implement drawAtlas natively on gpu-device

samplecode/SampleAtlas.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SampleCode.h"
 #include "SkAnimTimer.h"
 #include "SkView.h"
@@ skipping 50 matching lines @@
         void advance(const SkRect& bounds) {
             fCenter += fVelocity;
             if (fCenter.fX > bounds.right()) {
                 SkASSERT(fVelocity.fX > 0);
                 fVelocity.fX = -fVelocity.fX;
             } else if (fCenter.fX < bounds.left()) {
                 SkASSERT(fVelocity.fX < 0);
                 fVelocity.fX = -fVelocity.fX;
             }
             if (fCenter.fY > bounds.bottom()) {
-                SkASSERT(fVelocity.fY > 0);
-                fVelocity.fY = -fVelocity.fY;
+                if (fVelocity.fY > 0) {
+                    fVelocity.fY = -fVelocity.fY;
+                }
             } else if (fCenter.fY < bounds.top()) {
-                SkASSERT(fVelocity.fY < 0);
-                fVelocity.fY = -fVelocity.fY;
+                if (fVelocity.fY < 0) {
+                    fVelocity.fY = -fVelocity.fY;
+                }
             }
 
             fScale += fDScale;
             if (fScale > 2 || fScale < SK_Scalar1/2) {
                 fDScale = -fDScale;
             }
 
             fRadian += fDRadian;
             fRadian = SkScalarMod(fRadian, 2 * SK_ScalarPI);
 
@@ skipping 139 matching lines @@
 #endif
 
 private:
     typedef SampleView INHERITED;
 };
 
 //////////////////////////////////////////////////////////////////////////////
 
 static SkView* MyFactory() { return new DrawAtlasView; }
 static SkViewRegister reg(MyFactory);