diff --git a/libs/hwui/AmbientShadow.cpp b/libs/hwui/AmbientShadow.cpp
index 7834ef8..4873479 100644
--- a/libs/hwui/AmbientShadow.cpp
+++ b/libs/hwui/AmbientShadow.cpp
@@ -93,6 +93,10 @@
 
 inline int getExtraVertexNumber(const Vector2& vector1, const Vector2& vector2,
         float divisor) {
+    // When there is no distance difference, there is no need for extra vertices.
+    if (vector1.lengthSquared() == 0 || vector2.lengthSquared() == 0) {
+        return 0;
+    }
     // The formula is :
     // extraNumber = floor(acos(dot(n1, n2)) / (M_PI / EXTRA_VERTEX_PER_PI))
     // The value ranges for each step are: