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Last active October 22, 2016 20:24
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/**
* 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
*/
export function rgb2hsl (r, g, b) {
var rr, gg, bb,
r = arguments[0] / 255,
g = arguments[1] / 255,
b = arguments[2] / 255,
h, s,
v = Math.max(r, g, b),
diff = v - Math.min(r, g, b),
diffc = function(c){
return (v - c) / 6 / diff + 1 / 2;
};
if (diff == 0) {
h = s = 0;
} else {
s = diff / v;
rr = diffc(r);
gg = diffc(g);
bb = diffc(b);
if (r === v) {
h = bb - gg;
}else if (g === v) {
h = (1 / 3) + rr - bb;
}else if (b === v) {
h = (2 / 3) + gg - rr;
}
if (h < 0) {
h += 1;
}else if (h > 1) {
h -= 1;
}
}
return [h, s, v ]
}
/**
* 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
*/
export function hsl2rgb (h,s,v) {
var r,g,b,i,f,p,q,t,hue;
if (h.h !=null){
v=h.b;
s=h.s;
h=h.h;
}
h%=360;
if (h<1) h*=360;
s=s>1?1:s<0?0:s;
v=v>1?1:v<0?0:v;
hue=h
if (s==0) r=g=b=v;
else {
h/=60;
f=h-(i=Math.floor(h));
p=v*(1-s);
q=v*(1-s*f);
t=v*(1-s*(1-f));
switch (i) {
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 [ Math.floor(r * 255), Math.floor(g * 255), Math.floor(b * 255)]
}
/**
* Converts HEX color value to Array of integer representing the Red Green Blue channels.
*
* @param Number hex The hex value FFFFFF
* @return Array of 3 Number The RGB value [ [0, 255], [0, 255], [0, 255] ].
*/
export function hex2rgb (hex) {
return [ (hex >> 16) & 255, (hex >> 8) & 255, hex & 255 ];
}
/**
* Converts RGB color value to array of hex representing the Red Green Blue channels.
*
* @param Number r red in set [0,1]
* @param Number g green in set [0,1]
* @param Number b blue in set [0,1]
* @return Array of 3 Number The RGB value [ [0, 255], [0, 255], [0, 255] ].
*/
export function rgb2hex ( r, g, b) {
var hex = (r*65536+g*256+b).toString(16,6);
while ( hex.length < 6 ) {
hex = '0'+hex;
}
return hex;
}
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