New GM for testing circle blur optimization

gm/blurcircles.cpp

+/*
+* Copyright 2014 Google Inc.
+*
+* Use of this source code is governed by a BSD-style license that can be
+* found in the LICENSE file.
+*/
+
+#include "gm.h"
+#include "SkBlurMask.h"
+#include "SkBlurMaskFilter.h"
+#include "SkCanvas.h"
+#include "SkColorFilter.h"
+#include "SkLayerDrawLooper.h"

[bsalomon, 2014/05/07 17:31:45]

I think some of these #includes can be removed (path, draw looper, path, point,
rect, rrect, xfermode .

Otherwise lgtm if it passes mtklein's quilt dm test.

+#include "SkPaint.h"
+#include "SkPath.h"
+#include "SkPoint.h"
+#include "SkRect.h"
+#include "SkRRect.h"
+#include "SkString.h"
+#include "SkXfermode.h"
+
+class BlurCirclesGM : public skiagm::GM {
+public:
+    BlurCirclesGM()
+        : fName("blurcircles") {
+    }
+
+protected:
+
+    virtual SkString onShortName() SK_OVERRIDE {
+        return fName;
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE {
+        return SkISize::Make(950, 950);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        canvas->scale(1.5f, 1.5f);
+        canvas->translate(50,50);
+
+        const float blurRadii[] = { 1,5,10,20 };
+        const int circleRadii[] = { 5,10,25,50 };
+        for (size_t i = 0; i < SK_ARRAY_COUNT(blurRadii); ++i) {
+            SkAutoCanvasRestore autoRestore(canvas, true);
+            canvas->translate(0, SkIntToScalar(150*i));
+            for (size_t j = 0; j < SK_ARRAY_COUNT(circleRadii); ++j) {
+                SkMaskFilter* filter = SkBlurMaskFilter::Create(
+                    kNormal_SkBlurStyle,
+                    SkBlurMask::ConvertRadiusToSigma(SkIntToScalar(blurRadii[i])),
+                    SkBlurMaskFilter::kHighQuality_BlurFlag);
+                SkPaint paint;
+                paint.setColor(SK_ColorBLACK);
+                paint.setMaskFilter(filter)->unref();
+
+                canvas->drawCircle(SkIntToScalar(50),SkIntToScalar(50),SkIntToScalar(circleRadii[j]),paint);
+                canvas->translate(SkIntToScalar(150), 0);
+            }
+        }
+    }
+private:
+    const SkString  fName;
+
+    typedef         skiagm::GM INHERITED;
+};
+
+DEF_GM(return new BlurCirclesGM();)