Make SkImageFilter crop rects relative to the primitive origin, instead of relative to their parent

src/effects/SkBlurImageFilter.cpp

 /*
  * Copyright 2011 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 "SkBitmap.h"
 #include "SkBlurImageFilter.h"
 #include "SkColorPriv.h"
@@ skipping 119 matching lines @@
         *highOffset = d / 2;
         *lowOffset = *highOffset - 1;
         *kernelSize3 = d + 1;
     }
 }
 
 bool SkBlurImageFilter::onFilterImage(Proxy* proxy,
                                       const SkBitmap& source, const SkMatrix& ctm,
                                       SkBitmap* dst, SkIPoint* offset) {
     SkBitmap src = source;
-    if (getInput(0) && !getInput(0)->filterImage(proxy, source, ctm, &src, offset)) {
+    SkIPoint srcOffset = SkIPoint::Make(0, 0);
+    if (getInput(0) && !getInput(0)->filterImage(proxy, source, ctm, &src, &srcOffset)) {
         return false;
     }
 
     if (src.config() != SkBitmap::kARGB_8888_Config) {
         return false;
     }
 
     SkAutoLockPixels alp(src);
     if (!src.getPixels()) {
         return false;
     }
 
     SkIRect srcBounds, dstBounds;
     src.getBounds(&srcBounds);
+    srcBounds.offset(srcOffset);
     if (!this->applyCropRect(&srcBounds, ctm)) {
         return false;
     }
 
     dst->setConfig(src.config(), srcBounds.width(), srcBounds.height());
     dst->getBounds(&dstBounds);
     dst->allocPixels();
     if (!dst->getPixels()) {
         return false;
     }
@@ skipping 40 matching lines @@
         boxBlurXY(t, h,  d, kernelSizeY3, highOffsetY, highOffsetY, h, w);
     } else if (kernelSizeX > 0) {
         boxBlurX(s,  sw, d, kernelSizeX,  lowOffsetX,  highOffsetX, w, h);
         boxBlurX(d,  w,  t, kernelSizeX,  highOffsetX, lowOffsetX,  w, h);
         boxBlurX(t,  w,  d, kernelSizeX3, highOffsetX, highOffsetX, w, h);
     } else if (kernelSizeY > 0) {
         boxBlurYX(s, sw, d, kernelSizeY,  lowOffsetY,  highOffsetY, h, w);
         boxBlurX(d,  h,  t, kernelSizeY,  highOffsetY, lowOffsetY,  h, w);
         boxBlurXY(t, h,  d, kernelSizeY3, highOffsetY, highOffsetY, h, w);
     }
-    offset->fX += srcBounds.fLeft;
-    offset->fY += srcBounds.fTop;
+    offset->fX = srcBounds.fLeft;
+    offset->fY = srcBounds.fTop;
     return true;
 }
 
 bool SkBlurImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, const SkMatrix& ctm,
                                        SkBitmap* result, SkIPoint* offset) {
 #if SK_SUPPORT_GPU
     SkBitmap input;
     if (!SkImageFilterUtils::GetInputResultGPU(getInput(0), proxy, src, ctm, &input, offset)) {
         return false;
     }
     GrTexture* source = input.getTexture();
     SkIRect rect;
     src.getBounds(&rect);
     if (!this->applyCropRect(&rect, ctm)) {
         return false;
     }
     SkAutoTUnref<GrTexture> tex(SkGpuBlurUtils::GaussianBlur(source->getContext(),
                                                              source,
                                                              false,
                                                              SkRect::Make(rect),
                                                              true,
                                                              fSigma.width(),
                                                              fSigma.height()));
-    offset->fX += rect.fLeft;
-    offset->fY += rect.fTop;
+    offset->fX = rect.fLeft;
+    offset->fY = rect.fTop;
     return SkImageFilterUtils::WrapTexture(tex, rect.width(), rect.height(), result);
 #else
     SkDEBUGFAIL("Should not call in GPU-less build");
     return false;
 #endif
 }