Package arc.math

Class Mat

java.lang.Object

arc.math.Mat

public class Mat
extends Object

A 3x3 column major matrix; useful for 2D transforms.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	M00
static final int	M01
static final int	M02
static final int	M10
static final int	M11
static final int	M12
static final int	M20
static final int	M21
static final int	M22
float[]	val

Constructor Summary

Constructors

Constructor	Description
Mat()
Mat(float[] values)	Constructs a matrix from the given float array.
Mat(Mat matrix)

Method Summary

Modifier and Type	Method	Description
float	det()
float	getRotation()
float	getRotationRad()
Vec2	getScale(Vec2 scale)
Vec2	getTranslation(Vec2 position)
float[]	getValues()	Get the values in this matrix.
Mat	idt()	Sets this matrix to the identity matrix
Mat	inv()	Inverts this matrix given that the determinant is != 0.
Mat	mul(Mat m)	Postmultiplies this matrix with the provided matrix and stores the result in this matrix.
Mat	mulLeft(Mat m)	Premultiplies this matrix with the provided matrix and stores the result in this matrix.
Mat	rotate(float degrees)	Postmultiplies this matrix with a (counter-clockwise) rotation matrix.
Mat	rotateRad(float radians)	Postmultiplies this matrix with a (counter-clockwise) rotation matrix.
Mat	scale(float scaleX, float scaleY)	Postmultiplies this matrix with a scale matrix.
Mat	scale(Vec2 scale)	Postmultiplies this matrix with a scale matrix.
Mat	scl(float scale)	Scale the matrix in the both the x and y components by the scalar value.
Mat	scl(Vec2 scale)	Scale this matrix using the x and y components of the vector but leave the rest of the matrix alone.
Mat	scl(Vec3 scale)	Scale this matrix using the x and y components of the vector but leave the rest of the matrix alone.
Mat	set(float[] values)	Sets the matrix to the given matrix as a float array.
Mat	set(Affine2 affine)	Copies the values from the provided affine matrix to this matrix.
Mat	set(Mat mat)	Copies the values from the provided matrix to this matrix.
Mat	setOrtho(float x, float y, float width, float height)	Sets this matrix to an orthographic projection.
Mat	setToRotation(float degrees)	Sets this matrix to a rotation matrix that will rotate any vector in counter-clockwise direction around the z-axis.
Mat	setToRotation(Vec3 axis, float degrees)
Mat	setToRotation(Vec3 axis, float cos, float sin)
Mat	setToRotationRad(float radians)	Sets this matrix to a rotation matrix that will rotate any vector in counter-clockwise direction around the z-axis.
Mat	setToScaling(float scaleX, float scaleY)	Sets this matrix to a scaling matrix.
Mat	setToScaling(Vec2 scale)	Sets this matrix to a scaling matrix.
Mat	setToTranslation(float x, float y)	Sets this matrix to a translation matrix.
Mat	setToTranslation(Vec2 translation)	Sets this matrix to a translation matrix.
String	toString()
Mat	translate(float x, float y)	Postmultiplies this matrix by a translation matrix.
Mat	translate(Vec2 translation)	Postmultiplies this matrix by a translation matrix.
Mat	transpose()	Transposes the current matrix.
Mat	trn(float x, float y)	Adds a translational component to the matrix in the 3rd column.
Mat	trn(Vec2 vector)	Adds a translational component to the matrix in the 3rd column.
Mat	trn(Vec3 vector)	Adds a translational component to the matrix in the 3rd column.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

M00

public static final int M00

See Also:

• Constant Field Values

M01

public static final int M01

See Also:

• Constant Field Values

M02

public static final int M02

See Also:

• Constant Field Values

M10

public static final int M10

See Also:

• Constant Field Values

M11

public static final int M11

See Also:

• Constant Field Values

M12

public static final int M12

See Also:

• Constant Field Values

M20

public static final int M20

See Also:

• Constant Field Values

M21

public static final int M21

See Also:

• Constant Field Values

M22

public static final int M22

See Also:

• Constant Field Values

val

public float[] val

Constructor Details

Mat

public Mat()

Mat

public Mat(Mat matrix)

Mat

public Mat(float[] values)

Constructs a matrix from the given float array. The array must have at least 9 elements; the first 9 will be copied.

Parameters:

values - The float array to copy. Remember that this matrix is in column major order. (The float array is not modified.)

Method Details

setOrtho

public Mat setOrtho(float x,
 float y,
 float width,
 float height)

Sets this matrix to an orthographic projection.

idt

public Mat idt()

Sets this matrix to the identity matrix

Returns:

This matrix for the purpose of chaining operations.

mul

public Mat mul(Mat m)

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

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

Parameters:

m - Matrix to multiply by.

Returns:

This matrix for the purpose of chaining operations together.

mulLeft

public Mat mulLeft(Mat m)

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

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

Parameters:

m - The other Matrix to multiply by

Returns:

This matrix for the purpose of chaining operations.

setToRotation

public Mat 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 Mat 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 Mat setToRotation(Vec3 axis,
 float degrees)

setToRotation

public Mat setToRotation(Vec3 axis,
 float cos,
 float sin)

setToTranslation

public Mat 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 Mat setToTranslation(Vec2 translation)

Sets this matrix to a translation matrix.

Parameters:

translation - The translation vector.

Returns:

This matrix for the purpose of chaining operations.

setToScaling

public Mat 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 Mat setToScaling(Vec2 scale)

Sets this matrix to a scaling matrix.

Parameters:

scale - The scale vector.

Returns:

This matrix for the purpose of chaining operations.

toString

public String toString()

Overrides:

toString in class Object

det

public float det()

Returns:

The determinant of this matrix

inv

public Mat inv()

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

Returns:

This matrix for the purpose of chaining operations.

Throws:

ArcRuntimeException - if the matrix is singular (not invertible)

set

public Mat set(Mat mat)

Copies the values from the provided matrix to this matrix.

Parameters:

mat - The matrix to copy.

Returns:

This matrix for the purposes of chaining.

set

public Mat set(Affine2 affine)

Copies the values from the provided affine matrix to this matrix. The last row is set to (0, 0, 1).

Parameters:

affine - The affine matrix to copy.

Returns:

This matrix for the purposes of chaining.

set

public Mat set(float[] values)

Sets the matrix to the given matrix as a float array. The float array must have at least 9 elements; the first 9 will be copied.

Parameters:

values - The matrix, in float form, that is to be copied. Remember that this matrix is in column major order.

Returns:

This matrix for the purpose of chaining methods together.

trn

public Mat trn(Vec2 vector)

Adds a translational component to the matrix in the 3rd column. The other columns are untouched.

Parameters:

vector - The translation vector.

Returns:

This matrix for the purpose of chaining.

trn

public Mat trn(float x,
 float y)

Adds a translational component to the matrix in the 3rd column. The other columns are untouched.

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.

trn

public Mat trn(Vec3 vector)

Adds a translational component to the matrix in the 3rd column. The other columns are untouched.

Parameters:

vector - The translation vector. (The z-component of the vector is ignored because this is a 3x3 matrix)

Returns:

This matrix for the purpose of chaining.

translate

public Mat translate(float x,
 float y)

Postmultiplies this matrix by a translation matrix. Postmultiplication is also used by OpenGL ES' 1.x glTranslate/glRotate/glScale.

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 Mat translate(Vec2 translation)

Postmultiplies this matrix by a translation matrix. Postmultiplication is also used by OpenGL ES' 1.x glTranslate/glRotate/glScale.

Parameters:

translation - The translation vector.

Returns:

This matrix for the purpose of chaining.

rotate

public Mat rotate(float degrees)

Postmultiplies this matrix with a (counter-clockwise) rotation matrix. Postmultiplication is also used by OpenGL ES' 1.x glTranslate/glRotate/glScale.

Parameters:

degrees - The angle in degrees

Returns:

This matrix for the purpose of chaining.

rotateRad

public Mat rotateRad(float radians)

Postmultiplies this matrix with a (counter-clockwise) rotation matrix. Postmultiplication is also used by OpenGL ES' 1.x glTranslate/glRotate/glScale.

Parameters:

radians - The angle in radians

Returns:

This matrix for the purpose of chaining.

scale

public Mat scale(float scaleX,
 float scaleY)

Postmultiplies this matrix with a scale matrix. Postmultiplication is also used by OpenGL ES' 1.x glTranslate/glRotate/glScale.

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 Mat scale(Vec2 scale)

Postmultiplies this matrix with a scale matrix. Postmultiplication is also used by OpenGL ES' 1.x glTranslate/glRotate/glScale.

Parameters:

scale - The vector to scale the matrix by.

Returns:

This matrix for the purpose of chaining.

getValues

public float[] getValues()

Get the values in this matrix.

Returns:

The float values that make up this matrix in column-major order.

getTranslation

public Vec2 getTranslation(Vec2 position)

getScale

public Vec2 getScale(Vec2 scale)

getRotation

public float getRotation()

getRotationRad

public float getRotationRad()

scl

public Mat scl(float scale)

Scale the matrix in the both the x and y components by the scalar value.

Parameters:

scale - The single value that will be used to scale both the x and y components.

Returns:

This matrix for the purpose of chaining methods together.

scl

public Mat scl(Vec2 scale)

Scale this matrix using the x and y components of the vector but leave the rest of the matrix alone.

Parameters:

scale - The Vec3 to use to scale this matrix.

Returns:

This matrix for the purpose of chaining methods together.

scl

public Mat scl(Vec3 scale)

Scale this matrix using the x and y components of the vector but leave the rest of the matrix alone.

Parameters:

scale - The Vec3 to use to scale this matrix. The z component will be ignored.

Returns:

This matrix for the purpose of chaining methods together.

transpose

public Mat transpose()

Transposes the current matrix.

Returns:

This matrix for the purpose of chaining methods together.