org.gvsig.fmap.geom.jts.transform

Class Transform2D

java.lang.Object

org.gvsig.fmap.geom.jts.transform.Transform2D

All Implemented Interfaces:

Transform

public class Transform2D
extends java.lang.Object
implements Transform

Field Summary

Fields

Modifier and Type	Field and Description
static double	ACCURACY The constant used for testing results.
protected double	m00
protected double	m01
protected double	m02
protected double	m10
protected double	m11
protected double	m12

Constructor Summary

Constructors

Constructor and Description
Transform2D() Creates a new AffineTransform2D, initialized with Identity.
Transform2D(java.awt.geom.AffineTransform transform) Creates a new transform from a java AWT transform.
Transform2D(double[] coefs) Creates a new Affine Transform by directly specifying the coefficients, in the order m00, m01, m02, m10, m11, m12 (different order of java.awt.geom.AffineTransform).
Transform2D(double xx, double yx, double tx, double xy, double yy, double ty)

Method Summary

Modifier and Type	Method and Description
double[][]	affineMatrix() Returns the 3x3 square matrix representing the transform.
java.awt.geom.AffineTransform	asAwtTransform() Returns this transform as an instance of java AWT AffineTransform.
Transform	chain(Transform other) Returns the affine transform created by applying first this affine transform, then the affine transform given by that.
Transform2D	clone()
double[]	coefficients() Returns coefficients of the transform in a linear array of 6 double.
Transform	concatenate(Transform other) Returns the affine transform created by applying first the affine transform given by other, then this affine transform.
boolean	equals(java.lang.Object obj)
Transform	inverse() Returns the inverse transform.
boolean	isDirect() Tests if this affine transform is direct, i.e. the sign of the determinant of the associated matrix is positive.
boolean	isIdentity() Tests is this affine transform is equal to the identity transform.
boolean	isIsometry() Tests if this affine transform is an isometry, i.e. is equivalent to a compound of translations, rotations and reflections.
boolean	isMotion() Tests if this affine transform is a motion, i.e. is composed only of rotations and translations.
boolean	isSimilarity() Tests if this affine transform is a similarity.
Transform	preConcatenate(Transform other) Return the affine transform created by applying first this affine transform, then the affine transform given by that.
java.lang.String	toString() Displays the coefficients of the transform, row by row.
Point	transform(Point p) Computes the coordinates of the transformed point.
Point[]	transform(Point[] src, Point[] dst)

Methods inherited from class java.lang.Object

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

Field Detail

ACCURACY

public static final double ACCURACY

The constant used for testing results.

See Also:

Constant Field Values

m00

protected double m00

m01

protected double m01

m02

protected double m02

m10

protected double m10

m11

protected double m11

m12

protected double m12

Constructor Detail

Transform2D

public Transform2D()

Creates a new AffineTransform2D, initialized with Identity.

Transform2D

public Transform2D(java.awt.geom.AffineTransform transform)

Creates a new transform from a java AWT transform.

Parameters:

transform -

Transform2D

public Transform2D(double[] coefs)

Creates a new Affine Transform by directly specifying the coefficients, in the order m00, m01, m02, m10, m11, m12 (different order of java.awt.geom.AffineTransform).

Parameters:

coefs -

Transform2D

public Transform2D(double xx,
                   double yx,
                   double tx,
                   double xy,
                   double yy,
                   double ty)

Method Detail

coefficients

public double[] coefficients()

Returns coefficients of the transform in a linear array of 6 double.

Returns:

affineMatrix

public double[][] affineMatrix()

Returns the 3x3 square matrix representing the transform.

Returns:

the 3x3 affine transform representing the matrix

asAwtTransform

public java.awt.geom.AffineTransform asAwtTransform()

Returns this transform as an instance of java AWT AffineTransform.

Returns:

concatenate

public Transform concatenate(Transform other)

Returns the affine transform created by applying first the affine transform given by other, then this affine transform. This is the equivalent method of the 'concatenate' method in java.awt.geom.AffineTransform.

Specified by:

concatenate in interface Transform

Parameters:

other - the transform to apply first

Returns:

the composition this * that

chain

public Transform chain(Transform other)

Returns the affine transform created by applying first this affine transform, then the affine transform given by that. This the equivalent method of the 'preConcatenate' method in java.awt.geom.AffineTransform.

 shape = shape.transform(T1.chain(T2).chain(T3));
 

is equivalent to the sequence:

 shape = shape.transform(T1);
 shape = shape.transform(T2);
 shape = shape.transform(T3);
 

Parameters:

other - the transform to apply in a second step

Returns:

the composition that * this

preConcatenate

public Transform preConcatenate(Transform other)

Return the affine transform created by applying first this affine transform, then the affine transform given by that. This the equivalent method of the 'preConcatenate' method in java.awt.geom.AffineTransform.

Specified by:

preConcatenate in interface Transform

Parameters:

other - the transform to apply in a second step

Returns:

the composition that * this

isSimilarity

public boolean isSimilarity()

Tests if this affine transform is a similarity.

Returns:

isMotion

public boolean isMotion()

Tests if this affine transform is a motion, i.e. is composed only of rotations and translations.

Returns:

isIsometry

public boolean isIsometry()

Tests if this affine transform is an isometry, i.e. is equivalent to a compound of translations, rotations and reflections. Isometry keeps area of shapes unchanged, but can change orientation (direct or indirect).

Returns:

true in case of isometry.

isDirect

public boolean isDirect()

Tests if this affine transform is direct, i.e. the sign of the determinant of the associated matrix is positive. Direct transforms preserve the orientation of transformed shapes.

Returns:

isIdentity

public boolean isIdentity()

Tests is this affine transform is equal to the identity transform.

Specified by:

isIdentity in interface Transform

Returns:

true if this transform is the identity transform

inverse

public Transform inverse()

Returns the inverse transform. If the transform is not invertible, throws a new NonInvertibleTransformException.

Specified by:

inverse in interface Transform

Returns:

transform

public Point transform(Point p)

Computes the coordinates of the transformed point.

Specified by:

transform in interface Transform

Parameters:

p -

Returns:

transform

public Point[] transform(Point[] src,
                         Point[] dst)

Specified by:

transform in interface Transform

toString

public java.lang.String toString()

Displays the coefficients of the transform, row by row.

Overrides:

toString in class java.lang.Object

Returns:

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

clone

public Transform2D clone()

Overrides:

clone in class java.lang.Object