HSL to HEX triplet algorithm

hsl2hex.php

<?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.'';
}

?>