Added value actions for common value types; drop down list is now correctly aligned

git-svn-id: svn://svn.code.sf.net/p/magicseteditor/code/trunk@92 0fc631ac-6414-0410-93d0-97cfa31319b6

src/gfx/color.cpp

@@ -46,3 +46,13 @@ Color darken(const Color& c) {
 		c.Blue()  * 8 / 10
 	);
 }
+
+Color saturate(const Color& c, double amount) {
+	int r = c.Red(), g = c.Green(), b = c.Blue();
+	double l = (r + g + b) / 3;
+	return Color(
+		col((r - amount * l) / (1 - amount)),
+		col((g - amount * l) / (1 - amount)),
+		col((b - amount * l) / (1 - amount))
+	);
+}