Android example source code file (Matrix.java)
The Matrix.java Android example source code/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.graphics;
import java.io.PrintWriter;
/**
* The Matrix class holds a 3x3 matrix for transforming coordinates.
* Matrix does not have a constructor, so it must be explicitly initialized
* using either reset() - to construct an identity matrix, or one of the set..()
* functions (e.g. setTranslate, setRotate, etc.).
*/
public class Matrix {
public static final int MSCALE_X = 0; //!< use with getValues/setValues
public static final int MSKEW_X = 1; //!< use with getValues/setValues
public static final int MTRANS_X = 2; //!< use with getValues/setValues
public static final int MSKEW_Y = 3; //!< use with getValues/setValues
public static final int MSCALE_Y = 4; //!< use with getValues/setValues
public static final int MTRANS_Y = 5; //!< use with getValues/setValues
public static final int MPERSP_0 = 6; //!< use with getValues/setValues
public static final int MPERSP_1 = 7; //!< use with getValues/setValues
public static final int MPERSP_2 = 8; //!< use with getValues/setValues
/* package */ int native_instance;
/**
* Create an identity matrix
*/
public Matrix() {
native_instance = native_create(0);
}
/**
* Create a matrix that is a (deep) copy of src
* @param src The matrix to copy into this matrix
*/
public Matrix(Matrix src) {
native_instance = native_create(src != null ? src.native_instance : 0);
}
/**
* Returns true if the matrix is identity.
* This maybe faster than testing if (getType() == 0)
*/
public boolean isIdentity() {
return native_isIdentity(native_instance);
}
/**
* Returns true if will map a rectangle to another rectangle. This can be
* true if the matrix is identity, scale-only, or rotates a multiple of 90
* degrees.
*/
public boolean rectStaysRect() {
return native_rectStaysRect(native_instance);
}
/**
* (deep) copy the src matrix into this matrix. If src is null, reset this
* matrix to the identity matrix.
*/
public void set(Matrix src) {
if (src == null) {
reset();
} else {
native_set(native_instance, src.native_instance);
}
}
/** Returns true iff obj is a Matrix and its values equal our values.
*/
public boolean equals(Object obj) {
return obj != null &&
obj instanceof Matrix &&
native_equals(native_instance, ((Matrix)obj).native_instance);
}
/** Set the matrix to identity */
public void reset() {
native_reset(native_instance);
}
/** Set the matrix to translate by (dx, dy). */
public void setTranslate(float dx, float dy) {
native_setTranslate(native_instance, dx, dy);
}
/**
* Set the matrix to scale by sx and sy, with a pivot point at (px, py).
* The pivot point is the coordinate that should remain unchanged by the
* specified transformation.
*/
public void setScale(float sx, float sy, float px, float py) {
native_setScale(native_instance, sx, sy, px, py);
}
/** Set the matrix to scale by sx and sy. */
public void setScale(float sx, float sy) {
native_setScale(native_instance, sx, sy);
}
/**
* Set the matrix to rotate by the specified number of degrees, with a pivot
* point at (px, py). The pivot point is the coordinate that should remain
* unchanged by the specified transformation.
*/
public void setRotate(float degrees, float px, float py) {
native_setRotate(native_instance, degrees, px, py);
}
/**
* Set the matrix to rotate about (0,0) by the specified number of degrees.
*/
public void setRotate(float degrees) {
native_setRotate(native_instance, degrees);
}
/**
* Set the matrix to rotate by the specified sine and cosine values, with a
* pivot point at (px, py). The pivot point is the coordinate that should
* remain unchanged by the specified transformation.
*/
public void setSinCos(float sinValue, float cosValue, float px, float py) {
native_setSinCos(native_instance, sinValue, cosValue, px, py);
}
/** Set the matrix to rotate by the specified sine and cosine values. */
public void setSinCos(float sinValue, float cosValue) {
native_setSinCos(native_instance, sinValue, cosValue);
}
/**
* Set the matrix to skew by sx and sy, with a pivot point at (px, py).
* The pivot point is the coordinate that should remain unchanged by the
* specified transformation.
*/
public void setSkew(float kx, float ky, float px, float py) {
native_setSkew(native_instance, kx, ky, px, py);
}
/** Set the matrix to skew by sx and sy. */
public void setSkew(float kx, float ky) {
native_setSkew(native_instance, kx, ky);
}
/**
* Set the matrix to the concatenation of the two specified matrices,
* returning true if the the result can be represented. Either of the two
* matrices may also be the target matrix. this = a * b
*/
public boolean setConcat(Matrix a, Matrix b) {
return native_setConcat(native_instance, a.native_instance,
b.native_instance);
}
/**
* Preconcats the matrix with the specified translation.
* M' = M * T(dx, dy)
*/
public boolean preTranslate(float dx, float dy) {
return native_preTranslate(native_instance, dx, dy);
}
/**
* Preconcats the matrix with the specified scale.
* M' = M * S(sx, sy, px, py)
*/
public boolean preScale(float sx, float sy, float px, float py) {
return native_preScale(native_instance, sx, sy, px, py);
}
/**
* Preconcats the matrix with the specified scale.
* M' = M * S(sx, sy)
*/
public boolean preScale(float sx, float sy) {
return native_preScale(native_instance, sx, sy);
}
/**
* Preconcats the matrix with the specified rotation.
* M' = M * R(degrees, px, py)
*/
public boolean preRotate(float degrees, float px, float py) {
return native_preRotate(native_instance, degrees, px, py);
}
/**
* Preconcats the matrix with the specified rotation.
* M' = M * R(degrees)
*/
public boolean preRotate(float degrees) {
return native_preRotate(native_instance, degrees);
}
/**
* Preconcats the matrix with the specified skew.
* M' = M * K(kx, ky, px, py)
*/
public boolean preSkew(float kx, float ky, float px, float py) {
return native_preSkew(native_instance, kx, ky, px, py);
}
/**
* Preconcats the matrix with the specified skew.
* M' = M * K(kx, ky)
*/
public boolean preSkew(float kx, float ky) {
return native_preSkew(native_instance, kx, ky);
}
/**
* Preconcats the matrix with the specified matrix.
* M' = M * other
*/
public boolean preConcat(Matrix other) {
return native_preConcat(native_instance, other.native_instance);
}
/**
* Postconcats the matrix with the specified translation.
* M' = T(dx, dy) * M
*/
public boolean postTranslate(float dx, float dy) {
return native_postTranslate(native_instance, dx, dy);
}
/**
* Postconcats the matrix with the specified scale.
* M' = S(sx, sy, px, py) * M
*/
public boolean postScale(float sx, float sy, float px, float py) {
return native_postScale(native_instance, sx, sy, px, py);
}
/**
* Postconcats the matrix with the specified scale.
* M' = S(sx, sy) * M
*/
public boolean postScale(float sx, float sy) {
return native_postScale(native_instance, sx, sy);
}
/**
* Postconcats the matrix with the specified rotation.
* M' = R(degrees, px, py) * M
*/
public boolean postRotate(float degrees, float px, float py) {
return native_postRotate(native_instance, degrees, px, py);
}
/**
* Postconcats the matrix with the specified rotation.
* M' = R(degrees) * M
*/
public boolean postRotate(float degrees) {
return native_postRotate(native_instance, degrees);
}
/**
* Postconcats the matrix with the specified skew.
* M' = K(kx, ky, px, py) * M
*/
public boolean postSkew(float kx, float ky, float px, float py) {
return native_postSkew(native_instance, kx, ky, px, py);
}
/**
* Postconcats the matrix with the specified skew.
* M' = K(kx, ky) * M
*/
public boolean postSkew(float kx, float ky) {
return native_postSkew(native_instance, kx, ky);
}
/**
* Postconcats the matrix with the specified matrix.
* M' = other * M
*/
public boolean postConcat(Matrix other) {
return native_postConcat(native_instance, other.native_instance);
}
/** Controlls how the src rect should align into the dst rect for
setRectToRect().
*/
public enum ScaleToFit {
/**
* Scale in X and Y independently, so that src matches dst exactly.
* This may change the aspect ratio of the src.
*/
FILL (0),
/**
* Compute a scale that will maintain the original src aspect ratio,
* but will also ensure that src fits entirely inside dst. At least one
* axis (X or Y) will fit exactly. START aligns the result to the
* left and top edges of dst.
*/
START (1),
/**
* Compute a scale that will maintain the original src aspect ratio,
* but will also ensure that src fits entirely inside dst. At least one
* axis (X or Y) will fit exactly. The result is centered inside dst.
*/
CENTER (2),
/**
* Compute a scale that will maintain the original src aspect ratio,
* but will also ensure that src fits entirely inside dst. At least one
* axis (X or Y) will fit exactly. END aligns the result to the
* right and bottom edges of dst.
*/
END (3);
// the native values must match those in SkMatrix.h
ScaleToFit(int nativeInt) {
this.nativeInt = nativeInt;
}
final int nativeInt;
}
/**
* Set the matrix to the scale and translate values that map the source
* rectangle to the destination rectangle, returning true if the the result
* can be represented.
*
* @param src the source rectangle to map from.
* @param dst the destination rectangle to map to.
* @param stf the ScaleToFit option
* @return true if the matrix can be represented by the rectangle mapping.
*/
public boolean setRectToRect(RectF src, RectF dst, ScaleToFit stf) {
if (dst == null || src == null) {
throw new NullPointerException();
}
return native_setRectToRect(native_instance, src, dst, stf.nativeInt);
}
// private helper to perform range checks on arrays of "points"
private static void checkPointArrays(float[] src, int srcIndex,
float[] dst, int dstIndex,
int pointCount) {
// check for too-small and too-big indices
int srcStop = srcIndex + (pointCount << 1);
int dstStop = dstIndex + (pointCount << 1);
if ((pointCount | srcIndex | dstIndex | srcStop | dstStop) < 0 ||
srcStop > src.length || dstStop > dst.length) {
throw new ArrayIndexOutOfBoundsException();
}
}
/**
* Set the matrix such that the specified src points would map to the
* specified dst points. The "points" are represented as an array of floats,
* order [x0, y0, x1, y1, ...], where each "point" is 2 float values.
*
* @param src The array of src [x,y] pairs (points)
* @param srcIndex Index of the first pair of src values
* @param dst The array of dst [x,y] pairs (points)
* @param dstIndex Index of the first pair of dst values
* @param pointCount The number of pairs/points to be used. Must be [0..4]
* @return true if the matrix was set to the specified transformation
*/
public boolean setPolyToPoly(float[] src, int srcIndex,
float[] dst, int dstIndex,
int pointCount) {
if (pointCount > 4) {
throw new IllegalArgumentException();
}
checkPointArrays(src, srcIndex, dst, dstIndex, pointCount);
return native_setPolyToPoly(native_instance, src, srcIndex,
dst, dstIndex, pointCount);
}
/**
* If this matrix can be inverted, return true and if inverse is not null,
* set inverse to be the inverse of this matrix. If this matrix cannot be
* inverted, ignore inverse and return false.
*/
public boolean invert(Matrix inverse) {
return native_invert(native_instance, inverse.native_instance);
}
/**
* Apply this matrix to the array of 2D points specified by src, and write
* the transformed points into the array of points specified by dst. The
* two arrays represent their "points" as pairs of floats [x, y].
*
* @param dst The array of dst points (x,y pairs)
* @param dstIndex The index of the first [x,y] pair of dst floats
* @param src The array of src points (x,y pairs)
* @param srcIndex The index of the first [x,y] pair of src floats
* @param pointCount The number of points (x,y pairs) to transform
*/
public void mapPoints(float[] dst, int dstIndex, float[] src, int srcIndex,
int pointCount) {
checkPointArrays(src, srcIndex, dst, dstIndex, pointCount);
native_mapPoints(native_instance, dst, dstIndex, src, srcIndex,
pointCount, true);
}
/**
* Apply this matrix to the array of 2D vectors specified by src, and write
* the transformed vectors into the array of vectors specified by dst. The
* two arrays represent their "vectors" as pairs of floats [x, y].
*
* @param dst The array of dst vectors (x,y pairs)
* @param dstIndex The index of the first [x,y] pair of dst floats
* @param src The array of src vectors (x,y pairs)
* @param srcIndex The index of the first [x,y] pair of src floats
* @param vectorCount The number of vectors (x,y pairs) to transform
*/
public void mapVectors(float[] dst, int dstIndex, float[] src, int srcIndex,
int vectorCount) {
checkPointArrays(src, srcIndex, dst, dstIndex, vectorCount);
native_mapPoints(native_instance, dst, dstIndex, src, srcIndex,
vectorCount, false);
}
/**
* Apply this matrix to the array of 2D points specified by src, and write
* the transformed points into the array of points specified by dst. The
* two arrays represent their "points" as pairs of floats [x, y].
*
* @param dst The array of dst points (x,y pairs)
* @param src The array of src points (x,y pairs)
*/
public void mapPoints(float[] dst, float[] src) {
if (dst.length != src.length) {
throw new ArrayIndexOutOfBoundsException();
}
mapPoints(dst, 0, src, 0, dst.length >> 1);
}
/**
* Apply this matrix to the array of 2D vectors specified by src, and write
* the transformed vectors into the array of vectors specified by dst. The
* two arrays represent their "vectors" as pairs of floats [x, y].
*
* @param dst The array of dst vectors (x,y pairs)
* @param src The array of src vectors (x,y pairs)
*/
public void mapVectors(float[] dst, float[] src) {
if (dst.length != src.length) {
throw new ArrayIndexOutOfBoundsException();
}
mapVectors(dst, 0, src, 0, dst.length >> 1);
}
/**
* Apply this matrix to the array of 2D points, and write the transformed
* points back into the array
*
* @param pts The array [x0, y0, x1, y1, ...] of points to transform.
*/
public void mapPoints(float[] pts) {
mapPoints(pts, 0, pts, 0, pts.length >> 1);
}
/**
* Apply this matrix to the array of 2D vectors, and write the transformed
* vectors back into the array.
* @param vecs The array [x0, y0, x1, y1, ...] of vectors to transform.
*/
public void mapVectors(float[] vecs) {
mapVectors(vecs, 0, vecs, 0, vecs.length >> 1);
}
/**
* Apply this matrix to the src rectangle, and write the transformed
* rectangle into dst. This is accomplished by transforming the 4 corners of
* src, and then setting dst to the bounds of those points.
*
* @param dst Where the transformed rectangle is written.
* @param src The original rectangle to be transformed.
* @return the result of calling rectStaysRect()
*/
public boolean mapRect(RectF dst, RectF src) {
if (dst == null || src == null) {
throw new NullPointerException();
}
return native_mapRect(native_instance, dst, src);
}
/**
* Apply this matrix to the rectangle, and write the transformed rectangle
* back into it. This is accomplished by transforming the 4 corners of rect,
* and then setting it to the bounds of those points
*
* @param rect The rectangle to transform.
* @return the result of calling rectStaysRect()
*/
public boolean mapRect(RectF rect) {
return mapRect(rect, rect);
}
/**
* Return the mean radius of a circle after it has been mapped by
* this matrix. NOTE: in perspective this value assumes the circle
* has its center at the origin.
*/
public float mapRadius(float radius) {
return native_mapRadius(native_instance, radius);
}
/** Copy 9 values from the matrix into the array.
*/
public void getValues(float[] values) {
if (values.length < 9) {
throw new ArrayIndexOutOfBoundsException();
}
native_getValues(native_instance, values);
}
/** Copy 9 values from the array into the matrix.
Depending on the implementation of Matrix, these may be
transformed into 16.16 integers in the Matrix, such that
a subsequent call to getValues() will not yield exactly
the same values.
*/
public void setValues(float[] values) {
if (values.length < 9) {
throw new ArrayIndexOutOfBoundsException();
}
native_setValues(native_instance, values);
}
public String toString() {
StringBuilder sb = new StringBuilder(64);
sb.append("Matrix{");
toShortString(sb);
sb.append('}');
return sb.toString();
}
public String toShortString() {
StringBuilder sb = new StringBuilder(64);
toShortString(sb);
return sb.toString();
}
/**
* @hide
*/
public void toShortString(StringBuilder sb) {
float[] values = new float[9];
getValues(values);
sb.append('[');
sb.append(values[0]); sb.append(", "); sb.append(values[1]); sb.append(", ");
sb.append(values[2]); sb.append("][");
sb.append(values[3]); sb.append(", "); sb.append(values[4]); sb.append(", ");
sb.append(values[5]); sb.append("][");
sb.append(values[6]); sb.append(", "); sb.append(values[7]); sb.append(", ");
sb.append(values[8]); sb.append(']');
}
/**
* Print short string, to optimize dumping.
* @hide
*/
public void printShortString(PrintWriter pw) {
float[] values = new float[9];
getValues(values);
pw.print('[');
pw.print(values[0]); pw.print(", "); pw.print(values[1]); pw.print(", ");
pw.print(values[2]); pw.print("][");
pw.print(values[3]); pw.print(", "); pw.print(values[4]); pw.print(", ");
pw.print(values[5]); pw.print("][");
pw.print(values[6]); pw.print(", "); pw.print(values[7]); pw.print(", ");
pw.print(values[8]); pw.print(']');
}
protected void finalize() throws Throwable {
finalizer(native_instance);
}
/*package*/ final int ni() {
return native_instance;
}
private static native int native_create(int native_src_or_zero);
private static native boolean native_isIdentity(int native_object);
private static native boolean native_rectStaysRect(int native_object);
private static native void native_reset(int native_object);
private static native void native_set(int native_object, int other);
private static native void native_setTranslate(int native_object,
float dx, float dy);
private static native void native_setScale(int native_object,
float sx, float sy, float px, float py);
private static native void native_setScale(int native_object,
float sx, float sy);
private static native void native_setRotate(int native_object,
float degrees, float px, float py);
private static native void native_setRotate(int native_object,
float degrees);
private static native void native_setSinCos(int native_object,
float sinValue, float cosValue, float px, float py);
private static native void native_setSinCos(int native_object,
float sinValue, float cosValue);
private static native void native_setSkew(int native_object,
float kx, float ky, float px, float py);
private static native void native_setSkew(int native_object,
float kx, float ky);
private static native boolean native_setConcat(int native_object,
int a, int b);
private static native boolean native_preTranslate(int native_object,
float dx, float dy);
private static native boolean native_preScale(int native_object,
float sx, float sy, float px, float py);
private static native boolean native_preScale(int native_object,
float sx, float sy);
private static native boolean native_preRotate(int native_object,
float degrees, float px, float py);
private static native boolean native_preRotate(int native_object,
float degrees);
private static native boolean native_preSkew(int native_object,
float kx, float ky, float px, float py);
private static native boolean native_preSkew(int native_object,
float kx, float ky);
private static native boolean native_preConcat(int native_object,
int other_matrix);
private static native boolean native_postTranslate(int native_object,
float dx, float dy);
private static native boolean native_postScale(int native_object,
float sx, float sy, float px, float py);
private static native boolean native_postScale(int native_object,
float sx, float sy);
private static native boolean native_postRotate(int native_object,
float degrees, float px, float py);
private static native boolean native_postRotate(int native_object,
float degrees);
private static native boolean native_postSkew(int native_object,
float kx, float ky, float px, float py);
private static native boolean native_postSkew(int native_object,
float kx, float ky);
private static native boolean native_postConcat(int native_object,
int other_matrix);
private static native boolean native_setRectToRect(int native_object,
RectF src, RectF dst, int stf);
private static native boolean native_setPolyToPoly(int native_object,
float[] src, int srcIndex, float[] dst, int dstIndex, int pointCount);
private static native boolean native_invert(int native_object, int inverse);
private static native void native_mapPoints(int native_object,
float[] dst, int dstIndex, float[] src, int srcIndex,
int ptCount, boolean isPts);
private static native boolean native_mapRect(int native_object,
RectF dst, RectF src);
private static native float native_mapRadius(int native_object,
float radius);
private static native void native_getValues(int native_object,
float[] values);
private static native void native_setValues(int native_object,
float[] values);
private static native boolean native_equals(int native_a, int native_b);
private static native void finalizer(int native_instance);
}
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