Fix dst bound reported by SkTileImageFilter

In the example from the bug we had the filter DAG:

color filter (table)
    0: xfermode filter (arith)
        0: tile filter [0,80,34,114] -> [0,80,800,480]
             0: color filter (table)
                 0: bitmap src 34x34 -> [0,80,34,114]
        1: color filter (table)
             0: picture filter [0, 80, 800, 480]

computeFastBounds was coming out of the DAG with a bound of [0,80,34,114] which didn't represent the pixels that would be drawn.

This CL updates SkTileImageFilter to correctly set the bound for the pixels it will hit.

BUG=493783

Committed: https://skia.googlesource.com/skia/+/05be93bbdf09576f7903130e3b106b0a8c7c4b4e

Committed: https://skia.googlesource.com/skia/+/0be685755f942baea26c66a87226b569fc17e960

Review URL: https://codereview.chromium.org/1152553006

1 files changed, 6 insertions, 0 deletions

diff --git a/src/effects/SkTileImageFilter.cpp b/src/effects/SkTileImageFilter.cpp
index b2244b9629..2b7ed940d2 100644
--- a/src/effects/SkTileImageFilter.cpp
+++ b/src/effects/SkTileImageFilter.cpp
@@ -93,6 +93,12 @@ bool SkTileImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
     return true;
 }
 
+void SkTileImageFilter::computeFastBounds(const SkRect& src, SkRect* dst) const {
+    // This is a workaround for skia:3194.
+    *dst = src;
+    dst->join(fDstRect);
+}
+
 SkFlattenable* SkTileImageFilter::CreateProc(SkReadBuffer& buffer) {
     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
     SkRect src, dst;