Cap scales used for tessellation with minimum and maximum

bug:15615144
Change-Id: I3e833864af3a7b34e444bd13db34b6c90496a8b6

1 files changed, 17 insertions, 0 deletions

diff --git a/libs/hwui/utils/MathUtils.h b/libs/hwui/utils/MathUtils.h
index 66bc127..6fb0411 100644
--- a/libs/hwui/utils/MathUtils.h
+++ b/libs/hwui/utils/MathUtils.h
@@ -35,6 +35,9 @@ public:
         return value >= NON_ZERO_EPSILON;
     }
 
+    /**
+     * Clamps alpha value, and snaps when very near 0 or 1
+     */
     inline static float clampAlpha(float alpha) {
         if (alpha <= ALPHA_EPSILON) {
             return 0;
@@ -45,6 +48,20 @@ public:
         }
     }
 
+    /*
+     * Clamps positive tessellation scale values
+     */
+    inline static float clampTessellationScale(float scale) {
+        const float MIN_SCALE = 0.0001;
+        const float MAX_SCALE = 1e10;
+        if (scale < MIN_SCALE) {
+            return MIN_SCALE;
+        } else if (scale > MAX_SCALE) {
+            return MAX_SCALE;
+        }
+        return scale;
+    }
+
     inline static bool areEqual(float valueA, float valueB) {
         return isZero(valueA - valueB);
     }