Disallow negative scale matrices in merged Bitmap drawing

bug:10622962

Change-Id: I55ac18ad56b53dc9e6e6ea14cd3ec4bdafa98ac3

1 files changed, 8 insertions, 0 deletions

diff --git a/libs/hwui/Matrix.cpp b/libs/hwui/Matrix.cpp
index 65e7eae49c2d..1948778ceb7c 100644
--- a/libs/hwui/Matrix.cpp
+++ b/libs/hwui/Matrix.cpp
@@ -110,6 +110,10 @@ uint8_t Matrix4::getType() const {
                 mType |= kTypeRectToRect;
             }
         }
+
+        if (m00 > 0.0f && m11 > 0.0f) {
+            mType |= kTypePositiveScale;
+        }
     }
     return mType;
 }
@@ -122,6 +126,10 @@ bool Matrix4::rectToRect() const {
     return getType() & kTypeRectToRect;
 }
 
+bool Matrix4::positiveScale() const {
+    return getType() & kTypePositiveScale;
+}
+
 bool Matrix4::changesBounds() const {
     return getType() & (kTypeScale | kTypeAffine | kTypePerspective);
 }