check matrix does not have rotation or perspective transformation

When checking whether we need apply AA to a rect for non-msaa target,
simply checking that the mapped rect is integer is not enough.
We need to check whether the transformation matrix has transformations
other than simple translation.

Original-Author: Henry Song <henrysong@samsung.com>

Review URL: https://codereview.chromium.org/772953002

1 files changed, 4 insertions, 0 deletions

diff --git a/src/gpu/GrContext.cpp b/src/gpu/GrContext.cpp
index 607d3c3cc7..852afe01ba 100755
--- a/src/gpu/GrContext.cpp
+++ b/src/gpu/GrContext.cpp
@@ -650,6 +650,10 @@ static bool apply_aa_to_rect(GrDrawTarget* target,
 #endif
 
     combinedMatrix.mapRect(devBoundRect, rect);
+    if (!combinedMatrix.rectStaysRect()) {
+        return true;
+    }
+
     if (strokeWidth < 0) {
         return !is_irect(*devBoundRect);
     }