Add trivial rgba colour class

Makefile.am

@@ -10,6 +10,7 @@ UTIL_INCLUDE =  \
     annotations.hpp 	\
     backtrace.hpp   	\
     bitwise.hpp		\
+    colour.hpp		\
     debug.hpp   	\
     enable_if.hpp  	\
     endian.hpp		\
@@ -39,6 +40,7 @@ UTIL_INCLUDE =  \
 
 UTIL_FILES   =		\
     bitwise.cpp		\
+    colour.cpp		\
     debug.cpp   	\
     endian.cpp		\
     except.cpp  	\

colour.cpp

@@ -0,0 +1,55 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with libgim.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2010 Danny Robson <danny@blubinc.net>
+ */
+
+#include "colour.hpp"
+#include "range.hpp"
+
+using namespace util;
+
+
+colour::colour (double _red, double _green, double _blue, double _alpha):
+    red   (_red),
+    green (_green),
+    blue  (_blue),
+    alpha (_alpha)
+{ ; }
+
+
+namespace util {
+    template<>
+    colour
+    random (void) {
+        return colour (range<double>::UNIT.rand (),
+                       range<double>::UNIT.rand (),
+                       range<double>::UNIT.rand (),
+                       range<double>::UNIT.rand ());
+    }
+
+    template <>
+    colour&
+    randomise (colour &c)
+        { return c = random<colour> (); }
+}
+
+
+std::ostream&
+operator<< (std::ostream &os, const util::colour &c) {
+    os << "colour(" << c.red << ", " << c.green << ", " << c.blue << ", " << c.alpha << ")";
+    return os;
+}

colour.hpp

@@ -0,0 +1,43 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with libgim.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2010 Danny Robson <danny@blubinc.net>
+ */
+
+#ifndef __UTIL_COLOUR_HPP
+#define __UTIL_COLOUR_HPP
+
+#include "random.hpp"
+
+#include <iostream>
+
+namespace util {
+    struct colour {
+        colour (double red, double green, double blue, double alpha = 1.0);
+
+        double red;
+        double green;
+        double blue;
+        double alpha;
+    };
+
+    template <> colour& randomise (colour&);
+    template <> colour& random    (void);
+}
+
+std::ostream& operator<< (std::ostream&, const util::colour&);
+
+#endif