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/*
* Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*
*
*
*
*
*
*
*
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*
*
*
*
*
*
*
*
*/
package java.awt.geom;
import java.awt.Shape;
import java.beans.ConstructorProperties;
/**
* The <code>AffineTransform</code> 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.
* <p>
* 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:
* <pre>
* [ x'] [ m00 m01 m02 ] [ x ] [ m00x + m01y + m02 ]
* [ y'] = [ m10 m11 m12 ] [ y ] = [ m10x + m11y + m12 ]
* [ 1 ] [ 0 0 1 ] [ 1 ] [ 1 ]
* </pre>
* <h3><a name="quadrantapproximation">Handling 90-Degree Rotations</a></h3>
* <p>
* In some variations of the <code>rotate</code> methods in the
* <code>AffineTransform</code> 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.
* <p>
* Since 90 degrees is represented as <code>PI/2</code> 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 <code>PI/2</code> but never close enough
* for the sine or cosine to be exactly 0.0, 1.0 or -1.0.
* The implementations of <code>Math.sin()</code> and
* <code>Math.cos()</code> correspondingly never return 0.0
* for any case other than <code>Math.sin(0.0)</code>.
* 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.
* <p>
* The net result of these issues is that if the
* <code>Math.sin()</code> and <code>Math.cos()</code> 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 <code>rotate(Math.PI/2.0)</code>,
* 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.
* <p>
* 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 <em>theta</em> as a quadrant
* rotation if either <code>Math.sin(<em>theta</em>)</code> or
* <code>Math.cos(<em>theta</em>)</code> 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 <code>Math.PI/2.0</code>.
*
* @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 <code>AffineTransform</code> 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 <code>AffineTransform</code> that is a copy of
* the specified <code>AffineTransform</code> object.
* @param Tx the <code>AffineTransform</code> 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 <code>AffineTransform</code> 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 <code>AffineTransform</code> from an array of
* floating point 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 float array containing the values to be set
* in the new <code>AffineTransform</code> 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 <code>AffineTransform</code> 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 <code>AffineTransform</code> 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 <code>AffineTransform</code> 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:
* <pre>
* [ 1 0 tx ]
* [ 0 1 ty ]
* [ 0 0 1 ]
* </pre>
* @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 <code>AffineTransform</code> 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:
* <pre>
* [ cos(theta) -sin(theta) 0 ]
* [ sin(theta) cos(theta) 0 ]
* [ 0 0 1 ]
* </pre>
* Rotating by a positive angle theta rotates points on the positive
* X axis toward the positive Y axis.
* Note also the discussion of
* <a href="#quadrantapproximation">Handling 90-Degree Rotations</a>
* above.
* @param theta the angle of rotation measured in radians
* @return an <code>AffineTransform</code> 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).
* <p>
* This operation is equivalent to the following sequence of calls:
* <pre>
* 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
* </pre>
* The matrix representing the returned transform is:
* <pre>
* [ cos(theta) -sin(theta) x-x*cos+y*sin ]
* [ sin(theta) cos(theta) y-x*sin-y*cos ]
* [ 0 0 1 ]
* </pre>
* Rotating by a positive angle theta rotates points on the positive
* X axis toward the positive Y axis.
* Note also the discussion of
* <a href="#quadrantapproximation">Handling 90-Degree Rotations</a>
* 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 <code>AffineTransform</code> 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 <code>vecx</code> and <code>vecy</code> are 0.0,
* an identity transform is returned.
* This operation is equivalent to calling:
* <pre>
* AffineTransform.getRotateInstance(Math.atan2(vecy, vecx));
* </pre>
*
* @param vecx the X coordinate of the rotation vector
* @param vecy the Y coordinate of the rotation vector
* @return an <code>AffineTransform</code> 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 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 <code>vecx</code> and <code>vecy</code> are 0.0,
* an identity transform is returned.
* This operation is equivalent to calling:
* <pre>
* AffineTransform.getRotateInstance(Math.atan2(vecy, vecx),
* anchorx, anchory);
* </pre>
*
* @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 <code>AffineTransform</code> 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:
* <pre>
* AffineTransform.getRotateInstance(numquadrants * Math.PI / 2.0);
* </pre>
* 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 <code>AffineTransform</code> 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:
* <pre>
* AffineTransform.getRotateInstance(numquadrants * Math.PI / 2.0,
* anchorx, anchory);
* </pre>
* 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 <code>AffineTransform</code> 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:
* <pre>
* [ sx 0 0 ]
* [ 0 sy 0 ]
* [ 0 0 1 ]
* </pre>
* @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 <code>AffineTransform</code> 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:
* <pre>
* [ 1 shx 0 ]
* [ shy 1 0 ]
* [ 0 0 1 ]
* </pre>
* @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 <code>AffineTransform</code> 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
* appropriate flag bits.
* A valid combination of flag bits is an exclusive OR operation
* that can combine
* the TYPE_TRANSLATION flag bit
* in addition to either of the
* TYPE_UNIFORM_SCALE or TYPE_GENERAL_SCALE flag bits
* as well as either of the
* TYPE_QUADRANT_ROTATION or TYPE_GENERAL_ROTATION flag bits.
* @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
*/
@SuppressWarnings("fallthrough")
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;
}
/**