From ccc21b2ae8858c32a8a62b2fa16c1a96f7f6e679 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Tue, 13 Jan 2015 18:33:02 +1100
Subject: [PATCH] colour: derive from detail::coord

---
 colour.cpp | 49 +++++++++++++++++++++++++++++++++----------------
 colour.hpp | 21 ++++++++++++++-------
 2 files changed, 47 insertions(+), 23 deletions(-)

diff --git a/colour.cpp b/colour.cpp
index a8a2c3c0..9c612c08 100644
--- a/colour.cpp
+++ b/colour.cpp
@@ -28,21 +28,33 @@ using namespace util;
 
 
 //-----------------------------------------------------------------------------
-const util::colour util::colour::WHITE ({ 1.f, 1.f, 1.f, 1.f });
-const util::colour util::colour::BLACK ({ 0.f, 0.f, 0.f, 1.f });
+template <typename T>
+const util::colour<T>
+util::colour<T>::WHITE (1.f, 1.f, 1.f, 1.f);
 
-const util::colour util::colour::RED   ({ 1.f, 0.f, 0.f, 1.f });
-const util::colour util::colour::GREEN ({ 0.f, 1.f, 0.f, 1.f });
-const util::colour util::colour::BLUE  ({ 0.f, 0.f, 1.f, 1.f });
+template <typename T>
+const util::colour<T>
+util::colour<T>::BLACK (0.f, 0.f, 0.f, 1.f);
+
+template <typename T>
+const util::colour<T>
+util::colour<T>::RED (1.f, 0.f, 0.f, 1.f);
+
+template <typename T>
+const util::colour<T>
+util::colour<T>::GREEN (0.f, 1.f, 0.f, 1.f);
+
+template <typename T>
+const util::colour<T>
+util::colour<T>::BLUE (0.f, 0.f, 1.f, 1.f);
 
 
-//-----------------------------------------------------------------------------
 //! Extract a colour object from a JSON node.
 //! 
 //! Data must be an array or 3 or 4 numbers. Guarantees success, or throws a
 //! json::type_error.
 const json::node&
-operator>> (const json::node &node, colour &c) {
+operator>> (const json::node &node, colour4f &c) {
     c.r = static_cast<float> (node[0].as_number ());
     c.g = static_cast<float> (node[1].as_number ());
     c.b = static_cast<float> (node[2].as_number ());
@@ -60,24 +72,29 @@ operator>> (const json::node &node, colour &c) {
 //-----------------------------------------------------------------------------
 namespace util {
     template<>
-    colour
+    colour4f
     random (void) {
-        return colour ({ range<float>::UNIT.random (),
-                         range<float>::UNIT.random (),
-                         range<float>::UNIT.random (),
-                         range<float>::UNIT.random () });
+        return colour4f ({ range<float>::UNIT.random (),
+                           range<float>::UNIT.random (),
+                           range<float>::UNIT.random (),
+                           range<float>::UNIT.random () });
     }
 
     template <>
-    colour&
-    randomise (colour &c)
-        { return c = random<colour> (); }
+    colour4f&
+    randomise (colour4f &c)
+        { return c = random<colour4f> (); }
 }
 
 
 //-----------------------------------------------------------------------------
 std::ostream&
-util::operator<< (std::ostream &os, const util::colour &c) {
+util::operator<< (std::ostream &os, const util::colour4f &c) {
     os << "colour(" << c.r << ", " << c.g << ", " << c.b << ", " << c.a << ")";
     return os;
 }
+
+
+//-----------------------------------------------------------------------------
+template struct util::colour<float>;
+template struct util::colour<double>;
diff --git a/colour.hpp b/colour.hpp
index 37ab846e..c9802eee 100644
--- a/colour.hpp
+++ b/colour.hpp
@@ -20,17 +20,22 @@
 #ifndef __UTIL_COLOUR_HPP
 #define __UTIL_COLOUR_HPP
 
+#include "detail/coord.hpp"
+
 #include "json.hpp"
 
 #include <iostream>
 
 namespace util {
     /// An RGBA colour POD type.
-    struct colour {
-        float r;
-        float g;
-        float b;
-        float a;
+    template <typename T>
+    struct colour : public detail::coord<4, T> {
+        using detail::coord<4,T>::coord;
+
+        T r;
+        T g;
+        T b;
+        T a;
 
         static const colour WHITE;
         static const colour BLACK;
@@ -39,8 +44,10 @@ namespace util {
         static const colour GREEN;
     };
 
-    std::ostream& operator<< (std::ostream&, const util::colour&);
-    const json::node& operator>> (const json::node&, util::colour&);
+    typedef colour<float> colour4f;
+
+    const json::node& operator>> (const json::node&, util::colour4f&);
+    std::ostream& operator<< (std::ostream&, const util::colour4f&);
 }
 
 #endif