Fix quickReject computation for blurs

src/effects/SkBlurMask.h

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkBlurMask_DEFINED
@@ skipping 25 matching lines @@
     static bool Blur(SkMask* dst, const SkMask& src,
                      SkScalar radius, Style style, Quality quality,
                      SkIPoint* margin = NULL);
 
     // the "ground truth" blur does a gaussian convolution; it's slow
     // but useful for comparison purposes.
 
     static bool BlurGroundTruth(SkMask* dst, const SkMask& src,
                            SkScalar provided_radius, Style style,
                            SkIPoint* margin = NULL);
+
+    // This constant approximates the scaling done in the software path's
+    // "high quality" mode, in SkBlurMask::Blur() (1 / sqrt(3)).
+    // IMHO, it actually should be 1:  we blur "less" than we should do
+    // according to the CSS and canvas specs, simply because Safari does the same.
+    // Firefox used to do the same too, until 4.0 where they fixed it.  So at some
+    // point we should probably get rid of these scaling constants and rebaseline
+    // all the blur tests.
+    static const SkScalar kBLUR_SIGMA_SCALE;
+
+    // scale factor for the blur radius to match the behavior of the all existing blur
+    // code (both on the CPU and the GPU).  This magic constant is  1/sqrt(3).
+    // TODO: get rid of this fudge factor and move any required fudging up into
+    // the calling library
+    static const SkScalar kBlurRadiusFudgeFactor;
+
+    // To avoid unseemly allocation requests (esp. for finite platforms like
+    // handset) we limit the radius so something manageable. (as opposed to
+    // a request like 10,000)
+    static const SkScalar kMAX_BLUR_RADIUS;
+
 };
 
 #endif