Added a few bench for some image filters

bench/DisplacementBench.cpp

Index: bench/DisplacementBench.cpp
===================================================================
--- bench/DisplacementBench.cpp	(revision 0)
+++ bench/DisplacementBench.cpp	(revision 0)
@@ -0,0 +1,107 @@
+/*
+ * 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 "SkBitmapSource.h"
+#include "SkCanvas.h"
+#include "SkDevice.h"
+#include "SkDisplacementMapEffect.h"
+
+class DisplacementBench : public SkBenchmark {
+    SkBitmap fBitmap, fCheckerboard;
+    bool fInitialized;
+
+public:
+    DisplacementBench(void* param) : INHERITED(param) {
+    }
+
+protected:
+    virtual const char* onGetName() SK_OVERRIDE {
+        return "displacement";
+    }
+
+    virtual void onPreDraw() SK_OVERRIDE {
+        if (!fInitialized) {
+            make_bitmap();
+            make_checkerboard();
+            fInitialized = true;
+        }
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        canvas->clear(0x00000000);
+        SkPaint paint;
+        SkAutoTUnref<SkImageFilter> displ(SkNEW_ARGS(SkBitmapSource, (fCheckerboard)));
+        // 1 ) No displacement effect
+        paint.setImageFilter(SkNEW_ARGS(SkDisplacementMapEffect,
+            (SkDisplacementMapEffect::kR_ChannelSelectorType,
+             SkDisplacementMapEffect::kG_ChannelSelectorType, 0.0f, displ)))->unref();
+        drawClippedBitmap(canvas, 0, 0, paint);
+        // 2 ) Displacement, with 1 alpha component (which isn't pre-multiplied)

[Stephen White, 2013/04/15 15:34:21]

Should probably split these up into separate bench test cases, and ensure that
they cover all the getValue() template specializations in
SkDisplacementMapEffect, as well permutations of the shader generation (if they
have any perf impact).

[sugoi1, 2013/04/19 18:09:42]

Done.

+        paint.setImageFilter(SkNEW_ARGS(SkDisplacementMapEffect,
+            (SkDisplacementMapEffect::kB_ChannelSelectorType,
+             SkDisplacementMapEffect::kA_ChannelSelectorType, 16.0f, displ)))->unref();
+        drawClippedBitmap(canvas, 100, 0, paint);
+        // 2 ) Displacement, with 2 non-alpha components

[Stephen White, 2013/04/15 15:34:21]

Nit:  that's 2 2)'s.  :)

[sugoi1, 2013/04/19 18:09:42]

Done.

+        paint.setImageFilter(SkNEW_ARGS(SkDisplacementMapEffect,
+            (SkDisplacementMapEffect::kR_ChannelSelectorType,
+             SkDisplacementMapEffect::kB_ChannelSelectorType, 32.0f, displ)))->unref();
+        drawClippedBitmap(canvas, 200, 0, paint);
+    }
+
+private:
+    void make_bitmap() {
+        fBitmap.setConfig(SkBitmap::kARGB_8888_Config, 80, 80);
+        fBitmap.allocPixels();
+        SkDevice device(fBitmap);
+        SkCanvas canvas(&device);
+        canvas.clear(0x00000000);
+        SkPaint paint;
+        paint.setAntiAlias(true);
+        paint.setColor(0xFF884422);
+        paint.setTextSize(SkIntToScalar(96));
+        const char* str = "g";
+        canvas.drawText(str, strlen(str), SkIntToScalar(15), SkIntToScalar(55), paint);
+    }
+
+    void make_checkerboard() {
+        fCheckerboard.setConfig(SkBitmap::kARGB_8888_Config, 80, 80);
+        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 < 80; y += 16) {
+            for (int x = 0; x < 80; 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();
+            }
+        }
+    }
+
+    void drawClippedBitmap(SkCanvas* canvas, int x, int y, const SkPaint& paint) {
+        canvas->save();
+        canvas->clipRect(SkRect::MakeXYWH(SkIntToScalar(x), SkIntToScalar(y),
+            SkIntToScalar(fBitmap.width()), SkIntToScalar(fBitmap.height())));
+        canvas->drawBitmap(fBitmap, SkIntToScalar(x), SkIntToScalar(y), &paint);
+        canvas->restore();
+    }
+
+    typedef SkBenchmark INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+DEF_BENCH( return new DisplacementBench(p); )
+