added libs

libs/glm/gtx/texture.inl

@@ -0,0 +1,17 @@
+/// @ref gtx_texture
+
+namespace glm
+{
+	template <length_t L, typename T, qualifier Q>
+	inline T levels(vec<L, T, Q> const& Extent)
+	{
+		return glm::log2(compMax(Extent)) + static_cast<T>(1);
+	}
+
+	template <typename T>
+	inline T levels(T Extent)
+	{
+		return levels(vec<1, T, defaultp>(Extent));
+	}
+}//namespace glm
+