function HSL2RGB($h, $s, $l)
{
$r = $g = $b = 0;
if ($s == 0) {
$r = $g = $b = $l * 255.0;
} else {
if ($l < 0.5) {
$q = $l * ($s + 1.0);
} else {
$q = $l + $s - $l * $s;
}
$p = $l * 2.0 - $q;
$h = $h / 360.0;
$r = hue2rgb($p, $q, $h + 1.0 / 3.0) * 255.0;
$g = hue2rgb($p, $q, $h) * 255.0;
$b = hue2rgb($p, $q, $h - 1.0 / 3.0) * 255.0;
}
return array((int) $r, (int) $g, (int) $b);
}
/**
* Convert an HSL triplet to an RGB triplet.
*
* @param array $hsl The HSL triplet.
* @return array The RGB triplet.
*
* @package esoTalk
*/
function hsl2rgb($hsl)
{
$h = $hsl[0];
$s = $hsl[1];
$l = $hsl[2];
$m2 = $l <= 0.5 ? $l * ($s + 1) : $l + $s - $l * $s;
$m1 = $l * 2 - $m2;
return array(hue2rgb($m1, $m2, $h + 0.33333), hue2rgb($m1, $m2, $h), hue2rgb($m1, $m2, $h - 0.33333));
}
function hsl($h = null, $s = null, $l = null, $a = null)
{
$h = !$h ? 0 : $h;
$s = !$s ? 100 : $s;
$l = !$l ? 50 : $l;
$h = $h >= 360 || $h < 0 ? 0 : $h;
$h /= 360;
$s = $s > 100 ? 100 : $s;
$s = $s < 0 ? 0 : $s;
$s /= 100;
$l = $l > 100 ? 100 : $l;
$l = $l < 0 ? 0 : $l;
$l /= 100;
$r;
$g;
$b;
if ($s == 0) {
$r = $g = $b = $l;
} else {
function hue2rgb($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;
}
$q = $l < 0.5 ? $l * (1 + $s) : $l + $s - $l * $s;
$p = 2 * $l - $q;
$r = hue2rgb($p, $q, $h + 1 / 3);
$g = hue2rgb($p, $q, $h);
$b = hue2rgb($p, $q, $h - 1 / 3);
}
if ($a !== null) {
if (0 > $a) {
$a = 0;
} elseif ($a > 1) {
$a = 1;
}
return array($r, $g, $b, $a);
}
return array($r, $g, $b, 1);
}