added WritePixelsBench

bench/WritePixelsBench.cpp

Index: bench/WritePixelsBench.cpp
===================================================================
--- bench/WritePixelsBench.cpp	(revision 0)
+++ bench/WritePixelsBench.cpp	(revision 0)
@@ -0,0 +1,77 @@
+
+/*
+ * 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 "SkBenchmark.h"
+#include "SkCanvas.h"
+#include "SkConfig8888.h"
+#include "SkString.h"
+
+class WritePixelsBench : public SkBenchmark {
+public:
+    WritePixelsBench(void* param, SkCanvas::Config8888 config)
+        : INHERITED(param) 
+        , fConfig(config)
+        , fName("writepix") {
+        switch (config) {
+            case SkCanvas::kNative_Premul_Config8888:
+                fName.append("_native_PM");
+                break;
+            case SkCanvas::kNative_Unpremul_Config8888:
+                fName.append("_native_UPM");
+                break;
+            case SkCanvas::kBGRA_Premul_Config8888:
+                fName.append("_bgra_PM");
+                break;
+            case SkCanvas::kBGRA_Unpremul_Config8888:
+                fName.append("_bgra_UPM");
+                break;
+            case SkCanvas::kRGBA_Premul_Config8888:
+                fName.append("_rgba_PM");
+                break;
+            case SkCanvas::kRGBA_Unpremul_Config8888:
+                fName.append("_rgba_UPM");
+                break;
+            default: 
+                SK_CRASH();
+                break;
+        }
+    }
+
+protected:
+    virtual const char* onGetName() SK_OVERRIDE {
+        return fName.c_str();
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        SkISize size = canvas->getDeviceSize();
+
+        canvas->clear(0xFFFF0000);
+
+        SkBitmap bmp;
+        bmp.setConfig(SkBitmap::kARGB_8888_Config, size.width(), size.height());
+        canvas->readPixels(&bmp, 0, 0);
+
+        for (int loop = 0; loop < kLoopCount; ++loop) {
+            canvas->writePixels(bmp, 0, 0, fConfig);
+        }
+    }
+
+private:
+    static const int kLoopCount = SkBENCHLOOP(50);
+
+    SkCanvas::Config8888 fConfig;
+    SkString             fName;
+
+    typedef SkBenchmark INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_BENCH( return SkNEW_ARGS(WritePixelsBench, (p, SkCanvas::kRGBA_Premul_Config8888)); )
+DEF_BENCH( return SkNEW_ARGS(WritePixelsBench, (p, SkCanvas::kRGBA_Unpremul_Config8888)); )
+