AffineTransform class represents a 2D affine transform
* that performs a linear mapping from 2D coordinates to other 2D
* coordinates that preserves the "straightness" and
* "parallelness" of lines. Affine transformations can be constructed
* using sequences of translations, scales, flips, rotations, and shears.
* * Such a coordinate transformation can be represented by a 3 row by * 3 column matrix with an implied last row of [ 0 0 1 ]. This matrix * transforms source coordinates {@code (x,y)} into * destination coordinates {@code (x',y')} by considering * them to be a column vector and multiplying the coordinate vector * by the matrix according to the following process: *
* [ x'] [ m00 m01 m02 ] [ x ] [ m00x + m01y + m02 ] * [ y'] = [ m10 m11 m12 ] [ y ] = [ m10x + m11y + m12 ] * [ 1 ] [ 0 0 1 ] [ 1 ] [ 1 ] **
* Handling 90-Degree Rotations
*
* In some variations of the rotate methods in the
* AffineTransform class, a double-precision argument
* specifies the angle of rotation in radians.
* These methods have special handling for rotations of approximately
* 90 degrees (including multiples such as 180, 270, and 360 degrees),
* so that the common case of quadrant rotation is handled more
* efficiently.
* This special handling can cause angles very close to multiples of
* 90 degrees to be treated as if they were exact multiples of
* 90 degrees.
* For small multiples of 90 degrees the range of angles treated
* as a quadrant rotation is approximately 0.00000121 degrees wide.
* This section explains why such special care is needed and how
* it is implemented.
*
* Since 90 degrees is represented as PI/2 in radians,
* and since PI is a transcendental (and therefore irrational) number,
* it is not possible to exactly represent a multiple of 90 degrees as
* an exact double precision value measured in radians.
* As a result it is theoretically impossible to describe quadrant
* rotations (90, 180, 270 or 360 degrees) using these values.
* Double precision floating point values can get very close to
* non-zero multiples of PI/2 but never close enough
* for the sine or cosine to be exactly 0.0, 1.0 or -1.0.
* The implementations of Math.sin() and
* Math.cos() correspondingly never return 0.0
* for any case other than Math.sin(0.0).
* These same implementations do, however, return exactly 1.0 and
* -1.0 for some range of numbers around each multiple of 90
* degrees since the correct answer is so close to 1.0 or -1.0 that
* the double precision significand cannot represent the difference
* as accurately as it can for numbers that are near 0.0.
*
* The net result of these issues is that if the
* Math.sin() and Math.cos() methods
* are used to directly generate the values for the matrix modifications
* during these radian-based rotation operations then the resulting
* transform is never strictly classifiable as a quadrant rotation
* even for a simple case like rotate(Math.PI/2.0),
* due to minor variations in the matrix caused by the non-0.0 values
* obtained for the sine and cosine.
* If these transforms are not classified as quadrant rotations then
* subsequent code which attempts to optimize further operations based
* upon the type of the transform will be relegated to its most general
* implementation.
*
* Because quadrant rotations are fairly common,
* this class should handle these cases reasonably quickly, both in
* applying the rotations to the transform and in applying the resulting
* transform to the coordinates.
* To facilitate this optimal handling, the methods which take an angle
* of rotation measured in radians attempt to detect angles that are
* intended to be quadrant rotations and treat them as such.
* These methods therefore treat an angle theta as a quadrant
* rotation if either Math.sin(theta) or
* Math.cos(theta) returns exactly 1.0 or -1.0.
* As a rule of thumb, this property holds true for a range of
* approximately 0.0000000211 radians (or 0.00000121 degrees) around
* small multiples of Math.PI/2.0.
*
* @author Jim Graham
* @since 1.2
*/
public class AffineTransform implements Cloneable, java.io.Serializable {
/*
* This constant is only useful for the cached type field.
* It indicates that the type has been decached and must be recalculated.
*/
private static final int TYPE_UNKNOWN = -1;
/**
* This constant indicates that the transform defined by this object
* is an identity transform.
* An identity transform is one in which the output coordinates are
* always the same as the input coordinates.
* If this transform is anything other than the identity transform,
* the type will either be the constant GENERAL_TRANSFORM or a
* combination of the appropriate flag bits for the various coordinate
* conversions that this transform performs.
* @see #TYPE_TRANSLATION
* @see #TYPE_UNIFORM_SCALE
* @see #TYPE_GENERAL_SCALE
* @see #TYPE_FLIP
* @see #TYPE_QUADRANT_ROTATION
* @see #TYPE_GENERAL_ROTATION
* @see #TYPE_GENERAL_TRANSFORM
* @see #getType
* @since 1.2
*/
public static final int TYPE_IDENTITY = 0;
/**
* This flag bit indicates that the transform defined by this object
* performs a translation in addition to the conversions indicated
* by other flag bits.
* A translation moves the coordinates by a constant amount in x
* and y without changing the length or angle of vectors.
* @see #TYPE_IDENTITY
* @see #TYPE_UNIFORM_SCALE
* @see #TYPE_GENERAL_SCALE
* @see #TYPE_FLIP
* @see #TYPE_QUADRANT_ROTATION
* @see #TYPE_GENERAL_ROTATION
* @see #TYPE_GENERAL_TRANSFORM
* @see #getType
* @since 1.2
*/
public static final int TYPE_TRANSLATION = 1;
/**
* This flag bit indicates that the transform defined by this object
* performs a uniform scale in addition to the conversions indicated
* by other flag bits.
* A uniform scale multiplies the length of vectors by the same amount
* in both the x and y directions without changing the angle between
* vectors.
* This flag bit is mutually exclusive with the TYPE_GENERAL_SCALE flag.
* @see #TYPE_IDENTITY
* @see #TYPE_TRANSLATION
* @see #TYPE_GENERAL_SCALE
* @see #TYPE_FLIP
* @see #TYPE_QUADRANT_ROTATION
* @see #TYPE_GENERAL_ROTATION
* @see #TYPE_GENERAL_TRANSFORM
* @see #getType
* @since 1.2
*/
public static final int TYPE_UNIFORM_SCALE = 2;
/**
* This flag bit indicates that the transform defined by this object
* performs a general scale in addition to the conversions indicated
* by other flag bits.
* A general scale multiplies the length of vectors by different
* amounts in the x and y directions without changing the angle
* between perpendicular vectors.
* This flag bit is mutually exclusive with the TYPE_UNIFORM_SCALE flag.
* @see #TYPE_IDENTITY
* @see #TYPE_TRANSLATION
* @see #TYPE_UNIFORM_SCALE
* @see #TYPE_FLIP
* @see #TYPE_QUADRANT_ROTATION
* @see #TYPE_GENERAL_ROTATION
* @see #TYPE_GENERAL_TRANSFORM
* @see #getType
* @since 1.2
*/
public static final int TYPE_GENERAL_SCALE = 4;
/**
* This constant is a bit mask for any of the scale flag bits.
* @see #TYPE_UNIFORM_SCALE
* @see #TYPE_GENERAL_SCALE
* @since 1.2
*/
public static final int TYPE_MASK_SCALE = (TYPE_UNIFORM_SCALE |
TYPE_GENERAL_SCALE);
/**
* This flag bit indicates that the transform defined by this object
* performs a mirror image flip about some axis which changes the
* normally right handed coordinate system into a left handed
* system in addition to the conversions indicated by other flag bits.
* A right handed coordinate system is one where the positive X
* axis rotates counterclockwise to overlay the positive Y axis
* similar to the direction that the fingers on your right hand
* curl when you stare end on at your thumb.
* A left handed coordinate system is one where the positive X
* axis rotates clockwise to overlay the positive Y axis similar
* to the direction that the fingers on your left hand curl.
* There is no mathematical way to determine the angle of the
* original flipping or mirroring transformation since all angles
* of flip are identical given an appropriate adjusting rotation.
* @see #TYPE_IDENTITY
* @see #TYPE_TRANSLATION
* @see #TYPE_UNIFORM_SCALE
* @see #TYPE_GENERAL_SCALE
* @see #TYPE_QUADRANT_ROTATION
* @see #TYPE_GENERAL_ROTATION
* @see #TYPE_GENERAL_TRANSFORM
* @see #getType
* @since 1.2
*/
public static final int TYPE_FLIP = 64;
/* NOTE: TYPE_FLIP was added after GENERAL_TRANSFORM was in public
* circulation and the flag bits could no longer be conveniently
* renumbered without introducing binary incompatibility in outside
* code.
*/
/**
* This flag bit indicates that the transform defined by this object
* performs a quadrant rotation by some multiple of 90 degrees in
* addition to the conversions indicated by other flag bits.
* A rotation changes the angles of vectors by the same amount
* regardless of the original direction of the vector and without
* changing the length of the vector.
* This flag bit is mutually exclusive with the TYPE_GENERAL_ROTATION flag.
* @see #TYPE_IDENTITY
* @see #TYPE_TRANSLATION
* @see #TYPE_UNIFORM_SCALE
* @see #TYPE_GENERAL_SCALE
* @see #TYPE_FLIP
* @see #TYPE_GENERAL_ROTATION
* @see #TYPE_GENERAL_TRANSFORM
* @see #getType
* @since 1.2
*/
public static final int TYPE_QUADRANT_ROTATION = 8;
/**
* This flag bit indicates that the transform defined by this object
* performs a rotation by an arbitrary angle in addition to the
* conversions indicated by other flag bits.
* A rotation changes the angles of vectors by the same amount
* regardless of the original direction of the vector and without
* changing the length of the vector.
* This flag bit is mutually exclusive with the
* TYPE_QUADRANT_ROTATION flag.
* @see #TYPE_IDENTITY
* @see #TYPE_TRANSLATION
* @see #TYPE_UNIFORM_SCALE
* @see #TYPE_GENERAL_SCALE
* @see #TYPE_FLIP
* @see #TYPE_QUADRANT_ROTATION
* @see #TYPE_GENERAL_TRANSFORM
* @see #getType
* @since 1.2
*/
public static final int TYPE_GENERAL_ROTATION = 16;
/**
* This constant is a bit mask for any of the rotation flag bits.
* @see #TYPE_QUADRANT_ROTATION
* @see #TYPE_GENERAL_ROTATION
* @since 1.2
*/
public static final int TYPE_MASK_ROTATION = (TYPE_QUADRANT_ROTATION |
TYPE_GENERAL_ROTATION);
/**
* This constant indicates that the transform defined by this object
* performs an arbitrary conversion of the input coordinates.
* If this transform can be classified by any of the above constants,
* the type will either be the constant TYPE_IDENTITY or a
* combination of the appropriate flag bits for the various coordinate
* conversions that this transform performs.
* @see #TYPE_IDENTITY
* @see #TYPE_TRANSLATION
* @see #TYPE_UNIFORM_SCALE
* @see #TYPE_GENERAL_SCALE
* @see #TYPE_FLIP
* @see #TYPE_QUADRANT_ROTATION
* @see #TYPE_GENERAL_ROTATION
* @see #getType
* @since 1.2
*/
public static final int TYPE_GENERAL_TRANSFORM = 32;
/**
* This constant is used for the internal state variable to indicate
* that no calculations need to be performed and that the source
* coordinates only need to be copied to their destinations to
* complete the transformation equation of this transform.
* @see #APPLY_TRANSLATE
* @see #APPLY_SCALE
* @see #APPLY_SHEAR
* @see #state
*/
static final int APPLY_IDENTITY = 0;
/**
* This constant is used for the internal state variable to indicate
* that the translation components of the matrix (m02 and m12) need
* to be added to complete the transformation equation of this transform.
* @see #APPLY_IDENTITY
* @see #APPLY_SCALE
* @see #APPLY_SHEAR
* @see #state
*/
static final int APPLY_TRANSLATE = 1;
/**
* This constant is used for the internal state variable to indicate
* that the scaling components of the matrix (m00 and m11) need
* to be factored in to complete the transformation equation of
* this transform. If the APPLY_SHEAR bit is also set then it
* indicates that the scaling components are not both 0.0. If the
* APPLY_SHEAR bit is not also set then it indicates that the
* scaling components are not both 1.0. If neither the APPLY_SHEAR
* nor the APPLY_SCALE bits are set then the scaling components
* are both 1.0, which means that the x and y components contribute
* to the transformed coordinate, but they are not multiplied by
* any scaling factor.
* @see #APPLY_IDENTITY
* @see #APPLY_TRANSLATE
* @see #APPLY_SHEAR
* @see #state
*/
static final int APPLY_SCALE = 2;
/**
* This constant is used for the internal state variable to indicate
* that the shearing components of the matrix (m01 and m10) need
* to be factored in to complete the transformation equation of this
* transform. The presence of this bit in the state variable changes
* the interpretation of the APPLY_SCALE bit as indicated in its
* documentation.
* @see #APPLY_IDENTITY
* @see #APPLY_TRANSLATE
* @see #APPLY_SCALE
* @see #state
*/
static final int APPLY_SHEAR = 4;
/*
* For methods which combine together the state of two separate
* transforms and dispatch based upon the combination, these constants
* specify how far to shift one of the states so that the two states
* are mutually non-interfering and provide constants for testing the
* bits of the shifted (HI) state. The methods in this class use
* the convention that the state of "this" transform is unshifted and
* the state of the "other" or "argument" transform is shifted (HI).
*/
private static final int HI_SHIFT = 3;
private static final int HI_IDENTITY = APPLY_IDENTITY << HI_SHIFT;
private static final int HI_TRANSLATE = APPLY_TRANSLATE << HI_SHIFT;
private static final int HI_SCALE = APPLY_SCALE << HI_SHIFT;
private static final int HI_SHEAR = APPLY_SHEAR << HI_SHIFT;
/**
* The X coordinate scaling element of the 3x3
* affine transformation matrix.
*
* @serial
*/
double m00;
/**
* The Y coordinate shearing element of the 3x3
* affine transformation matrix.
*
* @serial
*/
double m10;
/**
* The X coordinate shearing element of the 3x3
* affine transformation matrix.
*
* @serial
*/
double m01;
/**
* The Y coordinate scaling element of the 3x3
* affine transformation matrix.
*
* @serial
*/
double m11;
/**
* The X coordinate of the translation element of the
* 3x3 affine transformation matrix.
*
* @serial
*/
double m02;
/**
* The Y coordinate of the translation element of the
* 3x3 affine transformation matrix.
*
* @serial
*/
double m12;
/**
* This field keeps track of which components of the matrix need to
* be applied when performing a transformation.
* @see #APPLY_IDENTITY
* @see #APPLY_TRANSLATE
* @see #APPLY_SCALE
* @see #APPLY_SHEAR
*/
transient int state;
/**
* This field caches the current transformation type of the matrix.
* @see #TYPE_IDENTITY
* @see #TYPE_TRANSLATION
* @see #TYPE_UNIFORM_SCALE
* @see #TYPE_GENERAL_SCALE
* @see #TYPE_FLIP
* @see #TYPE_QUADRANT_ROTATION
* @see #TYPE_GENERAL_ROTATION
* @see #TYPE_GENERAL_TRANSFORM
* @see #TYPE_UNKNOWN
* @see #getType
*/
private transient int type;
private AffineTransform(double m00, double m10,
double m01, double m11,
double m02, double m12,
int state) {
this.m00 = m00;
this.m10 = m10;
this.m01 = m01;
this.m11 = m11;
this.m02 = m02;
this.m12 = m12;
this.state = state;
this.type = TYPE_UNKNOWN;
}
/**
* Constructs a new AffineTransform representing the
* Identity transformation.
* @since 1.2
*/
public AffineTransform() {
m00 = m11 = 1.0;
// m01 = m10 = m02 = m12 = 0.0; /* Not needed. */
// state = APPLY_IDENTITY; /* Not needed. */
// type = TYPE_IDENTITY; /* Not needed. */
}
/**
* Constructs a new AffineTransform that is a copy of
* the specified AffineTransform object.
* @param Tx the AffineTransform object to copy
* @since 1.2
*/
public AffineTransform(AffineTransform Tx) {
this.m00 = Tx.m00;
this.m10 = Tx.m10;
this.m01 = Tx.m01;
this.m11 = Tx.m11;
this.m02 = Tx.m02;
this.m12 = Tx.m12;
this.state = Tx.state;
this.type = Tx.type;
}
/**
* Constructs a new AffineTransform from 6 floating point
* values representing the 6 specifiable entries of the 3x3
* transformation matrix.
*
* @param m00 the X coordinate scaling element of the 3x3 matrix
* @param m10 the Y coordinate shearing element of the 3x3 matrix
* @param m01 the X coordinate shearing element of the 3x3 matrix
* @param m11 the Y coordinate scaling element of the 3x3 matrix
* @param m02 the X coordinate translation element of the 3x3 matrix
* @param m12 the Y coordinate translation element of the 3x3 matrix
* @since 1.2
*/
@ConstructorProperties({ "scaleX", "shearY", "shearX", "scaleY", "translateX", "translateY" })
public AffineTransform(float m00, float m10,
float m01, float m11,
float m02, float m12) {
this.m00 = m00;
this.m10 = m10;
this.m01 = m01;
this.m11 = m11;
this.m02 = m02;
this.m12 = m12;
updateState();
}
/**
* Constructs a new AffineTransform from an array of
* floating point values representing either the 4 non-translation
* enries or the 6 specifiable entries of the 3x3 transformation
* matrix. The values are retrieved from the array as
* { m00 m10 m01 m11 [m02 m12]}.
* @param flatmatrix the float array containing the values to be set
* in the new AffineTransform object. The length of the
* array is assumed to be at least 4. If the length of the array is
* less than 6, only the first 4 values are taken. If the length of
* the array is greater than 6, the first 6 values are taken.
* @since 1.2
*/
public AffineTransform(float[] flatmatrix) {
m00 = flatmatrix[0];
m10 = flatmatrix[1];
m01 = flatmatrix[2];
m11 = flatmatrix[3];
if (flatmatrix.length > 5) {
m02 = flatmatrix[4];
m12 = flatmatrix[5];
}
updateState();
}
/**
* Constructs a new AffineTransform from 6 double
* precision values representing the 6 specifiable entries of the 3x3
* transformation matrix.
*
* @param m00 the X coordinate scaling element of the 3x3 matrix
* @param m10 the Y coordinate shearing element of the 3x3 matrix
* @param m01 the X coordinate shearing element of the 3x3 matrix
* @param m11 the Y coordinate scaling element of the 3x3 matrix
* @param m02 the X coordinate translation element of the 3x3 matrix
* @param m12 the Y coordinate translation element of the 3x3 matrix
* @since 1.2
*/
public AffineTransform(double m00, double m10,
double m01, double m11,
double m02, double m12) {
this.m00 = m00;
this.m10 = m10;
this.m01 = m01;
this.m11 = m11;
this.m02 = m02;
this.m12 = m12;
updateState();
}
/**
* Constructs a new AffineTransform from an array of
* double precision values representing either the 4 non-translation
* entries or the 6 specifiable entries of the 3x3 transformation
* matrix. The values are retrieved from the array as
* { m00 m10 m01 m11 [m02 m12]}.
* @param flatmatrix the double array containing the values to be set
* in the new AffineTransform object. The length of the
* array is assumed to be at least 4. If the length of the array is
* less than 6, only the first 4 values are taken. If the length of
* the array is greater than 6, the first 6 values are taken.
* @since 1.2
*/
public AffineTransform(double[] flatmatrix) {
m00 = flatmatrix[0];
m10 = flatmatrix[1];
m01 = flatmatrix[2];
m11 = flatmatrix[3];
if (flatmatrix.length > 5) {
m02 = flatmatrix[4];
m12 = flatmatrix[5];
}
updateState();
}
/**
* Returns a transform representing a translation transformation.
* The matrix representing the returned transform is:
*
* [ 1 0 tx ]
* [ 0 1 ty ]
* [ 0 0 1 ]
*
* @param tx the distance by which coordinates are translated in the
* X axis direction
* @param ty the distance by which coordinates are translated in the
* Y axis direction
* @return an AffineTransform object that represents a
* translation transformation, created with the specified vector.
* @since 1.2
*/
public static AffineTransform getTranslateInstance(double tx, double ty) {
AffineTransform Tx = new AffineTransform();
Tx.setToTranslation(tx, ty);
return Tx;
}
/**
* 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.
* @param theta the angle of rotation measured in radians
* @return an AffineTransform object that is a rotation
* transformation, created with the specified angle of rotation.
* @since 1.2
*/
public static AffineTransform getRotateInstance(double theta) {
AffineTransform Tx = new AffineTransform();
Tx.setToRotation(theta);
return Tx;
}
/**
* 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.
*
* @param theta the angle of rotation measured in radians
* @param anchorx the X coordinate of the rotation anchor point
* @param anchory the Y coordinate of the rotation anchor point
* @return an AffineTransform object that rotates
* coordinates around the specified point by the specified angle of
* rotation.
* @since 1.2
*/
public static AffineTransform getRotateInstance(double theta,
double anchorx,
double anchory)
{
AffineTransform Tx = new AffineTransform();
Tx.setToRotation(theta, anchorx, anchory);
return Tx;
}
/**
* 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));
*
*
* @param vecx the X coordinate of the rotation vector
* @param vecy the Y coordinate of the rotation vector
* @return an AffineTransform object that rotates
* coordinates according to the specified rotation vector.
* @since 1.6
*/
public static AffineTransform getRotateInstance(double vecx, double vecy) {
AffineTransform Tx = new AffineTransform();
Tx.setToRotation(vecx, vecy);
return Tx;
}
/**
* Returns a transform that rotates coordinates around an anchor
* point accordinate 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);
*
*
* @param vecx the X coordinate of the rotation vector
* @param vecy the Y coordinate of the rotation vector
* @param anchorx the X coordinate of the rotation anchor point
* @param anchory the Y coordinate of the rotation anchor point
* @return an AffineTransform object that rotates
* coordinates around the specified point according to the
* specified rotation vector.
* @since 1.6
*/
public static AffineTransform getRotateInstance(double vecx,
double vecy,
double anchorx,
double anchory)
{
AffineTransform Tx = new AffineTransform();
Tx.setToRotation(vecx, vecy, anchorx, anchory);
return Tx;
}
/**
* 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.
* @param numquadrants the number of 90 degree arcs to rotate by
* @return an AffineTransform object that rotates
* coordinates by the specified number of quadrants.
* @since 1.6
*/
public static AffineTransform getQuadrantRotateInstance(int numquadrants) {
AffineTransform Tx = new AffineTransform();
Tx.setToQuadrantRotation(numquadrants);
return Tx;
}
/**
* 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.
*
* @param numquadrants the number of 90 degree arcs to rotate by
* @param anchorx the X coordinate of the rotation anchor point
* @param anchory the Y coordinate of the rotation anchor point
* @return an AffineTransform object that rotates
* coordinates by the specified number of quadrants around the
* specified anchor point.
* @since 1.6
*/
public static AffineTransform getQuadrantRotateInstance(int numquadrants,
double anchorx,
double anchory)
{
AffineTransform Tx = new AffineTransform();
Tx.setToQuadrantRotation(numquadrants, anchorx, anchory);
return Tx;
}
/**
* Returns a transform representing a scaling transformation.
* The matrix representing the returned transform is:
*
* [ sx 0 0 ]
* [ 0 sy 0 ]
* [ 0 0 1 ]
*
* @param sx the factor by which coordinates are scaled along the
* X axis direction
* @param sy the factor by which coordinates are scaled along the
* Y axis direction
* @return an AffineTransform object that scales
* coordinates by the specified factors.
* @since 1.2
*/
public static AffineTransform getScaleInstance(double sx, double sy) {
AffineTransform Tx = new AffineTransform();
Tx.setToScale(sx, sy);
return Tx;
}
/**
* Returns a transform representing a shearing transformation.
* The matrix representing the returned transform is:
*
* [ 1 shx 0 ]
* [ shy 1 0 ]
* [ 0 0 1 ]
*
* @param shx the multiplier by which coordinates are shifted in the
* direction of the positive X axis as a factor of their Y coordinate
* @param shy the multiplier by which coordinates are shifted in the
* direction of the positive Y axis as a factor of their X coordinate
* @return an AffineTransform object that shears
* coordinates by the specified multipliers.
* @since 1.2
*/
public static AffineTransform getShearInstance(double shx, double shy) {
AffineTransform Tx = new AffineTransform();
Tx.setToShear(shx, shy);
return Tx;
}
/**
* 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
* appriopriate 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.
* @return the OR combination of any of the indicated flags that
* apply to this transform
* @see #TYPE_IDENTITY
* @see #TYPE_TRANSLATION
* @see #TYPE_UNIFORM_SCALE
* @see #TYPE_GENERAL_SCALE
* @see #TYPE_QUADRANT_ROTATION
* @see #TYPE_GENERAL_ROTATION
* @see #TYPE_GENERAL_TRANSFORM
* @since 1.2
*/
public int getType() {
if (type == TYPE_UNKNOWN) {
calculateType();
}
return type;
}
/**
* This is the utility function to calculate the flag bits when
* they have not been cached.
* @see #getType
*/
private void calculateType() {
int ret = TYPE_IDENTITY;
boolean sgn0, sgn1;
double M0, M1, M2, M3;
updateState();
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
ret = TYPE_TRANSLATION;
/* NOBREAK */
case (APPLY_SHEAR | APPLY_SCALE):
if ((M0 = m00) * (M2 = m01) + (M3 = m10) * (M1 = m11) != 0) {
// Transformed unit vectors are not perpendicular...
this.type = TYPE_GENERAL_TRANSFORM;
return;
}
sgn0 = (M0 >= 0.0);
sgn1 = (M1 >= 0.0);
if (sgn0 == sgn1) {
// sgn(M0) == sgn(M1) therefore sgn(M2) == -sgn(M3)
// This is the "unflipped" (right-handed) state
if (M0 != M1 || M2 != -M3) {
ret |= (TYPE_GENERAL_ROTATION | TYPE_GENERAL_SCALE);
} else if (M0 * M1 - M2 * M3 != 1.0) {
ret |= (TYPE_GENERAL_ROTATION | TYPE_UNIFORM_SCALE);
} else {
ret |= TYPE_GENERAL_ROTATION;
}
} else {
// sgn(M0) == -sgn(M1) therefore sgn(M2) == sgn(M3)
// This is the "flipped" (left-handed) state
if (M0 != -M1 || M2 != M3) {
ret |= (TYPE_GENERAL_ROTATION |
TYPE_FLIP |
TYPE_GENERAL_SCALE);
} else if (M0 * M1 - M2 * M3 != 1.0) {
ret |= (TYPE_GENERAL_ROTATION |
TYPE_FLIP |
TYPE_UNIFORM_SCALE);
} else {
ret |= (TYPE_GENERAL_ROTATION | TYPE_FLIP);
}
}
break;
case (APPLY_SHEAR | APPLY_TRANSLATE):
ret = TYPE_TRANSLATION;
/* NOBREAK */
case (APPLY_SHEAR):
sgn0 = ((M0 = m01) >= 0.0);
sgn1 = ((M1 = m10) >= 0.0);
if (sgn0 != sgn1) {
// Different signs - simple 90 degree rotation
if (M0 != -M1) {
ret |= (TYPE_QUADRANT_ROTATION | TYPE_GENERAL_SCALE);
} else if (M0 != 1.0 && M0 != -1.0) {
ret |= (TYPE_QUADRANT_ROTATION | TYPE_UNIFORM_SCALE);
} else {
ret |= TYPE_QUADRANT_ROTATION;
}
} else {
// Same signs - 90 degree rotation plus an axis flip too
if (M0 == M1) {
ret |= (TYPE_QUADRANT_ROTATION |
TYPE_FLIP |
TYPE_UNIFORM_SCALE);
} else {
ret |= (TYPE_QUADRANT_ROTATION |
TYPE_FLIP |
TYPE_GENERAL_SCALE);
}
}
break;
case (APPLY_SCALE | APPLY_TRANSLATE):
ret = TYPE_TRANSLATION;
/* NOBREAK */
case (APPLY_SCALE):
sgn0 = ((M0 = m00) >= 0.0);
sgn1 = ((M1 = m11) >= 0.0);
if (sgn0 == sgn1) {
if (sgn0) {
// Both scaling factors non-negative - simple scale
// Note: APPLY_SCALE implies M0, M1 are not both 1
if (M0 == M1) {
ret |= TYPE_UNIFORM_SCALE;
} else {
ret |= TYPE_GENERAL_SCALE;
}
} else {
// Both scaling factors negative - 180 degree rotation
if (M0 != M1) {
ret |= (TYPE_QUADRANT_ROTATION | TYPE_GENERAL_SCALE);
} else if (M0 != -1.0) {
ret |= (TYPE_QUADRANT_ROTATION | TYPE_UNIFORM_SCALE);
} else {
ret |= TYPE_QUADRANT_ROTATION;
}
}
} else {
// Scaling factor signs different - flip about some axis
if (M0 == -M1) {
if (M0 == 1.0 || M0 == -1.0) {
ret |= TYPE_FLIP;
} else {
ret |= (TYPE_FLIP | TYPE_UNIFORM_SCALE);
}
} else {
ret |= (TYPE_FLIP | TYPE_GENERAL_SCALE);
}
}
break;
case (APPLY_TRANSLATE):
ret = TYPE_TRANSLATION;
break;
case (APPLY_IDENTITY):
break;
}
this.type = ret;
}
/**
* 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 * {@link 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 |
*
*
* @return the determinant of the matrix used to transform the
* coordinates.
* @see #getType
* @see #createInverse
* @see #inverseTransform
* @see #TYPE_UNIFORM_SCALE
* @since 1.2
*/
public double getDeterminant() {
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
case (APPLY_SHEAR | APPLY_SCALE):
return m00 * m11 - m01 * m10;
case (APPLY_SHEAR | APPLY_TRANSLATE):
case (APPLY_SHEAR):
return -(m01 * m10);
case (APPLY_SCALE | APPLY_TRANSLATE):
case (APPLY_SCALE):
return m00 * m11;
case (APPLY_TRANSLATE):
case (APPLY_IDENTITY):
return 1.0;
}
}
/**
* Manually recalculates the state of the transform when the matrix
* changes too much to predict the effects on the state.
* The following table specifies what the various settings of the
* state field say about the values of the corresponding matrix
* element fields.
* Note that the rules governing the SCALE fields are slightly
* different depending on whether the SHEAR flag is also set.
*
* SCALE SHEAR TRANSLATE
* m00/m11 m01/m10 m02/m12
*
* IDENTITY 1.0 0.0 0.0
* TRANSLATE (TR) 1.0 0.0 not both 0.0
* SCALE (SC) not both 1.0 0.0 0.0
* TR | SC not both 1.0 0.0 not both 0.0
* SHEAR (SH) 0.0 not both 0.0 0.0
* TR | SH 0.0 not both 0.0 not both 0.0
* SC | SH not both 0.0 not both 0.0 0.0
* TR | SC | SH not both 0.0 not both 0.0 not both 0.0
*
*/
void updateState() {
if (m01 == 0.0 && m10 == 0.0) {
if (m00 == 1.0 && m11 == 1.0) {
if (m02 == 0.0 && m12 == 0.0) {
state = APPLY_IDENTITY;
type = TYPE_IDENTITY;
} else {
state = APPLY_TRANSLATE;
type = TYPE_TRANSLATION;
}
} else {
if (m02 == 0.0 && m12 == 0.0) {
state = APPLY_SCALE;
type = TYPE_UNKNOWN;
} else {
state = (APPLY_SCALE | APPLY_TRANSLATE);
type = TYPE_UNKNOWN;
}
}
} else {
if (m00 == 0.0 && m11 == 0.0) {
if (m02 == 0.0 && m12 == 0.0) {
state = APPLY_SHEAR;
type = TYPE_UNKNOWN;
} else {
state = (APPLY_SHEAR | APPLY_TRANSLATE);
type = TYPE_UNKNOWN;
}
} else {
if (m02 == 0.0 && m12 == 0.0) {
state = (APPLY_SHEAR | APPLY_SCALE);
type = TYPE_UNKNOWN;
} else {
state = (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE);
type = TYPE_UNKNOWN;
}
}
}
}
/*
* Convenience method used internally to throw exceptions when
* a case was forgotten in a switch statement.
*/
private void stateError() {
throw new InternalError("missing case in transform state switch");
}
/**
* 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 }
* @param flatmatrix the double array used to store the returned
* values.
* @see #getScaleX
* @see #getScaleY
* @see #getShearX
* @see #getShearY
* @see #getTranslateX
* @see #getTranslateY
* @since 1.2
*/
public void getMatrix(double[] flatmatrix) {
flatmatrix[0] = m00;
flatmatrix[1] = m10;
flatmatrix[2] = m01;
flatmatrix[3] = m11;
if (flatmatrix.length > 5) {
flatmatrix[4] = m02;
flatmatrix[5] = m12;
}
}
/**
* Returns the X coordinate scaling element (m00) of the 3x3
* affine transformation matrix.
* @return a double value that is the X coordinate of the scaling
* element of the affine transformation matrix.
* @see #getMatrix
* @since 1.2
*/
public double getScaleX() {
return m00;
}
/**
* Returns the Y coordinate scaling element (m11) of the 3x3
* affine transformation matrix.
* @return a double value that is the Y coordinate of the scaling
* element of the affine transformation matrix.
* @see #getMatrix
* @since 1.2
*/
public double getScaleY() {
return m11;
}
/**
* Returns the X coordinate shearing element (m01) of the 3x3
* affine transformation matrix.
* @return a double value that is the X coordinate of the shearing
* element of the affine transformation matrix.
* @see #getMatrix
* @since 1.2
*/
public double getShearX() {
return m01;
}
/**
* Returns the Y coordinate shearing element (m10) of the 3x3
* affine transformation matrix.
* @return a double value that is the Y coordinate of the shearing
* element of the affine transformation matrix.
* @see #getMatrix
* @since 1.2
*/
public double getShearY() {
return m10;
}
/**
* Returns the X coordinate of the translation element (m02) of the
* 3x3 affine transformation matrix.
* @return a double value that is the X coordinate of the translation
* element of the affine transformation matrix.
* @see #getMatrix
* @since 1.2
*/
public double getTranslateX() {
return m02;
}
/**
* Returns the Y coordinate of the translation element (m12) of the
* 3x3 affine transformation matrix.
* @return a double value that is the Y coordinate of the translation
* element of the affine transformation matrix.
* @see #getMatrix
* @since 1.2
*/
public double getTranslateY() {
return m12;
}
/**
* 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 ]
*
* @param tx the distance by which coordinates are translated in the
* X axis direction
* @param ty the distance by which coordinates are translated in the
* Y axis direction
* @since 1.2
*/
public void translate(double tx, double ty) {
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
m02 = tx * m00 + ty * m01 + m02;
m12 = tx * m10 + ty * m11 + m12;
if (m02 == 0.0 && m12 == 0.0) {
state = APPLY_SHEAR | APPLY_SCALE;
if (type != TYPE_UNKNOWN) {
type -= TYPE_TRANSLATION;
}
}
return;
case (APPLY_SHEAR | APPLY_SCALE):
m02 = tx * m00 + ty * m01;
m12 = tx * m10 + ty * m11;
if (m02 != 0.0 || m12 != 0.0) {
state = APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE;
type |= TYPE_TRANSLATION;
}
return;
case (APPLY_SHEAR | APPLY_TRANSLATE):
m02 = ty * m01 + m02;
m12 = tx * m10 + m12;
if (m02 == 0.0 && m12 == 0.0) {
state = APPLY_SHEAR;
if (type != TYPE_UNKNOWN) {
type -= TYPE_TRANSLATION;
}
}
return;
case (APPLY_SHEAR):
m02 = ty * m01;
m12 = tx * m10;
if (m02 != 0.0 || m12 != 0.0) {
state = APPLY_SHEAR | APPLY_TRANSLATE;
type |= TYPE_TRANSLATION;
}
return;
case (APPLY_SCALE | APPLY_TRANSLATE):
m02 = tx * m00 + m02;
m12 = ty * m11 + m12;
if (m02 == 0.0 && m12 == 0.0) {
state = APPLY_SCALE;
if (type != TYPE_UNKNOWN) {
type -= TYPE_TRANSLATION;
}
}
return;
case (APPLY_SCALE):
m02 = tx * m00;
m12 = ty * m11;
if (m02 != 0.0 || m12 != 0.0) {
state = APPLY_SCALE | APPLY_TRANSLATE;
type |= TYPE_TRANSLATION;
}
return;
case (APPLY_TRANSLATE):
m02 = tx + m02;
m12 = ty + m12;
if (m02 == 0.0 && m12 == 0.0) {
state = APPLY_IDENTITY;
type = TYPE_IDENTITY;
}
return;
case (APPLY_IDENTITY):
m02 = tx;
m12 = ty;
if (tx != 0.0 || ty != 0.0) {
state = APPLY_TRANSLATE;
type = TYPE_TRANSLATION;
}
return;
}
}
// Utility methods to optimize rotate methods.
// These tables translate the flags during predictable quadrant
// rotations where the shear and scale values are swapped and negated.
private static final int rot90conversion[] = {
/* IDENTITY => */ APPLY_SHEAR,
/* TRANSLATE (TR) => */ APPLY_SHEAR | APPLY_TRANSLATE,
/* SCALE (SC) => */ APPLY_SHEAR,
/* SC | TR => */ APPLY_SHEAR | APPLY_TRANSLATE,
/* SHEAR (SH) => */ APPLY_SCALE,
/* SH | TR => */ APPLY_SCALE | APPLY_TRANSLATE,
/* SH | SC => */ APPLY_SHEAR | APPLY_SCALE,
/* SH | SC | TR => */ APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE,
};
private final void rotate90() {
double M0 = m00;
m00 = m01;
m01 = -M0;
M0 = m10;
m10 = m11;
m11 = -M0;
int state = rot90conversion[this.state];
if ((state & (APPLY_SHEAR | APPLY_SCALE)) == APPLY_SCALE &&
m00 == 1.0 && m11 == 1.0)
{
state -= APPLY_SCALE;
}
this.state = state;
type = TYPE_UNKNOWN;
}
private final void rotate180() {
m00 = -m00;
m11 = -m11;
int state = this.state;
if ((state & (APPLY_SHEAR)) != 0) {
// If there was a shear, then this rotation has no
// effect on the state.
m01 = -m01;
m10 = -m10;
} else {
// No shear means the SCALE state may toggle when
// m00 and m11 are negated.
if (m00 == 1.0 && m11 == 1.0) {
this.state = state & ~APPLY_SCALE;
} else {
this.state = state | APPLY_SCALE;
}
}
type = TYPE_UNKNOWN;
}
private final void rotate270() {
double M0 = m00;
m00 = -m01;
m01 = M0;
M0 = m10;
m10 = -m11;
m11 = M0;
int state = rot90conversion[this.state];
if ((state & (APPLY_SHEAR | APPLY_SCALE)) == APPLY_SCALE &&
m00 == 1.0 && m11 == 1.0)
{
state -= APPLY_SCALE;
}
this.state = state;
type = TYPE_UNKNOWN;
}
/**
* 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.
* @param theta the angle of rotation measured in radians
* @since 1.2
*/
public void rotate(double theta) {
double sin = Math.sin(theta);
if (sin == 1.0) {
rotate90();
} else if (sin == -1.0) {
rotate270();
} else {
double cos = Math.cos(theta);
if (cos == -1.0) {
rotate180();
} else if (cos != 1.0) {
double M0, M1;
M0 = m00;
M1 = m01;
m00 = cos * M0 + sin * M1;
m01 = -sin * M0 + cos * M1;
M0 = m10;
M1 = m11;
m10 = cos * M0 + sin * M1;
m11 = -sin * M0 + cos * M1;
updateState();
}
}
}
/**
* 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.
*
* @param theta the angle of rotation measured in radians
* @param anchorx the X coordinate of the rotation anchor point
* @param anchory the Y coordinate of the rotation anchor point
* @since 1.2
*/
public void rotate(double theta, double anchorx, double anchory) {
// REMIND: Simple for now - optimize later
translate(anchorx, anchory);
rotate(theta);
translate(-anchorx, -anchory);
}
/**
* 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));
*
*
* @param vecx the X coordinate of the rotation vector
* @param vecy the Y coordinate of the rotation vector
* @since 1.6
*/
public void rotate(double vecx, double vecy) {
if (vecy == 0.0) {
if (vecx < 0.0) {
rotate180();
}
// If vecx > 0.0 - no rotation
// If vecx == 0.0 - undefined rotation - treat as no rotation
} else if (vecx == 0.0) {
if (vecy > 0.0) {
rotate90();
} else { // vecy must be < 0.0
rotate270();
}
} else {
double len = Math.sqrt(vecx * vecx + vecy * vecy);
double sin = vecy / len;
double cos = vecx / len;
double M0, M1;
M0 = m00;
M1 = m01;
m00 = cos * M0 + sin * M1;
m01 = -sin * M0 + cos * M1;
M0 = m10;
M1 = m11;
m10 = cos * M0 + sin * M1;
m11 = -sin * M0 + cos * M1;
updateState();
}
}
/**
* 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);
*
*
* @param vecx the X coordinate of the rotation vector
* @param vecy the Y coordinate of the rotation vector
* @param anchorx the X coordinate of the rotation anchor point
* @param anchory the Y coordinate of the rotation anchor point
* @since 1.6
*/
public void rotate(double vecx, double vecy,
double anchorx, double anchory)
{
// REMIND: Simple for now - optimize later
translate(anchorx, anchory);
rotate(vecx, vecy);
translate(-anchorx, -anchory);
}
/**
* 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.
* @param numquadrants the number of 90 degree arcs to rotate by
* @since 1.6
*/
public void quadrantRotate(int numquadrants) {
switch (numquadrants & 3) {
case 0:
break;
case 1:
rotate90();
break;
case 2:
rotate180();
break;
case 3:
rotate270();
break;
}
}
/**
* 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.
*
* @param numquadrants the number of 90 degree arcs to rotate by
* @param anchorx the X coordinate of the rotation anchor point
* @param anchory the Y coordinate of the rotation anchor point
* @since 1.6
*/
public void quadrantRotate(int numquadrants,
double anchorx, double anchory)
{
switch (numquadrants & 3) {
case 0:
return;
case 1:
m02 += anchorx * (m00 - m01) + anchory * (m01 + m00);
m12 += anchorx * (m10 - m11) + anchory * (m11 + m10);
rotate90();
break;
case 2:
m02 += anchorx * (m00 + m00) + anchory * (m01 + m01);
m12 += anchorx * (m10 + m10) + anchory * (m11 + m11);
rotate180();
break;
case 3:
m02 += anchorx * (m00 + m01) + anchory * (m01 - m00);
m12 += anchorx * (m10 + m11) + anchory * (m11 - m10);
rotate270();
break;
}
if (m02 == 0.0 && m12 == 0.0) {
state &= ~APPLY_TRANSLATE;
} else {
state |= APPLY_TRANSLATE;
}
}
/**
* 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 ]
*
* @param sx the factor by which coordinates are scaled along the
* X axis direction
* @param sy the factor by which coordinates are scaled along the
* Y axis direction
* @since 1.2
*/
public void scale(double sx, double sy) {
int state = this.state;
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
case (APPLY_SHEAR | APPLY_SCALE):
m00 *= sx;
m11 *= sy;
/* NOBREAK */
case (APPLY_SHEAR | APPLY_TRANSLATE):
case (APPLY_SHEAR):
m01 *= sy;
m10 *= sx;
if (m01 == 0 && m10 == 0) {
state &= APPLY_TRANSLATE;
if (m00 == 1.0 && m11 == 1.0) {
this.type = (state == APPLY_IDENTITY
? TYPE_IDENTITY
: TYPE_TRANSLATION);
} else {
state |= APPLY_SCALE;
this.type = TYPE_UNKNOWN;
}
this.state = state;
}
return;
case (APPLY_SCALE | APPLY_TRANSLATE):
case (APPLY_SCALE):
m00 *= sx;
m11 *= sy;
if (m00 == 1.0 && m11 == 1.0) {
this.state = (state &= APPLY_TRANSLATE);
this.type = (state == APPLY_IDENTITY
? TYPE_IDENTITY
: TYPE_TRANSLATION);
} else {
this.type = TYPE_UNKNOWN;
}
return;
case (APPLY_TRANSLATE):
case (APPLY_IDENTITY):
m00 = sx;
m11 = sy;
if (sx != 1.0 || sy != 1.0) {
this.state = state | APPLY_SCALE;
this.type = TYPE_UNKNOWN;
}
return;
}
}
/**
* 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 ]
*
* @param shx the multiplier by which coordinates are shifted in the
* direction of the positive X axis as a factor of their Y coordinate
* @param 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
*/
public void shear(double shx, double shy) {
int state = this.state;
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
case (APPLY_SHEAR | APPLY_SCALE):
double M0, M1;
M0 = m00;
M1 = m01;
m00 = M0 + M1 * shy;
m01 = M0 * shx + M1;
M0 = m10;
M1 = m11;
m10 = M0 + M1 * shy;
m11 = M0 * shx + M1;
updateState();
return;
case (APPLY_SHEAR | APPLY_TRANSLATE):
case (APPLY_SHEAR):
m00 = m01 * shy;
m11 = m10 * shx;
if (m00 != 0.0 || m11 != 0.0) {
this.state = state | APPLY_SCALE;
}
this.type = TYPE_UNKNOWN;
return;
case (APPLY_SCALE | APPLY_TRANSLATE):
case (APPLY_SCALE):
m01 = m00 * shx;
m10 = m11 * shy;
if (m01 != 0.0 || m10 != 0.0) {
this.state = state | APPLY_SHEAR;
}
this.type = TYPE_UNKNOWN;
return;
case (APPLY_TRANSLATE):
case (APPLY_IDENTITY):
m01 = shx;
m10 = shy;
if (m01 != 0.0 || m10 != 0.0) {
this.state = state | APPLY_SCALE | APPLY_SHEAR;
this.type = TYPE_UNKNOWN;
}
return;
}
}
/**
* Resets this transform to the Identity transform.
* @since 1.2
*/
public void setToIdentity() {
m00 = m11 = 1.0;
m10 = m01 = m02 = m12 = 0.0;
state = APPLY_IDENTITY;
type = TYPE_IDENTITY;
}
/**
* Sets this transform to a translation transformation.
* The matrix representing this transform becomes:
*
* [ 1 0 tx ]
* [ 0 1 ty ]
* [ 0 0 1 ]
*
* @param tx the distance by which coordinates are translated in the
* X axis direction
* @param ty the distance by which coordinates are translated in the
* Y axis direction
* @since 1.2
*/
public void setToTranslation(double tx, double ty) {
m00 = 1.0;
m10 = 0.0;
m01 = 0.0;
m11 = 1.0;
m02 = tx;
m12 = ty;
if (tx != 0.0 || ty != 0.0) {
state = APPLY_TRANSLATE;
type = TYPE_TRANSLATION;
} else {
state = APPLY_IDENTITY;
type = TYPE_IDENTITY;
}
}
/**
* 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.
* @param theta the angle of rotation measured in radians
* @since 1.2
*/
public void setToRotation(double theta) {
double sin = Math.sin(theta);
double cos;
if (sin == 1.0 || sin == -1.0) {
cos = 0.0;
state = APPLY_SHEAR;
type = TYPE_QUADRANT_ROTATION;
} else {
cos = Math.cos(theta);
if (cos == -1.0) {
sin = 0.0;
state = APPLY_SCALE;
type = TYPE_QUADRANT_ROTATION;
} else if (cos == 1.0) {
sin = 0.0;
state = APPLY_IDENTITY;
type = TYPE_IDENTITY;
} else {
state = APPLY_SHEAR | APPLY_SCALE;
type = TYPE_GENERAL_ROTATION;
}
}
m00 = cos;
m10 = sin;
m01 = -sin;
m11 = cos;
m02 = 0.0;
m12 = 0.0;
}
/**
* 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.
*
* @param theta the angle of rotation measured in radians
* @param anchorx the X coordinate of the rotation anchor point
* @param anchory the Y coordinate of the rotation anchor point
* @since 1.2
*/
public void setToRotation(double theta, double anchorx, double anchory) {
setToRotation(theta);
double sin = m10;
double oneMinusCos = 1.0 - m00;
m02 = anchorx * oneMinusCos + anchory * sin;
m12 = anchory * oneMinusCos - anchorx * sin;
if (m02 != 0.0 || m12 != 0.0) {
state |= APPLY_TRANSLATE;
type |= TYPE_TRANSLATION;
}
}
/**
* 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));
*
*
* @param vecx the X coordinate of the rotation vector
* @param vecy the Y coordinate of the rotation vector
* @since 1.6
*/
public void setToRotation(double vecx, double vecy) {
double sin, cos;
if (vecy == 0) {
sin = 0.0;
if (vecx < 0.0) {
cos = -1.0;
state = APPLY_SCALE;
type = TYPE_QUADRANT_ROTATION;
} else {
cos = 1.0;
state = APPLY_IDENTITY;
type = TYPE_IDENTITY;
}
} else if (vecx == 0) {
cos = 0.0;
sin = (vecy > 0.0) ? 1.0 : -1.0;
state = APPLY_SHEAR;
type = TYPE_QUADRANT_ROTATION;
} else {
double len = Math.sqrt(vecx * vecx + vecy * vecy);
cos = vecx / len;
sin = vecy / len;
state = APPLY_SHEAR | APPLY_SCALE;
type = TYPE_GENERAL_ROTATION;
}
m00 = cos;
m10 = sin;
m01 = -sin;
m11 = cos;
m02 = 0.0;
m12 = 0.0;
}
/**
* 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);
*
*
* @param vecx the X coordinate of the rotation vector
* @param vecy the Y coordinate of the rotation vector
* @param anchorx the X coordinate of the rotation anchor point
* @param anchory the Y coordinate of the rotation anchor point
* @since 1.6
*/
public void setToRotation(double vecx, double vecy,
double anchorx, double anchory)
{
setToRotation(vecx, vecy);
double sin = m10;
double oneMinusCos = 1.0 - m00;
m02 = anchorx * oneMinusCos + anchory * sin;
m12 = anchory * oneMinusCos - anchorx * sin;
if (m02 != 0.0 || m12 != 0.0) {
state |= APPLY_TRANSLATE;
type |= TYPE_TRANSLATION;
}
}
/**
* 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.
* @param numquadrants the number of 90 degree arcs to rotate by
* @since 1.6
*/
public void setToQuadrantRotation(int numquadrants) {
switch (numquadrants & 3) {
case 0:
m00 = 1.0;
m10 = 0.0;
m01 = 0.0;
m11 = 1.0;
m02 = 0.0;
m12 = 0.0;
state = APPLY_IDENTITY;
type = TYPE_IDENTITY;
break;
case 1:
m00 = 0.0;
m10 = 1.0;
m01 = -1.0;
m11 = 0.0;
m02 = 0.0;
m12 = 0.0;
state = APPLY_SHEAR;
type = TYPE_QUADRANT_ROTATION;
break;
case 2:
m00 = -1.0;
m10 = 0.0;
m01 = 0.0;
m11 = -1.0;
m02 = 0.0;
m12 = 0.0;
state = APPLY_SCALE;
type = TYPE_QUADRANT_ROTATION;
break;
case 3:
m00 = 0.0;
m10 = -1.0;
m01 = 1.0;
m11 = 0.0;
m02 = 0.0;
m12 = 0.0;
state = APPLY_SHEAR;
type = TYPE_QUADRANT_ROTATION;
break;
}
}
/**
* 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.
*
* @param numquadrants the number of 90 degree arcs to rotate by
* @param anchorx the X coordinate of the rotation anchor point
* @param anchory the Y coordinate of the rotation anchor point
* @since 1.6
*/
public void setToQuadrantRotation(int numquadrants,
double anchorx, double anchory)
{
switch (numquadrants & 3) {
case 0:
m00 = 1.0;
m10 = 0.0;
m01 = 0.0;
m11 = 1.0;
m02 = 0.0;
m12 = 0.0;
state = APPLY_IDENTITY;
type = TYPE_IDENTITY;
break;
case 1:
m00 = 0.0;
m10 = 1.0;
m01 = -1.0;
m11 = 0.0;
m02 = anchorx + anchory;
m12 = anchory - anchorx;
if (m02 == 0.0 && m12 == 0.0) {
state = APPLY_SHEAR;
type = TYPE_QUADRANT_ROTATION;
} else {
state = APPLY_SHEAR | APPLY_TRANSLATE;
type = TYPE_QUADRANT_ROTATION | TYPE_TRANSLATION;
}
break;
case 2:
m00 = -1.0;
m10 = 0.0;
m01 = 0.0;
m11 = -1.0;
m02 = anchorx + anchorx;
m12 = anchory + anchory;
if (m02 == 0.0 && m12 == 0.0) {
state = APPLY_SCALE;
type = TYPE_QUADRANT_ROTATION;
} else {
state = APPLY_SCALE | APPLY_TRANSLATE;
type = TYPE_QUADRANT_ROTATION | TYPE_TRANSLATION;
}
break;
case 3:
m00 = 0.0;
m10 = -1.0;
m01 = 1.0;
m11 = 0.0;
m02 = anchorx - anchory;
m12 = anchory + anchorx;
if (m02 == 0.0 && m12 == 0.0) {
state = APPLY_SHEAR;
type = TYPE_QUADRANT_ROTATION;
} else {
state = APPLY_SHEAR | APPLY_TRANSLATE;
type = TYPE_QUADRANT_ROTATION | TYPE_TRANSLATION;
}
break;
}
}
/**
* Sets this transform to a scaling transformation.
* The matrix representing this transform becomes:
*
* [ sx 0 0 ]
* [ 0 sy 0 ]
* [ 0 0 1 ]
*
* @param sx the factor by which coordinates are scaled along the
* X axis direction
* @param sy the factor by which coordinates are scaled along the
* Y axis direction
* @since 1.2
*/
public void setToScale(double sx, double sy) {
m00 = sx;
m10 = 0.0;
m01 = 0.0;
m11 = sy;
m02 = 0.0;
m12 = 0.0;
if (sx != 1.0 || sy != 1.0) {
state = APPLY_SCALE;
type = TYPE_UNKNOWN;
} else {
state = APPLY_IDENTITY;
type = TYPE_IDENTITY;
}
}
/**
* Sets this transform to a shearing transformation.
* The matrix representing this transform becomes:
*
* [ 1 shx 0 ]
* [ shy 1 0 ]
* [ 0 0 1 ]
*
* @param shx the multiplier by which coordinates are shifted in the
* direction of the positive X axis as a factor of their Y coordinate
* @param 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
*/
public void setToShear(double shx, double shy) {
m00 = 1.0;
m01 = shx;
m10 = shy;
m11 = 1.0;
m02 = 0.0;
m12 = 0.0;
if (shx != 0.0 || shy != 0.0) {
state = (APPLY_SHEAR | APPLY_SCALE);
type = TYPE_UNKNOWN;
} else {
state = APPLY_IDENTITY;
type = TYPE_IDENTITY;
}
}
/**
* Sets this transform to a copy of the transform in the specified
* AffineTransform object.
* @param Tx the AffineTransform object from which to
* copy the transform
* @since 1.2
*/
public void setTransform(AffineTransform Tx) {
this.m00 = Tx.m00;
this.m10 = Tx.m10;
this.m01 = Tx.m01;
this.m11 = Tx.m11;
this.m02 = Tx.m02;
this.m12 = Tx.m12;
this.state = Tx.state;
this.type = Tx.type;
}
/**
* Sets this transform to the matrix specified by the 6
* double precision values.
*
* @param m00 the X coordinate scaling element of the 3x3 matrix
* @param m10 the Y coordinate shearing element of the 3x3 matrix
* @param m01 the X coordinate shearing element of the 3x3 matrix
* @param m11 the Y coordinate scaling element of the 3x3 matrix
* @param m02 the X coordinate translation element of the 3x3 matrix
* @param m12 the Y coordinate translation element of the 3x3 matrix
* @since 1.2
*/
public void setTransform(double m00, double m10,
double m01, double m11,
double m02, double m12) {
this.m00 = m00;
this.m10 = m10;
this.m01 = m01;
this.m11 = m11;
this.m02 = m02;
this.m12 = m12;
updateState();
}
/**
* 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]
*
* @param Tx the AffineTransform object to be
* concatenated with this AffineTransform object.
* @see #preConcatenate
* @since 1.2
*/
public void concatenate(AffineTransform Tx) {
double M0, M1;
double T00, T01, T10, T11;
double T02, T12;
int mystate = state;
int txstate = Tx.state;
switch ((txstate << HI_SHIFT) | mystate) {
/* ---------- Tx == IDENTITY cases ---------- */
case (HI_IDENTITY | APPLY_IDENTITY):
case (HI_IDENTITY | APPLY_TRANSLATE):
case (HI_IDENTITY | APPLY_SCALE):
case (HI_IDENTITY | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_IDENTITY | APPLY_SHEAR):
case (HI_IDENTITY | APPLY_SHEAR | APPLY_TRANSLATE):
case (HI_IDENTITY | APPLY_SHEAR | APPLY_SCALE):
case (HI_IDENTITY | APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
return;
/* ---------- this == IDENTITY cases ---------- */
case (HI_SHEAR | HI_SCALE | HI_TRANSLATE | APPLY_IDENTITY):
m01 = Tx.m01;
m10 = Tx.m10;
/* NOBREAK */
case (HI_SCALE | HI_TRANSLATE | APPLY_IDENTITY):
m00 = Tx.m00;
m11 = Tx.m11;
/* NOBREAK */
case (HI_TRANSLATE | APPLY_IDENTITY):
m02 = Tx.m02;
m12 = Tx.m12;
state = txstate;
type = Tx.type;
return;
case (HI_SHEAR | HI_SCALE | APPLY_IDENTITY):
m01 = Tx.m01;
m10 = Tx.m10;
/* NOBREAK */
case (HI_SCALE | APPLY_IDENTITY):
m00 = Tx.m00;
m11 = Tx.m11;
state = txstate;
type = Tx.type;
return;
case (HI_SHEAR | HI_TRANSLATE | APPLY_IDENTITY):
m02 = Tx.m02;
m12 = Tx.m12;
/* NOBREAK */
case (HI_SHEAR | APPLY_IDENTITY):
m01 = Tx.m01;
m10 = Tx.m10;
m00 = m11 = 0.0;
state = txstate;
type = Tx.type;
return;
/* ---------- Tx == TRANSLATE cases ---------- */
case (HI_TRANSLATE | APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_TRANSLATE | APPLY_SHEAR | APPLY_SCALE):
case (HI_TRANSLATE | APPLY_SHEAR | APPLY_TRANSLATE):
case (HI_TRANSLATE | APPLY_SHEAR):
case (HI_TRANSLATE | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_TRANSLATE | APPLY_SCALE):
case (HI_TRANSLATE | APPLY_TRANSLATE):
translate(Tx.m02, Tx.m12);
return;
/* ---------- Tx == SCALE cases ---------- */
case (HI_SCALE | APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_SCALE | APPLY_SHEAR | APPLY_SCALE):
case (HI_SCALE | APPLY_SHEAR | APPLY_TRANSLATE):
case (HI_SCALE | APPLY_SHEAR):
case (HI_SCALE | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_SCALE | APPLY_SCALE):
case (HI_SCALE | APPLY_TRANSLATE):
scale(Tx.m00, Tx.m11);
return;
/* ---------- Tx == SHEAR cases ---------- */
case (HI_SHEAR | APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_SHEAR | APPLY_SHEAR | APPLY_SCALE):
T01 = Tx.m01; T10 = Tx.m10;
M0 = m00;
m00 = m01 * T10;
m01 = M0 * T01;
M0 = m10;
m10 = m11 * T10;
m11 = M0 * T01;
type = TYPE_UNKNOWN;
return;
case (HI_SHEAR | APPLY_SHEAR | APPLY_TRANSLATE):
case (HI_SHEAR | APPLY_SHEAR):
m00 = m01 * Tx.m10;
m01 = 0.0;
m11 = m10 * Tx.m01;
m10 = 0.0;
state = mystate ^ (APPLY_SHEAR | APPLY_SCALE);
type = TYPE_UNKNOWN;
return;
case (HI_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_SHEAR | APPLY_SCALE):
m01 = m00 * Tx.m01;
m00 = 0.0;
m10 = m11 * Tx.m10;
m11 = 0.0;
state = mystate ^ (APPLY_SHEAR | APPLY_SCALE);
type = TYPE_UNKNOWN;
return;
case (HI_SHEAR | APPLY_TRANSLATE):
m00 = 0.0;
m01 = Tx.m01;
m10 = Tx.m10;
m11 = 0.0;
state = APPLY_TRANSLATE | APPLY_SHEAR;
type = TYPE_UNKNOWN;
return;
}
// If Tx has more than one attribute, it is not worth optimizing
// all of those cases...
T00 = Tx.m00; T01 = Tx.m01; T02 = Tx.m02;
T10 = Tx.m10; T11 = Tx.m11; T12 = Tx.m12;
switch (mystate) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE):
state = mystate | txstate;
/* NOBREAK */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
M0 = m00;
M1 = m01;
m00 = T00 * M0 + T10 * M1;
m01 = T01 * M0 + T11 * M1;
m02 += T02 * M0 + T12 * M1;
M0 = m10;
M1 = m11;
m10 = T00 * M0 + T10 * M1;
m11 = T01 * M0 + T11 * M1;
m12 += T02 * M0 + T12 * M1;
type = TYPE_UNKNOWN;
return;
case (APPLY_SHEAR | APPLY_TRANSLATE):
case (APPLY_SHEAR):
M0 = m01;
m00 = T10 * M0;
m01 = T11 * M0;
m02 += T12 * M0;
M0 = m10;
m10 = T00 * M0;
m11 = T01 * M0;
m12 += T02 * M0;
break;
case (APPLY_SCALE | APPLY_TRANSLATE):
case (APPLY_SCALE):
M0 = m00;
m00 = T00 * M0;
m01 = T01 * M0;
m02 += T02 * M0;
M0 = m11;
m10 = T10 * M0;
m11 = T11 * M0;
m12 += T12 * M0;
break;
case (APPLY_TRANSLATE):
m00 = T00;
m01 = T01;
m02 += T02;
m10 = T10;
m11 = T11;
m12 += T12;
state = txstate | APPLY_TRANSLATE;
type = TYPE_UNKNOWN;
return;
}
updateState();
}
/**
* 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]
*
* @param Tx the AffineTransform object to be
* concatenated with this AffineTransform object.
* @see #concatenate
* @since 1.2
*/
public void preConcatenate(AffineTransform Tx) {
double M0, M1;
double T00, T01, T10, T11;
double T02, T12;
int mystate = state;
int txstate = Tx.state;
switch ((txstate << HI_SHIFT) | mystate) {
case (HI_IDENTITY | APPLY_IDENTITY):
case (HI_IDENTITY | APPLY_TRANSLATE):
case (HI_IDENTITY | APPLY_SCALE):
case (HI_IDENTITY | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_IDENTITY | APPLY_SHEAR):
case (HI_IDENTITY | APPLY_SHEAR | APPLY_TRANSLATE):
case (HI_IDENTITY | APPLY_SHEAR | APPLY_SCALE):
case (HI_IDENTITY | APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
// Tx is IDENTITY...
return;
case (HI_TRANSLATE | APPLY_IDENTITY):
case (HI_TRANSLATE | APPLY_SCALE):
case (HI_TRANSLATE | APPLY_SHEAR):
case (HI_TRANSLATE | APPLY_SHEAR | APPLY_SCALE):
// Tx is TRANSLATE, this has no TRANSLATE
m02 = Tx.m02;
m12 = Tx.m12;
state = mystate | APPLY_TRANSLATE;
type |= TYPE_TRANSLATION;
return;
case (HI_TRANSLATE | APPLY_TRANSLATE):
case (HI_TRANSLATE | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_TRANSLATE | APPLY_SHEAR | APPLY_TRANSLATE):
case (HI_TRANSLATE | APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
// Tx is TRANSLATE, this has one too
m02 = m02 + Tx.m02;
m12 = m12 + Tx.m12;
return;
case (HI_SCALE | APPLY_TRANSLATE):
case (HI_SCALE | APPLY_IDENTITY):
// Only these two existing states need a new state
state = mystate | APPLY_SCALE;
/* NOBREAK */
case (HI_SCALE | APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_SCALE | APPLY_SHEAR | APPLY_SCALE):
case (HI_SCALE | APPLY_SHEAR | APPLY_TRANSLATE):
case (HI_SCALE | APPLY_SHEAR):
case (HI_SCALE | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_SCALE | APPLY_SCALE):
// Tx is SCALE, this is anything
T00 = Tx.m00;
T11 = Tx.m11;
if ((mystate & APPLY_SHEAR) != 0) {
m01 = m01 * T00;
m10 = m10 * T11;
if ((mystate & APPLY_SCALE) != 0) {
m00 = m00 * T00;
m11 = m11 * T11;
}
} else {
m00 = m00 * T00;
m11 = m11 * T11;
}
if ((mystate & APPLY_TRANSLATE) != 0) {
m02 = m02 * T00;
m12 = m12 * T11;
}
type = TYPE_UNKNOWN;
return;
case (HI_SHEAR | APPLY_SHEAR | APPLY_TRANSLATE):
case (HI_SHEAR | APPLY_SHEAR):
mystate = mystate | APPLY_SCALE;
/* NOBREAK */
case (HI_SHEAR | APPLY_TRANSLATE):
case (HI_SHEAR | APPLY_IDENTITY):
case (HI_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_SHEAR | APPLY_SCALE):
state = mystate ^ APPLY_SHEAR;
/* NOBREAK */
case (HI_SHEAR | APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
case (HI_SHEAR | APPLY_SHEAR | APPLY_SCALE):
// Tx is SHEAR, this is anything
T01 = Tx.m01;
T10 = Tx.m10;
M0 = m00;
m00 = m10 * T01;
m10 = M0 * T10;
M0 = m01;
m01 = m11 * T01;
m11 = M0 * T10;
M0 = m02;
m02 = m12 * T01;
m12 = M0 * T10;
type = TYPE_UNKNOWN;
return;
}
// If Tx has more than one attribute, it is not worth optimizing
// all of those cases...
T00 = Tx.m00; T01 = Tx.m01; T02 = Tx.m02;
T10 = Tx.m10; T11 = Tx.m11; T12 = Tx.m12;
switch (mystate) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
M0 = m02;
M1 = m12;
T02 += M0 * T00 + M1 * T01;
T12 += M0 * T10 + M1 * T11;
/* NOBREAK */
case (APPLY_SHEAR | APPLY_SCALE):
m02 = T02;
m12 = T12;
M0 = m00;
M1 = m10;
m00 = M0 * T00 + M1 * T01;
m10 = M0 * T10 + M1 * T11;
M0 = m01;
M1 = m11;
m01 = M0 * T00 + M1 * T01;
m11 = M0 * T10 + M1 * T11;
break;
case (APPLY_SHEAR | APPLY_TRANSLATE):
M0 = m02;
M1 = m12;
T02 += M0 * T00 + M1 * T01;
T12 += M0 * T10 + M1 * T11;
/* NOBREAK */
case (APPLY_SHEAR):
m02 = T02;
m12 = T12;
M0 = m10;
m00 = M0 * T01;
m10 = M0 * T11;
M0 = m01;
m01 = M0 * T00;
m11 = M0 * T10;
break;
case (APPLY_SCALE | APPLY_TRANSLATE):
M0 = m02;
M1 = m12;
T02 += M0 * T00 + M1 * T01;
T12 += M0 * T10 + M1 * T11;
/* NOBREAK */
case (APPLY_SCALE):
m02 = T02;
m12 = T12;
M0 = m00;
m00 = M0 * T00;
m10 = M0 * T10;
M0 = m11;
m01 = M0 * T01;
m11 = M0 * T11;
break;
case (APPLY_TRANSLATE):
M0 = m02;
M1 = m12;
T02 += M0 * T00 + M1 * T01;
T12 += M0 * T10 + M1 * T11;
/* NOBREAK */
case (APPLY_IDENTITY):
m02 = T02;
m12 = T12;
m00 = T00;
m10 = T10;
m01 = T01;
m11 = T11;
state = mystate | txstate;
type = TYPE_UNKNOWN;
return;
}
updateState();
}
/**
* 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.
* @return a new AffineTransform object representing the
* inverse transformation.
* @see #getDeterminant
* @exception NoninvertibleTransformException
* if the matrix cannot be inverted.
* @since 1.2
*/
public AffineTransform createInverse()
throws NoninvertibleTransformException
{
double det;
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
det = m00 * m11 - m01 * m10;
if (Math.abs(det) <= Double.MIN_VALUE) {
throw new NoninvertibleTransformException("Determinant is "+
det);
}
return new AffineTransform( m11 / det, -m10 / det,
-m01 / det, m00 / det,
(m01 * m12 - m11 * m02) / det,
(m10 * m02 - m00 * m12) / det,
(APPLY_SHEAR |
APPLY_SCALE |
APPLY_TRANSLATE));
case (APPLY_SHEAR | APPLY_SCALE):
det = m00 * m11 - m01 * m10;
if (Math.abs(det) <= Double.MIN_VALUE) {
throw new NoninvertibleTransformException("Determinant is "+
det);
}
return new AffineTransform( m11 / det, -m10 / det,
-m01 / det, m00 / det,
0.0, 0.0,
(APPLY_SHEAR | APPLY_SCALE));
case (APPLY_SHEAR | APPLY_TRANSLATE):
if (m01 == 0.0 || m10 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
return new AffineTransform( 0.0, 1.0 / m01,
1.0 / m10, 0.0,
-m12 / m10, -m02 / m01,
(APPLY_SHEAR | APPLY_TRANSLATE));
case (APPLY_SHEAR):
if (m01 == 0.0 || m10 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
return new AffineTransform(0.0, 1.0 / m01,
1.0 / m10, 0.0,
0.0, 0.0,
(APPLY_SHEAR));
case (APPLY_SCALE | APPLY_TRANSLATE):
if (m00 == 0.0 || m11 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
return new AffineTransform( 1.0 / m00, 0.0,
0.0, 1.0 / m11,
-m02 / m00, -m12 / m11,
(APPLY_SCALE | APPLY_TRANSLATE));
case (APPLY_SCALE):
if (m00 == 0.0 || m11 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
return new AffineTransform(1.0 / m00, 0.0,
0.0, 1.0 / m11,
0.0, 0.0,
(APPLY_SCALE));
case (APPLY_TRANSLATE):
return new AffineTransform( 1.0, 0.0,
0.0, 1.0,
-m02, -m12,
(APPLY_TRANSLATE));
case (APPLY_IDENTITY):
return new AffineTransform();
}
/* NOTREACHED */
}
/**
* 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.
* @see #getDeterminant
* @exception NoninvertibleTransformException
* if the matrix cannot be inverted.
* @since 1.6
*/
public void invert()
throws NoninvertibleTransformException
{
double M00, M01, M02;
double M10, M11, M12;
double det;
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
M00 = m00; M01 = m01; M02 = m02;
M10 = m10; M11 = m11; M12 = m12;
det = M00 * M11 - M01 * M10;
if (Math.abs(det) <= Double.MIN_VALUE) {
throw new NoninvertibleTransformException("Determinant is "+
det);
}
m00 = M11 / det;
m10 = -M10 / det;
m01 = -M01 / det;
m11 = M00 / det;
m02 = (M01 * M12 - M11 * M02) / det;
m12 = (M10 * M02 - M00 * M12) / det;
break;
case (APPLY_SHEAR | APPLY_SCALE):
M00 = m00; M01 = m01;
M10 = m10; M11 = m11;
det = M00 * M11 - M01 * M10;
if (Math.abs(det) <= Double.MIN_VALUE) {
throw new NoninvertibleTransformException("Determinant is "+
det);
}
m00 = M11 / det;
m10 = -M10 / det;
m01 = -M01 / det;
m11 = M00 / det;
// m02 = 0.0;
// m12 = 0.0;
break;
case (APPLY_SHEAR | APPLY_TRANSLATE):
M01 = m01; M02 = m02;
M10 = m10; M12 = m12;
if (M01 == 0.0 || M10 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
// m00 = 0.0;
m10 = 1.0 / M01;
m01 = 1.0 / M10;
// m11 = 0.0;
m02 = -M12 / M10;
m12 = -M02 / M01;
break;
case (APPLY_SHEAR):
M01 = m01;
M10 = m10;
if (M01 == 0.0 || M10 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
// m00 = 0.0;
m10 = 1.0 / M01;
m01 = 1.0 / M10;
// m11 = 0.0;
// m02 = 0.0;
// m12 = 0.0;
break;
case (APPLY_SCALE | APPLY_TRANSLATE):
M00 = m00; M02 = m02;
M11 = m11; M12 = m12;
if (M00 == 0.0 || M11 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
m00 = 1.0 / M00;
// m10 = 0.0;
// m01 = 0.0;
m11 = 1.0 / M11;
m02 = -M02 / M00;
m12 = -M12 / M11;
break;
case (APPLY_SCALE):
M00 = m00;
M11 = m11;
if (M00 == 0.0 || M11 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
m00 = 1.0 / M00;
// m10 = 0.0;
// m01 = 0.0;
m11 = 1.0 / M11;
// m02 = 0.0;
// m12 = 0.0;
break;
case (APPLY_TRANSLATE):
// m00 = 1.0;
// m10 = 0.0;
// m01 = 0.0;
// m11 = 1.0;
m02 = -m02;
m12 = -m12;
break;
case (APPLY_IDENTITY):
// m00 = 1.0;
// m10 = 0.0;
// m01 = 0.0;
// m11 = 1.0;
// m02 = 0.0;
// m12 = 0.0;
break;
}
}
/**
* Transforms the specified ptSrc and stores the result
* in ptDst.
* If ptDst is null, a new {@link 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.
* @param ptSrc the specified Point2D to be transformed
* @param ptDst the specified Point2D that stores the
* result of transforming ptSrc
* @return the ptDst after transforming
* ptSrc and stroring the result in ptDst.
* @since 1.2
*/
public Point2D transform(Point2D ptSrc, Point2D ptDst) {
if (ptDst == null) {
if (ptSrc instanceof Point2D.Double) {
ptDst = new Point2D.Double();
} else {
ptDst = new Point2D.Float();
}
}
// Copy source coords into local variables in case src == dst
double x = ptSrc.getX();
double y = ptSrc.getY();
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
ptDst.setLocation(x * m00 + y * m01 + m02,
x * m10 + y * m11 + m12);
return ptDst;
case (APPLY_SHEAR | APPLY_SCALE):
ptDst.setLocation(x * m00 + y * m01, x * m10 + y * m11);
return ptDst;
case (APPLY_SHEAR | APPLY_TRANSLATE):
ptDst.setLocation(y * m01 + m02, x * m10 + m12);
return ptDst;
case (APPLY_SHEAR):
ptDst.setLocation(y * m01, x * m10);
return ptDst;
case (APPLY_SCALE | APPLY_TRANSLATE):
ptDst.setLocation(x * m00 + m02, y * m11 + m12);
return ptDst;
case (APPLY_SCALE):
ptDst.setLocation(x * m00, y * m11);
return ptDst;
case (APPLY_TRANSLATE):
ptDst.setLocation(x + m02, y + m12);
return ptDst;
case (APPLY_IDENTITY):
ptDst.setLocation(x, y);
return ptDst;
}
/* NOTREACHED */
}
/**
* 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.
* @param ptSrc the array containing the source point objects
* @param ptDst the array into which the transform point objects are
* returned
* @param srcOff the offset to the first point object to be
* transformed in the source array
* @param dstOff the offset to the location of the first
* transformed point object that is stored in the destination array
* @param numPts the number of point objects to be transformed
* @since 1.2
*/
public void transform(Point2D[] ptSrc, int srcOff,
Point2D[] ptDst, int dstOff,
int numPts) {
int state = this.state;
while (--numPts >= 0) {
// Copy source coords into local variables in case src == dst
Point2D src = ptSrc[srcOff++];
double x = src.getX();
double y = src.getY();
Point2D dst = ptDst[dstOff++];
if (dst == null) {
if (src instanceof Point2D.Double) {
dst = new Point2D.Double();
} else {
dst = new Point2D.Float();
}
ptDst[dstOff - 1] = dst;
}
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
dst.setLocation(x * m00 + y * m01 + m02,
x * m10 + y * m11 + m12);
break;
case (APPLY_SHEAR | APPLY_SCALE):
dst.setLocation(x * m00 + y * m01, x * m10 + y * m11);
break;
case (APPLY_SHEAR | APPLY_TRANSLATE):
dst.setLocation(y * m01 + m02, x * m10 + m12);
break;
case (APPLY_SHEAR):
dst.setLocation(y * m01, x * m10);
break;
case (APPLY_SCALE | APPLY_TRANSLATE):
dst.setLocation(x * m00 + m02, y * m11 + m12);
break;
case (APPLY_SCALE):
dst.setLocation(x * m00, y * m11);
break;
case (APPLY_TRANSLATE):
dst.setLocation(x + m02, y + m12);
break;
case (APPLY_IDENTITY):
dst.setLocation(x, y);
break;
}
}
/* NOTREACHED */
}
/**
* 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].
* @param srcPts the array containing the source point coordinates.
* Each point is stored as a pair of x, y coordinates.
* @param dstPts the array into which the transformed point coordinates
* are returned. Each point is stored as a pair of x, y
* coordinates.
* @param srcOff the offset to the first point to be transformed
* in the source array
* @param dstOff the offset to the location of the first
* transformed point that is stored in the destination array
* @param numPts the number of points to be transformed
* @since 1.2
*/
public void transform(float[] srcPts, int srcOff,
float[] dstPts, int dstOff,
int numPts) {
double M00, M01, M02, M10, M11, M12; // For caching
if (dstPts == srcPts &&
dstOff > srcOff && dstOff < srcOff + numPts * 2)
{
// If the arrays overlap partially with the destination higher
// than the source and we transform the coordinates normally
// we would overwrite some of the later source coordinates
// with results of previous transformations.
// To get around this we use arraycopy to copy the points
// to their final destination with correct overwrite
// handling and then transform them in place in the new
// safer location.
System.arraycopy(srcPts, srcOff, dstPts, dstOff, numPts * 2);
// srcPts = dstPts; // They are known to be equal.
srcOff = dstOff;
}
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
M00 = m00; M01 = m01; M02 = m02;
M10 = m10; M11 = m11; M12 = m12;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
double y = srcPts[srcOff++];
dstPts[dstOff++] = (float) (M00 * x + M01 * y + M02);
dstPts[dstOff++] = (float) (M10 * x + M11 * y + M12);
}
return;
case (APPLY_SHEAR | APPLY_SCALE):
M00 = m00; M01 = m01;
M10 = m10; M11 = m11;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
double y = srcPts[srcOff++];
dstPts[dstOff++] = (float) (M00 * x + M01 * y);
dstPts[dstOff++] = (float) (M10 * x + M11 * y);
}
return;
case (APPLY_SHEAR | APPLY_TRANSLATE):
M01 = m01; M02 = m02;
M10 = m10; M12 = m12;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
dstPts[dstOff++] = (float) (M01 * srcPts[srcOff++] + M02);
dstPts[dstOff++] = (float) (M10 * x + M12);
}
return;
case (APPLY_SHEAR):
M01 = m01; M10 = m10;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
dstPts[dstOff++] = (float) (M01 * srcPts[srcOff++]);
dstPts[dstOff++] = (float) (M10 * x);
}
return;
case (APPLY_SCALE | APPLY_TRANSLATE):
M00 = m00; M02 = m02;
M11 = m11; M12 = m12;
while (--numPts >= 0) {
dstPts[dstOff++] = (float) (M00 * srcPts[srcOff++] + M02);
dstPts[dstOff++] = (float) (M11 * srcPts[srcOff++] + M12);
}
return;
case (APPLY_SCALE):
M00 = m00; M11 = m11;
while (--numPts >= 0) {
dstPts[dstOff++] = (float) (M00 * srcPts[srcOff++]);
dstPts[dstOff++] = (float) (M11 * srcPts[srcOff++]);
}
return;
case (APPLY_TRANSLATE):
M02 = m02; M12 = m12;
while (--numPts >= 0) {
dstPts[dstOff++] = (float) (srcPts[srcOff++] + M02);
dstPts[dstOff++] = (float) (srcPts[srcOff++] + M12);
}
return;
case (APPLY_IDENTITY):
if (srcPts != dstPts || srcOff != dstOff) {
System.arraycopy(srcPts, srcOff, dstPts, dstOff,
numPts * 2);
}
return;
}
/* NOTREACHED */
}
/**
* 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].
* @param srcPts the array containing the source point coordinates.
* Each point is stored as a pair of x, y coordinates.
* @param dstPts the array into which the transformed point
* coordinates are returned. Each point is stored as a pair of
* x, y coordinates.
* @param srcOff the offset to the first point to be transformed
* in the source array
* @param dstOff the offset to the location of the first
* transformed point that is stored in the destination array
* @param numPts the number of point objects to be transformed
* @since 1.2
*/
public void transform(double[] srcPts, int srcOff,
double[] dstPts, int dstOff,
int numPts) {
double M00, M01, M02, M10, M11, M12; // For caching
if (dstPts == srcPts &&
dstOff > srcOff && dstOff < srcOff + numPts * 2)
{
// If the arrays overlap partially with the destination higher
// than the source and we transform the coordinates normally
// we would overwrite some of the later source coordinates
// with results of previous transformations.
// To get around this we use arraycopy to copy the points
// to their final destination with correct overwrite
// handling and then transform them in place in the new
// safer location.
System.arraycopy(srcPts, srcOff, dstPts, dstOff, numPts * 2);
// srcPts = dstPts; // They are known to be equal.
srcOff = dstOff;
}
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
M00 = m00; M01 = m01; M02 = m02;
M10 = m10; M11 = m11; M12 = m12;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
double y = srcPts[srcOff++];
dstPts[dstOff++] = M00 * x + M01 * y + M02;
dstPts[dstOff++] = M10 * x + M11 * y + M12;
}
return;
case (APPLY_SHEAR | APPLY_SCALE):
M00 = m00; M01 = m01;
M10 = m10; M11 = m11;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
double y = srcPts[srcOff++];
dstPts[dstOff++] = M00 * x + M01 * y;
dstPts[dstOff++] = M10 * x + M11 * y;
}
return;
case (APPLY_SHEAR | APPLY_TRANSLATE):
M01 = m01; M02 = m02;
M10 = m10; M12 = m12;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
dstPts[dstOff++] = M01 * srcPts[srcOff++] + M02;
dstPts[dstOff++] = M10 * x + M12;
}
return;
case (APPLY_SHEAR):
M01 = m01; M10 = m10;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
dstPts[dstOff++] = M01 * srcPts[srcOff++];
dstPts[dstOff++] = M10 * x;
}
return;
case (APPLY_SCALE | APPLY_TRANSLATE):
M00 = m00; M02 = m02;
M11 = m11; M12 = m12;
while (--numPts >= 0) {
dstPts[dstOff++] = M00 * srcPts[srcOff++] + M02;
dstPts[dstOff++] = M11 * srcPts[srcOff++] + M12;
}
return;
case (APPLY_SCALE):
M00 = m00; M11 = m11;
while (--numPts >= 0) {
dstPts[dstOff++] = M00 * srcPts[srcOff++];
dstPts[dstOff++] = M11 * srcPts[srcOff++];
}
return;
case (APPLY_TRANSLATE):
M02 = m02; M12 = m12;
while (--numPts >= 0) {
dstPts[dstOff++] = srcPts[srcOff++] + M02;
dstPts[dstOff++] = srcPts[srcOff++] + M12;
}
return;
case (APPLY_IDENTITY):
if (srcPts != dstPts || srcOff != dstOff) {
System.arraycopy(srcPts, srcOff, dstPts, dstOff,
numPts * 2);
}
return;
}
/* NOTREACHED */
}
/**
* 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].
* @param srcPts the array containing the source point coordinates.
* Each point is stored as a pair of x, y coordinates.
* @param dstPts the array into which the transformed point coordinates
* are returned. Each point is stored as a pair of x, y
* coordinates.
* @param srcOff the offset to the first point to be transformed
* in the source array
* @param dstOff the offset to the location of the first
* transformed point that is stored in the destination array
* @param numPts the number of points to be transformed
* @since 1.2
*/
public void transform(float[] srcPts, int srcOff,
double[] dstPts, int dstOff,
int numPts) {
double M00, M01, M02, M10, M11, M12; // For caching
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
M00 = m00; M01 = m01; M02 = m02;
M10 = m10; M11 = m11; M12 = m12;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
double y = srcPts[srcOff++];
dstPts[dstOff++] = M00 * x + M01 * y + M02;
dstPts[dstOff++] = M10 * x + M11 * y + M12;
}
return;
case (APPLY_SHEAR | APPLY_SCALE):
M00 = m00; M01 = m01;
M10 = m10; M11 = m11;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
double y = srcPts[srcOff++];
dstPts[dstOff++] = M00 * x + M01 * y;
dstPts[dstOff++] = M10 * x + M11 * y;
}
return;
case (APPLY_SHEAR | APPLY_TRANSLATE):
M01 = m01; M02 = m02;
M10 = m10; M12 = m12;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
dstPts[dstOff++] = M01 * srcPts[srcOff++] + M02;
dstPts[dstOff++] = M10 * x + M12;
}
return;
case (APPLY_SHEAR):
M01 = m01; M10 = m10;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
dstPts[dstOff++] = M01 * srcPts[srcOff++];
dstPts[dstOff++] = M10 * x;
}
return;
case (APPLY_SCALE | APPLY_TRANSLATE):
M00 = m00; M02 = m02;
M11 = m11; M12 = m12;
while (--numPts >= 0) {
dstPts[dstOff++] = M00 * srcPts[srcOff++] + M02;
dstPts[dstOff++] = M11 * srcPts[srcOff++] + M12;
}
return;
case (APPLY_SCALE):
M00 = m00; M11 = m11;
while (--numPts >= 0) {
dstPts[dstOff++] = M00 * srcPts[srcOff++];
dstPts[dstOff++] = M11 * srcPts[srcOff++];
}
return;
case (APPLY_TRANSLATE):
M02 = m02; M12 = m12;
while (--numPts >= 0) {
dstPts[dstOff++] = srcPts[srcOff++] + M02;
dstPts[dstOff++] = srcPts[srcOff++] + M12;
}
return;
case (APPLY_IDENTITY):
while (--numPts >= 0) {
dstPts[dstOff++] = srcPts[srcOff++];
dstPts[dstOff++] = srcPts[srcOff++];
}
return;
}
/* NOTREACHED */
}
/**
* 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].
* @param srcPts the array containing the source point coordinates.
* Each point is stored as a pair of x, y coordinates.
* @param dstPts the array into which the transformed point
* coordinates are returned. Each point is stored as a pair of
* x, y coordinates.
* @param srcOff the offset to the first point to be transformed
* in the source array
* @param dstOff the offset to the location of the first
* transformed point that is stored in the destination array
* @param numPts the number of point objects to be transformed
* @since 1.2
*/
public void transform(double[] srcPts, int srcOff,
float[] dstPts, int dstOff,
int numPts) {
double M00, M01, M02, M10, M11, M12; // For caching
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
M00 = m00; M01 = m01; M02 = m02;
M10 = m10; M11 = m11; M12 = m12;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
double y = srcPts[srcOff++];
dstPts[dstOff++] = (float) (M00 * x + M01 * y + M02);
dstPts[dstOff++] = (float) (M10 * x + M11 * y + M12);
}
return;
case (APPLY_SHEAR | APPLY_SCALE):
M00 = m00; M01 = m01;
M10 = m10; M11 = m11;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
double y = srcPts[srcOff++];
dstPts[dstOff++] = (float) (M00 * x + M01 * y);
dstPts[dstOff++] = (float) (M10 * x + M11 * y);
}
return;
case (APPLY_SHEAR | APPLY_TRANSLATE):
M01 = m01; M02 = m02;
M10 = m10; M12 = m12;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
dstPts[dstOff++] = (float) (M01 * srcPts[srcOff++] + M02);
dstPts[dstOff++] = (float) (M10 * x + M12);
}
return;
case (APPLY_SHEAR):
M01 = m01; M10 = m10;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
dstPts[dstOff++] = (float) (M01 * srcPts[srcOff++]);
dstPts[dstOff++] = (float) (M10 * x);
}
return;
case (APPLY_SCALE | APPLY_TRANSLATE):
M00 = m00; M02 = m02;
M11 = m11; M12 = m12;
while (--numPts >= 0) {
dstPts[dstOff++] = (float) (M00 * srcPts[srcOff++] + M02);
dstPts[dstOff++] = (float) (M11 * srcPts[srcOff++] + M12);
}
return;
case (APPLY_SCALE):
M00 = m00; M11 = m11;
while (--numPts >= 0) {
dstPts[dstOff++] = (float) (M00 * srcPts[srcOff++]);
dstPts[dstOff++] = (float) (M11 * srcPts[srcOff++]);
}
return;
case (APPLY_TRANSLATE):
M02 = m02; M12 = m12;
while (--numPts >= 0) {
dstPts[dstOff++] = (float) (srcPts[srcOff++] + M02);
dstPts[dstOff++] = (float) (srcPts[srcOff++] + M12);
}
return;
case (APPLY_IDENTITY):
while (--numPts >= 0) {
dstPts[dstOff++] = (float) (srcPts[srcOff++]);
dstPts[dstOff++] = (float) (srcPts[srcOff++]);
}
return;
}
/* NOTREACHED */
}
/**
* 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.
* @param ptSrc the point to be inverse transformed
* @param ptDst the resulting transformed point
* @return ptDst, which contains the result of the
* inverse transform.
* @exception NoninvertibleTransformException if the matrix cannot be
* inverted.
* @since 1.2
*/
public Point2D inverseTransform(Point2D ptSrc, Point2D ptDst)
throws NoninvertibleTransformException
{
if (ptDst == null) {
if (ptSrc instanceof Point2D.Double) {
ptDst = new Point2D.Double();
} else {
ptDst = new Point2D.Float();
}
}
// Copy source coords into local variables in case src == dst
double x = ptSrc.getX();
double y = ptSrc.getY();
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
x -= m02;
y -= m12;
/* NOBREAK */
case (APPLY_SHEAR | APPLY_SCALE):
double det = m00 * m11 - m01 * m10;
if (Math.abs(det) <= Double.MIN_VALUE) {
throw new NoninvertibleTransformException("Determinant is "+
det);
}
ptDst.setLocation((x * m11 - y * m01) / det,
(y * m00 - x * m10) / det);
return ptDst;
case (APPLY_SHEAR | APPLY_TRANSLATE):
x -= m02;
y -= m12;
/* NOBREAK */
case (APPLY_SHEAR):
if (m01 == 0.0 || m10 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
ptDst.setLocation(y / m10, x / m01);
return ptDst;
case (APPLY_SCALE | APPLY_TRANSLATE):
x -= m02;
y -= m12;
/* NOBREAK */
case (APPLY_SCALE):
if (m00 == 0.0 || m11 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
ptDst.setLocation(x / m00, y / m11);
return ptDst;
case (APPLY_TRANSLATE):
ptDst.setLocation(x - m02, y - m12);
return ptDst;
case (APPLY_IDENTITY):
ptDst.setLocation(x, y);
return ptDst;
}
/* NOTREACHED */
}
/**
* 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].
* @param srcPts the array containing the source point coordinates.
* Each point is stored as a pair of x, y coordinates.
* @param dstPts the array into which the transformed point
* coordinates are returned. Each point is stored as a pair of
* x, y coordinates.
* @param srcOff the offset to the first point to be transformed
* in the source array
* @param dstOff the offset to the location of the first
* transformed point that is stored in the destination array
* @param numPts the number of point objects to be transformed
* @exception NoninvertibleTransformException if the matrix cannot be
* inverted.
* @since 1.2
*/
public void inverseTransform(double[] srcPts, int srcOff,
double[] dstPts, int dstOff,
int numPts)
throws NoninvertibleTransformException
{
double M00, M01, M02, M10, M11, M12; // For caching
double det;
if (dstPts == srcPts &&
dstOff > srcOff && dstOff < srcOff + numPts * 2)
{
// If the arrays overlap partially with the destination higher
// than the source and we transform the coordinates normally
// we would overwrite some of the later source coordinates
// with results of previous transformations.
// To get around this we use arraycopy to copy the points
// to their final destination with correct overwrite
// handling and then transform them in place in the new
// safer location.
System.arraycopy(srcPts, srcOff, dstPts, dstOff, numPts * 2);
// srcPts = dstPts; // They are known to be equal.
srcOff = dstOff;
}
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
M00 = m00; M01 = m01; M02 = m02;
M10 = m10; M11 = m11; M12 = m12;
det = M00 * M11 - M01 * M10;
if (Math.abs(det) <= Double.MIN_VALUE) {
throw new NoninvertibleTransformException("Determinant is "+
det);
}
while (--numPts >= 0) {
double x = srcPts[srcOff++] - M02;
double y = srcPts[srcOff++] - M12;
dstPts[dstOff++] = (x * M11 - y * M01) / det;
dstPts[dstOff++] = (y * M00 - x * M10) / det;
}
return;
case (APPLY_SHEAR | APPLY_SCALE):
M00 = m00; M01 = m01;
M10 = m10; M11 = m11;
det = M00 * M11 - M01 * M10;
if (Math.abs(det) <= Double.MIN_VALUE) {
throw new NoninvertibleTransformException("Determinant is "+
det);
}
while (--numPts >= 0) {
double x = srcPts[srcOff++];
double y = srcPts[srcOff++];
dstPts[dstOff++] = (x * M11 - y * M01) / det;
dstPts[dstOff++] = (y * M00 - x * M10) / det;
}
return;
case (APPLY_SHEAR | APPLY_TRANSLATE):
M01 = m01; M02 = m02;
M10 = m10; M12 = m12;
if (M01 == 0.0 || M10 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
while (--numPts >= 0) {
double x = srcPts[srcOff++] - M02;
dstPts[dstOff++] = (srcPts[srcOff++] - M12) / M10;
dstPts[dstOff++] = x / M01;
}
return;
case (APPLY_SHEAR):
M01 = m01; M10 = m10;
if (M01 == 0.0 || M10 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
while (--numPts >= 0) {
double x = srcPts[srcOff++];
dstPts[dstOff++] = srcPts[srcOff++] / M10;
dstPts[dstOff++] = x / M01;
}
return;
case (APPLY_SCALE | APPLY_TRANSLATE):
M00 = m00; M02 = m02;
M11 = m11; M12 = m12;
if (M00 == 0.0 || M11 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
while (--numPts >= 0) {
dstPts[dstOff++] = (srcPts[srcOff++] - M02) / M00;
dstPts[dstOff++] = (srcPts[srcOff++] - M12) / M11;
}
return;
case (APPLY_SCALE):
M00 = m00; M11 = m11;
if (M00 == 0.0 || M11 == 0.0) {
throw new NoninvertibleTransformException("Determinant is 0");
}
while (--numPts >= 0) {
dstPts[dstOff++] = srcPts[srcOff++] / M00;
dstPts[dstOff++] = srcPts[srcOff++] / M11;
}
return;
case (APPLY_TRANSLATE):
M02 = m02; M12 = m12;
while (--numPts >= 0) {
dstPts[dstOff++] = srcPts[srcOff++] - M02;
dstPts[dstOff++] = srcPts[srcOff++] - M12;
}
return;
case (APPLY_IDENTITY):
if (srcPts != dstPts || srcOff != dstOff) {
System.arraycopy(srcPts, srcOff, dstPts, dstOff,
numPts * 2);
}
return;
}
/* NOTREACHED */
}
/**
* 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.
* @param ptSrc the distance vector to be delta transformed
* @param ptDst the resulting transformed distance vector
* @return ptDst, which contains the result of the
* transformation.
* @since 1.2
*/
public Point2D deltaTransform(Point2D ptSrc, Point2D ptDst) {
if (ptDst == null) {
if (ptSrc instanceof Point2D.Double) {
ptDst = new Point2D.Double();
} else {
ptDst = new Point2D.Float();
}
}
// Copy source coords into local variables in case src == dst
double x = ptSrc.getX();
double y = ptSrc.getY();
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
case (APPLY_SHEAR | APPLY_SCALE):
ptDst.setLocation(x * m00 + y * m01, x * m10 + y * m11);
return ptDst;
case (APPLY_SHEAR | APPLY_TRANSLATE):
case (APPLY_SHEAR):
ptDst.setLocation(y * m01, x * m10);
return ptDst;
case (APPLY_SCALE | APPLY_TRANSLATE):
case (APPLY_SCALE):
ptDst.setLocation(x * m00, y * m11);
return ptDst;
case (APPLY_TRANSLATE):
case (APPLY_IDENTITY):
ptDst.setLocation(x, y);
return ptDst;
}
/* NOTREACHED */
}
/**
* 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].
* @param srcPts the array containing the source distance vectors.
* Each vector is stored as a pair of relative x, y coordinates.
* @param dstPts the array into which the transformed distance vectors
* are returned. Each vector is stored as a pair of relative
* x, y coordinates.
* @param srcOff the offset to the first vector to be transformed
* in the source array
* @param dstOff the offset to the location of the first
* transformed vector that is stored in the destination array
* @param numPts the number of vector coordinate pairs to be
* transformed
* @since 1.2
*/
public void deltaTransform(double[] srcPts, int srcOff,
double[] dstPts, int dstOff,
int numPts) {
double M00, M01, M10, M11; // For caching
if (dstPts == srcPts &&
dstOff > srcOff && dstOff < srcOff + numPts * 2)
{
// If the arrays overlap partially with the destination higher
// than the source and we transform the coordinates normally
// we would overwrite some of the later source coordinates
// with results of previous transformations.
// To get around this we use arraycopy to copy the points
// to their final destination with correct overwrite
// handling and then transform them in place in the new
// safer location.
System.arraycopy(srcPts, srcOff, dstPts, dstOff, numPts * 2);
// srcPts = dstPts; // They are known to be equal.
srcOff = dstOff;
}
switch (state) {
default:
stateError();
/* NOTREACHED */
case (APPLY_SHEAR | APPLY_SCALE | APPLY_TRANSLATE):
case (APPLY_SHEAR | APPLY_SCALE):
M00 = m00; M01 = m01;
M10 = m10; M11 = m11;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
double y = srcPts[srcOff++];
dstPts[dstOff++] = x * M00 + y * M01;
dstPts[dstOff++] = x * M10 + y * M11;
}
return;
case (APPLY_SHEAR | APPLY_TRANSLATE):
case (APPLY_SHEAR):
M01 = m01; M10 = m10;
while (--numPts >= 0) {
double x = srcPts[srcOff++];
dstPts[dstOff++] = srcPts[srcOff++] * M01;
dstPts[dstOff++] = x * M10;
}
return;
case (APPLY_SCALE | APPLY_TRANSLATE):
case (APPLY_SCALE):
M00 = m00; M11 = m11;
while (--numPts >= 0) {
dstPts[dstOff++] = srcPts[srcOff++] * M00;
dstPts[dstOff++] = srcPts[srcOff++] * M11;
}
return;
case (APPLY_TRANSLATE):
case (APPLY_IDENTITY):
if (srcPts != dstPts || srcOff != dstOff) {
System.arraycopy(srcPts, srcOff, dstPts, dstOff,
numPts * 2);
}
return;
}
/* NOTREACHED */
}
/**
* Returns a new {@link Shape} object defined by the geometry of the
* specified Shape after it has been transformed by
* this transform.
* @param pSrc the specified Shape object to be
* transformed by this transform.
* @return a new Shape object that defines the geometry
* of the transformed Shape, or null if {@code pSrc} is null.
* @since 1.2
*/
public Shape createTransformedShape(Shape pSrc) {
if (pSrc == null) {
return null;
}
return new Path2D.Double(pSrc, this);
}
// Round values to sane precision for printing
// Note that Math.sin(Math.PI) has an error of about 10^-16
private static double _matround(double matval) {
return Math.rint(matval * 1E15) / 1E15;
}
/**
* Returns a String that represents the value of this
* {@link Object}.
* @return a String representing the value of this
* Object.
* @since 1.2
*/
public String toString() {
return ("AffineTransform[["
+ _matround(m00) + ", "
+ _matround(m01) + ", "
+ _matround(m02) + "], ["
+ _matround(m10) + ", "
+ _matround(m11) + ", "
+ _matround(m12) + "]]");
}
/**
* Returns true if this AffineTransform is
* an identity transform.
* @return true if this AffineTransform is
* an identity transform; false otherwise.
* @since 1.2
*/
public boolean isIdentity() {
return (state == APPLY_IDENTITY || (getType() == TYPE_IDENTITY));
}
/**
* Returns a copy of this AffineTransform object.
* @return an Object that is a copy of this
* AffineTransform object.
* @since 1.2
*/
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {
// this shouldn't happen, since we are Cloneable
throw new InternalError();
}
}
/**
* Returns the hashcode for this transform.
* @return a hash code for this transform.
* @since 1.2
*/
public int hashCode() {
long bits = Double.doubleToLongBits(m00);
bits = bits * 31 + Double.doubleToLongBits(m01);
bits = bits * 31 + Double.doubleToLongBits(m02);
bits = bits * 31 + Double.doubleToLongBits(m10);
bits = bits * 31 + Double.doubleToLongBits(m11);
bits = bits * 31 + Double.doubleToLongBits(m12);
return (((int) bits) ^ ((int) (bits >> 32)));
}
/**
* Returns true if this AffineTransform
* represents the same affine coordinate transform as the specified
* argument.
* @param obj the Object to test for equality with this
* AffineTransform
* @return true if obj equals this
* AffineTransform object; false otherwise.
* @since 1.2
*/
public boolean equals(Object obj) {
if (!(obj instanceof AffineTransform)) {
return false;
}
AffineTransform a = (AffineTransform)obj;
return ((m00 == a.m00) && (m01 == a.m01) && (m02 == a.m02) &&
(m10 == a.m10) && (m11 == a.m11) && (m12 == a.m12));
}
/* Serialization support. A readObject method is neccessary because
* the state field is part of the implementation of this particular
* AffineTransform and not part of the public specification. The
* state variable's value needs to be recalculated on the fly by the
* readObject method as it is in the 6-argument matrix constructor.
*/
/*
* JDK 1.2 serialVersionUID
*/
private static final long serialVersionUID = 1330973210523860834L;
private void writeObject(java.io.ObjectOutputStream s)
throws java.lang.ClassNotFoundException, java.io.IOException
{
s.defaultWriteObject();
}
private void readObject(java.io.ObjectInputStream s)
throws java.lang.ClassNotFoundException, java.io.IOException
{
s.defaultReadObject();
updateState();
}
}