com.badlogic.gdx.math

Class Affine2

java.lang.Object

com.badlogic.gdx.math.Affine2

All Implemented Interfaces:

Serializable

public final class Affine2
extends Object
implements Serializable

A specialized 3x3 matrix that can represent sequences of 2D translations, scales, flips, rotations, and shears. Affine transformations preserve straight lines, and parallel lines remain parallel after the transformation. Operations on affine matrices are faster because the last row can always be assumed (0, 0, 1).

Author:

vmilea

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
float	m00
float	m01
float	m02
float	m10
float	m11
float	m12

Constructor Summary

Constructors

Constructor and Description
Affine2() Constructs an identity matrix.
Affine2(Affine2 other) Constructs a matrix from the given affine matrix.

Method Summary

Modifier and Type	Method and Description
void	applyTo(Vector2 point) Applies the affine transformation on a vector.
float	det() Calculates the determinant of the matrix.
Vector2	getTranslation(Vector2 position) Get the x-y translation component of the matrix.
Affine2	idt() Sets this matrix to the identity matrix
Affine2	inv() Inverts this matrix given that the determinant is != 0.
boolean	isIdt() Check if this is an indentity matrix.
boolean	isTranslation() Check if the this is a plain translation matrix.
Affine2	mul(Affine2 other) Postmultiplies this matrix with the provided matrix and stores the result in this matrix.
Affine2	preMul(Affine2 other) Premultiplies this matrix with the provided matrix and stores the result in this matrix.
Affine2	preRotate(float degrees) Premultiplies this matrix with a (counter-clockwise) rotation matrix.
Affine2	preRotateRad(float radians) Premultiplies this matrix with a (counter-clockwise) rotation matrix.
Affine2	preScale(float scaleX, float scaleY) Premultiplies this matrix with a scale matrix.
Affine2	preScale(Vector2 scale) Premultiplies this matrix with a scale matrix.
Affine2	preShear(float shearX, float shearY) Premultiplies this matrix by a shear matrix.
Affine2	preShear(Vector2 shear) Premultiplies this matrix by a shear matrix.
Affine2	preTranslate(float x, float y) Premultiplies this matrix by a translation matrix.
Affine2	preTranslate(Vector2 trn) Premultiplies this matrix by a translation matrix.
Affine2	rotate(float degrees) Postmultiplies this matrix with a (counter-clockwise) rotation matrix.
Affine2	rotateRad(float radians) Postmultiplies this matrix with a (counter-clockwise) rotation matrix.
Affine2	scale(float scaleX, float scaleY) Postmultiplies this matrix with a scale matrix.
Affine2	scale(Vector2 scale) Postmultiplies this matrix with a scale matrix.
Affine2	set(Affine2 other) Copies the values from the provided affine matrix to this matrix.
Affine2	set(Matrix3 matrix) Copies the values from the provided matrix to this matrix.
Affine2	set(Matrix4 matrix) Copies the 2D transformation components from the provided 4x4 matrix.
Affine2	setToProduct(Affine2 l, Affine2 r) Sets this matrix to the product of two matrices.
Affine2	setToRotation(float degrees) Sets this matrix to a rotation matrix that will rotate any vector in counter-clockwise direction around the z-axis.
Affine2	setToRotation(float cos, float sin) Sets this matrix to a rotation matrix that will rotate any vector in counter-clockwise direction around the z-axis.
Affine2	setToRotationRad(float radians) Sets this matrix to a rotation matrix that will rotate any vector in counter-clockwise direction around the z-axis.
Affine2	setToScaling(float scaleX, float scaleY) Sets this matrix to a scaling matrix.
Affine2	setToScaling(Vector2 scale) Sets this matrix to a scaling matrix.
Affine2	setToShearing(float shearX, float shearY) Sets this matrix to a shearing matrix.
Affine2	setToShearing(Vector2 shear) Sets this matrix to a shearing matrix.
Affine2	setToTranslation(float x, float y) Sets this matrix to a translation matrix.
Affine2	setToTranslation(Vector2 trn) Sets this matrix to a translation matrix.
Affine2	setToTrnRotRadScl(float x, float y, float radians, float scaleX, float scaleY) Sets this matrix to a concatenation of translation, rotation and scale.
Affine2	setToTrnRotRadScl(Vector2 trn, float radians, Vector2 scale) Sets this matrix to a concatenation of translation, rotation and scale.
Affine2	setToTrnRotScl(float x, float y, float degrees, float scaleX, float scaleY) Sets this matrix to a concatenation of translation, rotation and scale.
Affine2	setToTrnRotScl(Vector2 trn, float degrees, Vector2 scale) Sets this matrix to a concatenation of translation, rotation and scale.
Affine2	setToTrnScl(float x, float y, float scaleX, float scaleY) Sets this matrix to a concatenation of translation and scale.
Affine2	setToTrnScl(Vector2 trn, Vector2 scale) Sets this matrix to a concatenation of translation and scale.
Affine2	shear(float shearX, float shearY) Postmultiplies this matrix by a shear matrix.
Affine2	shear(Vector2 shear) Postmultiplies this matrix by a shear matrix.
String	toString()
Affine2	translate(float x, float y) Postmultiplies this matrix by a translation matrix.
Affine2	translate(Vector2 trn) Postmultiplies this matrix by a translation matrix.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

m00

public float m00

m01

public float m01

m02

public float m02

m10

public float m10

m11

public float m11

m12

public float m12

Constructor Detail

Affine2

public Affine2()

Constructs an identity matrix.

Affine2

public Affine2(Affine2 other)

Constructs a matrix from the given affine matrix.

Parameters:

other - The affine matrix to copy. This matrix will not be modified.

Method Detail

idt

public Affine2 idt()

Sets this matrix to the identity matrix

Returns:

This matrix for the purpose of chaining operations.

set

public Affine2 set(Affine2 other)

Copies the values from the provided affine matrix to this matrix.

Parameters:

other - The affine matrix to copy.

Returns:

This matrix for the purposes of chaining.

set

public Affine2 set(Matrix3 matrix)

Copies the values from the provided matrix to this matrix.

Parameters:

matrix - The matrix to copy, assumed to be an affine transformation.

Returns:

This matrix for the purposes of chaining.

set

public Affine2 set(Matrix4 matrix)

Copies the 2D transformation components from the provided 4x4 matrix. The values are mapped as follows:

      [  M00  M01  M03  ]
      [  M10  M11  M13  ]
      [   0    0    1   ]
 

Parameters:

matrix - The source matrix, assumed to be an affine transformation within XY plane. This matrix will not be modified.

Returns:

This matrix for the purpose of chaining operations.

setToTranslation

public Affine2 setToTranslation(float x,
                                float y)

Sets this matrix to a translation matrix.

Parameters:

x - The translation in x

y - The translation in y

Returns:

This matrix for the purpose of chaining operations.

setToTranslation

public Affine2 setToTranslation(Vector2 trn)

Sets this matrix to a translation matrix.

Parameters:

trn - The translation vector.

Returns:

This matrix for the purpose of chaining operations.

setToScaling

public Affine2 setToScaling(float scaleX,
                            float scaleY)

Sets this matrix to a scaling matrix.

Parameters:

scaleX - The scale in x.

scaleY - The scale in y.

Returns:

This matrix for the purpose of chaining operations.

setToScaling

public Affine2 setToScaling(Vector2 scale)

Sets this matrix to a scaling matrix.

Parameters:

scale - The scale vector.

Returns:

This matrix for the purpose of chaining operations.

setToRotation

public Affine2 setToRotation(float degrees)

Sets this matrix to a rotation matrix that will rotate any vector in counter-clockwise direction around the z-axis.

Parameters:

degrees - The angle in degrees.

Returns:

This matrix for the purpose of chaining operations.

setToRotationRad

public Affine2 setToRotationRad(float radians)

Sets this matrix to a rotation matrix that will rotate any vector in counter-clockwise direction around the z-axis.

Parameters:

radians - The angle in radians.

Returns:

This matrix for the purpose of chaining operations.

setToRotation

public Affine2 setToRotation(float cos,
                             float sin)

Sets this matrix to a rotation matrix that will rotate any vector in counter-clockwise direction around the z-axis.

Parameters:

cos - The angle cosine.

sin - The angle sine.

Returns:

This matrix for the purpose of chaining operations.

setToShearing

public Affine2 setToShearing(float shearX,
                             float shearY)

Sets this matrix to a shearing matrix.

Parameters:

shearX - The shear in x direction.

shearY - The shear in y direction.

Returns:

This matrix for the purpose of chaining operations.

setToShearing

public Affine2 setToShearing(Vector2 shear)

Sets this matrix to a shearing matrix.

Parameters:

shear - The shear vector.

Returns:

This matrix for the purpose of chaining operations.

setToTrnRotScl

public Affine2 setToTrnRotScl(float x,
                              float y,
                              float degrees,
                              float scaleX,
                              float scaleY)

Sets this matrix to a concatenation of translation, rotation and scale. It is a more efficient form for: idt().translate(x, y).rotate(degrees).scale(scaleX, scaleY)

Parameters:

x - The translation in x.

y - The translation in y.

degrees - The angle in degrees.

scaleX - The scale in y.

scaleY - The scale in x.

Returns:

This matrix for the purpose of chaining operations.

setToTrnRotScl

public Affine2 setToTrnRotScl(Vector2 trn,
                              float degrees,
                              Vector2 scale)

Sets this matrix to a concatenation of translation, rotation and scale. It is a more efficient form for: idt().translate(trn).rotate(degrees).scale(scale)

Parameters:

trn - The translation vector.

degrees - The angle in degrees.

scale - The scale vector.

Returns:

This matrix for the purpose of chaining operations.

setToTrnRotRadScl

public Affine2 setToTrnRotRadScl(float x,
                                 float y,
                                 float radians,
                                 float scaleX,
                                 float scaleY)

Sets this matrix to a concatenation of translation, rotation and scale. It is a more efficient form for: idt().translate(x, y).rotateRad(radians).scale(scaleX, scaleY)

Parameters:

x - The translation in x.

y - The translation in y.

radians - The angle in radians.

scaleX - The scale in y.

scaleY - The scale in x.

Returns:

This matrix for the purpose of chaining operations.

setToTrnRotRadScl

public Affine2 setToTrnRotRadScl(Vector2 trn,
                                 float radians,
                                 Vector2 scale)

Sets this matrix to a concatenation of translation, rotation and scale. It is a more efficient form for: idt().translate(trn).rotateRad(radians).scale(scale)

Parameters:

trn - The translation vector.

radians - The angle in radians.

scale - The scale vector.

Returns:

This matrix for the purpose of chaining operations.

setToTrnScl

public Affine2 setToTrnScl(float x,
                           float y,
                           float scaleX,
                           float scaleY)

Sets this matrix to a concatenation of translation and scale. It is a more efficient form for: idt().translate(x, y).scale(scaleX, scaleY)

Parameters:

x - The translation in x.

y - The translation in y.

scaleX - The scale in y.

scaleY - The scale in x.

Returns:

This matrix for the purpose of chaining operations.

setToTrnScl

public Affine2 setToTrnScl(Vector2 trn,
                           Vector2 scale)

Sets this matrix to a concatenation of translation and scale. It is a more efficient form for: idt().translate(trn).scale(scale)

Parameters:

trn - The translation vector.

scale - The scale vector.

Returns:

This matrix for the purpose of chaining operations.

setToProduct

public Affine2 setToProduct(Affine2 l,
                            Affine2 r)

Sets this matrix to the product of two matrices.

Parameters:

l - Left matrix.

r - Right matrix.

Returns:

This matrix for the purpose of chaining operations.

inv

public Affine2 inv()

Inverts this matrix given that the determinant is != 0.

Returns:

This matrix for the purpose of chaining operations.

Throws:

GdxRuntimeException - if the matrix is singular (not invertible)

mul

public Affine2 mul(Affine2 other)

Postmultiplies this matrix with the provided matrix and stores the result in this matrix. For example:

 A.mul(B) results in A := AB
 

Parameters:

other - Matrix to multiply by.

Returns:

This matrix for the purpose of chaining operations together.

preMul

public Affine2 preMul(Affine2 other)

Premultiplies this matrix with the provided matrix and stores the result in this matrix. For example:

 A.preMul(B) results in A := BA
 

Parameters:

other - The other Matrix to multiply by

Returns:

This matrix for the purpose of chaining operations.

translate

public Affine2 translate(float x,
                         float y)

Postmultiplies this matrix by a translation matrix.

Parameters:

x - The x-component of the translation vector.

y - The y-component of the translation vector.

Returns:

This matrix for the purpose of chaining.

translate

public Affine2 translate(Vector2 trn)

Postmultiplies this matrix by a translation matrix.

Parameters:

trn - The translation vector.

Returns:

This matrix for the purpose of chaining.

preTranslate

public Affine2 preTranslate(float x,
                            float y)

Premultiplies this matrix by a translation matrix.

Parameters:

x - The x-component of the translation vector.

y - The y-component of the translation vector.

Returns:

This matrix for the purpose of chaining.

preTranslate

public Affine2 preTranslate(Vector2 trn)

Premultiplies this matrix by a translation matrix.

Parameters:

trn - The translation vector.

Returns:

This matrix for the purpose of chaining.

scale

public Affine2 scale(float scaleX,
                     float scaleY)

Postmultiplies this matrix with a scale matrix.

Parameters:

scaleX - The scale in the x-axis.

scaleY - The scale in the y-axis.

Returns:

This matrix for the purpose of chaining.

scale

public Affine2 scale(Vector2 scale)

Postmultiplies this matrix with a scale matrix.

Parameters:

scale - The scale vector.

Returns:

This matrix for the purpose of chaining.

preScale

public Affine2 preScale(float scaleX,
                        float scaleY)

Premultiplies this matrix with a scale matrix.

Parameters:

scaleX - The scale in the x-axis.

scaleY - The scale in the y-axis.

Returns:

This matrix for the purpose of chaining.

preScale

public Affine2 preScale(Vector2 scale)

Premultiplies this matrix with a scale matrix.

Parameters:

scale - The scale vector.

Returns:

This matrix for the purpose of chaining.

rotate

public Affine2 rotate(float degrees)

Postmultiplies this matrix with a (counter-clockwise) rotation matrix.

Parameters:

degrees - The angle in degrees

Returns:

This matrix for the purpose of chaining.

rotateRad

public Affine2 rotateRad(float radians)

Postmultiplies this matrix with a (counter-clockwise) rotation matrix.

Parameters:

radians - The angle in radians

Returns:

This matrix for the purpose of chaining.

preRotate

public Affine2 preRotate(float degrees)

Premultiplies this matrix with a (counter-clockwise) rotation matrix.

Parameters:

degrees - The angle in degrees

Returns:

This matrix for the purpose of chaining.

preRotateRad

public Affine2 preRotateRad(float radians)

Premultiplies this matrix with a (counter-clockwise) rotation matrix.

Parameters:

radians - The angle in radians

Returns:

This matrix for the purpose of chaining.

shear

public Affine2 shear(float shearX,
                     float shearY)

Postmultiplies this matrix by a shear matrix.

Parameters:

shearX - The shear in x direction.

shearY - The shear in y direction.

Returns:

This matrix for the purpose of chaining.

shear

public Affine2 shear(Vector2 shear)

Postmultiplies this matrix by a shear matrix.

Parameters:

shear - The shear vector.

Returns:

This matrix for the purpose of chaining.

preShear

public Affine2 preShear(float shearX,
                        float shearY)

Premultiplies this matrix by a shear matrix.

Parameters:

shearX - The shear in x direction.

shearY - The shear in y direction.

Returns:

This matrix for the purpose of chaining.

preShear

public Affine2 preShear(Vector2 shear)

Premultiplies this matrix by a shear matrix.

Parameters:

shear - The shear vector.

Returns:

This matrix for the purpose of chaining.

det

public float det()

Calculates the determinant of the matrix.

Returns:

The determinant of this matrix.

getTranslation

public Vector2 getTranslation(Vector2 position)

Get the x-y translation component of the matrix.

Parameters:

position - Output vector.

Returns:

Filled position.

isTranslation

public boolean isTranslation()

Check if the this is a plain translation matrix.

Returns:

True if scale is 1 and rotation is 0.

isIdt

public boolean isIdt()

Check if this is an indentity matrix.

Returns:

True if scale is 1 and rotation is 0.

applyTo

public void applyTo(Vector2 point)

Applies the affine transformation on a vector.

toString

public String toString()

Overrides:

toString in class Object