add bench for blurred rectori case

bench/RectoriBench.cpp

+/*
+ * 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"
+#include "SkBlurMaskFilter.h"
+#include "SkLayerDrawLooper.h"
+
+// This bench replicates a problematic use case of a draw looper used
+// to create an inner blurred rect
+class RectoriBench : public SkBenchmark {
+public:
+    RectoriBench(void* param) : INHERITED(param) {}
+
+protected:
+
+    virtual const char* onGetName() {
+        return "rectori";
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        SkMWCRandom Random;
+
+        for (int i = 0; i < N; i++) {
+            SkScalar blurRad = Random.nextRangeScalar(1.5f, 25.0f);
+            SkScalar size = Random.nextRangeScalar(20*blurRad, 50*blurRad);
+
+            SkScalar x = Random.nextRangeScalar(0.0f, W - size);
+            SkScalar y = Random.nextRangeScalar(0.0f, H - size);
+
+            SkRect inner = { x, y, x + size, y + size };
+
+            SkRect outer(inner);
+            // outer is always outset either 2x or 4x the blur radius (we go with 2x)
+            outer.outset(SkIntToScalar(2*blurRad), SkIntToScalar(2*blurRad));
+
+            SkPath p;
+
+            p.addRect(outer);
+            p.addRect(inner);
+            p.setFillType(SkPath::kEvenOdd_FillType);
+
+            // This will be used to translate the normal draw outside the
+            // clip rect and translate the blurred version back inside
+            SkScalar translate = 2.0f * size;
+
+            SkPaint paint;
+            paint.setLooper(this->createLooper(-translate, blurRad))->unref();
+            paint.setColor(0xff000000 | Random.nextU());
+            paint.setAntiAlias(true);
+
+            canvas->save();
+            // clip always equals inner rect so we get the inside blur
+            canvas->clipRect(inner);
+            canvas->translate(translate, 0);
+            canvas->drawPath(p, paint);
+            canvas->restore();
+        }
+    }
+
+private:
+    enum {
+        W = 640,
+        H = 480,
+    };
+
+    enum { N = SkBENCHLOOP(100) };
+
+    SkLayerDrawLooper* createLooper(SkScalar xOff, SkScalar radius) {
+        SkLayerDrawLooper* looper = new SkLayerDrawLooper;
+
+        //-----------------------------------------------
+        SkLayerDrawLooper::LayerInfo info;
+
+        info.fFlagsMask = 0;
+        // TODO: add a color filter to better match what is seen in the wild
+        info.fPaintBits = /* SkLayerDrawLooper::kColorFilter_Bit |*/ 
+                          SkLayerDrawLooper::kMaskFilter_Bit;
+        info.fColorMode = SkXfermode::kDst_Mode;
+        info.fOffset.set(xOff, 0);
+        info.fPostTranslate = false;
+
+        SkPaint* paint = looper->addLayer(info);
+
+        SkMaskFilter* mf = SkBlurMaskFilter::Create(SkIntToScalar(radius),
+                                                    SkBlurMaskFilter::kNormal_BlurStyle,
+                                                    SkBlurMaskFilter::kHighQuality_BlurFlag);
+        paint->setMaskFilter(mf)->unref();
+
+        //-----------------------------------------------
+        info.fPaintBits = 0;
+        info.fOffset.set(0, 0);
+
+        paint = looper->addLayer(info);
+        return looper;
+    }
+
+    typedef SkBenchmark INHERITED;
+};
+
+
+DEF_BENCH( return SkNEW_ARGS(RectoriBench, (p)); )