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

src/effects/SkDropShadowImageFilter.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 "SkDropShadowImageFilter.h"
 
 #include "SkBitmap.h"
@@ skipping 39 matching lines @@
 void SkDropShadowImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const
 {
     this->INHERITED::flatten(buffer);
     buffer.writeScalar(fDx);
     buffer.writeScalar(fDy);
     buffer.writeScalar(fSigmaX);
     buffer.writeScalar(fSigmaY);
     buffer.writeColor(fColor);
 }
 
-bool SkDropShadowImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& source, const SkMatrix& matrix, SkBitmap* result, SkIPoint* loc)
+bool SkDropShadowImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& source, const SkMatrix& matrix, SkBitmap* result, SkIPoint* offset)
 {
     SkBitmap src = source;
-    if (getInput(0) && !getInput(0)->filterImage(proxy, source, matrix, &src, loc))
+    SkIPoint srcOffset = SkIPoint::Make(0, 0);
+    if (getInput(0) && !getInput(0)->filterImage(proxy, source, matrix, &src, &srcOffset))
         return false;
 
     SkIRect bounds;
     src.getBounds(&bounds);
+    bounds.offset(srcOffset);
     if (!this->applyCropRect(&bounds, matrix)) {
         return false;
     }
 
     SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(), bounds.height()));
     if (NULL == device.get()) {
         return false;
     }
     SkCanvas canvas(device.get());
 
     SkAutoTUnref<SkImageFilter> blurFilter(new SkBlurImageFilter(fSigmaX, fSigmaY));
     SkAutoTUnref<SkColorFilter> colorFilter(SkColorFilter::CreateModeFilter(fColor, SkXfermode::kSrcIn_Mode));
     SkPaint paint;
     paint.setImageFilter(blurFilter.get());
     paint.setColorFilter(colorFilter.get());
     paint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
     canvas.translate(-SkIntToScalar(bounds.fLeft), -SkIntToScalar(bounds.fTop));
     canvas.drawBitmap(src, fDx, fDy, &paint);
     canvas.drawBitmap(src, 0, 0);
     *result = device->accessBitmap(false);
-    loc->fX += bounds.fLeft;
-    loc->fY += bounds.fTop;
+    offset->fX = bounds.fLeft;
+    offset->fY = bounds.fTop;
     return true;
 }