Module org.opengis.geoapi.example

Package org.opengis.example.referencing

Class AffineTransform2D

Object

AffineTransform

AffineTransform2D

All Implemented Interfaces:

Serializable, Cloneable, MathTransform, MathTransform2D

public class AffineTransform2D
extends AffineTransform
implements MathTransform2D

A MathTransform2D backed by the Java2D AffineTransform.

Affine transforms are very commons in GIS - they can be used for scaling, flipping the y axis, applying unit conversions, etc.. The standard Java2D library provides an efficient general-purpose implementation of affine transform. This class extends the Java2D class for efficiency and for inter-operability with Java2D.

This affine transform is a special case of ProjectiveTransform restricted to the following cases:

• The number of source and target dimensions are 2.
• The last matrix row contains the [0 0 1] values.

Since:

3.1

See Also:

• Serialized Form

Field Summary

Fields inherited from class AffineTransform

TYPE_FLIP, TYPE_GENERAL_ROTATION, TYPE_GENERAL_SCALE, TYPE_GENERAL_TRANSFORM, TYPE_IDENTITY, TYPE_MASK_ROTATION, TYPE_MASK_SCALE, TYPE_QUADRANT_ROTATION, TYPE_TRANSLATION, TYPE_UNIFORM_SCALE

Constructor Summary

Constructors

Constructor	Description
AffineTransform2D()	Creates a new transform initialized to the identity transform.
AffineTransform2D(AffineTransform tr)	Creates a new transform initialized to the values of the given transform.

Method Summary

Modifier and Type	Method	Description
Matrix	derivative(Point2D point)	Gets the derivative of this transform at a point.
Matrix	derivative(DirectPosition point)	Gets the derivative of this transform at a point.
final int	getSourceDimensions()	Returns the source dimension, which is 2.
final int	getTargetDimensions()	Returns the target dimension, which is 2.
MathTransform2D	inverse()	Returns the inverse of this affine transform.
void	setTransform(Matrix matrix)	Sets this affine transform to the values of the given matrix.
String	toWKT()	Unsupported operation.
DirectPosition	transform(DirectPosition ptSrc, DirectPosition ptDst)	Transforms the specified ptSrc and stores the result in ptDst.

Methods inherited from class AffineTransform

clone, concatenate, createInverse, createTransformedShape, deltaTransform, deltaTransform, equals, getDeterminant, getMatrix, getQuadrantRotateInstance, getQuadrantRotateInstance, getRotateInstance, getRotateInstance, getRotateInstance, getRotateInstance, getScaleInstance, getScaleX, getScaleY, getShearInstance, getShearX, getShearY, getTranslateInstance, getTranslateX, getTranslateY, getType, hashCode, inverseTransform, inverseTransform, invert, isIdentity, preConcatenate, quadrantRotate, quadrantRotate, rotate, rotate, rotate, rotate, scale, setToIdentity, setToQuadrantRotation, setToQuadrantRotation, setToRotation, setToRotation, setToRotation, setToRotation, setToScale, setToShear, setToTranslation, setTransform, setTransform, shear, toString, transform, transform, transform, transform, transform, transform, translate

Methods inherited from class Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface MathTransform

isIdentity, transform, transform, transform, transform

Methods inherited from interface MathTransform2D

createTransformedShape, transform

Constructor Details

AffineTransform2D

public AffineTransform2D()

Creates a new transform initialized to the identity transform.

AffineTransform2D

public AffineTransform2D(AffineTransform tr)

Creates a new transform initialized to the values of the given transform.

Parameters:

tr - the transform to copy.

Method Details

setTransform

public void setTransform(Matrix matrix)
                  throws IllegalArgumentException

Sets this affine transform to the values of the given matrix. The matrix size must be 3×3 and the last row shall contain the [0 0 1] values.

Parameters:

matrix - the matrix to copy in this affine transform.

Throws:

IllegalArgumentException - if the matrix size is not 3×3, or the transform is not affine.

getSourceDimensions

public final int getSourceDimensions()

Returns the source dimension, which is 2. This number of dimensions cannot be changed.

Specified by:

getSourceDimensions in interface MathTransform

Returns:

the number of dimensions of input points.

See Also:

• OperationMethod.getSourceDimensions()

getTargetDimensions

public final int getTargetDimensions()

Returns the target dimension, which is 2. This number of dimensions cannot be changed.

Specified by:

getTargetDimensions in interface MathTransform

Returns:

the number of dimensions of output points.

See Also:

• OperationMethod.getTargetDimensions()

transform

public DirectPosition transform(DirectPosition ptSrc,
 DirectPosition ptDst)
                         throws MismatchedDimensionException

Transforms the specified ptSrc and stores the result in ptDst. This method delegates its work to AffineTransform.transform(Point2D, Point2D).

Specified by:

transform in interface MathTransform

Parameters:

ptSrc - the coordinate point to be transformed.

ptDst - the coordinate point that stores the transform result, or null.

Returns:

the coordinate point after transforming ptSrc and storing the result in ptDst, or a newly created point if ptDst was null.

Throws:

MismatchedDimensionException - if ptSrc or ptDst does not have exactly 2 dimensions.

derivative

public Matrix derivative(DirectPosition point)
                  throws MismatchedDimensionException

Gets the derivative of this transform at a point. This method delegates its work to derivative(Point2D).

Specified by:

derivative in interface MathTransform

Parameters:

point - ignored (except for the dimension, which is checked as a matter of principle).

Returns:

the derivative (never null).

Throws:

MismatchedDimensionException - if point does not have the expected dimension.

derivative

public Matrix derivative(Point2D point)

Gets the derivative of this transform at a point. The derivative of an affine transform is constant everywhere.

Specified by:

derivative in interface MathTransform2D

Parameters:

point - ignored - may be null.

Returns:

the derivative (never null).

inverse

public MathTransform2D inverse()
                        throws NoninvertibleTransformException

Returns the inverse of this affine transform.

Specified by:

inverse in interface MathTransform

Specified by:

inverse in interface MathTransform2D

Returns:

the inverse transform.

Throws:

NoninvertibleTransformException - if the transform cannot be inverted.

See Also:

• AffineTransform.createInverse()

toWKT

public String toWKT()
             throws UnsupportedOperationException

Unsupported operation.

Specified by:

toWKT in interface MathTransform

Returns:

the Well-Known Text (WKT) for this object.

Throws:

UnsupportedOperationException - if this object cannot be formatted as WKT.

See Also:

• MathTransformFactory.createFromWKT(String)