Simple GPU based dithering

gm/shallowgradient.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #include "SkGradientShader.h"
 
@@ skipping 48 matching lines @@
 
     virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
         const SkColor colors[] = { 0xFF555555, 0xFF444444 };
         const int colorCount = SK_ARRAY_COUNT(colors);
 
         SkRect r = { 0, 0, this->width(), this->height() };
         SkSize size = SkSize::Make(r.width(), r.height());
 
         SkPaint paint;
         paint.setShader(fProc(colors, colorCount, size))->unref();
+        paint.setDither(true);

[egdaniel, 2014/06/11 14:05:10]

You may want to consider adding this gm to the gm exception list with this cl so
that you don't turn all the bots red when you commit it. And then you can
rebaseline after it has landed.

         canvas->drawRect(r, paint);
     }
 
 private:
     MakeShaderProc fProc;
     SkString fName;
 
     typedef skiagm::GM INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 DEF_GM( return new ShallowGradientGM(shader_linear, "linear"); )
 DEF_GM( return new ShallowGradientGM(shader_radial, "radial"); )
 DEF_GM( return new ShallowGradientGM(shader_conical, "conical"); )
 DEF_GM( return new ShallowGradientGM(shader_sweep, "sweep"); )