Add ktx

ktx/other_include/glm/gtx/normal.inl

@@ -0,0 +1,16 @@
+/// @ref gtx_normal
+/// @file glm/gtx/normal.inl
+
+namespace glm
+{
+	template<typename T, precision P> 
+	GLM_FUNC_QUALIFIER vec<3, T, P> triangleNormal
+	(
+		vec<3, T, P> const & p1, 
+		vec<3, T, P> const & p2, 
+		vec<3, T, P> const & p3
+	)
+	{
+		return normalize(cross(p1 - p2, p1 - p3));
+	}
+}//namespace glm