From 9b5bec81f2c110f92271abe78154f5599f9c1f2f Mon Sep 17 00:00:00 2001
From: Christophe Riccio <mail@g-truc.net>
Date: Wed, 25 Dec 2013 05:58:11 +0100
Subject: [PATCH] Factorize glm::inverse code for matrices

---
 glm/detail/func_matrix.hpp |  68 ++---------
 glm/detail/func_matrix.inl | 223 ++++++++++++++++++++-----------------
 2 files changed, 130 insertions(+), 161 deletions(-)

diff --git a/glm/detail/func_matrix.hpp b/glm/detail/func_matrix.hpp
index 238b3ad9..34f4f61d 100644
--- a/glm/detail/func_matrix.hpp
+++ b/glm/detail/func_matrix.hpp
@@ -40,15 +40,9 @@
 #ifndef GLM_CORE_func_matrix
 #define GLM_CORE_func_matrix
 
-#include "type_mat2x2.hpp"
-#include "type_mat2x3.hpp"
-#include "type_mat2x4.hpp"
-#include "type_mat3x2.hpp"
-#include "type_mat3x3.hpp"
-#include "type_mat3x4.hpp"
-#include "type_mat4x2.hpp"
-#include "type_mat4x3.hpp"
-#include "type_mat4x4.hpp"
+// Dependencies
+#include "../detail/precision.hpp"
+#include "../detail/setup.hpp"
 
 namespace glm
 {
@@ -92,65 +86,25 @@ namespace glm
 	GLM_FUNC_DECL typename matType::transpose_type transpose(
 		matType const & x);
 	
-	/// Return the determinant of a mat2 matrix.
+	/// Return the determinant of a squared matrix.
 	/// 
 	/// @tparam valType Floating-point scalar types.
 	///
 	/// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/determinant.xml">GLSL determinant man page</a>
 	/// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.6 Matrix Functions</a>	
-	template <typename T, precision P>
-	GLM_FUNC_DECL typename detail::tmat2x2<T, P>::value_type determinant(
-		detail::tmat2x2<T, P> const & m);
+	template <typename T, precision P, template <typename, precision> class matType>
+	GLM_FUNC_DECL T determinant(
+		matType<T, P> const & m);
 
-	/// Return the determinant of a mat3 matrix.
-	/// 
-	/// @tparam valType Floating-point scalar types.
-	///
-	/// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/determinant.xml">GLSL determinant man page</a>
-	/// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.6 Matrix Functions</a>	
-	template <typename T, precision P>
-	GLM_FUNC_DECL typename detail::tmat3x3<T, P>::value_type determinant(
-		detail::tmat3x3<T, P> const & m);
-
-	/// Return the determinant of a mat4 matrix.
-	/// 
-	/// @tparam valType Floating-point scalar types.
-	///
-	/// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/determinant.xml">GLSL determinant man page</a>
-	/// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.6 Matrix Functions</a>		
-	template <typename T, precision P>
-	GLM_FUNC_DECL typename detail::tmat4x4<T, P>::value_type determinant(
-		detail::tmat4x4<T, P> const & m);
-
-	/// Return the inverse of a mat2 matrix.
+	/// Return the inverse of a squared matrix.
 	/// 
 	/// @tparam valType Floating-point scalar types.
 	///
 	/// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/inverse.xml">GLSL inverse man page</a>
 	/// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.6 Matrix Functions</a>	 
-	template <typename T, precision P>
-	GLM_FUNC_DECL detail::tmat2x2<T, P> inverse(
-		detail::tmat2x2<T, P> const & m);
-
-	/// Return the inverse of a mat3 matrix.
-	/// 
-	/// @tparam valType Floating-point scalar types.
-	///
-	/// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/inverse.xml">GLSL inverse man page</a>
-	/// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.6 Matrix Functions</a> 
-	template <typename T, precision P>
-	GLM_FUNC_DECL detail::tmat3x3<T, P> inverse(
-		detail::tmat3x3<T, P> const & m);
-
-	/// Return the inverse of a mat4 matrix.
-	/// 
-	/// @tparam valType Floating-point scalar types.
-	///
-	/// @see <a href="http://www.opengl.org/sdk/docs/manglsl/xhtml/inverse.xml">GLSL inverse man page</a>
-	/// @see <a href="http://www.opengl.org/registry/doc/GLSLangSpec.4.20.8.pdf">GLSL 4.20.8 specification, section 8.6 Matrix Functions</a>
-	template <typename T, precision P>
-	GLM_FUNC_DECL detail::tmat4x4<T, P> inverse(
-		detail::tmat4x4<T, P> const & m);
+	template <typename T, precision P, template <typename, precision> class matType>
+	GLM_FUNC_DECL matType<T, P> inverse(
+		matType<T, P> const & m);
 
 	/// @}
 }//namespace glm
diff --git a/glm/detail/func_matrix.inl b/glm/detail/func_matrix.inl
index d1509e60..3f178bb2 100644
--- a/glm/detail/func_matrix.inl
+++ b/glm/detail/func_matrix.inl
@@ -30,6 +30,15 @@
 #include "../vec2.hpp"
 #include "../vec3.hpp"
 #include "../vec4.hpp"
+#include "type_mat2x2.hpp"
+#include "type_mat2x3.hpp"
+#include "type_mat2x4.hpp"
+#include "type_mat3x2.hpp"
+#include "type_mat3x3.hpp"
+#include "type_mat3x4.hpp"
+#include "type_mat4x2.hpp"
+#include "type_mat4x3.hpp"
+#include "type_mat4x4.hpp"
 #include <limits>
 
 namespace glm
@@ -474,115 +483,121 @@ namespace glm
 				+ m[0][3] * DetCof[3];
 	}
 
+namespace detail
+{
+	template <template <class, precision> class matType, typename T, precision P>
+	struct compute_inverse{};
+
 	template <typename T, precision P>
-	GLM_FUNC_QUALIFIER detail::tmat2x2<T, P> inverse
+	struct compute_inverse<detail::tmat2x2, T, P>
+	{
+		static detail::tmat2x2<T, P> call(detail::tmat2x2<T, P> const & m)
+		{
+			T Determinant = determinant(m);
+
+			detail::tmat2x2<T, P> Inverse(
+				+ m[1][1] / Determinant,
+				- m[0][1] / Determinant,
+				- m[1][0] / Determinant,
+				+ m[0][0] / Determinant);
+
+			return Inverse;
+		}
+	};
+
+	template <typename T, precision P>
+	struct compute_inverse<detail::tmat3x3, T, P>
+	{
+		static detail::tmat3x3<T, P> call(detail::tmat3x3<T, P> const & m)
+		{
+			T Determinant = determinant(m);
+
+			detail::tmat3x3<T, P> Inverse(detail::tmat3x3<T, P>::_null);
+			Inverse[0][0] = + (m[1][1] * m[2][2] - m[2][1] * m[1][2]);
+			Inverse[1][0] = - (m[1][0] * m[2][2] - m[2][0] * m[1][2]);
+			Inverse[2][0] = + (m[1][0] * m[2][1] - m[2][0] * m[1][1]);
+			Inverse[0][1] = - (m[0][1] * m[2][2] - m[2][1] * m[0][2]);
+			Inverse[1][1] = + (m[0][0] * m[2][2] - m[2][0] * m[0][2]);
+			Inverse[2][1] = - (m[0][0] * m[2][1] - m[2][0] * m[0][1]);
+			Inverse[0][2] = + (m[0][1] * m[1][2] - m[1][1] * m[0][2]);
+			Inverse[1][2] = - (m[0][0] * m[1][2] - m[1][0] * m[0][2]);
+			Inverse[2][2] = + (m[0][0] * m[1][1] - m[1][0] * m[0][1]);
+			Inverse /= Determinant;
+
+			return Inverse;
+		}
+	};
+
+	template <typename T, precision P>
+	struct compute_inverse<detail::tmat4x4, T, P>
+	{
+		static detail::tmat4x4<T, P> call(detail::tmat4x4<T, P> const & m)
+		{
+			T Coef00 = m[2][2] * m[3][3] - m[3][2] * m[2][3];
+			T Coef02 = m[1][2] * m[3][3] - m[3][2] * m[1][3];
+			T Coef03 = m[1][2] * m[2][3] - m[2][2] * m[1][3];
+
+			T Coef04 = m[2][1] * m[3][3] - m[3][1] * m[2][3];
+			T Coef06 = m[1][1] * m[3][3] - m[3][1] * m[1][3];
+			T Coef07 = m[1][1] * m[2][3] - m[2][1] * m[1][3];
+
+			T Coef08 = m[2][1] * m[3][2] - m[3][1] * m[2][2];
+			T Coef10 = m[1][1] * m[3][2] - m[3][1] * m[1][2];
+			T Coef11 = m[1][1] * m[2][2] - m[2][1] * m[1][2];
+
+			T Coef12 = m[2][0] * m[3][3] - m[3][0] * m[2][3];
+			T Coef14 = m[1][0] * m[3][3] - m[3][0] * m[1][3];
+			T Coef15 = m[1][0] * m[2][3] - m[2][0] * m[1][3];
+
+			T Coef16 = m[2][0] * m[3][2] - m[3][0] * m[2][2];
+			T Coef18 = m[1][0] * m[3][2] - m[3][0] * m[1][2];
+			T Coef19 = m[1][0] * m[2][2] - m[2][0] * m[1][2];
+
+			T Coef20 = m[2][0] * m[3][1] - m[3][0] * m[2][1];
+			T Coef22 = m[1][0] * m[3][1] - m[3][0] * m[1][1];
+			T Coef23 = m[1][0] * m[2][1] - m[2][0] * m[1][1];
+
+			detail::tvec4<T, P> const SignA(+1, -1, +1, -1);
+			detail::tvec4<T, P> const SignB(-1, +1, -1, +1);
+
+			detail::tvec4<T, P> Fac0(Coef00, Coef00, Coef02, Coef03);
+			detail::tvec4<T, P> Fac1(Coef04, Coef04, Coef06, Coef07);
+			detail::tvec4<T, P> Fac2(Coef08, Coef08, Coef10, Coef11);
+			detail::tvec4<T, P> Fac3(Coef12, Coef12, Coef14, Coef15);
+			detail::tvec4<T, P> Fac4(Coef16, Coef16, Coef18, Coef19);
+			detail::tvec4<T, P> Fac5(Coef20, Coef20, Coef22, Coef23);
+
+			detail::tvec4<T, P> Vec0(m[1][0], m[0][0], m[0][0], m[0][0]);
+			detail::tvec4<T, P> Vec1(m[1][1], m[0][1], m[0][1], m[0][1]);
+			detail::tvec4<T, P> Vec2(m[1][2], m[0][2], m[0][2], m[0][2]);
+			detail::tvec4<T, P> Vec3(m[1][3], m[0][3], m[0][3], m[0][3]);
+
+			detail::tvec4<T, P> Inv0 = SignA * (Vec1 * Fac0 - Vec2 * Fac1 + Vec3 * Fac2);
+			detail::tvec4<T, P> Inv1 = SignB * (Vec0 * Fac0 - Vec2 * Fac3 + Vec3 * Fac4);
+			detail::tvec4<T, P> Inv2 = SignA * (Vec0 * Fac1 - Vec1 * Fac3 + Vec3 * Fac5);
+			detail::tvec4<T, P> Inv3 = SignB * (Vec0 * Fac2 - Vec1 * Fac4 + Vec2 * Fac5);
+
+			detail::tmat4x4<T, P> Inverse(Inv0, Inv1, Inv2, Inv3);
+
+			detail::tvec4<T, P> Row0(Inverse[0][0], Inverse[1][0], Inverse[2][0], Inverse[3][0]);
+
+			T Determinant = dot(m[0], Row0);
+
+			Inverse /= Determinant;
+
+			return Inverse;
+		}
+	};
+}//namespace detail
+
+	template <typename T, precision P, template <typename, precision> class matType>
+	GLM_FUNC_DECL matType<T, P> inverse
 	(
-		detail::tmat2x2<T, P> const & m
+		matType<T, P> const & m
 	)
 	{
 		GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559, "'inverse' only accept floating-point inputs");
-			
-		//valType Determinant = m[0][0] * m[1][1] - m[1][0] * m[0][1];
-		T Determinant = determinant(m);
-
-		detail::tmat2x2<T, P> Inverse(
-			+ m[1][1] / Determinant,
-			- m[0][1] / Determinant,
-			- m[1][0] / Determinant,
-			+ m[0][0] / Determinant);
-
-		return Inverse;
+		return detail::compute_inverse<matType, T, P>::call(m);
 	}
 
-	template <typename T, precision P>
-	GLM_FUNC_QUALIFIER detail::tmat3x3<T, P> inverse
-	(
-		detail::tmat3x3<T, P> const & m
-	)
-	{
-		GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559, "'inverse' only accept floating-point inputs");
-
-		//valType Determinant = m[0][0] * (m[1][1] * m[2][2] - m[2][1] * m[1][2])
-		//					- m[1][0] * (m[0][1] * m[2][2] - m[2][1] * m[0][2])
-		//					+ m[2][0] * (m[0][1] * m[1][2] - m[1][1] * m[0][2]);
-
-		T Determinant = determinant(m);
-
-		detail::tmat3x3<T, P> Inverse(detail::tmat3x3<T, P>::_null);
-		Inverse[0][0] = + (m[1][1] * m[2][2] - m[2][1] * m[1][2]);
-		Inverse[1][0] = - (m[1][0] * m[2][2] - m[2][0] * m[1][2]);
-		Inverse[2][0] = + (m[1][0] * m[2][1] - m[2][0] * m[1][1]);
-		Inverse[0][1] = - (m[0][1] * m[2][2] - m[2][1] * m[0][2]);
-		Inverse[1][1] = + (m[0][0] * m[2][2] - m[2][0] * m[0][2]);
-		Inverse[2][1] = - (m[0][0] * m[2][1] - m[2][0] * m[0][1]);
-		Inverse[0][2] = + (m[0][1] * m[1][2] - m[1][1] * m[0][2]);
-		Inverse[1][2] = - (m[0][0] * m[1][2] - m[1][0] * m[0][2]);
-		Inverse[2][2] = + (m[0][0] * m[1][1] - m[1][0] * m[0][1]);
-		Inverse /= Determinant;
-
-		return Inverse;
-	}
-
-	template <typename T, precision P>
-	GLM_FUNC_QUALIFIER detail::tmat4x4<T, P> inverse
-	(
-		detail::tmat4x4<T, P> const & m
-	)
-	{
-		GLM_STATIC_ASSERT(std::numeric_limits<T>::is_iec559, "'inverse' only accept floating-point inputs");
-
-		T Coef00 = m[2][2] * m[3][3] - m[3][2] * m[2][3];
-		T Coef02 = m[1][2] * m[3][3] - m[3][2] * m[1][3];
-		T Coef03 = m[1][2] * m[2][3] - m[2][2] * m[1][3];
-
-		T Coef04 = m[2][1] * m[3][3] - m[3][1] * m[2][3];
-		T Coef06 = m[1][1] * m[3][3] - m[3][1] * m[1][3];
-		T Coef07 = m[1][1] * m[2][3] - m[2][1] * m[1][3];
-
-		T Coef08 = m[2][1] * m[3][2] - m[3][1] * m[2][2];
-		T Coef10 = m[1][1] * m[3][2] - m[3][1] * m[1][2];
-		T Coef11 = m[1][1] * m[2][2] - m[2][1] * m[1][2];
-
-		T Coef12 = m[2][0] * m[3][3] - m[3][0] * m[2][3];
-		T Coef14 = m[1][0] * m[3][3] - m[3][0] * m[1][3];
-		T Coef15 = m[1][0] * m[2][3] - m[2][0] * m[1][3];
-
-		T Coef16 = m[2][0] * m[3][2] - m[3][0] * m[2][2];
-		T Coef18 = m[1][0] * m[3][2] - m[3][0] * m[1][2];
-		T Coef19 = m[1][0] * m[2][2] - m[2][0] * m[1][2];
-
-		T Coef20 = m[2][0] * m[3][1] - m[3][0] * m[2][1];
-		T Coef22 = m[1][0] * m[3][1] - m[3][0] * m[1][1];
-		T Coef23 = m[1][0] * m[2][1] - m[2][0] * m[1][1];
-
-		detail::tvec4<T, P> const SignA(+1, -1, +1, -1);
-		detail::tvec4<T, P> const SignB(-1, +1, -1, +1);
-
-		detail::tvec4<T, P> Fac0(Coef00, Coef00, Coef02, Coef03);
-		detail::tvec4<T, P> Fac1(Coef04, Coef04, Coef06, Coef07);
-		detail::tvec4<T, P> Fac2(Coef08, Coef08, Coef10, Coef11);
-		detail::tvec4<T, P> Fac3(Coef12, Coef12, Coef14, Coef15);
-		detail::tvec4<T, P> Fac4(Coef16, Coef16, Coef18, Coef19);
-		detail::tvec4<T, P> Fac5(Coef20, Coef20, Coef22, Coef23);
-
-		detail::tvec4<T, P> Vec0(m[1][0], m[0][0], m[0][0], m[0][0]);
-		detail::tvec4<T, P> Vec1(m[1][1], m[0][1], m[0][1], m[0][1]);
-		detail::tvec4<T, P> Vec2(m[1][2], m[0][2], m[0][2], m[0][2]);
-		detail::tvec4<T, P> Vec3(m[1][3], m[0][3], m[0][3], m[0][3]);
-
-		detail::tvec4<T, P> Inv0 = SignA * (Vec1 * Fac0 - Vec2 * Fac1 + Vec3 * Fac2);
-		detail::tvec4<T, P> Inv1 = SignB * (Vec0 * Fac0 - Vec2 * Fac3 + Vec3 * Fac4);
-		detail::tvec4<T, P> Inv2 = SignA * (Vec0 * Fac1 - Vec1 * Fac3 + Vec3 * Fac5);
-		detail::tvec4<T, P> Inv3 = SignB * (Vec0 * Fac2 - Vec1 * Fac4 + Vec2 * Fac5);
-
-		detail::tmat4x4<T, P> Inverse(Inv0, Inv1, Inv2, Inv3);
-
-		detail::tvec4<T, P> Row0(Inverse[0][0], Inverse[1][0], Inverse[2][0], Inverse[3][0]);
-
-		T Determinant = dot(m[0], Row0);
-
-		Inverse /= Determinant;
-
-		return Inverse;
-	}
 }//namespace glm