Added color utilities; implemented more of Graph related classes

git-svn-id: svn://svn.code.sf.net/p/magicseteditor/code/trunk@76 0fc631ac-6414-0410-93d0-97cfa31319b6

src/gfx/gfx.hpp

@@ -144,7 +144,7 @@ class ContourMask {
 	UInt *lefts, *rights;
 };
 
-// ----------------------------------------------------------------------------- : Utility
+// ----------------------------------------------------------------------------- : Color utility functions
 
 inline int bot(int x) { return max(0,   x); } ///< bottom range check for color values
 inline int top(int x) { return min(255, x); } ///< top    range check for color values
@@ -153,5 +153,11 @@ inline int col(int x) { return top(bot(x)); } ///< top and bottom range check fo
 /// Linear interpolation between colors
 Color lerp(const Color& a, const Color& b, double t);
 
+/// convert HSL to RGB, h,s,l must be in range [0...1)
+Color hsl2rgb(double h, double s, double l);
+
+/// A darker version of a color
+Color darken(const Color& c);
+
 // ----------------------------------------------------------------------------- : EOF
 #endif