PDA

View Full Version : Colour tools

liorean
01-16-2004, 12:35 AM
Because of the thread <http://codingforums.com/showthread.php?s=&postid=163715> I created some RGB-to-HSL and HSL-to-RGB functions for JavaScript that I think might be useful for some of you.
function fnRgbToHsl(r, g, b){ // R G B as integers, 0..255.
r /= 255;
g /= 255;
b /= 255;
var
max = Math.max(r, g, b),
min = Math.min(r, g, b),
l = (max + min) / 2;
h = 0,
s = 0;
if(max != min){
s = (l < .5)?
(max - min) / (max + min):
(max - min) / (2 - max - min)
h = (max != r)?
(max != g)?
4 * (r - g) / (max - min):
2 * (b - r) / (max - min):
(g - b) / (max - min);
}
h *= 60;
if(h < 0)
h += 360;
return [h, s, l];
}

function fnHslToRgb(h, s, l){ // H as degrees 0..360, S L as decimals, 0..1.
h /= 360;
function fnHueToRgb(x, y, h){
if(h < 0)
h += 1;
else if(h > 1)
h -= 1;
return ((h * 6 < 1)?
x +(y - x) * h * 6:
(h * 2 < 1)?
y:
(h * 3 < 2)?
x + (y - x) * (2 / 3 - h) * 6:
x);
}
var
y = (l > .5)?
l + s - l * s:
l * (s + 1),
x = l * 2 - y,
r = fnHueToRgb(x, y, h + 1 / 3) * 255,
g = fnHueToRgb(x, y, h) * 255,
b = fnHueToRgb(x, y, h - 1 / 3) * 255;
return [r, g, b];
}If I get the time, I'll build some tools around them, such as methods of getting triad colours, complementary and split complimentary colours, analogous colours, saturation variations, luminance variations (tints and shades) and hue variations (chromatic variations).

kansel
01-16-2004, 05:32 PM
lol, i'm working on this very thing in my spare time... unfortunately since i recently bought a house i have very little of that.

Antoniohawk
01-29-2004, 03:35 AM
Surprisingly enough I was thinking about doint the same thing. I get sick of opening up photoshop to color create.