Add special case circle blur for Ganesh

src/effects/SkBlurMask.cpp

 
 /*
  * 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.
  */
 
 
 #include "SkBlurMask.h"
@@ skipping 660 matching lines @@
     point values between 0 and 255 for the profile signature of
     a blurred half-plane with the given blur radius.  Since we're
     going to be doing screened multiplications (i.e., 1 - (1-x)(1-y))
     all the time, we actually fill in the profile pre-inverted
     (already done 255-x).
 
     It's the responsibility of the caller to delete the
     memory returned in profile_out.
 */
 
-void SkBlurMask::ComputeBlurProfile(SkScalar sigma, uint8_t **profile_out) {
+uint8_t* SkBlurMask::ComputeBlurProfile(SkScalar sigma) {
     int size = SkScalarCeilToInt(6*sigma);
 
     int center = size >> 1;
     uint8_t* profile = new uint8_t[size];
 
     float invr = 1.f/(2*sigma);
 
     profile[0] = 255;
     for (int x = 1 ; x < size ; ++x) {
         float scaled_x = (center - x - .5f) * invr;
         float gi = gaussianIntegral(scaled_x);
         profile[x] = 255 - (uint8_t) (255.f * gi);
     }
 
-    *profile_out = profile;
+    return profile;
 }
 
 // TODO MAYBE: Maintain a profile cache to avoid recomputing this for
 // commonly used radii.  Consider baking some of the most common blur radii
 // directly in as static data?
 
 // Implementation adapted from Michael Herf's approach:
 // http://stereopsis.com/shadowrect/
 
 uint8_t SkBlurMask::ProfileLookup(const uint8_t *profile, int loc, int blurred_width, int sharp_width) {
@@ skipping 55 matching lines @@
     if (createMode == SkMask::kJustComputeBounds_CreateMode) {
         if (style == kInner_SkBlurStyle) {
             dst->fBounds.set(SkScalarRoundToInt(src.fLeft),
                              SkScalarRoundToInt(src.fTop),
                              SkScalarRoundToInt(src.fRight),
                              SkScalarRoundToInt(src.fBottom)); // restore trimmed bounds
             dst->fRowBytes = sw;
         }
         return true;
     }
-    uint8_t *profile = nullptr;
 
-    ComputeBlurProfile(sigma, &profile);
-    SkAutoTDeleteArray<uint8_t> ada(profile);
+    SkAutoTDeleteArray<uint8_t> profile(ComputeBlurProfile(sigma));
 
     size_t dstSize = dst->computeImageSize();
     if (0 == dstSize) {
         return false;   // too big to allocate, abort
     }
 
     uint8_t*        dp = SkMask::AllocImage(dstSize);
 
     dst->fImage = dp;
 
     int dstHeight = dst->fBounds.height();
     int dstWidth = dst->fBounds.width();
 
     uint8_t *outptr = dp;
 
     SkAutoTMalloc<uint8_t> horizontalScanline(dstWidth);
     SkAutoTMalloc<uint8_t> verticalScanline(dstHeight);
 
-    ComputeBlurredScanline(horizontalScanline, profile, dstWidth, sigma);
-    ComputeBlurredScanline(verticalScanline, profile, dstHeight, sigma);
+    ComputeBlurredScanline(horizontalScanline, profile.get(), dstWidth, sigma);
+    ComputeBlurredScanline(verticalScanline, profile.get(), dstHeight, sigma);
 
     for (int y = 0 ; y < dstHeight ; ++y) {
         for (int x = 0 ; x < dstWidth ; x++) {
             unsigned int maskval = SkMulDiv255Round(horizontalScanline[x], verticalScanline[y]);
             *(outptr++) = maskval;
         }
     }
 
     if (style == kInner_SkBlurStyle) {
         // now we allocate the "real" dst, mirror the size of src
@@ skipping 181 matching lines @@
         (void)autoCall.detach();
     }
 
     if (style == kInner_SkBlurStyle) {
         dst->fBounds = src.fBounds; // restore trimmed bounds
         dst->fRowBytes = src.fRowBytes;
     }
 
     return true;
 }