Update GLM to latest version (0.9.9.3). This includes GLM's change of matrices no longer default initializing to the identity matrix. This commit thus also includes the update of all of LearnOpenGL's code to reflect this: all matrices are now constructor-initialized to the identity matrix where relevant.

includes/glm/gtx/exterior_product.hpp

@@ -0,0 +1,41 @@
+/// @ref gtx_exterior_product
+/// @file glm/gtx/exterior_product.hpp
+///
+/// @see core (dependence)
+/// @see gtx_exterior_product (dependence)
+///
+/// @defgroup gtx_exterior_product GLM_GTX_exterior_product
+/// @ingroup gtx
+///
+/// Include <glm/gtx/exterior_product.hpp> to use the features of this extension.
+///
+/// @brief Allow to perform bit operations on integer values
+
+#pragma once
+
+// Dependencies
+#include "../detail/setup.hpp"
+#include "../detail/qualifier.hpp"
+
+#if GLM_MESSAGES == GLM_ENABLE && !defined(GLM_EXT_INCLUDED)
+#	pragma message("GLM: GLM_GTX_exterior_product extension included")
+#endif
+
+namespace glm
+{
+	/// @addtogroup gtx_exterior_product
+	/// @{
+
+	/// Returns the cross product of x and y.
+	///
+	/// @tparam T Floating-point scalar types
+	/// @tparam Q Value from qualifier enum
+	///
+	/// @see <a href="https://en.wikipedia.org/wiki/Exterior_algebra#Cross_and_triple_products">Exterior product</a>
+	template<typename T, qualifier Q>
+	GLM_FUNC_DECL T cross(vec<2, T, Q> const& v, vec<2, T, Q> const& u);
+
+	/// @}
+} //namespace glm
+
+#include "exterior_product.inl"