Push sigma-based blur interface into our GMs/benches/tests/samplecode

gm/megalooper.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 "gm.h"
 #include "SkCanvas.h"
 #include "SkBlurMaskFilter.h"
@@ skipping 92 matching lines @@
             SkRect rect = { -kHalfSquareSize, -kHalfSquareSize, kHalfSquareSize, kHalfSquareSize };
             rect.offset(gBlurOffsets[i]);
             rect.offset(x, y);
             canvas->drawRect(rect, paint);
         }
 
         canvas->restore();
     }
 
     SkMaskFilter* createBlur() {
-        static const SkScalar kBlurRadius = 25.0f;
+        static const SkScalar kBlurSigma = SkFloatToScalar(14.93375f);
 
-        return SkBlurMaskFilter::Create(kBlurRadius,
-                                        SkBlurMaskFilter::kNormal_BlurStyle,
+        return SkBlurMaskFilter::Create(SkBlurMaskFilter::kNormal_BlurStyle,
+                                        kBlurSigma,
                                         SkBlurMaskFilter::kHighQuality_BlurFlag);
     }
 
     // This draws 4 blurred shadows around a single square (centered at x, y).
     // Each blur is offset +/- half the square's side in x & y from the original
     // (so each blurred rect is centered at one of the corners of the original).
     // For each blur a large outer clip is centered around the blurred rect
     // while a difference clip stays at the location of the original rect.
     // Each blurred rect is drawn with a draw looper where the original (non-
     // blurred rect) is offset to reside outside of the large outer clip (so
@@ skipping 114 matching lines @@
     { -kHalfSquareSize, -kHalfSquareSize }
 };
 
 const SkColor MegaLooperGM::gColors[4] = {
     SK_ColorGREEN, SK_ColorYELLOW, SK_ColorBLUE, SK_ColorRED
 };
 
 DEF_GM( return new MegaLooperGM(MegaLooperGM::k0x0_Type); )
 DEF_GM( return new MegaLooperGM(MegaLooperGM::k4x1_Type); )
 DEF_GM( return new MegaLooperGM(MegaLooperGM::k1x4_Type); )