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/matrix_factorisation.hpp

@@ -0,0 +1,69 @@
+/// @ref gtx_matrix_factorisation
+/// @file glm/gtx/matrix_factorisation.hpp
+///
+/// @see core (dependence)
+///
+/// @defgroup gtx_matrix_factorisation GLM_GTX_matrix_factorisation
+/// @ingroup gtx
+///
+/// Include <glm/gtx/matrix_factorisation.hpp> to use the features of this extension.
+///
+/// Functions to factor matrices in various forms
+
+#pragma once
+
+// Dependency:
+#include "../glm.hpp"
+
+#ifndef GLM_ENABLE_EXPERIMENTAL
+#	error "GLM: GLM_GTX_matrix_factorisation is an experimental extension and may change in the future. Use #define GLM_ENABLE_EXPERIMENTAL before including it, if you really want to use it."
+#endif
+
+#if GLM_MESSAGES == GLM_ENABLE && !defined(GLM_EXT_INCLUDED)
+#	pragma message("GLM: GLM_GTX_matrix_factorisation extension included")
+#endif
+
+/*
+Suggestions:
+ - Move helper functions flipud and fliplr to another file: They may be helpful in more general circumstances.
+ - Implement other types of matrix factorisation, such as: QL and LQ, L(D)U, eigendecompositions, etc...
+*/
+
+namespace glm
+{
+	/// @addtogroup gtx_matrix_factorisation
+	/// @{
+
+	/// Flips the matrix rows up and down.
+	///
+	/// From GLM_GTX_matrix_factorisation extension.
+	template <length_t C, length_t R, typename T, qualifier Q>
+	GLM_FUNC_DECL mat<C, R, T, Q> flipud(mat<C, R, T, Q> const& in);
+
+	/// Flips the matrix columns right and left.
+	///
+	/// From GLM_GTX_matrix_factorisation extension.
+	template <length_t C, length_t R, typename T, qualifier Q>
+	GLM_FUNC_DECL mat<C, R, T, Q> fliplr(mat<C, R, T, Q> const& in);
+
+	/// Performs QR factorisation of a matrix.
+	/// Returns 2 matrices, q and r, such that the columns of q are orthonormal and span the same subspace than those of the input matrix, r is an upper triangular matrix, and q*r=in.
+	/// Given an n-by-m input matrix, q has dimensions min(n,m)-by-m, and r has dimensions n-by-min(n,m).
+	///
+	/// From GLM_GTX_matrix_factorisation extension.
+	template <length_t C, length_t R, typename T, qualifier Q>
+	GLM_FUNC_DECL void qr_decompose(mat<C, R, T, Q> const& in, mat<(C < R ? C : R), R, T, Q>& q, mat<C, (C < R ? C : R), T, Q>& r);
+
+	/// Performs RQ factorisation of a matrix.
+	/// Returns 2 matrices, r and q, such that r is an upper triangular matrix, the rows of q are orthonormal and span the same subspace than those of the input matrix, and r*q=in.
+	/// Note that in the context of RQ factorisation, the diagonal is seen as starting in the lower-right corner of the matrix, instead of the usual upper-left.
+	/// Given an n-by-m input matrix, r has dimensions min(n,m)-by-m, and q has dimensions n-by-min(n,m).
+	///
+	/// From GLM_GTX_matrix_factorisation extension.
+	template <length_t C, length_t R, typename T, qualifier Q>
+	GLM_FUNC_DECL void rq_decompose(mat<C, R, T, Q> const& in, mat<(C < R ? C : R), R, T, Q>& r, mat<C, (C < R ? C : R), T, Q>& q);
+
+	/// @}
+}
+
+#include "matrix_factorisation.inl"