org.deegree.model.csct.ct
Class MatrixTransform

java.lang.Object
  org.deegree.model.csct.ct.AbstractMathTransform
      org.deegree.model.csct.ct.MatrixTransform

All Implemented Interfaces:

Serializable, MathTransform

final class MatrixTransform
extends AbstractMathTransform
implements Serializable

Transforms multi-dimensional coordinate points using a Matrix.

Version:

1.00

Author:

OpenGIS (www.opengis.org), Martin Desruisseaux

Nested Class Summary

(package private) static class

MatrixTransform.Provider The provider for MatrixTransform.

Nested classes/interfaces inherited from class org.deegree.model.csct.ct.AbstractMathTransform

AbstractMathTransform.Inverse

Constructor Summary

protected

MatrixTransform(javax.vecmath.GMatrix matrix) Construct a transform.

Method Summary

Matrix	derivative(CoordinatePoint point) Gets the derivative of this transform at a point.
Matrix	derivative(Point2D point) Gets the derivative of this transform at a point.
boolean	equals(Object object) Compares the specified object with this math transform for equality.
int	getDimSource() Gets the dimension of input points.
int	getDimTarget() Gets the dimension of output points.
Matrix	getMatrix() Returns a copy of the matrix.
int	hashCode() Returns a hash value for this transform.
MathTransform	inverse() Creates the inverse transform of this object.
boolean	isIdentity() Tests whether this transform does not move any points.
String	toString() Returns the WKT for this math transform.
(package private) static String	toString(Matrix matrix) Returns the WKT for an affine transform using the specified matrix.
void	transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts) Transforms an array of floating point coordinates by this matrix.
void	transform(float[] srcPts, int srcOff, float[] dstPts, int dstOff, int numPts) Transforms an array of floating point coordinates by this matrix.

Methods inherited from class org.deegree.model.csct.ct.AbstractMathTransform

addParameter, addParameter, createTransformedShape, createTransformedShape, getName, paramMT, transform, transform

Methods inherited from class java.lang.Object

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

Constructor Detail

MatrixTransform

protected MatrixTransform(javax.vecmath.GMatrix matrix)

Construct a transform.

Method Detail

transform

public void transform(float[] srcPts,
                      int srcOff,
                      float[] dstPts,
                      int dstOff,
                      int numPts)

Transforms an array of floating point coordinates by this matrix. Point coordinates must have a dimension equals to GMatrix.getNumCol()-1. For example, for square matrix of size 4×4, coordinate points are three-dimensional and stored in the arrays starting at the specified offset (srcOff) in the order [x0, y0, z0, x1, y1, z1..., xn, yn, zn]. The transformed points (x',y',z') are computed as below (note that this computation is similar to PerspectiveTransform):

  [ u ]     [ m<sub>00</sub>  m<sub>01</sub>  m<sub>02</sub>  m<sub>03</sub> ] [ x ]
  [ v ]  =  [ m<sub>10</sub>  m<sub>11</sub>  m<sub>12</sub>  m<sub>13</sub> ] [ y ]
  [ w ]     [ m<sub>20</sub>  m<sub>21</sub>  m<sub>22</sub>  m<sub>23</sub> ] [ z ]
  [ t ]     [ m<sub>30</sub>  m<sub>31</sub>  m<sub>32</sub>  m<sub>33</sub> ] [ 1 ]
 
    x' = u/t
    y' = v/t
    y' = w/t
 

Specified by:

transform in interface MathTransform

Overrides:

transform in class AbstractMathTransform

Parameters:

srcPts - The array containing the source point coordinates.

srcOff - The offset to the first point to be transformed in the source array.

dstPts - The array into which the transformed point coordinates are returned.

dstOff - The offset to the location of the first transformed point that is stored in the destination array. The source and destination array sections can be overlaps.

numPts - The number of points to be transformed

transform

public void transform(double[] srcPts,
                      int srcOff,
                      double[] dstPts,
                      int dstOff,
                      int numPts)

Transforms an array of floating point coordinates by this matrix. Point coordinates must have a dimension equals to GMatrix.getNumCol()-1. For example, for square matrix of size 4×4, coordinate points are three-dimensional and stored in the arrays starting at the specified offset (srcOff) in the order [x0, y0, z0, x1, y1, z1..., xn, yn, zn]. The transformed points (x',y',z') are computed as below (note that this computation is similar to PerspectiveTransform):

  [ u ]     [ m<sub>00</sub>  m<sub>01</sub>  m<sub>02</sub>  m<sub>03</sub> ] [ x ]
  [ v ]  =  [ m<sub>10</sub>  m<sub>11</sub>  m<sub>12</sub>  m<sub>13</sub> ] [ y ]
  [ w ]     [ m<sub>20</sub>  m<sub>21</sub>  m<sub>22</sub>  m<sub>23</sub> ] [ z ]
  [ t ]     [ m<sub>30</sub>  m<sub>31</sub>  m<sub>32</sub>  m<sub>33</sub> ] [ 1 ]
 
    x' = u/t
    y' = v/t
    y' = w/t
 

Specified by:

transform in interface MathTransform

Parameters:

srcPts - The array containing the source point coordinates.

srcOff - The offset to the first point to be transformed in the source array.

dstPts - The array into which the transformed point coordinates are returned.

dstOff - The offset to the location of the first transformed point that is stored in the destination array. The source and destination array sections can be overlaps.

numPts - The number of points to be transformed

derivative

public Matrix derivative(Point2D point)

Gets the derivative of this transform at a point. For a matrix transform, the derivative is the same everywhere.

Overrides:

derivative in class AbstractMathTransform

Parameters:

point - The coordinate point where to evaluate the derivative.

Returns:

The derivative at the specified point as a 2x2 matrix.

See Also:

MathTransform2D.derivative(Point2D)

derivative

public Matrix derivative(CoordinatePoint point)

Gets the derivative of this transform at a point. For a matrix transform, the derivative is the same everywhere.

Specified by:

derivative in interface MathTransform

Overrides:

derivative in class AbstractMathTransform

Parameters:

point - The coordinate point where to evaluate the derivative.

Returns:

The derivative at the specified point (never null).

getMatrix

public Matrix getMatrix()

Returns a copy of the matrix.

getDimSource

public int getDimSource()

Gets the dimension of input points.

Specified by:

getDimSource in interface MathTransform

Returns:

the dimension of input points.

See Also:

"org.opengis.ct.CT_MathTransform#getDimSource()"

getDimTarget

public int getDimTarget()

Gets the dimension of output points.

Specified by:

getDimTarget in interface MathTransform

Returns:

the dimension of output points.

See Also:

"org.opengis.ct.CT_MathTransform#getDimTarget()"

isIdentity

public boolean isIdentity()

Tests whether this transform does not move any points.

Specified by:

isIdentity in interface MathTransform

Returns:

true if this MathTransform is an identity transform; false otherwise.

inverse

public MathTransform inverse()
                      throws NoninvertibleTransformException

Creates the inverse transform of this object.

Specified by:

inverse in interface MathTransform

Overrides:

inverse in class AbstractMathTransform

Returns:

The inverse transform.

Throws:

NoninvertibleTransformException - if the transform can't be inversed.

hashCode

public int hashCode()

Returns a hash value for this transform. This value need not remain consistent between different implementations of the same class.

Overrides:

hashCode in class AbstractMathTransform

equals

public boolean equals(Object object)

Compares the specified object with this math transform for equality.

Overrides:

equals in class AbstractMathTransform

toString

public String toString()

Returns the WKT for this math transform.

Overrides:

toString in class AbstractMathTransform

toString

static String toString(Matrix matrix)

Returns the WKT for an affine transform using the specified matrix.