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

src/core/SkCanvas.cpp

Index: src/core/SkCanvas.cpp
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 62021cb535c77786ad152f1e89815f4948774be1..29c09d1e7aec139fc51bbd8b16b6b38f1f8b2f26 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -998,13 +998,15 @@ void SkCanvas::internalDrawDevice(SkBaseDevice* srcDev, int x, int y,
         if (filter && !dstDev->canHandleImageFilter(filter)) {
             SkDeviceImageFilterProxy proxy(dstDev);
             SkBitmap dst;
+            SkIPoint offset = SkIPoint::Make(0, 0);

[reed1, 2014/01/03 16:42:07]

Why is this initialized if it is purely an out-parameter now?

[Stephen White, 2014/01/03 16:48:35]

Before this patch, some of the callees were leaving it unchanged (i.e.,
uninitialized), and I was nervous that I might have missed some cases, so I left
this in as a just-in-case.

If you like, we can remove it, and rely on valgrind to let me know if I screwed
up.

             const SkBitmap& src = srcDev->accessBitmap(false);
             SkMatrix matrix = *iter.fMatrix;
             matrix.postTranslate(SkIntToScalar(-x), SkIntToScalar(-y));
-            if (filter->filterImage(&proxy, src, matrix, &dst, &pos)) {
+            if (filter->filterImage(&proxy, src, matrix, &dst, &offset)) {
                 SkPaint tmpUnfiltered(*paint);
                 tmpUnfiltered.setImageFilter(NULL);
-                dstDev->drawSprite(iter, dst, pos.x(), pos.y(), tmpUnfiltered);
+                dstDev->drawSprite(iter, dst, pos.x() + offset.x(), pos.y() + offset.y(),
+                                   tmpUnfiltered);
             }
         } else {
             dstDev->drawDevice(iter, srcDev, pos.x(), pos.y(), *paint);
@@ -1036,12 +1038,13 @@ void SkCanvas::drawSprite(const SkBitmap& bitmap, int x, int y,
         if (filter && !iter.fDevice->canHandleImageFilter(filter)) {
             SkDeviceImageFilterProxy proxy(iter.fDevice);
             SkBitmap dst;
+            SkIPoint offset = SkIPoint::Make(0, 0);
             SkMatrix matrix = *iter.fMatrix;
             matrix.postTranslate(SkIntToScalar(-x), SkIntToScalar(-y));
-            if (filter->filterImage(&proxy, bitmap, matrix, &dst, &pos)) {
+            if (filter->filterImage(&proxy, bitmap, matrix, &dst, &offset)) {
                 SkPaint tmpUnfiltered(*paint);
                 tmpUnfiltered.setImageFilter(NULL);
-                iter.fDevice->drawSprite(iter, dst, pos.x(), pos.y(),
+                iter.fDevice->drawSprite(iter, dst, pos.x() + offset.x(), pos.y() + offset.y(),
                                          tmpUnfiltered);
             }
         } else {