Class AffineTransform

Method Details

• getTranslateInstance

  public static AffineTransform getTranslateInstance(double tx, double ty)

  Returns a transform representing a translation transformation. The matrix representing the returned transform is:

            [   1    0    tx  ]
            [   0    1    ty  ]
            [   0    0    1   ]
   

  Parameters:

  tx - the distance by which coordinates are translated in the X axis direction

  ty - the distance by which coordinates are translated in the Y axis direction

  Returns:

  an AffineTransform object that represents a translation transformation, created with the specified vector.

  Since:

  1.2

• getRotateInstance

  public static AffineTransform getRotateInstance(double theta)

  Returns a transform representing a rotation transformation. The matrix representing the returned transform is:

            [   cos(theta)    -sin(theta)    0   ]
            [   sin(theta)     cos(theta)    0   ]
            [       0              0         1   ]
   

  Rotating by a positive angle theta rotates points on the positive X axis toward the positive Y axis. Note also the discussion of Handling 90-Degree Rotations above.

  Parameters:

  theta - the angle of rotation measured in radians

  Returns:

  an AffineTransform object that is a rotation transformation, created with the specified angle of rotation.

  Since:

  1.2

• getRotateInstance

  public static AffineTransform getRotateInstance(double theta, double anchorx, double anchory)

  Returns a transform that rotates coordinates around an anchor point. This operation is equivalent to translating the coordinates so that the anchor point is at the origin (S1), then rotating them about the new origin (S2), and finally translating so that the intermediate origin is restored to the coordinates of the original anchor point (S3).

  This operation is equivalent to the following sequence of calls:

       AffineTransform Tx = new AffineTransform();
       Tx.translate(anchorx, anchory);    // S3: final translation
       Tx.rotate(theta);                  // S2: rotate around anchor
       Tx.translate(-anchorx, -anchory);  // S1: translate anchor to origin
   

  The matrix representing the returned transform is:

            [   cos(theta)    -sin(theta)    x-x*cos+y*sin  ]
            [   sin(theta)     cos(theta)    y-x*sin-y*cos  ]
            [       0              0               1        ]
   

  Rotating by a positive angle theta rotates points on the positive X axis toward the positive Y axis. Note also the discussion of Handling 90-Degree Rotations above.

  Parameters:

  theta - the angle of rotation measured in radians

  anchorx - the X coordinate of the rotation anchor point

  anchory - the Y coordinate of the rotation anchor point

  Returns:

  an AffineTransform object that rotates coordinates around the specified point by the specified angle of rotation.

  Since:

  1.2

• getRotateInstance

  public static AffineTransform getRotateInstance(double vecx, double vecy)

  Returns a transform that rotates coordinates according to a rotation vector. All coordinates rotate about the origin by the same amount. The amount of rotation is such that coordinates along the former positive X axis will subsequently align with the vector pointing from the origin to the specified vector coordinates. If both vecx and vecy are 0.0, an identity transform is returned. This operation is equivalent to calling:

       AffineTransform.getRotateInstance(Math.atan2(vecy, vecx));
   

  Parameters:

  vecx - the X coordinate of the rotation vector

  vecy - the Y coordinate of the rotation vector

  Returns:

  an AffineTransform object that rotates coordinates according to the specified rotation vector.

  Since:

  1.6

• getRotateInstance

  public static AffineTransform getRotateInstance(double vecx, double vecy, double anchorx, double anchory)

  Returns a transform that rotates coordinates around an anchor point according to a rotation vector. All coordinates rotate about the specified anchor coordinates by the same amount. The amount of rotation is such that coordinates along the former positive X axis will subsequently align with the vector pointing from the origin to the specified vector coordinates. If both vecx and vecy are 0.0, an identity transform is returned. This operation is equivalent to calling:

       AffineTransform.getRotateInstance(Math.atan2(vecy, vecx),
                                         anchorx, anchory);
   

  Parameters:

  vecx - the X coordinate of the rotation vector

  vecy - the Y coordinate of the rotation vector

  anchorx - the X coordinate of the rotation anchor point

  anchory - the Y coordinate of the rotation anchor point

  Returns:

  an AffineTransform object that rotates coordinates around the specified point according to the specified rotation vector.

  Since:

  1.6

• getQuadrantRotateInstance

  public static AffineTransform getQuadrantRotateInstance(int numquadrants)

  Returns a transform that rotates coordinates by the specified number of quadrants. This operation is equivalent to calling:

       AffineTransform.getRotateInstance(numquadrants * Math.PI / 2.0);
   

  Rotating by a positive number of quadrants rotates points on the positive X axis toward the positive Y axis.

  Parameters:

  numquadrants - the number of 90 degree arcs to rotate by

  Returns:

  an AffineTransform object that rotates coordinates by the specified number of quadrants.

  Since:

  1.6

• getQuadrantRotateInstance

  public static AffineTransform getQuadrantRotateInstance(int numquadrants, double anchorx, double anchory)

  Returns a transform that rotates coordinates by the specified number of quadrants around the specified anchor point. This operation is equivalent to calling:

       AffineTransform.getRotateInstance(numquadrants * Math.PI / 2.0,
                                         anchorx, anchory);
   

  Rotating by a positive number of quadrants rotates points on the positive X axis toward the positive Y axis.

  Parameters:

  numquadrants - the number of 90 degree arcs to rotate by

  anchorx - the X coordinate of the rotation anchor point

  anchory - the Y coordinate of the rotation anchor point

  Returns:

  an AffineTransform object that rotates coordinates by the specified number of quadrants around the specified anchor point.

  Since:

  1.6

• getScaleInstance

  public static AffineTransform getScaleInstance(double sx, double sy)

  Returns a transform representing a scaling transformation. The matrix representing the returned transform is:

            [   sx   0    0   ]
            [   0    sy   0   ]
            [   0    0    1   ]
   

  Parameters:

  sx - the factor by which coordinates are scaled along the X axis direction

  sy - the factor by which coordinates are scaled along the Y axis direction

  Returns:

  an AffineTransform object that scales coordinates by the specified factors.

  Since:

  1.2

• getShearInstance

  public static AffineTransform getShearInstance(double shx, double shy)

  Returns a transform representing a shearing transformation. The matrix representing the returned transform is:

            [   1   shx   0   ]
            [  shy   1    0   ]
            [   0    0    1   ]
   

  Parameters:

  shx - the multiplier by which coordinates are shifted in the direction of the positive X axis as a factor of their Y coordinate

  shy - the multiplier by which coordinates are shifted in the direction of the positive Y axis as a factor of their X coordinate

  Returns:

  an AffineTransform object that shears coordinates by the specified multipliers.

  Since:

  1.2

• getType

  public int getType()

  Retrieves the flag bits describing the conversion properties of this transform. The return value is either one of the constants TYPE_IDENTITY or TYPE_GENERAL_TRANSFORM, or a combination of the appropriate flag bits. A valid combination of flag bits is an exclusive OR operation that can combine the TYPE_TRANSLATION flag bit in addition to either of the TYPE_UNIFORM_SCALE or TYPE_GENERAL_SCALE flag bits as well as either of the TYPE_QUADRANT_ROTATION or TYPE_GENERAL_ROTATION flag bits.

  Returns:

  the OR combination of any of the indicated flags that apply to this transform

  Since:

  1.2

  See Also:

  • TYPE_IDENTITY
  • TYPE_TRANSLATION
  • TYPE_UNIFORM_SCALE
  • TYPE_GENERAL_SCALE
  • TYPE_QUADRANT_ROTATION
  • TYPE_GENERAL_ROTATION
  • TYPE_GENERAL_TRANSFORM

• getDeterminant

  public double getDeterminant()

  Returns the determinant of the matrix representation of the transform. The determinant is useful both to determine if the transform can be inverted and to get a single value representing the combined X and Y scaling of the transform.

  If the determinant is non-zero, then this transform is invertible and the various methods that depend on the inverse transform do not need to throw a NoninvertibleTransformException. If the determinant is zero then this transform can not be inverted since the transform maps all input coordinates onto a line or a point. If the determinant is near enough to zero then inverse transform operations might not carry enough precision to produce meaningful results.

  If this transform represents a uniform scale, as indicated by the getType method then the determinant also represents the square of the uniform scale factor by which all of the points are expanded from or contracted towards the origin. If this transform represents a non-uniform scale or more general transform then the determinant is not likely to represent a value useful for any purpose other than determining if inverse transforms are possible.

  Mathematically, the determinant is calculated using the formula:

            |  m00  m01  m02  |
            |  m10  m11  m12  |  =  m00 * m11 - m01 * m10
            |   0    0    1   |
   

  Returns:

  the determinant of the matrix used to transform the coordinates.

  Since:

  1.2

  See Also:

  • getType()
  • createInverse()
  • inverseTransform(java.awt.geom.Point2D, java.awt.geom.Point2D)
  • TYPE_UNIFORM_SCALE

• getMatrix

  public void getMatrix(double[] flatmatrix)

  Retrieves the 6 specifiable values in the 3x3 affine transformation matrix and places them into an array of double precisions values. The values are stored in the array as { m00 m10 m01 m11 m02 m12 }. An array of 4 doubles can also be specified, in which case only the first four elements representing the non-transform parts of the array are retrieved and the values are stored into the array as { m00 m10 m01 m11 }

  Parameters:

  flatmatrix - the double array used to store the returned values.

  Since:

  1.2

  See Also:

  • getScaleX()
  • getScaleY()
  • getShearX()
  • getShearY()
  • getTranslateX()
  • getTranslateY()

• getScaleX

  public double getScaleX()

  Returns the m00 element of the 3x3 affine transformation matrix. This matrix factor determines how input X coordinates will affect output X coordinates and is one element of the scale of the transform. To measure the full amount by which X coordinates are stretched or contracted by this transform, use the following code:

       Point2D p = new Point2D.Double(1, 0);
       p = tx.deltaTransform(p, p);
       double scaleX = p.distance(0, 0);
   

  Returns:

  a double value that is m00 element of the 3x3 affine transformation matrix.

  Since:

  1.2

  See Also:

  • getMatrix(double[])

• getScaleY

  public double getScaleY()

  Returns the m11 element of the 3x3 affine transformation matrix. This matrix factor determines how input Y coordinates will affect output Y coordinates and is one element of the scale of the transform. To measure the full amount by which Y coordinates are stretched or contracted by this transform, use the following code:

       Point2D p = new Point2D.Double(0, 1);
       p = tx.deltaTransform(p, p);
       double scaleY = p.distance(0, 0);
   

  Returns:

  a double value that is m11 element of the 3x3 affine transformation matrix.

  Since:

  1.2

  See Also:

  • getMatrix(double[])

• getShearX

  public double getShearX()

  Returns the X coordinate shearing element (m01) of the 3x3 affine transformation matrix.

  Returns:

  a double value that is the X coordinate of the shearing element of the affine transformation matrix.

  Since:

  1.2

  See Also:

  • getMatrix(double[])

• getShearY

  public double getShearY()

  Returns the Y coordinate shearing element (m10) of the 3x3 affine transformation matrix.

  Returns:

  a double value that is the Y coordinate of the shearing element of the affine transformation matrix.

  Since:

  1.2

  See Also:

  • getMatrix(double[])

• getTranslateX

  public double getTranslateX()

  Returns the X coordinate of the translation element (m02) of the 3x3 affine transformation matrix.

  Returns:

  a double value that is the X coordinate of the translation element of the affine transformation matrix.

  Since:

  1.2

  See Also:

  • getMatrix(double[])

• getTranslateY

  public double getTranslateY()

  Returns the Y coordinate of the translation element (m12) of the 3x3 affine transformation matrix.

  Returns:

  a double value that is the Y coordinate of the translation element of the affine transformation matrix.

  Since:

  1.2

  See Also:

  • getMatrix(double[])

• translate

  public void translate(double tx, double ty)

  Concatenates this transform with a translation transformation. This is equivalent to calling concatenate(T), where T is an AffineTransform represented by the following matrix:

            [   1    0    tx  ]
            [   0    1    ty  ]
            [   0    0    1   ]
   

  Parameters:

  tx - the distance by which coordinates are translated in the X axis direction

  ty - the distance by which coordinates are translated in the Y axis direction

  Since:

  1.2

• rotate

  public void rotate(double theta)

  Concatenates this transform with a rotation transformation. This is equivalent to calling concatenate(R), where R is an AffineTransform represented by the following matrix:

            [   cos(theta)    -sin(theta)    0   ]
            [   sin(theta)     cos(theta)    0   ]
            [       0              0         1   ]
   

  Rotating by a positive angle theta rotates points on the positive X axis toward the positive Y axis. Note also the discussion of Handling 90-Degree Rotations above.

  Parameters:

  theta - the angle of rotation measured in radians

  Since:

  1.2

• rotate

  public void rotate(double theta, double anchorx, double anchory)

  Concatenates this transform with a transform that rotates coordinates around an anchor point. This operation is equivalent to translating the coordinates so that the anchor point is at the origin (S1), then rotating them about the new origin (S2), and finally translating so that the intermediate origin is restored to the coordinates of the original anchor point (S3).

  This operation is equivalent to the following sequence of calls:

       translate(anchorx, anchory);      // S3: final translation
       rotate(theta);                    // S2: rotate around anchor
       translate(-anchorx, -anchory);    // S1: translate anchor to origin
   

  Rotating by a positive angle theta rotates points on the positive X axis toward the positive Y axis. Note also the discussion of Handling 90-Degree Rotations above.

  Parameters:

  theta - the angle of rotation measured in radians

  anchorx - the X coordinate of the rotation anchor point

  anchory - the Y coordinate of the rotation anchor point

  Since:

  1.2

• rotate

  public void rotate(double vecx, double vecy)

  Concatenates this transform with a transform that rotates coordinates according to a rotation vector. All coordinates rotate about the origin by the same amount. The amount of rotation is such that coordinates along the former positive X axis will subsequently align with the vector pointing from the origin to the specified vector coordinates. If both vecx and vecy are 0.0, no additional rotation is added to this transform. This operation is equivalent to calling:

            rotate(Math.atan2(vecy, vecx));
   

  Parameters:

  vecx - the X coordinate of the rotation vector

  vecy - the Y coordinate of the rotation vector

  Since:

  1.6

• rotate

  public void rotate(double vecx, double vecy, double anchorx, double anchory)

  Concatenates this transform with a transform that rotates coordinates around an anchor point according to a rotation vector. All coordinates rotate about the specified anchor coordinates by the same amount. The amount of rotation is such that coordinates along the former positive X axis will subsequently align with the vector pointing from the origin to the specified vector coordinates. If both vecx and vecy are 0.0, the transform is not modified in any way. This method is equivalent to calling:

       rotate(Math.atan2(vecy, vecx), anchorx, anchory);
   

  Parameters:

  vecx - the X coordinate of the rotation vector

  vecy - the Y coordinate of the rotation vector

  anchorx - the X coordinate of the rotation anchor point

  anchory - the Y coordinate of the rotation anchor point

  Since:

  1.6

• quadrantRotate

  public void quadrantRotate(int numquadrants)

  Concatenates this transform with a transform that rotates coordinates by the specified number of quadrants. This is equivalent to calling:

       rotate(numquadrants * Math.PI / 2.0);
   

  Rotating by a positive number of quadrants rotates points on the positive X axis toward the positive Y axis.

  Parameters:

  numquadrants - the number of 90 degree arcs to rotate by

  Since:

  1.6

• quadrantRotate

  public void quadrantRotate(int numquadrants, double anchorx, double anchory)

  Concatenates this transform with a transform that rotates coordinates by the specified number of quadrants around the specified anchor point. This method is equivalent to calling:

       rotate(numquadrants * Math.PI / 2.0, anchorx, anchory);
   

  Rotating by a positive number of quadrants rotates points on the positive X axis toward the positive Y axis.

  Parameters:

  numquadrants - the number of 90 degree arcs to rotate by

  anchorx - the X coordinate of the rotation anchor point

  anchory - the Y coordinate of the rotation anchor point

  Since:

  1.6

• scale

  public void scale(double sx, double sy)

  Concatenates this transform with a scaling transformation. This is equivalent to calling concatenate(S), where S is an AffineTransform represented by the following matrix:

            [   sx   0    0   ]
            [   0    sy   0   ]
            [   0    0    1   ]
   

  Parameters:

  sx - the factor by which coordinates are scaled along the X axis direction

  sy - the factor by which coordinates are scaled along the Y axis direction

  Since:

  1.2

• shear

  public void shear(double shx, double shy)

  Concatenates this transform with a shearing transformation. This is equivalent to calling concatenate(SH), where SH is an AffineTransform represented by the following matrix:

            [   1   shx   0   ]
            [  shy   1    0   ]
            [   0    0    1   ]
   

  Parameters:

  shx - the multiplier by which coordinates are shifted in the direction of the positive X axis as a factor of their Y coordinate

  shy - the multiplier by which coordinates are shifted in the direction of the positive Y axis as a factor of their X coordinate

  Since:

  1.2

• setToIdentity

  public void setToIdentity()

  Resets this transform to the Identity transform.

  Since:

  1.2

• setToTranslation

  public void setToTranslation(double tx, double ty)

  Sets this transform to a translation transformation. The matrix representing this transform becomes:

            [   1    0    tx  ]
            [   0    1    ty  ]
            [   0    0    1   ]
   

  Parameters:

  tx - the distance by which coordinates are translated in the X axis direction

  ty - the distance by which coordinates are translated in the Y axis direction

  Since:

  1.2

• setToRotation

  public void setToRotation(double theta)

  Sets this transform to a rotation transformation. The matrix representing this transform becomes:

            [   cos(theta)    -sin(theta)    0   ]
            [   sin(theta)     cos(theta)    0   ]
            [       0              0         1   ]
   

  Rotating by a positive angle theta rotates points on the positive X axis toward the positive Y axis. Note also the discussion of Handling 90-Degree Rotations above.

  Parameters:

  theta - the angle of rotation measured in radians

  Since:

  1.2

• setToRotation

  public void setToRotation(double theta, double anchorx, double anchory)

  Sets this transform to a translated rotation transformation. This operation is equivalent to translating the coordinates so that the anchor point is at the origin (S1), then rotating them about the new origin (S2), and finally translating so that the intermediate origin is restored to the coordinates of the original anchor point (S3).

  This operation is equivalent to the following sequence of calls:

       setToTranslation(anchorx, anchory); // S3: final translation
       rotate(theta);                      // S2: rotate around anchor
       translate(-anchorx, -anchory);      // S1: translate anchor to origin
   

  The matrix representing this transform becomes:

            [   cos(theta)    -sin(theta)    x-x*cos+y*sin  ]
            [   sin(theta)     cos(theta)    y-x*sin-y*cos  ]
            [       0              0               1        ]
   

  Rotating by a positive angle theta rotates points on the positive X axis toward the positive Y axis. Note also the discussion of Handling 90-Degree Rotations above.

  Parameters:

  theta - the angle of rotation measured in radians

  anchorx - the X coordinate of the rotation anchor point

  anchory - the Y coordinate of the rotation anchor point

  Since:

  1.2

• setToRotation

  public void setToRotation(double vecx, double vecy)

  Sets this transform to a rotation transformation that rotates coordinates according to a rotation vector. All coordinates rotate about the origin by the same amount. The amount of rotation is such that coordinates along the former positive X axis will subsequently align with the vector pointing from the origin to the specified vector coordinates. If both vecx and vecy are 0.0, the transform is set to an identity transform. This operation is equivalent to calling:

       setToRotation(Math.atan2(vecy, vecx));
   

  Parameters:

  vecx - the X coordinate of the rotation vector

  vecy - the Y coordinate of the rotation vector

  Since:

  1.6

• setToRotation

  public void setToRotation(double vecx, double vecy, double anchorx, double anchory)

  Sets this transform to a rotation transformation that rotates coordinates around an anchor point according to a rotation vector. All coordinates rotate about the specified anchor coordinates by the same amount. The amount of rotation is such that coordinates along the former positive X axis will subsequently align with the vector pointing from the origin to the specified vector coordinates. If both vecx and vecy are 0.0, the transform is set to an identity transform. This operation is equivalent to calling:

       setToTranslation(Math.atan2(vecy, vecx), anchorx, anchory);
   

  Parameters:

  vecx - the X coordinate of the rotation vector

  vecy - the Y coordinate of the rotation vector

  anchorx - the X coordinate of the rotation anchor point

  anchory - the Y coordinate of the rotation anchor point

  Since:

  1.6

• setToQuadrantRotation

  public void setToQuadrantRotation(int numquadrants)

  Sets this transform to a rotation transformation that rotates coordinates by the specified number of quadrants. This operation is equivalent to calling:

       setToRotation(numquadrants * Math.PI / 2.0);
   

  Rotating by a positive number of quadrants rotates points on the positive X axis toward the positive Y axis.

  Parameters:

  numquadrants - the number of 90 degree arcs to rotate by

  Since:

  1.6

• setToQuadrantRotation

  public void setToQuadrantRotation(int numquadrants, double anchorx, double anchory)

  Sets this transform to a translated rotation transformation that rotates coordinates by the specified number of quadrants around the specified anchor point. This operation is equivalent to calling:

       setToRotation(numquadrants * Math.PI / 2.0, anchorx, anchory);
   

  Rotating by a positive number of quadrants rotates points on the positive X axis toward the positive Y axis.

  Parameters:

  numquadrants - the number of 90 degree arcs to rotate by

  anchorx - the X coordinate of the rotation anchor point

  anchory - the Y coordinate of the rotation anchor point

  Since:

  1.6

• setToScale

  public void setToScale(double sx, double sy)

  Sets this transform to a scaling transformation. The matrix representing this transform becomes:

            [   sx   0    0   ]
            [   0    sy   0   ]
            [   0    0    1   ]
   

  Parameters:

  sx - the factor by which coordinates are scaled along the X axis direction

  sy - the factor by which coordinates are scaled along the Y axis direction

  Since:

  1.2

• setToShear

  public void setToShear(double shx, double shy)

  Sets this transform to a shearing transformation. The matrix representing this transform becomes:

            [   1   shx   0   ]
            [  shy   1    0   ]
            [   0    0    1   ]
   

  Parameters:

  shx - the multiplier by which coordinates are shifted in the direction of the positive X axis as a factor of their Y coordinate

  shy - the multiplier by which coordinates are shifted in the direction of the positive Y axis as a factor of their X coordinate

  Since:

  1.2

• setTransform

  public void setTransform(AffineTransform Tx)

  Sets this transform to a copy of the transform in the specified AffineTransform object.

  Parameters:

  Tx - the AffineTransform object from which to copy the transform

  Since:

  1.2

• setTransform

  public void setTransform(double m00, double m10, double m01, double m11, double m02, double m12)

  Sets this transform to the matrix specified by the 6 double precision values.

  Parameters:

  m00 - the X coordinate scaling element of the 3x3 matrix

  m10 - the Y coordinate shearing element of the 3x3 matrix

  m01 - the X coordinate shearing element of the 3x3 matrix

  m11 - the Y coordinate scaling element of the 3x3 matrix

  m02 - the X coordinate translation element of the 3x3 matrix

  m12 - the Y coordinate translation element of the 3x3 matrix

  Since:

  1.2

• concatenate

  public void concatenate(AffineTransform Tx)

  Concatenates an AffineTransform Tx to this AffineTransform Cx in the most commonly useful way to provide a new user space that is mapped to the former user space by Tx. Cx is updated to perform the combined transformation. Transforming a point p by the updated transform Cx' is equivalent to first transforming p by Tx and then transforming the result by the original transform Cx like this: Cx'(p) = Cx(Tx(p)) In matrix notation, if this transform Cx is represented by the matrix [this] and Tx is represented by the matrix [Tx] then this method does the following:

            [this] = [this] x [Tx]
   

  Parameters:

  Tx - the AffineTransform object to be concatenated with this AffineTransform object.

  Since:

  1.2

  See Also:

  • preConcatenate(java.awt.geom.AffineTransform)

• preConcatenate

  public void preConcatenate(AffineTransform Tx)

  Concatenates an AffineTransform Tx to this AffineTransform Cx in a less commonly used way such that Tx modifies the coordinate transformation relative to the absolute pixel space rather than relative to the existing user space. Cx is updated to perform the combined transformation. Transforming a point p by the updated transform Cx' is equivalent to first transforming p by the original transform Cx and then transforming the result by Tx like this: Cx'(p) = Tx(Cx(p)) In matrix notation, if this transform Cx is represented by the matrix [this] and Tx is represented by the matrix [Tx] then this method does the following:

            [this] = [Tx] x [this]
   

  Parameters:

  Tx - the AffineTransform object to be concatenated with this AffineTransform object.

  Since:

  1.2

  See Also:

  • concatenate(java.awt.geom.AffineTransform)

• createInverse

  public AffineTransform createInverse() throws NoninvertibleTransformException

  Returns an AffineTransform object representing the inverse transformation. The inverse transform Tx' of this transform Tx maps coordinates transformed by Tx back to their original coordinates. In other words, Tx'(Tx(p)) = p = Tx(Tx'(p)).

  If this transform maps all coordinates onto a point or a line then it will not have an inverse, since coordinates that do not lie on the destination point or line will not have an inverse mapping. The getDeterminant method can be used to determine if this transform has no inverse, in which case an exception will be thrown if the createInverse method is called.

  Returns:

  a new AffineTransform object representing the inverse transformation.

  Throws:

  NoninvertibleTransformException - if the matrix cannot be inverted.

  Since:

  1.2

  See Also:

  • getDeterminant()

• invert

  public void invert() throws NoninvertibleTransformException

  Sets this transform to the inverse of itself. The inverse transform Tx' of this transform Tx maps coordinates transformed by Tx back to their original coordinates. In other words, Tx'(Tx(p)) = p = Tx(Tx'(p)).

  If this transform maps all coordinates onto a point or a line then it will not have an inverse, since coordinates that do not lie on the destination point or line will not have an inverse mapping. The getDeterminant method can be used to determine if this transform has no inverse, in which case an exception will be thrown if the invert method is called.

  Throws:

  NoninvertibleTransformException - if the matrix cannot be inverted.

  Since:

  1.6

  See Also:

  • getDeterminant()

• transform

  public Point2D transform(Point2D ptSrc, Point2D ptDst)

  Transforms the specified ptSrc and stores the result in ptDst. If ptDst is null, a new Point2D object is allocated and then the result of the transformation is stored in this object. In either case, ptDst, which contains the transformed point, is returned for convenience. If ptSrc and ptDst are the same object, the input point is correctly overwritten with the transformed point.

  Parameters:

  ptSrc - the specified Point2D to be transformed

  ptDst - the specified Point2D that stores the result of transforming ptSrc

  Returns:

  the ptDst after transforming ptSrc and storing the result in ptDst.

  Since:

  1.2

• transform

  public void transform(Point2D[] ptSrc, int srcOff, Point2D[] ptDst, int dstOff, int numPts)

  Transforms an array of point objects by this transform. If any element of the ptDst array is null, a new Point2D object is allocated and stored into that element before storing the results of the transformation.

  Note that this method does not take any precautions to avoid problems caused by storing results into Point2D objects that will be used as the source for calculations further down the source array. This method does guarantee that if a specified Point2D object is both the source and destination for the same single point transform operation then the results will not be stored until the calculations are complete to avoid storing the results on top of the operands. If, however, the destination Point2D object for one operation is the same object as the source Point2D object for another operation further down the source array then the original coordinates in that point are overwritten before they can be converted.

  Parameters:

  ptSrc - the array containing the source point objects

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

  ptDst - the array into which the transform point objects are returned

  dstOff - the offset to the location of the first transformed point object that is stored in the destination array

  numPts - the number of point objects to be transformed

  Since:

  1.2

• transform

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

  Transforms an array of floating point coordinates by this transform. The two coordinate array sections can be exactly the same or can be overlapping sections of the same array without affecting the validity of the results. This method ensures that no source coordinates are overwritten by a previous operation before they can be transformed. The coordinates are stored in the arrays starting at the specified offset in the order [x0, y0, x1, y1, ..., xn, yn].

  Parameters:

  srcPts - the array containing the source point coordinates. Each point is stored as a pair of x, y 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. Each point is stored as a pair of x, y coordinates.

  dstOff - the offset to the location of the first transformed point that is stored in the destination array

  numPts - the number of points to be transformed

  Since:

  1.2

• transform

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

  Transforms an array of double precision coordinates by this transform. The two coordinate array sections can be exactly the same or can be overlapping sections of the same array without affecting the validity of the results. This method ensures that no source coordinates are overwritten by a previous operation before they can be transformed. The coordinates are stored in the arrays starting at the indicated offset in the order [x0, y0, x1, y1, ..., xn, yn].

  Parameters:

  srcPts - the array containing the source point coordinates. Each point is stored as a pair of x, y 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. Each point is stored as a pair of x, y coordinates.

  dstOff - the offset to the location of the first transformed point that is stored in the destination array

  numPts - the number of point objects to be transformed

  Since:

  1.2

• transform

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

  Transforms an array of floating point coordinates by this transform and stores the results into an array of doubles. The coordinates are stored in the arrays starting at the specified offset in the order [x0, y0, x1, y1, ..., xn, yn].

  Parameters:

  srcPts - the array containing the source point coordinates. Each point is stored as a pair of x, y 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. Each point is stored as a pair of x, y coordinates.

  dstOff - the offset to the location of the first transformed point that is stored in the destination array

  numPts - the number of points to be transformed

  Since:

  1.2

• transform

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

  Transforms an array of double precision coordinates by this transform and stores the results into an array of floats. The coordinates are stored in the arrays starting at the specified offset in the order [x0, y0, x1, y1, ..., xn, yn].

  Parameters:

  srcPts - the array containing the source point coordinates. Each point is stored as a pair of x, y 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. Each point is stored as a pair of x, y coordinates.

  dstOff - the offset to the location of the first transformed point that is stored in the destination array

  numPts - the number of point objects to be transformed

  Since:

  1.2

• inverseTransform

  public Point2D inverseTransform(Point2D ptSrc, Point2D ptDst) throws NoninvertibleTransformException

  Inverse transforms the specified ptSrc and stores the result in ptDst. If ptDst is null, a new Point2D object is allocated and then the result of the transform is stored in this object. In either case, ptDst, which contains the transformed point, is returned for convenience. If ptSrc and ptDst are the same object, the input point is correctly overwritten with the transformed point.

  Parameters:

  ptSrc - the point to be inverse transformed

  ptDst - the resulting transformed point

  Returns:

  ptDst, which contains the result of the inverse transform.

  Throws:

  NoninvertibleTransformException - if the matrix cannot be inverted.

  Since:

  1.2

• inverseTransform

  public void inverseTransform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts) throws NoninvertibleTransformException

  Inverse transforms an array of double precision coordinates by this transform. The two coordinate array sections can be exactly the same or can be overlapping sections of the same array without affecting the validity of the results. This method ensures that no source coordinates are overwritten by a previous operation before they can be transformed. The coordinates are stored in the arrays starting at the specified offset in the order [x0, y0, x1, y1, ..., xn, yn].

  Parameters:

  srcPts - the array containing the source point coordinates. Each point is stored as a pair of x, y 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. Each point is stored as a pair of x, y coordinates.

  dstOff - the offset to the location of the first transformed point that is stored in the destination array

  numPts - the number of point objects to be transformed

  Throws:

  NoninvertibleTransformException - if the matrix cannot be inverted.

  Since:

  1.2

• deltaTransform

  public Point2D deltaTransform(Point2D ptSrc, Point2D ptDst)

  Transforms the relative distance vector specified by ptSrc and stores the result in ptDst. A relative distance vector is transformed without applying the translation components of the affine transformation matrix using the following equations:

    [  x' ]   [  m00  m01 (m02) ] [  x  ]   [ m00x + m01y ]
    [  y' ] = [  m10  m11 (m12) ] [  y  ] = [ m10x + m11y ]
    [ (1) ]   [  (0)  (0) ( 1 ) ] [ (1) ]   [     (1)     ]
   

  If ptDst is null, a new Point2D object is allocated and then the result of the transform is stored in this object. In either case, ptDst, which contains the transformed point, is returned for convenience. If ptSrc and ptDst are the same object, the input point is correctly overwritten with the transformed point.

  Parameters:

  ptSrc - the distance vector to be delta transformed

  ptDst - the resulting transformed distance vector

  Returns:

  ptDst, which contains the result of the transformation.

  Since:

  1.2

• deltaTransform

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

  Transforms an array of relative distance vectors by this transform. A relative distance vector is transformed without applying the translation components of the affine transformation matrix using the following equations:

    [  x' ]   [  m00  m01 (m02) ] [  x  ]   [ m00x + m01y ]
    [  y' ] = [  m10  m11 (m12) ] [  y  ] = [ m10x + m11y ]
    [ (1) ]   [  (0)  (0) ( 1 ) ] [ (1) ]   [     (1)     ]
   

  The two coordinate array sections can be exactly the same or can be overlapping sections of the same array without affecting the validity of the results. This method ensures that no source coordinates are overwritten by a previous operation before they can be transformed. The coordinates are stored in the arrays starting at the indicated offset in the order [x0, y0, x1, y1, ..., xn, yn].

  Parameters:

  srcPts - the array containing the source distance vectors. Each vector is stored as a pair of relative x, y coordinates.

  srcOff - the offset to the first vector to be transformed in the source array

  dstPts - the array into which the transformed distance vectors are returned. Each vector is stored as a pair of relative x, y coordinates.

  dstOff - the offset to the location of the first transformed vector that is stored in the destination array

  numPts - the number of vector coordinate pairs to be transformed

  Since:

  1.2

• createTransformedShape

  public Shape createTransformedShape(Shape pSrc)

  Returns a new Shape object defined by the geometry of the specified Shape after it has been transformed by this transform.

  Parameters:

  pSrc - the specified Shape object to be transformed by this transform.

  Returns:

  a new Shape object that defines the geometry of the transformed Shape, or null if pSrc is null.

  Since:

  1.2

• toString

  public String toString()

  Returns a String that represents the value of this Object.

  Overrides:

  toString in class Object

  Returns:

  a String representing the value of this Object.

  Since:

  1.2

• isIdentity

  public boolean isIdentity()

  Returns true if this AffineTransform is an identity transform.

  Returns:

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

  Since:

  1.2

• clone

  public Object clone()

  Returns a copy of this AffineTransform object.

  Overrides:

  clone in class Object

  Returns:

  an Object that is a copy of this AffineTransform object.

  Since:

  1.2

  See Also:

  • Cloneable

• hashCode

  public int hashCode()

  Returns the hashcode for this transform.

  Overrides:

  hashCode in class Object

  Returns:

  a hash code for this transform.

  Since:

  1.2

  See Also:

  • Object.equals(java.lang.Object)
  • System.identityHashCode(java.lang.Object)

• equals

  public boolean equals(Object obj)

  Returns true if this AffineTransform represents the same affine coordinate transform as the specified argument.

  Overrides:

  equals in class Object

  Parameters:

  obj - the Object to test for equality with this AffineTransform

  Returns:

  true if obj equals this AffineTransform object; false otherwise.

  Since:

  1.2

  See Also:

  • Object.hashCode()
  • HashMap