add SkCanvas::drawAtlas

src/core/SkMatrix.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkMatrix.h"
 #include "SkFloatBits.h"
+#include "SkRSXform.h"
 #include "SkString.h"
 #include "SkNx.h"
 
 #include <stddef.h>
 
 static void normalize_perspective(SkScalar mat[9]) {
     // If it was interesting to never store the last element, we could divide all 8 other
     // elements here by the 9th, making it 1.0...
     //
     // When SkScalar was SkFixed, we would sometimes rescale the entire matrix to keep its
@@ skipping 413 matching lines @@
     fMat[kMSkewY]   = sinV;
     fMat[kMScaleY]  = cosV;
     fMat[kMTransY]  = sdot(-sinV, px, oneMinusCosV, py);
 
     fMat[kMPersp0] = fMat[kMPersp1] = 0;
     fMat[kMPersp2] = 1;
 
     this->setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask);
 }
 
+SkMatrix& SkMatrix::setRSXform(const SkRSXform& xform) {
+    fMat[kMScaleX]  = xform.fSCos;
+    fMat[kMSkewX]   = -xform.fSSin;
+    fMat[kMTransX]  = xform.fTx;
+    
+    fMat[kMSkewY]   = xform.fSSin;
+    fMat[kMScaleY]  = xform.fSCos;
+    fMat[kMTransY]  = xform.fTy;
+    
+    fMat[kMPersp0] = fMat[kMPersp1] = 0;
+    fMat[kMPersp2] = 1;
+    

[robertphillips, 2015/06/15 16:12:55]

Seems like we could do better than this.

[reed1, 2015/06/15 18:52:33]

Acknowledged.

+    this->setTypeMask(kUnknown_Mask | kOnlyPerspectiveValid_Mask);
+    return *this;
+}
+
 void SkMatrix::setSinCos(SkScalar sinV, SkScalar cosV) {
     fMat[kMScaleX]  = cosV;
     fMat[kMSkewX]   = -sinV;
     fMat[kMTransX]  = 0;
 
     fMat[kMSkewY]   = sinV;
     fMat[kMScaleY]  = cosV;
     fMat[kMTransY]  = 0;
 
     fMat[kMPersp0] = fMat[kMPersp1] = 0;
@@ skipping 1340 matching lines @@
         rotation1->fX = cos1;
         rotation1->fY = sin1;
     }
     if (rotation2) {
         rotation2->fX = cos2;
         rotation2->fY = sin2;
     }
 
     return true;
 }
+
+//////////////////////////////////////////////////////////////////////////////////////////////////
+
+void SkRSXform::toQuad(SkScalar width, SkScalar height, SkPoint quad[4]) const {
+    quad[0].set(0, 0);
+    quad[1].set(width, 0);
+    quad[2].set(width, height);
+    quad[3].set(0, height);
+    SkMatrix m;
+    m.setRSXform(*this).mapPoints(quad, quad, 4);
+}
+