Package org.spongepowered.api.util

Class DiscreteTransform2

java.lang.Object

org.spongepowered.api.util.DiscreteTransform2

public class DiscreteTransform2
extends Object

Represents a transform. It is 2 dimensional and discrete. It will never cause aliasing.

Rotations are performed around tile centers unless the tile corner flags are set to true. To prevent aliasing, quarter turn rotations are only legal on block centers or corners. Half turns can be performed additionally on line centers.

Field Summary

Fields

Modifier and Type	Field	Description
static DiscreteTransform2	IDENTITY	Represents an identity transformation.

Method Summary

Modifier and Type	Method	Description
DiscreteTransform2	andThen(DiscreteTransform2 that)	Returns a transform that is the composition of the given transform with this transform.
DiscreteTransform2	compose(DiscreteTransform2 that)	Returns a transform that is the composition of this transform and the given transform.
static DiscreteTransform2	fromRotation(int quarterTurns)	Returns a new transform representing a rotation in the xy plane around the origin.
static DiscreteTransform2	fromRotation(int quarterTurns, Vector2i point, boolean tileCorner)	Returns a new transform representing a rotation in the xy plane, around a given point.
static DiscreteTransform2	fromRotation(int halfTurns, Vector2i point, boolean tileCornerX, boolean tileCornerY)	Returns a new transform representing a rotation in the xy plane, around a given point.
static DiscreteTransform2	fromScale(int a)	Returns a new transform representing a scaling.
static DiscreteTransform2	fromScale(int x, int y)	Returns a new transform representing a scaling on each axis.
static DiscreteTransform2	fromScale(Vector2i vector)	Returns a new transform representing a scaling on each axis.
static DiscreteTransform2	fromTranslation(int x, int y)	Returns a new transform representing a translation.
static DiscreteTransform2	fromTranslation(Vector2i vector)	Returns a new transform representing a translation.
DiscreteTransform2	invert()	Inverts the transform and returns it as a new transform.
Matrix3d	matrix()	Returns the matrix representation of the transform.
static Optional<DiscreteTransform2>	of(Matrix3d matrix)	Returns a new transform from the given transformation matrix, if the resulting transform would be discrete.
static DiscreteTransform2	rotationAroundCenter(int quarterTurns, Vector2i size)	Returns a new transform representing a centered rotation of an area of tiles.
Vector2i	transform(int x, int y)	Transform a vector represented as a pair of coordinates using this transform.
Vector2i	transform(Vector2i vector)	Transforms a vector using this transforms.
int	transformX(int x, int y)	Transforms the x coordinate of a vector using this transform.
int	transformX(Vector2i vector)	Transforms the x coordinate of a vector using this transform.
int	transformY(int x, int y)	Transforms the y coordinate of a vector using this transform.
int	transformY(Vector2i vector)	Transforms the y coordinate of a vector using this transform.
DiscreteTransform2	withRotation(int quarterTurns)	Adds a rotation to this transform, in the xy plane, around the origin and returns it as a new transform.
DiscreteTransform2	withRotation(int quarterTurns, Vector2i point, boolean tileCorner)	Adds a a rotation to this transform, in the xy plane, around a given point, and returns it as a new transform.
DiscreteTransform2	withRotation(int halfTurns, Vector2i point, boolean tileCornerX, boolean tileCornerY)	Adds a a rotation to this transform, in the xy plane, around a given point, and returns it as a new transform.
DiscreteTransform2	withScale(int a)	Adds a scale factor to this transform and returns it as a new transform.
DiscreteTransform2	withScale(int x, int y)	Adds a scale factor for each axis to this transform and returns it as a new transform.
DiscreteTransform2	withScale(Vector2i vector)	Adds a scale factor for each axis to this transform and returns it as a new transform.
DiscreteTransform2	withTransformation(DiscreteTransform2 transform)	Adds another transformation to this transformation and returns int as a new transform.
DiscreteTransform2	withTranslation(int x, int y)	Adds a translation to this transform and returns it as a new transform.
DiscreteTransform2	withTranslation(Vector2i vector)	Adds a translation to this transform and returns it as a new transform.

Methods inherited from class java.lang.Object

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

Field Detail

IDENTITY

public static final DiscreteTransform2 IDENTITY

Represents an identity transformation. Does nothing!

Method Detail

matrix

public Matrix3d matrix()

Returns the matrix representation of the transform. It is 3D to allow it to include a translation.

Returns:

The matrix for this transform

transform

public Vector2i transform(Vector2i vector)

Transforms a vector using this transforms.

Parameters:

vector - The original vector

Returns:

The transformed vector

transform

public Vector2i transform(int x,
                          int y)

Transform a vector represented as a pair of coordinates using this transform.

Parameters:

x - The x coordinate of the original vector

y - The y coordinate of the original vector

Returns:

The transformed vector

transformX

public int transformX(Vector2i vector)

Transforms the x coordinate of a vector using this transform. Only creates a new object on the first call.

Parameters:

vector - The original vector

Returns:

The transformed x coordinate

transformX

public int transformX(int x,
                      int y)

Transforms the x coordinate of a vector using this transform. Only creates a new object on the first call.

Parameters:

x - The x coordinate of the original vector

y - The y coordinate of the original vector

Returns:

The transformed x coordinate

transformY

public int transformY(Vector2i vector)

Transforms the y coordinate of a vector using this transform. Only creates a new object on the first call.

Parameters:

vector - The original vector

Returns:

The transformed y coordinate

transformY

public int transformY(int x,
                      int y)

Transforms the y coordinate of a vector using this transform. Only creates a new object on the first call.

Parameters:

x - The x coordinate of the original vector

y - The y coordinate of the original vector

Returns:

The transformed y coordinate

invert

public DiscreteTransform2 invert()

Inverts the transform and returns it as a new transform.

Returns:

The inverse of this transform

compose

public DiscreteTransform2 compose(DiscreteTransform2 that)

Returns a transform that is the composition of this transform and the given transform. The result will apply this transformation after the given one.

Parameters:

that - The transform to compose with

Returns:

The new composed transform

andThen

public DiscreteTransform2 andThen(DiscreteTransform2 that)

Returns a transform that is the composition of the given transform with this transform. The result will apply the given transformation after this one.

Parameters:

that - The transform to compose with

Returns:

The new composed transform

withTranslation

public DiscreteTransform2 withTranslation(Vector2i vector)

Adds a translation to this transform and returns it as a new transform.

Parameters:

vector - The translation vector

Returns:

The translated transform as a copy

withTranslation

public DiscreteTransform2 withTranslation(int x,
                                          int y)

Adds a translation to this transform and returns it as a new transform.

Parameters:

x - The x coordinate of the translation

y - The y coordinate of the translation

Returns:

The translated transform as a copy

withScale

public DiscreteTransform2 withScale(int a)

Adds a scale factor to this transform and returns it as a new transform. This factor must be non-zero.

Parameters:

a - The scale factor

Returns:

The scaled transform as a copy

withScale

public DiscreteTransform2 withScale(Vector2i vector)

Adds a scale factor for each axis to this transform and returns it as a new transform. The factors must be non-zero.

Parameters:

vector - The scale vector

Returns:

The scaled transform as a copy

withScale

public DiscreteTransform2 withScale(int x,
                                    int y)

Adds a scale factor for each axis to this transform and returns it as a new transform. The factors must be non-zero.

Parameters:

x - The scale factor on x

y - The scale factor on y

Returns:

The scaled transform as a copy

withRotation

public DiscreteTransform2 withRotation(int quarterTurns)

Adds a rotation to this transform, in the xy plane, around the origin and returns it as a new transform. The rotation is given is quarter turns. The actual rotation is quarterTurns * 90. The rotation is around the block center, not the corner.

Parameters:

quarterTurns - The number of quarter turns in this rotation

Returns:

The rotated transform as a copy

withRotation

public DiscreteTransform2 withRotation(int quarterTurns,
                                       Vector2i point,
                                       boolean tileCorner)

Adds a a rotation to this transform, in the xy plane, around a given point, and returns it as a new transform. The rotation is given is quarter turns. The actual rotation is quarterTurns * 90. The tile corner flag changes the point to be the tile upper corner instead of the center.

Parameters:

quarterTurns - The number of quarter turns in this rotation

point - The point of rotation, as tile coordinates

tileCorner - Whether or not to use the corner of the tile instead of the center

Returns:

The rotated transform as a copy

withRotation

public DiscreteTransform2 withRotation(int halfTurns,
                                       Vector2i point,
                                       boolean tileCornerX,
                                       boolean tileCornerY)

Adds a a rotation to this transform, in the xy plane, around a given point, and returns it as a new transform. The rotation is given is half turns. The actual rotation is halfTurns * 180. The tile corner flags change the point to be the tile corner or edge instead of the center. When both flags are false, the center is used. When only one is true the edge on the opposite axis to the flag is used. When both are true the upper corner is used.

Parameters:

halfTurns - The number of half turns in this rotation

point - The point of rotation, as tile coordinates

tileCornerX - Whether or not to use the corner of the tile instead of the center on the x axis

tileCornerY - Whether or not to use the corner of the tile instead of the center on the y axis

Returns:

The rotated transform as a copy

withTransformation

public DiscreteTransform2 withTransformation(DiscreteTransform2 transform)

Adds another transformation to this transformation and returns int as a new transform.

Parameters:

transform - The transformation to add

Returns:

The added transforms as a copy

of

public static Optional<DiscreteTransform2> of(Matrix3d matrix)

Returns a new transform from the given transformation matrix, if the resulting transform would be discrete.

Parameters:

matrix - The matrix to use for the transform

Returns:

The new transform, or Optional.empty()

fromTranslation

public static DiscreteTransform2 fromTranslation(Vector2i vector)

Returns a new transform representing a translation.

Parameters:

vector - The translation vector

Returns:

The new translation transform

fromTranslation

public static DiscreteTransform2 fromTranslation(int x,
                                                 int y)

Returns a new transform representing a translation.

Parameters:

x - The x coordinate of the translation

y - The y coordinate of the translation

Returns:

The new translation transform

fromScale

public static DiscreteTransform2 fromScale(int a)

Returns a new transform representing a scaling. The scale factor must be non-zero.

Parameters:

a - The scale factor

Returns:

The new scale transform

fromScale

public static DiscreteTransform2 fromScale(Vector2i vector)

Returns a new transform representing a scaling on each axis. The scale factors must be non-zero.

Parameters:

vector - The scale vector

Returns:

The new scale transform

fromScale

public static DiscreteTransform2 fromScale(int x,
                                           int y)

Returns a new transform representing a scaling on each axis. The scale factors must be non-zero.

Parameters:

x - The scale factor on x

y - The scale factor on y

Returns:

The new scale transform

fromRotation

public static DiscreteTransform2 fromRotation(int quarterTurns)

Returns a new transform representing a rotation in the xy plane around the origin. The rotation is given is quarter turns. The actual rotation is quarterTurns * 90. The rotation is around the block center, not the corner.

Parameters:

quarterTurns - The number of quarter turns in this rotation

Returns:

The new rotation transform

fromRotation

public static DiscreteTransform2 fromRotation(int quarterTurns,
                                              Vector2i point,
                                              boolean tileCorner)

Returns a new transform representing a rotation in the xy plane, around a given point. The rotation is given is quarter turns. The actual rotation is quarterTurns * 90. The tile corner flag change the point to be the tile corner instead of the center.

Parameters:

quarterTurns - The number of quarter turns in this rotation

point - The point of rotation, as tile coordinates

tileCorner - Whether or not to use the corner of the tile instead of the center

Returns:

The new rotation transform

fromRotation

public static DiscreteTransform2 fromRotation(int halfTurns,
                                              Vector2i point,
                                              boolean tileCornerX,
                                              boolean tileCornerY)

Returns a new transform representing a rotation in the xy plane, around a given point. The rotation is given is half turns. The actual rotation is halfTurns * 180. The tile corner flags change the point to be the tile corner or edge instead of the center. When both flags are false, the center is used. When only one is true the edge on the opposite axis to the flag is used. When both are true the upper corner is used.

Parameters:

halfTurns - The number of half turns in this rotation

point - The point of rotation, as tile coordinates

tileCornerX - Whether or not to use the corner of the tile instead of the center on the x axis

tileCornerY - Whether or not to use the corner of the tile instead of the center on the y axis

Returns:

The new rotation transform

rotationAroundCenter

public static DiscreteTransform2 rotationAroundCenter(int quarterTurns,
                                                      Vector2i size)

Returns a new transform representing a centered rotation of an area of tiles. The rotation is given is quarter turns. The actual rotation is quarterTurns * 90. Areas with differing parities on the axes can only be rotated by multiples of 180 degrees.

Parameters:

quarterTurns - The amount of quarter turns in this rotation

size - The size of the area to rotate

Returns:

The new rotation transform