gembin · November 16, 2021 08:08 · Apr 4, 2013 · Apr 4, 2013
diff --git a/color-conversion-algorithms.js b/color-conversion-algorithms.js
@@ -9,19 +9,19 @@
  * @param   Number  b       The blue color value
  * @return  Array           The HSL representation
  */
-function rgbToHsl(r, g, b){
+function rgbToHsl(r, g, b) {
   r /= 255, g /= 255, b /= 255;
 
   var max = Math.max(r, g, b), min = Math.min(r, g, b);
   var h, s, l = (max + min) / 2;
 
-  if(max == min){
+  if (max == min) {
     h = s = 0; // achromatic
   } else {
     var d = max - min;
     s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
 
-    switch(max){
+    switch (max) {
       case r: h = (g - b) / d + (g < b ? 6 : 0); break;
       case g: h = (b - r) / d + 2; break;
       case b: h = (r - g) / d + 4; break;
@@ -44,7 +44,7 @@ function rgbToHsl(r, g, b){
  * @param   Number  l       The lightness
  * @return  Array           The RGB representation
  */
-function hslToRgb(h, s, l){
+function hslToRgb(h, s, l) {
   var r, g, b;
 
   if (s == 0) {
@@ -61,6 +61,7 @@ function hslToRgb(h, s, l){
 
     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);
@@ -80,7 +81,7 @@ function hslToRgb(h, s, l){
  * @param   Number  b       The blue color value
  * @return  Array           The HSV representation
  */
-function rgbToHsv(r, g, b){
+function rgbToHsv(r, g, b) {
   r /= 255, g /= 255, b /= 255;
 
   var max = Math.max(r, g, b), min = Math.min(r, g, b);
@@ -115,7 +116,7 @@ function rgbToHsv(r, g, b){
  * @param   Number  v       The value
  * @return  Array           The RGB representation
  */
-function hsvToRgb(h, s, v){
+function hsvToRgb(h, s, v) {
   var r, g, b;
 
   var i = Math.floor(h * 6);

diff --git a/color-conversion-algorithms.js b/color-conversion-algorithms.js
@@ -0,0 +1,137 @@
+/**
+ * Converts an RGB color value to HSL. Conversion formula
+ * adapted from http://en.wikipedia.org/wiki/HSL_color_space.
+ * Assumes r, g, and b are contained in the set [0, 255] and
+ * returns h, s, and l in the set [0, 1].
+ *
+ * @param   Number  r       The red color value
+ * @param   Number  g       The green color value
+ * @param   Number  b       The blue color value
+ * @return  Array           The HSL representation
+ */
+function rgbToHsl(r, g, b){
+  r /= 255, g /= 255, b /= 255;
+
+  var max = Math.max(r, g, b), min = Math.min(r, g, b);
+  var h, s, l = (max + min) / 2;
+
+  if(max == min){
+    h = s = 0; // achromatic
+  } else {
+    var d = max - min;
+    s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
+
+    switch(max){
+      case r: h = (g - b) / d + (g < b ? 6 : 0); break;
+      case g: h = (b - r) / d + 2; break;
+      case b: h = (r - g) / d + 4; break;
+    }
+
+    h /= 6;
+  }
+
+  return [ h, s, l ];
+}
+
+/**
+ * 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
+ */
+function 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 [ r * 255, g * 255, b * 255 ];
+}
+
+/**
+ * Converts an RGB color value to HSV. Conversion formula
+ * adapted from http://en.wikipedia.org/wiki/HSV_color_space.
+ * Assumes r, g, and b are contained in the set [0, 255] and
+ * returns h, s, and v in the set [0, 1].
+ *
+ * @param   Number  r       The red color value
+ * @param   Number  g       The green color value
+ * @param   Number  b       The blue color value
+ * @return  Array           The HSV representation
+ */
+function rgbToHsv(r, g, b){
+  r /= 255, g /= 255, b /= 255;
+
+  var max = Math.max(r, g, b), min = Math.min(r, g, b);
+  var h, s, v = max;
+
+  var d = max - min;
+  s = max == 0 ? 0 : d / max;
+
+  if (max == min) {
+    h = 0; // achromatic
+  } else {
+    switch (max) {
+      case r: h = (g - b) / d + (g < b ? 6 : 0); break;
+      case g: h = (b - r) / d + 2; break;
+      case b: h = (r - g) / d + 4; break;
+    }
+
+    h /= 6;
+  }
+
+  return [ h, s, v ];
+}
+
+/**
+ * Converts an HSV color value to RGB. Conversion formula
+ * adapted from http://en.wikipedia.org/wiki/HSV_color_space.
+ * Assumes h, s, and v 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  v       The value
+ * @return  Array           The RGB representation
+ */
+function hsvToRgb(h, s, v){
+  var r, g, b;
+
+  var i = Math.floor(h * 6);
+  var f = h * 6 - i;
+  var p = v * (1 - s);
+  var q = v * (1 - f * s);
+  var t = v * (1 - (1 - f) * s);
+
+  switch (i % 6) {
+    case 0: r = v, g = t, b = p; break;
+    case 1: r = q, g = v, b = p; break;
+    case 2: r = p, g = v, b = t; break;
+    case 3: r = p, g = q, b = v; break;
+    case 4: r = t, g = p, b = v; break;
+    case 5: r = v, g = p, b = q; break;
+  }
+
+  return [ r * 255, g * 255, b * 255 ];
+}