1 files changed, 50 insertions, 0 deletions
diff --git a/app/services/color-service.ts b/app/services/color-service.ts
new file mode 100644
index 0000000..37183c0
--- /dev/null
+++ b/app/services/color-service.ts
@@ -0,0 +1,50 @@
+export class ColorService {
+       /**
+        * http://stackoverflow.com/questions/2353211/hsl-to-rgb-color-conversion
+        *
+        * Converts an HSL color value to RGB. Conversion formula
+        * adapted from http://en.wikipedia.org/wiki/HSL_color_space.
+        * Assumes h, s, and l are contained in the set [0, 1] and
+        * returns r, g, and b in the set [0, 255].
+        *
+        * @param   Number  h       The hue
+        * @param   Number  s       The saturation
+        * @param   Number  l       The lightness
+        * @return  Array           The RGB representation
+        */
+       hslToRgb(h, s, l) {
+           var r, g, b;
+
+           if (s == 0) {
+               r = g = b = l; // achromatic
+           } else {
+               function hue2rgb(p, q, t) {
+                   if (t < 0) t += 1;
+                   if (t > 1) t -= 1;
+                   if (t < 1 / 6) return p + (q - p) * 6 * t;
+                   if (t < 1 / 2) return q;
+                   if (t < 2 / 3) return p + (q - p) * (2 / 3 - t) * 6;
+                   return p;
+               }
+
+               var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
+               var p = 2 * l - q;
+               r = hue2rgb(p, q, h + 1 / 3);
+               g = hue2rgb(p, q, h);
+               b = hue2rgb(p, q, h - 1 / 3);
+           }
+
+           return [Math.floor(r * 255), Math.floor(g * 255), Math.floor(b * 255)];
+       }
+
+       // convert a number to a color using hsl
+       numberToColorHsl(i) {
+           // as the function expects a value between 0 and 1, and red = 0° and green = 120°
+           // we convert the input to the appropriate hue value
+           var hue = i * 100 * 1.2 / 360;
+           // we convert hsl to rgb (saturation 100%, lightness 50%)
+           var rgb = this.hslToRgb(hue, .9, .4);
+           // we format to css value and return
+           return 'rgb(' + rgb[0] + ',' + rgb[1] + ',' + rgb[2] + ')';
+       }
+}