More GPU blur fixes.

- clamp the max. radius to 128, as the software path does
- use a more accurate radius-to-sigma conversion (0.6 instead of 0.6666)
- make SampleBlur derive from SampleView, not SkView, so benchmark mode ('f')
works
- implement a new BigBlur sample to test large radii

Review URL:  http://codereview.appspot.com/4726043



git-svn-id: http://skia.googlecode.com/svn/trunk@1871 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleBigBlur.cpp b/samplecode/SampleBigBlur.cpp
new file mode 100644
index 0000000..243e0df
--- /dev/null
+++ b/samplecode/SampleBigBlur.cpp
@@ -0,0 +1,43 @@
+#include "SampleCode.h"
+#include "SkBlurMaskFilter.h"
+#include "SkView.h"
+#include "SkCanvas.h"
+
+class BigBlurView : public SampleView {
+public:
+    BigBlurView() {
+    }
+
+protected:
+    // overrides from SkEventSink
+    virtual bool onQuery(SkEvent* evt) {
+        if (SampleCode::TitleQ(*evt)) {
+            SampleCode::TitleR(evt, "BigBlur");
+            return true;
+        }
+        return this->INHERITED::onQuery(evt);
+    }
+
+    virtual void onDrawContent(SkCanvas* canvas) {
+        SkPaint paint;
+        canvas->save();
+        paint.setColor(SK_ColorBLUE);
+        SkMaskFilter* mf = SkBlurMaskFilter::Create(
+            128,
+            SkBlurMaskFilter::kNormal_BlurStyle,
+            SkBlurMaskFilter::kHighQuality_BlurFlag);
+        paint.setMaskFilter(mf)->unref();
+        canvas->translate(200, 200);
+        canvas->drawCircle(100, 100, 250, paint);
+        canvas->restore();
+    }
+
+private:
+    typedef SkView INHERITED;
+};
+
+//////////////////////////////////////////////////////////////////////////////
+
+static SkView* MyFactory() { return new BigBlurView; }
+static SkViewRegister reg(MyFactory);
+