TRS Struct Reference

TRS comes from scenegraph terminology and is used to store a Translate/Rotate/Scale 2d transform in a canonical way. More...

List of all members.

Classes
class	Local
	Some aliases for commonly used points that can be passed to Centering. More...
Public Member Functions
void	Rotate (float angle)
	Rotate the object by an angle.
void	Rotate (Vector2 rotation)
	Rotate the object by an angle.
	TRS (Bounds2 a_bounds)
	Convert from Bounds2: a_bounds.Min becomes T and a_bounds.Size becomes S (no rotation).
Bounds2	Bounds2 ()
	Convert to Bounds2.
void	Centering (Vector2 normalized_pos)
	Translate the TRS so that the normalized point given in input becomes (0,0).
override string	ToString ()
Static Public Member Functions
static TRS	Tile (Vector2i num_tiles, Vector2i tile_index, TRS source_area)
	Get a subregion from source_area, given a number of tiles and a tile index, assuming evenly spaced subdivision.
Public Attributes
Vector2	T
	Translation.
Vector2	R
	Rotation - stored as a unit vector (cos,sin).
Vector2	S
	Scale (or Size).
Static Public Attributes
static TRS	Quad0_1
	A TRS that covers the unit quad that goes from (0,0) to (1,1).
static TRS	QuadMinus1_1
	A TRS that covers the quad that goes from (-1,-1) to (1,1).
Properties
Vector2	X [get]
	The support X vector, which goes from bottom left to bottom right.
Vector2	Y [get]
	The support Y vector, which goes from bottom left to top left.
Vector2	Point00 [get]
	The bottom left point (the base point), (0,0) in 'local' coordinates.
Vector2	Point10 [get]
	The bottom right point, (1,0) in 'local' coordinates.
Vector2	Point01 [get]
	The top left point, (0,1) in 'local' coordinates.
Vector2	Point11 [get]
	The top right point, (1,1) in 'local' coordinates.
Vector2	Center [get]
	Return the center of the oriented box defined by this TRS.
Vector2	RotationNormalize [get, set]
	RotationNormalize is like Rotation, but it normalizes on set, to prevent the unit vector from drifting because of accumulated numerical imprecision.
float	Angle [get, set]
	This property lets you set/get rotation as a angle.

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Detailed Description

TRS comes from scenegraph terminology and is used to store a Translate/Rotate/Scale 2d transform in a canonical way.

It also defines an oriented bounding box. We use it for storing both sprite positionning/size and sprite UV.

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Member Function Documentation

Bounds2 Bounds2

(

)

Convert to Bounds2.

Note that end points won't match if there is a Rotation, but in all cases the returned bounds fully contains the TRS.

void Centering

(

Vector2

normalized_pos

)

Translate the TRS so that the normalized point given in input becomes (0,0).

There are a few predefined normalized points in TRS.Local.

Parameters:

normalized_pos

The normalized position that will become the new center. For example (0.5,0.5) represents the center of the TRS, regardless of the actual size, position and orientation of the TRS. (0,0) is the bottom left point, (1,1) is the top right point etc.

void Rotate

(

Vector2

rotation

)

Rotate the object by an angle.

Parameters:

rotation

The (cos(angle),sin(angle)) unit vector representing the rotation.

This lets you precompute the cos,sin needed during rotation.

void Rotate

(

float

angle

)

Rotate the object by an angle.

Parameters:

angle

Rotation angle in radian.

static TRS Tile	(	Vector2i	num_tiles,
		Vector2i	tile_index,
		TRS	source_area
	)		[static]

Get a subregion from source_area, given a number of tiles and a tile index, assuming evenly spaced subdivision.

Typically source_area will be Quad0_1 (the unit quad, means the whole texture) and we return the uv info for a given tile in the tiled texture.

override string ToString

(

)

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Property Documentation

float Angle [get, set]

This property lets you set/get rotation as a angle.

This is expensive and brings the usual angle discontinuity problems. The angle is always stored and returned in the the range -pi,pi.