# HG changeset patch
# User Eris Caffee <discordia@eldalin.com>
# Date 1369024228 18000
# Node ID 2ac83ae9129becfac892c9fdb037824a6351daf5
# Parent  ea32c94fc4951219e35efb91306d26045eb36b2b
Added get_ortho_mat44()

diff -r ea32c94fc495 -r 2ac83ae9129b include/Matrix.h
--- a/include/Matrix.h	Sun May 19 20:17:16 2013 -0500
+++ b/include/Matrix.h	Sun May 19 23:30:28 2013 -0500
@@ -818,7 +818,7 @@
       //////////////////////////////////////////////////////////////////////////
       // Matrix functions
       // TODO: The determinant functions suffer from some bad round off error.
-      // If it significant?  I don't know.  None of the other game engines
+      // Is it significant?  I don't know.  None of the other game engines
       // I've checked bother to do anything to calculate det more accurately.
       // So maybe it just doesn't matter enough for game purposes.
 
diff -r ea32c94fc495 -r 2ac83ae9129b include/Transform.h
--- a/include/Transform.h	Sun May 19 20:17:16 2013 -0500
+++ b/include/Transform.h	Sun May 19 23:30:28 2013 -0500
@@ -39,14 +39,21 @@
         // (x = 0, y = 1, z = 2)
         template <typename T>
         void get_shear_mat44(arda::Math::Matrix44<T> & M, int i, int j, float s);
-      
+
+        // Transformation matrix for combination of translation by d and rotation by angle around v.
         template <typename T>
         void get_transform_mat44(arda::Math::Matrix44<T> & M, float angle, arda::Math::Vector3<T> v, arda::Math::Vector3<T> d);
 
         // Rotate by angle around v with center of rotation p.
         template <typename T>
         void get_rot_about_point_mat44(arda::Math::Matrix33<T> & M, float angle, arda::Math::Vector3<T> v, arda::Math::Vector3<T> p);
-      
+
+        ////////////////////////////////////////      
+        // Projection matrices
+
+        template <typename T>
+        void get_ortho_mat44(arda::Math::Matrix44<T> & M, T near, T far, T left, T right, T bottom, T top);
+
         } // namespace Math
    
     } // namespace arda
@@ -196,4 +203,17 @@
     M[15] = T(1);
     }
 
+////////////////////////////////////////////////////////////////////////////////
+template <typename T>
+void arda::Math::get_ortho_mat44(arda::Math::Matrix44<T> & M, T near, T far, T left, T right, T bottom, T top)
+    {
+    M.assign(
+        2 / (right - left),                T(0),                              T(0),                          T(0),
+        T(0),                              2 / (top - bottom),                T(0),                          T(0),
+        T(0),                              T(0),                              - 2 / (far - near),            T(0),
+        - (right + left) / (right - left), - (top + bottom) / (top - bottom), - (far + near) / (far - near), T(1) );
+    
+    }
+
+
 #endif