Created
March 27, 2017 10:12
-
-
Save surajmandalcell/7da83f03a09edf6307abc631e954e90e to your computer and use it in GitHub Desktop.
Javascript junctions to convert javascript to hsl and hsl to javscript
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
// `rgbToHsl` | |
// Converts an RGB color value to HSL. | |
// *Assumes:* r, g, and b are contained in [0, 255] or [0, 1] | |
// *Returns:* { h, s, l } in [0,1] | |
function rgbToHsl(r, g, b) { | |
r = bound01(r, 255); | |
g = bound01(g, 255); | |
b = bound01(b, 255); | |
var max = mathMax(r, g, b), min = mathMin(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: h, s: s, l: l }; | |
} | |
// `hslToRgb` | |
// Converts an HSL color value to RGB. | |
// *Assumes:* h is contained in [0, 1] or [0, 360] and s and l are contained [0, 1] or [0, 100] | |
// *Returns:* { r, g, b } in the set [0, 255] | |
function hslToRgb(h, s, l) { | |
var r, g, b; | |
h = bound01(h, 360); | |
s = bound01(s, 100); | |
l = bound01(l, 100); | |
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; | |
} | |
if(s === 0) { | |
r = g = b = l; // achromatic | |
} | |
else { | |
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: r * 255, g: g * 255, b: b * 255 }; | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment