From 173e7c8f278c2feba69526e13fdedfae8dd72341 Mon Sep 17 00:00:00 2001
From: Marcel Klehr <marcel.klehr@gmx.de>
Date: Wed, 29 Feb 2012 14:16:20 +0100
Subject: [PATCH] Extend colorutils

Add color invertion and calculation of complementary colors.
---
 static/js/colorutils.js | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/static/js/colorutils.js b/static/js/colorutils.js
index 9bba39ad2..5fbefb4df 100644
--- a/static/js/colorutils.js
+++ b/static/js/colorutils.js
@@ -120,4 +120,19 @@ colorutils.blend = function(c1, c2, t)
   return [colorutils.scale(t, c1[0], c2[0]), colorutils.scale(t, c1[1], c2[1]), colorutils.scale(t, c1[2], c2[2])];
 }
 
+colorutils.invert = function(c)
+{
+  return [1 - c[0], 1 - c[1], 1- c[2]];
+}
+
+colorutils.complementary = function(c)
+{
+  var inv = colorutils.invert(c);
+  return [
+    (inv[0] >= c[0]) ? Math.min(inv[0] * 1.30, 1) : (c[0] * 0.30),
+    (inv[1] >= c[1]) ? Math.min(inv[1] * 1.59, 1) : (c[1] * 0.59),
+    (inv[2] >= c[2]) ? Math.min(inv[2] * 1.11, 1) : (c[2] * 0.11)
+  ];
+}
+
 exports.colorutils = colorutils;