Added a few bench for some image filters

bench/ColorFilterBench.cpp

Index: bench/ColorFilterBench.cpp
===================================================================
--- bench/ColorFilterBench.cpp	(revision 0)
+++ bench/ColorFilterBench.cpp	(revision 0)
@@ -0,0 +1,96 @@
+/*
+ * 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 "SkColorFilterImageFilter.h"
+#include "SkColorMatrixFilter.h"
+
+#define FILTER_WIDTH    SkIntToScalar(30)
+#define FILTER_HEIGHT   SkIntToScalar(30)
+
+class ColorFilterBench : public SkBenchmark {
+
+public:
+    ColorFilterBench(void* param) : INHERITED(param) {
+    }
+
+protected:
+    virtual const char* onGetName() SK_OVERRIDE {
+        return "colorfilter";
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        SkRect r = SkRect::MakeWH(FILTER_WIDTH, FILTER_HEIGHT);
+        SkPaint paint;
+        paint.setColor(SK_ColorRED);
+        for (float brightness = -1.0f; brightness <= 1.0f; brightness += 0.2f) {
+            SkAutoTUnref<SkImageFilter> dim(make_brightness(-brightness));
+            SkAutoTUnref<SkImageFilter> bright(make_brightness(brightness, dim));
+            paint.setImageFilter(bright);
+            canvas->drawRect(r, paint);
+        }
+        {
+            SkAutoTUnref<SkImageFilter> brightness(make_brightness(0.9f));
+            SkAutoTUnref<SkImageFilter> grayscale(make_grayscale(brightness));
+            paint.setImageFilter(grayscale);
+            canvas->drawRect(r, paint);
+        }
+        {
+            SkAutoTUnref<SkImageFilter> grayscale(make_grayscale());
+            SkAutoTUnref<SkImageFilter> brightness(make_brightness(0.9f, grayscale));
+            paint.setImageFilter(brightness);
+            canvas->drawRect(r, paint);
+        }
+        {
+            SkAutoTUnref<SkImageFilter> blue(make_mode_blue());
+            SkAutoTUnref<SkImageFilter> brightness(make_brightness(1.0f, blue));
+            paint.setImageFilter(brightness);
+            canvas->drawRect(r, paint);
+        }
+        {
+            SkAutoTUnref<SkImageFilter> brightness(make_brightness(1.0f));
+            SkAutoTUnref<SkImageFilter> blue(make_mode_blue(brightness));
+            paint.setImageFilter(blue);
+            canvas->drawRect(r, paint);

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

We probably want to break these out into separate benches as well, since they
exercise the color filter matrix collapse optimization.

We should probably have a test case for a single SkColorFilter as well.

We also probably should have a test that exercises SkTableColorFilter.

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

Done.

+        }
+    }
+
+private:
+    static SkImageFilter* make_brightness(float amount, SkImageFilter* input = NULL) {
+        SkScalar amount255 = SkScalarMul(SkFloatToScalar(amount), SkIntToScalar(255));
+        SkScalar matrix[20] = { 1, 0, 0, 0, amount255,
+                                0, 1, 0, 0, amount255,
+                                0, 0, 1, 0, amount255,
+                                0, 0, 0, 1, 0 };
+        SkAutoTUnref<SkColorFilter> filter(new SkColorMatrixFilter(matrix));
+        return SkColorFilterImageFilter::Create(filter, input);
+    }
+
+    static SkImageFilter* make_grayscale(SkImageFilter* input = NULL) {
+        SkScalar matrix[20];
+        memset(matrix, 0, 20 * sizeof(SkScalar));
+        matrix[0] = matrix[5] = matrix[10] = SkFloatToScalar(0.2126f);
+        matrix[1] = matrix[6] = matrix[11] = SkFloatToScalar(0.7152f);
+        matrix[2] = matrix[7] = matrix[12] = SkFloatToScalar(0.0722f);
+        matrix[18] = SkFloatToScalar(1.0f);
+        SkAutoTUnref<SkColorFilter> filter(new SkColorMatrixFilter(matrix));
+        return SkColorFilterImageFilter::Create(filter, input);
+    }
+
+    static SkImageFilter* make_mode_blue(SkImageFilter* input = NULL) {
+        SkAutoTUnref<SkColorFilter> filter(
+            SkColorFilter::CreateModeFilter(SK_ColorBLUE, SkXfermode::kSrcIn_Mode));
+        return SkColorFilterImageFilter::Create(filter, input);
+    }
+
+    typedef SkBenchmark INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+DEF_BENCH( return new ColorFilterBench(p); )
+