add gpu backend (not hooked up yet)
git-svn-id: http://skia.googlecode.com/svn/trunk@649 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gpu/include/GrMatrix.h b/gpu/include/GrMatrix.h
new file mode 100644
index 0000000..43fd4a5
--- /dev/null
+++ b/gpu/include/GrMatrix.h
@@ -0,0 +1,370 @@
+/*
+ Copyright 2010 Google Inc.
+
+ 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.
+ */
+
+
+#ifndef GrMatrix_DEFINED
+#define GrMatrix_DEFINED
+
+#include "GrPoint.h"
+
+struct GrRect;
+
+/*
+ * 3x3 matrix
+ */
+class GrMatrix {
+public:
+ static const GrMatrix& I();
+ static const GrScalar gRESCALE;
+ /**
+ * Handy index constants
+ */
+ enum {
+ kScaleX,
+ kSkewX,
+ kTransX,
+ kSkewY,
+ kScaleY,
+ kTransY,
+ kPersp0,
+ kPersp1,
+ kPersp2
+ };
+
+ /**
+ * Create an uninitialized matrix
+ */
+ GrMatrix() {
+ fTypeMask = 0;
+ }
+
+ /**
+ * Create a matrix from an array of values
+ * @param values row-major array of matrix components
+ */
+ explicit GrMatrix(GrScalar* values) {
+ setToArray(values);
+ }
+
+ /**
+ * Create a matrix from values
+ * @param scaleX (0,0) matrix element
+ * @param skewX (0,1) matrix element
+ * @param transX (0,2) matrix element
+ * @param skewY (1,0) matrix element
+ * @param scaleY (1,1) matrix element
+ * @param transY (1,2) matrix element
+ * @param persp0 (2,0) matrix element
+ * @param persp1 (2,1) matrix element
+ * @param persp2 (2,2) matrix element
+ */
+ GrMatrix(GrScalar scaleX,
+ GrScalar skewX,
+ GrScalar transX,
+ GrScalar skewY,
+ GrScalar scaleY,
+ GrScalar transY,
+ GrScalar persp0,
+ GrScalar persp1,
+ GrScalar persp2) {
+ setAll(scaleX, skewX, transX,
+ skewY, scaleY, transY,
+ persp0, persp1, persp2);
+ }
+
+ /**
+ * access matrix component
+ * @return matrix component value
+ */
+ const GrScalar& operator[] (int idx) const {
+ GrAssert((unsigned)idx < 9);
+ return fM[idx];
+ }
+
+ /**
+ * Set a matrix from an array of values
+ * @param values row-major array of matrix components
+ */
+ void setToArray(GrScalar* values) {
+ for (int i = 0; i < 9; ++i) {
+ fM[i] = values[i];
+ }
+ setTypeMask();
+ }
+
+ /**
+ * Create a matrix from values
+ * @param scaleX (0,0) matrix element
+ * @param skewX (0,1) matrix element
+ * @param transX (0,2) matrix element
+ * @param skewY (1,0) matrix element
+ * @param scaleY (1,1) matrix element
+ * @param transY (1,2) matrix element
+ * @param persp0 (2,0) matrix element
+ * @param persp1 (2,1) matrix element
+ * @param persp2 (2,2) matrix element
+ */
+ void setAll(GrScalar scaleX,
+ GrScalar skewX,
+ GrScalar transX,
+ GrScalar skewY,
+ GrScalar scaleY,
+ GrScalar transY,
+ GrScalar persp0,
+ GrScalar persp1,
+ GrScalar persp2) {
+ fM[kScaleX] = scaleX;
+ fM[kSkewX] = skewX;
+ fM[kTransX] = transX;
+ fM[kSkewY] = skewY;
+ fM[kScaleY] = scaleY;
+ fM[kTransY] = transY;
+ fM[kPersp0] = persp0;
+ fM[kPersp1] = persp1;
+ fM[kPersp2] = persp2;
+
+ setTypeMask();
+ }
+
+ /**
+ * set matrix component
+ * @param idx index of component to set
+ * @param value value to set component to
+ */
+ inline void set(int idx, GrScalar value);
+
+ /**
+ * make this matrix an identity matrix
+ */
+ void setIdentity();
+
+ /**
+ * overwrite entire matrix to be a translation matrix
+ * @param dx amount to translate by in x
+ * @param dy amount to translate by in y
+ */
+ void setTranslate(GrScalar dx, GrScalar dy);
+
+ /**
+ * overwrite entire matrix to be a scaling matrix
+ * @param sx x scale factor
+ * @param sy y scale factor
+ */
+ void setScale(GrScalar sx, GrScalar sy);
+
+ /**
+ * overwrite entire matrix to be a skew matrix
+ * @param skx x skew factor
+ * @param sky y skew factor
+ */
+ void setSkew(GrScalar skx, GrScalar sky);
+
+ /**
+ * set this matrix to be a concantenation of two
+ * matrices (a*b). Either a, b, or both can be this matrix.
+ * @param a first matrix to multiply
+ * @param b second matrix to multiply
+ */
+ void setConcat(const GrMatrix& a, const GrMatrix& b);
+
+ /**
+ * Set this matrix to this*m
+ * @param m matrix to concatenate
+ */
+ void preConcat(const GrMatrix& m);
+
+ /**
+ * Set this matrix to m*this
+ * @param m matrix to concatenate
+ */
+ void postConcat(const GrMatrix& m);
+
+ /**
+ * Compute the inverse of this matrix, and return true if it is invertible,
+ * or false if not.
+ *
+ * If inverted is not null, and the matrix is invertible, then the inverse
+ * is written into it. If the matrix is not invertible (this method returns
+ * false) then inverted is left unchanged.
+ */
+ bool invert(GrMatrix* inverted) const;
+
+ /**
+ * Transforms a point by the matrix
+ *
+ * @param src the point to transform
+ * @return the transformed point
+ */
+ GrPoint mapPoint(const GrPoint& src) const {
+ GrPoint result;
+ (this->*gMapProcs[fTypeMask])(&result, &src, 1);
+ return result;
+ }
+
+ /**
+ * Transforms an array of points by the matrix.
+ *
+ * @param dstPts the array to write transformed points into
+ * @param srcPts the array of points to transform
+ @ @param count the number of points to transform
+ */
+ void mapPoints(GrPoint dstPts[],
+ const GrPoint srcPts[],
+ uint32_t count) const {
+ (this->*gMapProcs[fTypeMask])(dstPts, srcPts, count);
+ }
+
+ /**
+ * Transforms pts with arbitrary stride in place.
+ *
+ * @param start pointer to first point to transform
+ * @param stride distance in bytes between consecutive points
+ @ @param count the number of points to transform
+ */
+ void mapPointsWithStride(GrPoint* start,
+ size_t stride,
+ uint32_t count) const {
+ for (uint32_t i = 0; i < count; ++i) {
+ this->mapPoints(start, start, 1);
+ start = (GrPoint*)((intptr_t)start + stride);
+ }
+ }
+
+ /**
+ * Transform the 4 corners of the src rect, and return the bounding rect
+ * in the dst rect. Note: src and dst may point to the same memory.
+ */
+ void mapRect(GrRect* dst, const GrRect& src) const;
+
+ /**
+ * Transform the 4 corners of the rect, and return their bounds in the rect
+ */
+ void mapRect(GrRect* rect) const {
+ this->mapRect(rect, *rect);
+ }
+
+ /**
+ * Checks if matrix is a perspective matrix.
+ * @return true if third row is not (0, 0, 1)
+ */
+ bool hasPerspective() const;
+
+ /**
+ * Checks whether matrix is identity
+ * @return true if matrix is idenity
+ */
+ bool isIdentity() const;
+
+ /**
+ * Calculates the maximum stretching factor of the matrix. Only defined if
+ * the matrix does not have perspective.
+ *
+ * @return maximum strecthing factor or negative if matrix has perspective.
+ */
+ GrScalar getMaxStretch() const;
+
+ /**
+ * Checks for matrix equality. Test is element-by-element equality,
+ * not a homogeneous test.
+ * @return true if matrices are equal, false otherwise
+ */
+ bool operator == (const GrMatrix& m) const;
+
+ /**
+ * Checks for matrix inequality. Test is element-by-element inequality,
+ * not a homogeneous test.
+ * @return true if matrices are not equal, false otherwise
+ */
+ bool operator != (const GrMatrix& m) const;
+
+ static void UnitTest();
+
+private:
+
+ void setTypeMask();
+
+ double determinant() const;
+
+ enum TypeBits {
+ kScale_TypeBit = 1 << 0, // set if scales are not both 1
+ kTranslate_TypeBit = 1 << 1, // set if translates are not both 0
+ kSkew_TypeBit = 1 << 2, // set if skews are not both 0
+ kPerspective_TypeBit = 1 << 3, // set if perspective
+ kZeroScale_TypeBit = 1 << 4, // set if scales are both zero
+ };
+
+ void mapIdentity(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ void mapScale(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ void mapTranslate(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ void mapScaleAndTranslate(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ void mapSkew(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ void mapScaleAndSkew(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ void mapSkewAndTranslate(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ void mapNonPerspective(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ void mapPerspective(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ void mapZero(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ void mapSetToTranslate(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ void mapSwappedScale(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ void mapSwappedScaleAndTranslate(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+
+ void mapInvalid(GrPoint* dst, const GrPoint* src, uint32_t count) const;
+
+ typedef void (GrMatrix::*MapProc) (GrPoint* dst, const GrPoint* src, uint32_t count) const;
+ static const MapProc gMapProcs[];
+
+ int fTypeMask;
+
+ GrScalar fM[9];
+};
+
+void GrMatrix::set(int idx, GrScalar value) {
+ GrAssert((unsigned)idx < 9);
+ fM[idx] = value;
+ if (idx > 5) {
+ if (0 != fM[kPersp0] || 0 != fM[kPersp1] ||
+ gRESCALE != fM[kPersp2]) {
+ fTypeMask |= kPerspective_TypeBit;
+ } else {
+ fTypeMask &= ~kPerspective_TypeBit;
+ }
+ } else if (!(idx % 4)) {
+ if ((GR_Scalar1 == fM[kScaleX] && GR_Scalar1 == fM[kScaleY])) {
+ fTypeMask &= ~kScale_TypeBit;
+ fTypeMask &= ~kZeroScale_TypeBit;
+ } else {
+ fTypeMask |= kScale_TypeBit;
+ if ((0 == fM[kScaleX] && 0 == fM[kScaleY])) {
+ fTypeMask |= kZeroScale_TypeBit;
+ } else {
+ fTypeMask &= ~kZeroScale_TypeBit;
+ }
+ }
+ } else if (2 == (idx % 3)) {
+ if (0 != fM[kTransX] || 0 != fM[kTransY]) {
+ fTypeMask |= kTranslate_TypeBit;
+ } else {
+ fTypeMask &= ~kTranslate_TypeBit;
+ }
+ } else {
+ if (0 != fM[kSkewX] || 0 != fM[kSkewY]) {
+ fTypeMask |= kSkew_TypeBit;
+ } else {
+ fTypeMask &= ~kSkew_TypeBit;
+ }
+ }
+}
+
+#endif