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

src/effects/SkOffsetImageFilter.cpp

 /*
  * Copyright 2012 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 "SkOffsetImageFilter.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
 #include "SkDevice.h"
 #include "SkFlattenableBuffers.h"
 #include "SkMatrix.h"
 #include "SkPaint.h"
 
 bool SkOffsetImageFilter::onFilterImage(Proxy* proxy, const SkBitmap& source,
                                         const SkMatrix& matrix,
                                         SkBitmap* result,
-                                        SkIPoint* loc) {
+                                        SkIPoint* offset) {
     SkImageFilter* input = getInput(0);
     SkBitmap src = source;
+    SkIPoint srcOffset = SkIPoint::Make(0, 0);
 #ifdef SK_DISABLE_OFFSETIMAGEFILTER_OPTIMIZATION
     if (false) {
 #else
     if (!cropRectIsSet()) {
 #endif
-        if (input && !input->filterImage(proxy, source, matrix, &src, loc)) {
+        if (input && !input->filterImage(proxy, source, matrix, &src, &srcOffset)) {
             return false;
         }
 
         SkVector vec;
         matrix.mapVectors(&vec, &fOffset, 1);
 
-        loc->fX += SkScalarRoundToInt(vec.fX);
-        loc->fY += SkScalarRoundToInt(vec.fY);
+        offset->fX = srcOffset.fX + SkScalarRoundToInt(vec.fX);
+        offset->fY = srcOffset.fY + SkScalarRoundToInt(vec.fY);
         *result = src;
     } else {
-        SkIPoint srcOffset = SkIPoint::Make(0, 0);
         if (input && !input->filterImage(proxy, source, matrix, &src, &srcOffset)) {
             return false;
         }
 
         SkIRect bounds;
         src.getBounds(&bounds);
+        bounds.offset(srcOffset);
 
         if (!applyCropRect(&bounds, matrix)) {
             return false;
         }
 
         SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(), bounds.height()));
         if (NULL == device.get()) {
             return false;
         }
         SkCanvas canvas(device);
         SkPaint paint;
         paint.setXfermodeMode(SkXfermode::kSrc_Mode);
-        canvas.drawBitmap(src, fOffset.fX - bounds.left(), fOffset.fY - bounds.top(), &paint);
+        canvas.translate(SkIntToScalar(srcOffset.fX - bounds.fLeft),
+                         SkIntToScalar(srcOffset.fY - bounds.fTop));
+        canvas.drawBitmap(src, fOffset.x(), fOffset.y(), &paint);
         *result = device->accessBitmap(false);
-        loc->fX += bounds.left();
-        loc->fY += bounds.top();
+        offset->fX = bounds.fLeft;
+        offset->fY = bounds.fTop;
     }
     return true;
 }
 
 bool SkOffsetImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
                                          SkIRect* dst) {
     SkVector vec;
     ctm.mapVectors(&vec, &fOffset, 1);
 
     *dst = src;
@@ skipping 10 matching lines @@
                                          const CropRect* cropRect) : INHERITED(input, cropRect) {
     fOffset.set(dx, dy);
 }
 
 SkOffsetImageFilter::SkOffsetImageFilter(SkFlattenableReadBuffer& buffer)
   : INHERITED(1, buffer) {
     buffer.readPoint(&fOffset);
     buffer.validate(SkScalarIsFinite(fOffset.fX) &&
                     SkScalarIsFinite(fOffset.fY));
 }