fix `glm::bounceEaseInOut()` easing formula

glm/gtx/easing.inl

@@ -425,7 +425,7 @@ namespace glm{
 
 		if(a < static_cast<genType>(0.5))
 		{
-			return static_cast<genType>(0.5) * (one<genType>() - bounceEaseOut(a * static_cast<genType>(2)));
+			return static_cast<genType>(0.5) * (one<genType>() - bounceEaseOut(one<genType>() - a * static_cast<genType>(2)));
 		}
 		else
 		{