Added a few bench for some image filters

bench/MagnifierBench.cpp

Index: bench/MagnifierBench.cpp
===================================================================
--- bench/MagnifierBench.cpp	(revision 0)
+++ bench/MagnifierBench.cpp	(revision 0)
@@ -0,0 +1,85 @@
+/*
+ * 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 "SkDevice.h"
+#include "SkMagnifierImageFilter.h"
+#include "SkRandom.h"
+
+#define FILTER_WIDTH_SMALL  SkIntToScalar(32)
+#define FILTER_HEIGHT_SMALL SkIntToScalar(32)
+#define FILTER_WIDTH_LARGE  SkIntToScalar(256)
+#define FILTER_HEIGHT_LARGE SkIntToScalar(256)
+
+class MagnifierBench : public SkBenchmark {
+public:
+    MagnifierBench(void* param, bool small) :
+        INHERITED(param), fIsSmall(small), fInitialized(false) {
+    }
+
+protected:
+    virtual const char* onGetName() SK_OVERRIDE {
+        return fIsSmall ? "magnifier_small" : "magnifier_large";
+    }
+
+    virtual void onPreDraw() SK_OVERRIDE {
+        if (!fInitialized) {
+            make_checkerboard();
+            fInitialized = true;
+        }
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        const int w = fIsSmall ? FILTER_WIDTH_SMALL : FILTER_WIDTH_LARGE;
+        const int h = fIsSmall ? FILTER_HEIGHT_SMALL : FILTER_HEIGHT_LARGE;
+        SkPaint paint;
+        paint.setImageFilter(
+            new SkMagnifierImageFilter(
+                SkRect::MakeXYWH(SkIntToScalar(w / 4),
+                                 SkIntToScalar(h / 4),
+                                 SkIntToScalar(w / 2),
+                                 SkIntToScalar(h / 2)), 100))->unref();
+        canvas->drawBitmap(fCheckerboard, 0, 0, &paint);
+    }
+
+private:
+    void make_checkerboard() {
+        const int w = fIsSmall ? FILTER_WIDTH_SMALL : FILTER_WIDTH_LARGE;
+        const int h = fIsSmall ? FILTER_HEIGHT_LARGE : FILTER_HEIGHT_LARGE;
+        fCheckerboard.setConfig(SkBitmap::kARGB_8888_Config, w, h);
+        fCheckerboard.allocPixels();
+        SkDevice device(fCheckerboard);
+        SkCanvas canvas(&device);
+        canvas.clear(0x00000000);
+        SkPaint darkPaint;
+        darkPaint.setColor(0xFF804020);
+        SkPaint lightPaint;
+        lightPaint.setColor(0xFF244484);
+        for (int y = 0; y < h; y += 16) {
+            for (int x = 0; x < w; x += 16) {
+                canvas.save();
+                canvas.translate(SkIntToScalar(x), SkIntToScalar(y));
+                canvas.drawRect(SkRect::MakeXYWH(0, 0, 8, 8), darkPaint);
+                canvas.drawRect(SkRect::MakeXYWH(8, 0, 8, 8), lightPaint);
+                canvas.drawRect(SkRect::MakeXYWH(0, 8, 8, 8), lightPaint);
+                canvas.drawRect(SkRect::MakeXYWH(8, 8, 8, 8), darkPaint);
+                canvas.restore();
+            }
+        }
+    }
+
+    bool fIsSmall;
+    bool fInitialized;
+    SkBitmap fCheckerboard;
+    typedef SkBenchmark INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+DEF_BENCH( return new MagnifierBench(p, true); )
+DEF_BENCH( return new MagnifierBench(p, false); )
+