Skip to content

Instantly share code, notes, and snippets.

@nkcmr
Created December 11, 2012 14:51
Show Gist options
  • Save nkcmr/4259085 to your computer and use it in GitHub Desktop.
Save nkcmr/4259085 to your computer and use it in GitHub Desktop.
HSL to HEX triplet algorithm
<?php
function HSL2HEX($h,$s,$l){
function hue2rgb($v1, $v2, $vH){
if($vH<0) $vH += 1;
if($vH>1) $vH -= 1;
if((6*$vH)<1) return $v1+($v2-$v1)*6*$vH;
if((2*$vH)<1) return $v2;
if((3*$vH)<2) return $v1+($v2-$v1)*((2/3)-$vH)*6;
return $v1;
}
$h /= 360;
$s /= 100;
$l /= 100;
$r=$g=$b=NULL;
if($s==0){
$r=$l*255;
$g=$l*255;
$b=$l*255;
}else{
if($l<0.5)
$var_2 = $l*(1+$s);
else
$var_2 = ($l+$s)-($s*$l);
$var_1 = 2*$l-$var_2;
$r = 255*hue2rgb($var_1, $var_2, $h+(1/3));
$g = 255*hue2rgb($var_1, $var_2, $h);
$b = 255*hue2rgb($var_1, $var_2, $h-(1/3));
}
$r = dechex(round($r));
$g = dechex(round($g));
$b = dechex(round($b));
$r = strlen($r)==1 ? '0'.$r : $r;
$g = strlen($g)==1 ? '0'.$g : $g;
$b = strlen($b)==1 ? '0'.$b : $b;
return $r.$g.$b.'';
}
?>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment