:

Then, once again assuming everything went OK, you should see the message shown in the following screenshot:

Congratulations, your application has just been submitted to Sony and awaits further approval.

You can now log in to the PSM portal and check on the status of your application, or make further changes:

You can withdraw your application if required. Once approved, this is where you set pricing information for your application and any DLC you might have included. The portal also has reports for tracking your applications performance in the online store.

Index

A

- Aabb / How it works...

- ActionManager

- about / Introduction

- working with / Working with the ActionManager object, How to do it..., How it works...

- Add Product button / How to do it...

- AdHocDraw function / Adding a grid

- AdHocDraw method / How it works...

- analog joysticks

- about / Using the analog joysticks

- using / Getting ready, How to do it...

- working / How it works...

- and (&) operation / How it works...

- Animate() method / How it works...

- animated model

- sword adding, bones used / Using bones to add a sword to our animated model, How to do it..., There's more...

- application

- deploying, to Android device / Deploying to PlayStation Mobile certified Android devices, Getting ready, How to do it..., There's more...

- DLC, creating / Creating downloadable content (DLC) for your application, How it works...

- publishing / Publishing your application

- application assembly

- resource, retrieving / Embedding and retrieving a resource from the application assembly, How to do it..., How it works...

- resource, embedding / Embedding and retrieving a resource from the application assembly, How to do it..., How it works...

- application configuration

- PublishingUtility, using / Configuring your application using PublishingUtility, How to do it..., There's more…

- Application Name tab / How to do it..., Preparing your application for publication

- application publish

- process overview / Process overview

- developer license, obtaining / Obtaining a developer license

- publisher keys / Your publisher keys

- preparing steps / Preparing your application for publication

- steps / Publishing your application

- Apply to layout button / How to do it...

B

- background music

- playing / Getting ready, How to do it..., How it works..., There's more...

- BasicProgram

- using, for shader effects / Using BasicProgram to perform texture and shader effects, How to do it..., How it works..., There's more...

- using, for texture / Using BasicProgram to perform texture and shader effects, How to do it..., How it works..., There's more...

- scene lighting control / Controlling lighting using BasicProgram, How to do it...

- working / How it works..., See also

- BEPU physics engine / There's more...

- bones

- used, for sword adding / Using bones to add a sword to our animated model, How to do it..., There's more...

- BunjeeEffect / There's more...

C

- camera system

- implementing / Implementing a simple camera system, Getting ready, How to do it...

- working / How it works..., See also

- Circle (D key) / How to do it...

- Clipboard.GetText() method / How it works...

- CodePlex / There's more...

- collision

- detecting / Simple collision detection, How to do it..., How it works...

- checking / Querying if a collision occurred, How to do it..., How it works...

- common widgets / Common widgets

- compiler / Compiler and runtime

- container widgets / Container widgets

- Control key / How it works...

- copying

- Clipboard used / Copying and pasting using Clipboard, How to do it..., How it works...

- Crop() function / How it works...

- CSV / There's more...

- currentLanguageId property / How to do it...

- CurrentMotion property / How it works...

D

- 2D particle system

- creating / Creating a 2D particle system

- working / How it works...

- 3D model

- importing, for PlayStation Mobile / Importing a 3D model for use in PlayStation Mobile, How to do it..., How it works..., There's more...

- displaying in / Loading and displaying a 3D model, How to do it...

- loading / Loading and displaying a 3D model, How to do it..., How it works..., There's more...

- displaing in / How it works..., There's more...

- bones / There's more...

- 3D scene

- creating / Getting ready, How to do it...

- working / How it works..., There's more...

- Director function / How it works...

- Dispose() method / How it works...

- DLC

- creating, for application / Creating downloadable content (DLC) for your application, How it works...

- Draw() method / How it works..., There's more...

- DrawText() function / How it works...

- Dynamic / How it works...

E

- E key / How to do it...

- emulated button / There's more...

- event loop / How it works...

- ExampleScene class / How it works...

- external library

- using / Building and using an external library, How to do it..., How it works...

- building / Building and using an external library, How to do it..., How it works...

F

- F5 key / How to do it..., How to do it...

- F18 sprite / How to do it...

- FarSeer physics engine / There's more...

- file storage locations

- /Application / There's more...

- /Documents / There's more...

- /Temp / There's more...

- filesystem

- working with / Working with the filesystem, How it works..., There's more...

- FMath.Radians()utility function / How it works...

- force

- applying, to rigid body / Applying force and picking a physics scene object, Getting ready, How to do it..., How it works...

- FPS / How it works...

- fragment shader

- creating / A fragment (pixel) shader in action, How to do it..., There's more..., See also

- input semantics / There's more...

- output semantics / There's more...

- FxComposer / See also

G

- GameEngine2D / Introduction

- about / Introduction

- used, for game loop creating / A game loop, GameEngine2D style, Getting ready, How it works..., There's more..., See also

- GameEngine2D application

- UI library, using / Using the UI library within a GameEngine2D application, How to do it..., How it works...

- game loop

- creating, GameEngine2D used / A game loop, GameEngine2D style, Getting ready, How it works..., There's more..., See also

- gamepad’s buttons

- handling / Handling the controller's d-pad and buttons, How it works..., There's more..., See also

- gamepad’s d-pad

- handling / Handling the controller's d-pad and buttons, How it works..., There's more..., See also

- Generate App Key Ring button / How to do it...

- Generate Publisher Key button / Your publisher keys

H

- HandleButtonGoButtonAction function / How it works...

- Hello World application

- creating, from HighLevel.UI library / "Hello World" – HighLevel.UI style, How to do it..., There's more...

- working / How it works...

- HighLevel.UI toolkit / Introduction

- HTC Hero One X

- system requirements / HTC Hero One X specifications

- HttpWebRequest

- used, for data accessing / Accessing (Twitter) data over the network using REST and HttpWebRequest, How to do it..., How it works..., See also

I

- image

- manipulating dynamically / Manipulating an image dynamically, Getting ready, There's more...

- Image tab / Preparing your application for publication

- In-App Purchase tab / How to do it..., How to do it...

- IncomingSocket function / How it works...

- Initialize() function / How to do it...

- Initialize() method / How to do it...

- Input2 wrapper class

- about / Using the Input2 wrapper class

- using / Getting ready, How to do it...

- working / How it works...

J

- joint

- simulating / Creating a (physics!) joint, Getting ready, How to do it..., How it works...

K

- keys / There's more...

- Kinematic / How it works...

L

- language localization

- handling / Handling language localization, How to do it..., There's more...

M

- Main() function / How to do it...

- MessageBox dialog

- about / Displaying a MessageBox dialog

- displaying / How to do it...

- working / How it works...

- Metadata tab / Preparing your application for publication

- model

- animating / Getting ready, How to do it..., How it works...

- ModelConverter

- file formats / There's more...

- ModelViewer / There's more...

- modes / There's more...

- MonoGame library / There's more...

- motion sensors

- using / Getting ready, How to do it...

- working / How it works...

- MoveEffect / There's more...

- multiple animations

- handling / Getting ready, How to do it..., How it works..., There's more...

N

- .NET libraries / Compiler and runtime

O

- offscreen frame buffer

- using / Using an offscreen frame buffer to take a screenshot, How to do it..., See Also

- OnEnter() method / How it works...

- OnRestored event / How it works...

- onscreen controls

- creating, for non-gamepad devices / Creating onscreen controls for devices without gamepads, Getting ready, How to do it…, There's more...

- onscreen controls, on Android device

- configuring / Configuring an Android application to use onscreen controls, Getting ready, How to do it…

P

- pasting

- Clipboard used / Copying and pasting using Clipboard, How to do it..., How it works...

- Physics2D

- about / Introduction

- physics body toggling

- between dynamic and kinematic / Switching between dynamic and kinematic, How to do it..., How it works..., There's more...

- physics scene object

- picking / Applying force and picking a physics scene object, Getting ready, How to do it..., How it works...

- Play() method / How it works...

- PlayStation Mobile

- about / Introduction

- portal, accessing / Accessing the PlayStation Mobile portal, How to do it..., How it works...

- tools, installing / Installing the PlayStation Mobile SDK, How to do it...

- 3D model, importing / Importing a 3D model for use in PlayStation Mobile, How to do it..., How it works..., There's more...

- PlayStation Mobile Android devices

- resolutions / There's more...

- PlayStation Mobile certified devices

- about / PlayStation Mobile certified devices

- PlayStation Vita, system requirements / PlayStation Vita specifications

- HTC Hero One X, system requirements / HTC Hero One X specifications

- PlayStation Mobile portal

- accessing / Accessing the PlayStation Mobile portal, How to do it..., How it works...

- PlayStation Mobile SDK

- about / A tour of the PlayStation Mobile SDK

- PSM Studio IDE / PSM Studio IDE

- runtime / Compiler and runtime

- compiler / Compiler and runtime

- UIComposer / UIComposer

- other utilities / Other utilities

- certified devices / PlayStation Mobile certified devices

- PlayStation Mobile tools

- installing / Installing the PlayStation Mobile SDK, How to do it...

- PlayStation Vita

- system requirements / PlayStation Vita specifications

- configuring / Deploying to a PlayStation Vita, How to do it..., There's more...

- port 9210 / There's more...

- predefined actions

- using / Using predefined actions, How to do it...

- working / How it works...

- GameEngine2D library actions / There's more...

- PS button / There's more...

- PSM Studio IDE / PSM Studio IDE

- PublishingUtility

- used, for application configuration / Configuring your application using PublishingUtility, How to do it..., There's more…

- Purchase() method / There's more...

R

- rasterized / There's more...

- Rating Check tab / How to do it..., Preparing your application for publication

- Render() method / How to do it...

- Resize() function / How it works...

- REST

- used, for data accessing / Accessing (Twitter) data over the network using REST and HttpWebRequest, How to do it..., How it works..., See also

- about / There's more...

- restitution of coefficient / There's more...

- rigid body collision shapes

- about / Rigid body collision shapes, How to do it..., How it works...

- RootWidget / Common widgets

S

- Sce.PlayStation.Core.Graphics library / Introduction

- scenes

- creating / Creating scenes, How to do it..., How it works...

- grid, adding / Adding a grid

- sprite, adding / Adding a sprite to a scene, How it works..., There's more...

- transitioning between / Transitioning between scenes, How to do it..., How it works..., There's more...

- light, adding / Adding lighting to your scene, How to do it..., How it works..., There's more...

- Scheduler

- about / Introduction

- used, for update handling / Handling updates with Scheduler, Getting ready, How to do it...

- working / How it works...

- server networking / Socket-based client and server networking, How to do it..., How it works...

- SetPixel() function / How it works...

- SetVertices() method / How it works...

- SFX Asset Library / There's more...

- simple game loop

- creating / Creating a simple game loop, How to do it...

- working / How it works..., There's more...

- simple simulation, with gravity

- creating / Getting ready, How to do it..., How it works..., There's more...

- Single Screen tab / How to do it…

- S key / How to do it...

- socket-based client / Socket-based client and server networking, How to do it..., How it works...

- sound effects

- playing / Getting ready, How to do it..., How it works..., See also

- SoundPlayer class / There's more...

- sprite

- adding, to scenes / Adding a sprite to a scene, How it works..., There's more...

- SpriteLists

- using, benefits / Batching a sprite with SpriteLists, How to do it..., How it works..., There's more...

- sprite sheet

- creating / How to do it...

- working / How it works...

- using, in code / Using a sprite sheet in code, Getting ready, How to do it..., How it works..., There's more...

- batching, with SpriteLists / Batching a sprite with SpriteLists, How to do it..., How it works..., There's more...

- SpritesheetScene / How it works...

- SpriteTile class / There's more...

- Square button (A key) / How to do it...

- Start button / There's more...

- system events

- handling / Handling system events

- working / How it works...

T

- Take() method / How it works...

- Text property / Getting ready

- texture

- creating / "Hello World" drawing text on an image, How to do it..., How it works..., There's more...

- displaying / "Hello World" drawing text on an image, How to do it..., How it works..., There's more...

- texture 3D object

- about / Displaying a textured 3D object

- displaying / How to do it..., How it works..., There's more...

- limits / There's more...

- textured image

- translating / Loading, displaying, and translating a textured image, How to do it..., How it works..., There's more...

- displaying / Loading, displaying, and translating a textured image, How to do it..., How it works..., There's more...

- loading / Loading, displaying, and translating a textured image, How to do it..., How it works..., There's more...

- texture’s pixels

- manipulating / Manipulating a texture's pixels, How it works...

- ToBuffer() function / How it works...

- touch events

- handling / Handling touch events, How it works...

- working / How it works..., There's more...

- touch gestures

- handling / How to do it..., How it works..., See also

- TriangleStrip / There's more...

U

- UI

- creating, UIComposer used / Creating a UI visually using UIComposer, How to do it..., There's more...

- UIComposer / UIComposer

- used, for UI creating / Creating a UI visually using UIComposer, How to do it..., There's more...

- UI effect objects / There's more...

- UI library

- using, within GameEngine2D application / Using the UI library within a GameEngine2D application, How to do it..., How it works...

- UI special effects

- applying / How to do it..., How it works..., See also

- Update() method / How it works...

- update handling

- Scheduler, using / Handling updates with Scheduler, Getting ready, How to do it...

V

- vertex shader

- creating / A vertex shader in action, How to do it...

- working / How it works..., There's more...

- input semantics / There's more...

- output semantics / There's more...

W

- web browser

- loading / Opening and loading a web browser, How to do it..., How it works...

- opening / Opening and loading a web browser, How to do it..., How it works...

- widget hierarchies

- creating / How to do it..., How it works...

- using / How to do it..., How it works...

- container widget / Container widgets

- common widget / Common widgets

X

- X button / How it works..., How to do it...

- X key / There's more...

Z

- Z key / There's more...