Adding a helper rgb-to-hsl function. Gonna' use it real soon now.

functions.cpp

@@ -123,6 +123,33 @@ namespace Sass {
     }
     
     // HSL Functions ///////////////////////////////////////////////////////
+
+    // Utility rgb to hsl function so we can do hsl operations
+    Node rgb_to_hsl(double r, double g, double b, Node_Factory& new_Node) {
+      r = r/255.0;
+      g = g/255.0;
+      b = b/255.0;
+      double v, m, vm, r2, g2, b2;
+      double h = 0, s = 0, l = 0;
+      v = r > g ? r : g;
+      v = v > b ? v : b;
+      m = r < g ? r : g;
+      m = m < b ? m : b;
+      l = (m + v)/2.0;
+      if (l <= 0.0) return new_Node("", 0, h, s, l);
+      vm = v - m;
+      s = vm;
+      if (s > 0.0) s /= (l <= 0.5) ? (v + m) : (2.0 - v - m);
+      else         return new_Node("", 0, h, s, l);
+      r2 = (v - r)/vm;
+      g2 = (v - g)/vm;
+      b2 = (v - b)/vm;
+      if (r == v)      h = (g == m ? 5.0 + b2 : 1.0 - g2);
+      else if (g == v) h = (b == m ? 1.0 + r2 : 3.0 - b2);
+      else             h = (r == m ? 3.0 + g2 : 5.0 - r2);
+      h /= 6.0;
+      return new_Node("", 0, h, s, l);
+    }
     
     double h_to_rgb(double m1, double m2, double h) {
       if (h < 0) ++h;