Merge "Limit dotProduct value to 1.0f, so acosf would not return NaN."

1 files changed, 3 insertions, 0 deletions

diff --git a/libs/hwui/ShadowTessellator.cpp b/libs/hwui/ShadowTessellator.cpp
index 93d4b317f03b..c1b0f7ff2365 100644
--- a/libs/hwui/ShadowTessellator.cpp
+++ b/libs/hwui/ShadowTessellator.cpp
@@ -20,6 +20,7 @@
 #include <math.h>
 #include <utils/Log.h>
 #include <utils/Trace.h>
+#include <utils/MathUtils.h>
 
 #include "AmbientShadow.h"
 #include "Caches.h"
@@ -264,6 +265,8 @@ int ShadowTessellator::getExtraVertexNumber(const Vector2& vector1,
     // acos( )     --- [0, M_PI]
     // floor(...)  --- [0, EXTRA_VERTEX_PER_PI]
     float dotProduct = vector1.dot(vector2);
+    // make sure that dotProduct value is in acsof input range [-1, 1]
+    dotProduct = MathUtils::clamp(dotProduct, -1.0f, 1.0f);
     // TODO: Use look up table for the dotProduct to extraVerticesNumber
     // computation, if needed.
     float angle = acosf(dotProduct);