Fix quickReject's handling of AA ramp geometry

By having quickReject round out the window-space geometry bounds, we
prevent the AA perimeter (which falls outside the local bounds passed
in) from drawing outside the clip.

Change-Id: I8ee36be9039a9c47906815ee2f0dbaa5eb910b82

1 files changed, 14 insertions, 0 deletions

diff --git a/libs/hwui/Rect.h b/libs/hwui/Rect.h
index 7531769..7605307 100644
--- a/libs/hwui/Rect.h
+++ b/libs/hwui/Rect.h
@@ -170,6 +170,20 @@ public:
         bottom += delta;
     }
 
+    /**
+     * Similar to snapToPixelBoundaries, but used for AA geometry with a ramp perimeter.
+     *
+     * We inset the data by a fudge factor of slightly over 1/16 (similar to when drawing non-AA
+     * lines) before rounding out so that insignificant amounts of ramp geometry (esp. from rounding
+     * errors) are ignored.
+     */
+    void snapOutToPixelBoundaries() {
+        left = floorf(left + 0.065f);
+        top = floorf(top + 0.065f);
+        right = ceilf(right - 0.065f);
+        bottom = ceilf(bottom - 0.065f);
+    }
+
     void snapToPixelBoundaries() {
         left = floorf(left + 0.5f);
         top = floorf(top + 0.5f);