Add fullscreen rect bench

R=robertphillips@google.com

Review URL: https://codereview.chromium.org/21592002

git-svn-id: http://skia.googlecode.com/svn/trunk@10510 2bbb7eff-a529-9590-31e7-b0007b416f81

bench/FSRectBench.cpp

@@ -0,0 +1,66 @@
+
+/*
+ * 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 "SkPaint.h"
+#include "SkRandom.h"
+
+/**
+ * Draws full screen opaque rectangles. It is designed to test any optimizations in the GPU backend
+ * to turn such draws into clears.
+ */
+class FSRectBench : public SkBenchmark {
+public:
+    FSRectBench(void* param)
+        : INHERITED(param)
+        , fInit(false) {
+    }
+
+protected:
+    virtual const char* onGetName() SK_OVERRIDE { return "fullscreen_rects"; }
+
+    virtual void onPreDraw() SK_OVERRIDE {
+        if (!fInit) {
+            SkMWCRandom rand;
+            static const SkScalar kMinOffset = 0;
+            static const SkScalar kMaxOffset = 100 * SK_Scalar1;
+            static const SkScalar kOffsetRange = kMaxOffset - kMinOffset;
+            for (int i = 0; i < N; ++i) {
+                fRects[i].fLeft = -kMinOffset - SkScalarMul(rand.nextUScalar1(), kOffsetRange);
+                fRects[i].fTop = -kMinOffset - SkScalarMul(rand.nextUScalar1(), kOffsetRange);
+                fRects[i].fRight = W + kMinOffset + SkScalarMul(rand.nextUScalar1(), kOffsetRange);
+                fRects[i].fBottom = H + kMinOffset + SkScalarMul(rand.nextUScalar1(), kOffsetRange);
+                fColors[i] = rand.nextU() | 0xFF000000;
+            }
+            fInit = true;
+        }
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        SkPaint paint;
+        for (int i = 0; i < N; ++i) {
+            paint.setColor(fColors[i]);
+            canvas->drawRect(fRects[i], paint);
+        }
+    }
+
+private:
+    enum {
+        W = 640,
+        H = 480,
+        N = SkBENCHLOOP(300)
+    };
+    SkRect  fRects[N];
+    SkColor fColors[N];
+    bool fInit;
+
+    typedef SkBenchmark INHERITED;
+};
+
+DEF_BENCH( return SkNEW_ARGS(FSRectBench, (p)); )

gyp/bench.gypi

@@ -25,6 +25,7 @@
     '../bench/DisplacementBench.cpp',
     '../bench/FontCacheBench.cpp',
     '../bench/FontScalerBench.cpp',
+    '../bench/FSRectBench.cpp',
     '../bench/GameBench.cpp',
     '../bench/GradientBench.cpp',
     '../bench/GrMemoryPoolBench.cpp',