From afdbba7d82eda8486bf2566f4282c77ec323c757 Mon Sep 17 00:00:00 2001
From: Christophe Riccio <g.truc.creation@gmail.com>
Date: Fri, 21 Jan 2011 00:37:42 +0000
Subject: [PATCH] Uniformalized matrix transform function

---
 glm/gtc/matrix_transform.hpp |  1 +
 glm/gtc/matrix_transform.inl |  3 ++-
 glm/gtx/transform2.hpp       |  8 ++++++++
 glm/gtx/transform2.inl       | 29 +++++++++++++++++++++++++++++
 4 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/glm/gtc/matrix_transform.hpp b/glm/gtc/matrix_transform.hpp
index 8b6d82c9..1daca18b 100644
--- a/glm/gtc/matrix_transform.hpp
+++ b/glm/gtc/matrix_transform.hpp
@@ -137,6 +137,7 @@ namespace glm
 		//! From GLM_GTC_matrix_transform extension.
 		template <typename T> 
 		detail::tmat4x4<T> lookAt(
+			detail::tmat4x4<T> const & m,
 			detail::tvec3<T> const & eye, 
 			detail::tvec3<T> const & center, 
 			detail::tvec3<T> const & up);
diff --git a/glm/gtc/matrix_transform.inl b/glm/gtc/matrix_transform.inl
index ba1f75dc..9dc1cf38 100644
--- a/glm/gtc/matrix_transform.inl
+++ b/glm/gtc/matrix_transform.inl
@@ -326,6 +326,7 @@ namespace matrix_transform
 
     template <typename T> 
     inline detail::tmat4x4<T> lookAt(
+		detail::tmat4x4<T> const & m,
 		const detail::tvec3<T>& eye, 
 		const detail::tvec3<T>& center, 
 		const detail::tvec3<T>& up)
@@ -350,7 +351,7 @@ namespace matrix_transform
         Result[3][1] =-dot(y, eye);
         Result[3][2] = dot(f, eye);
     */  
-		return gtc::matrix_transform::translate(Result, -eye);
+		return m * gtc::matrix_transform::translate(Result, -eye);
     }
 }//namespace matrix_transform
 }//namespace gtc
diff --git a/glm/gtx/transform2.hpp b/glm/gtx/transform2.hpp
index 9f05976c..c32a4bf6 100644
--- a/glm/gtx/transform2.hpp
+++ b/glm/gtx/transform2.hpp
@@ -109,6 +109,14 @@ namespace glm
 			valType scale, 
 			valType bias);
 
+		//! Build a look at view matrix.
+		//! From GLM_GTX_transform2 extension.
+		template <typename T>
+		detail::tmat4x4<T> lookAt(
+			detail::tvec3<T> const & eye,
+			detail::tvec3<T> const & center,
+			detail::tvec3<T> const & up);
+
 	}//namespace transform2
     }//namespace gtx
 }//namespace glm
diff --git a/glm/gtx/transform2.inl b/glm/gtx/transform2.inl
index 841d180c..7e449a8c 100644
--- a/glm/gtx/transform2.inl
+++ b/glm/gtx/transform2.inl
@@ -153,6 +153,35 @@ namespace transform2
 		return m * scaleBias(scale, bias);
 	}
 
+	template <typename T>
+	inline detail::tmat4x4<T> lookAt(
+		const detail::tvec3<T>& eye,
+		const detail::tvec3<T>& center,
+		const detail::tvec3<T>& up)
+	{
+		detail::tvec3<T> f = normalize(center - eye);
+		detail::tvec3<T> u = normalize(up);
+		detail::tvec3<T> s = normalize(cross(f, u));
+		u = cross(s, f);
+
+		detail::tmat4x4<T> Result(1);
+		Result[0][0] = s.x;
+		Result[1][0] = s.y;
+		Result[2][0] = s.z;
+		Result[0][1] = u.x;
+		Result[1][1] = u.y;
+		Result[2][1] = u.z;
+		Result[0][2] =-f.x;
+		Result[1][2] =-f.y;
+		Result[2][2] =-f.z;
+	/*  Test this instead of translate3D
+		Result[3][0] =-dot(s, eye);
+		Result[3][1] =-dot(y, eye);
+		Result[3][2] = dot(f, eye);
+	*/
+		return gtc::matrix_transform::translate(Result, -eye);
+	}
+
 }//namespace transform2
 }//namespace gtx
 }//namespace glm