From a4ed6568be3cb522023952ba3dff17792ad9d570 Mon Sep 17 00:00:00 2001
From: Christophe Riccio <christopheri@unity3d.com>
Date: Thu, 1 Oct 2015 22:20:30 +0200
Subject: [PATCH] Fixed GTC_matrix_inverse affineInverse #192

---
 glm/gtc/matrix_inverse.inl | 25 +++++++++++++------------
 readme.md                  |  1 +
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/glm/gtc/matrix_inverse.inl b/glm/gtc/matrix_inverse.inl
index d88a3319..d2437d5d 100644
--- a/glm/gtc/matrix_inverse.inl
+++ b/glm/gtc/matrix_inverse.inl
@@ -35,23 +35,24 @@ namespace glm
 	template <typename T, precision P>
 	GLM_FUNC_QUALIFIER tmat3x3<T, P> affineInverse(tmat3x3<T, P> const & m)
 	{
-		tmat3x3<T, P> Result(m);
-		Result[2] = tvec3<T, P>(0, 0, 1);
-		Result = transpose(Result);
-		tvec3<T, P> Translation = Result * tvec3<T, P>(-tvec2<T, P>(m[2]), m[2][2]);
-		Result[2] = Translation;
-		return Result;
+		tmat2x2<T, P> const Inv(inverse(tmat2x2<T, P>(m)));
+
+		return tmat3x3<T, P>(
+			tvec3<T, P>(Inv[0], static_cast<T>(0)),
+			tvec3<T, P>(Inv[1], static_cast<T>(0)),
+			tvec3<T, P>(-Inv * tvec2<T, P>(m[2]), static_cast<T>(1)));
 	}
 
 	template <typename T, precision P>
 	GLM_FUNC_QUALIFIER tmat4x4<T, P> affineInverse(tmat4x4<T, P> const & m)
 	{
-		tmat4x4<T, P> Result(m);
-		Result[3] = tvec4<T, P>(0, 0, 0, 1);
-		Result = transpose(Result);
-		tvec4<T, P> Translation = Result * tvec4<T, P>(-tvec3<T, P>(m[3]), m[3][3]);
-		Result[3] = Translation;
-		return Result;
+		tmat3x3<T, P> const Inv(inverse(tmat3x3<T, P>(m)));
+
+		return tmat4x4<T, P>(
+			tvec4<T, P>(Inv[0], static_cast<T>(0)),
+			tvec4<T, P>(Inv[1], static_cast<T>(0)),
+			tvec4<T, P>(Inv[2], static_cast<T>(0)),
+			tvec4<T, P>(-Inv * tvec3<T, P>(m[3]), static_cast<T>(1)));
 	}
 
 	template <typename T, precision P>
diff --git a/readme.md b/readme.md
index 8265447a..8d18090f 100644
--- a/readme.md
+++ b/readme.md
@@ -55,6 +55,7 @@ glm::mat4 camera(float Translate, glm::vec2 const & Rotate)
 ##### Fixes:
 - Fixed GTC_round floorMultiple/ceilMultiple #412
 - Fixed GTC_packing unpackUnorm3x10_1x2 #414
+- Fixed GTC_matrix_inverse affineInverse #192
 
 #### [GLM 0.9.7.1](https://github.com/g-truc/glm/releases/tag/0.9.7.1) - 2015-09-07
 ##### Improvements: