commit 7d2ad0fdef01f3fdfadd11c3082b002688b0cab0
author Michael Ludwig <michaelludwig@google.com> Fri May 03 17:09:47 2019 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Mon May 06 15:11:40 2019 +0000
tree e0def0f8658406062837c0b1a7a575cb0c18ae98
parent 2f3637bf2ed44ef75966786ab4c2974d17c9f649

Fix local matrix for crop rects in backdrop image filters

Bug: chromium:955467
Change-Id: I1c4cae2499db926aa6b629e8d730fcc8cb45be6d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/212030
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>

src/core/SkCanvas.cpp

diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index e021fb5..1df0f72 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -938,13 +938,17 @@
     draw.fMatrix = &SkMatrix::I();
     draw.fRC = &rc;
 
-    SkPaint p;
-    if (filter) {
-        p.setImageFilter(filter->makeWithLocalMatrix(ctm));
-    }
-
     int x = src->getOrigin().x() - dstOrigin.x();
     int y = src->getOrigin().y() - dstOrigin.y();
+
+    SkPaint p;
+    if (filter) {
+        SkMatrix actm = ctm;
+        // Account for the origin offset in the local matrix
+        actm.postTranslate(x, y);
+        p.setImageFilter(filter->makeWithLocalMatrix(actm));
+    }
+
     auto special = src->snapSpecial();
     if (special) {
         dst->drawSpecial(special.get(), x, y, p, nullptr, SkMatrix::I());