X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;f=src%2Fvideo%2Fcolor.hpp;h=f0bd76d6b0ee87e78802b7823c521a96d81f4146;hb=4f423b9bbb6fa694b8c6bcc338e069aad45db3e3;hp=e94b362d0b3a8cdb3105d16321f253db4ad0bd1e;hpb=5e0bb78e0d7679399eb0f687ecaf93a91cfcb577;p=supertux.git

diff --git a/src/video/color.hpp b/src/video/color.hpp
index e94b362d0..f0bd76d6b 100644
--- a/src/video/color.hpp
+++ b/src/video/color.hpp
@@ -66,7 +66,26 @@ public:
       log_warning << "color value out of range: " << red << ", " << green << ", " << blue << ", " << alpha << std::endl;
   }
 
+  float greyscale() const
+  {
+    return red * 0.30 + green * 0.59 + blue * 0.11;
+  }
+
+  bool operator < (const Color& other) const
+  {
+    return greyscale() < other.greyscale();
+  }
+
   float red, green, blue, alpha;
+
+  static const Color BLACK;
+  static const Color RED;
+  static const Color GREEN;
+  static const Color BLUE;
+  static const Color CYAN;
+  static const Color MAGENTA;
+  static const Color YELLOW;
+  static const Color WHITE;
 };
 
 #endif