Add perspective support to SkMatrix44 initializers.

src/utils/SkMatrix44.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkMatrix44.h"
 
 static inline bool eq4(const SkMScalar* SK_RESTRICT a,
@@ skipping 862 matching lines @@
     SkDebugf(format,
              fMat[0][0], fMat[0][1], fMat[0][2], fMat[0][3],
              fMat[1][0], fMat[1][1], fMat[1][2], fMat[1][3],
              fMat[2][0], fMat[2][1], fMat[2][2], fMat[2][3],
              fMat[3][0], fMat[3][1], fMat[3][2], fMat[3][3]);
 #endif
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
-// TODO: make this support src' perspective elements
-//
 static void initFromMatrix(SkMScalar dst[4][4], const SkMatrix& src) {
     sk_bzero(dst, 16 * sizeof(SkMScalar));
     dst[0][0] = SkScalarToMScalar(src[SkMatrix::kMScaleX]);
     dst[1][0] = SkScalarToMScalar(src[SkMatrix::kMSkewX]);
     dst[3][0] = SkScalarToMScalar(src[SkMatrix::kMTransX]);
     dst[0][1] = SkScalarToMScalar(src[SkMatrix::kMSkewY]);
     dst[1][1] = SkScalarToMScalar(src[SkMatrix::kMScaleY]);
     dst[3][1] = SkScalarToMScalar(src[SkMatrix::kMTransY]);
-    dst[2][2] = dst[3][3] = 1;
+    dst[0][3] = SkScalarToMScalar(src[SkMatrix::kMPersp0]);
+    dst[1][3] = SkScalarToMScalar(src[SkMatrix::kMPersp1]);
+    dst[3][3] = SkScalarToMScalar(src[SkMatrix::kMPersp2]);
+    dst[2][2] = 1;
 }
 
 SkMatrix44::SkMatrix44(const SkMatrix& src) {
     initFromMatrix(fMat, src);
 }
 
 SkMatrix44& SkMatrix44::operator=(const SkMatrix& src) {
     initFromMatrix(fMat, src);
 
     if (src.isIdentity()) {
         this->setTypeMask(kIdentity_Mask);
     } else {
         this->dirtyTypeMask();
     }
     return *this;
 }
 
-// TODO: make this support our perspective elements
-//
 SkMatrix44::operator SkMatrix() const {
     SkMatrix dst;
-    dst.reset();    // setup our perspective correctly for identity
 
     dst[SkMatrix::kMScaleX]  = SkMScalarToScalar(fMat[0][0]);
     dst[SkMatrix::kMSkewX]  = SkMScalarToScalar(fMat[1][0]);
     dst[SkMatrix::kMTransX] = SkMScalarToScalar(fMat[3][0]);
 
     dst[SkMatrix::kMSkewY]  = SkMScalarToScalar(fMat[0][1]);
     dst[SkMatrix::kMScaleY] = SkMScalarToScalar(fMat[1][1]);
     dst[SkMatrix::kMTransY] = SkMScalarToScalar(fMat[3][1]);
 
+    dst[SkMatrix::kMPersp0] = SkMScalarToScalar(fMat[0][3]);
+    dst[SkMatrix::kMPersp1] = SkMScalarToScalar(fMat[1][3]);
+    dst[SkMatrix::kMPersp2] = SkMScalarToScalar(fMat[3][3]);
+
     return dst;
 }