From 2fc9073901fe82968c05f246d976eee0c58dd0e5 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Mon, 15 Dec 2014 13:45:17 +1100
Subject: [PATCH] matrix: add affine definitions and translate impl

---
 matrix.cpp | 14 ++++++++++++++
 matrix.hpp |  5 +++++
 2 files changed, 19 insertions(+)

diff --git a/matrix.cpp b/matrix.cpp
index 61f64fcc..63f05fa6 100644
--- a/matrix.cpp
+++ b/matrix.cpp
@@ -501,6 +501,20 @@ matrix<T>::look_at (util::point<3> eye,
 }
 
 
+//-----------------------------------------------------------------------------
+template <typename T>
+matrix<T>
+matrix<T>::translate (util::vector<3> v)
+{
+    return { {
+        { 1.f, 0.f, 0.f, v.x },
+        { 0.f, 1.f, 0.f, v.y },
+        { 0.f, 0.f, 1.f, v.z },
+        { 0.f, 0.f, 0.f, 1.f },
+    } };
+}
+
+
 //-----------------------------------------------------------------------------
 template <typename T>
 const matrix<T>
diff --git a/matrix.hpp b/matrix.hpp
index f3270586..cd29ab68 100644
--- a/matrix.hpp
+++ b/matrix.hpp
@@ -65,6 +65,11 @@ namespace util {
         static matrix<T> perspective (T fov, T aspect, T near, T far);
         static matrix<T> look_at (util::point<3> eye, util::point<3> centre, util::vector<3> up);
 
+        // Affine matrices
+        static matrix<T> translate (util::vector<3>);
+        static matrix<T> scale     (util::vector<3>);
+        static matrix<T> rotate    (util::vector<3> about, T angle);
+
         // Constant matrices
         static const matrix<T> IDENTITY;
         static const matrix<T> ZEROES;