<?php
function ColorLuminance($hex, $lum)
{
// validate hex string
$hex = preg_replace("/[^0-9a-f]/i", "", $hex);
if (strlen($hex) < 6) {
$hex = $hex[0] + $hex[0] + $hex[1] + $hex[1] + $hex[2] + $hex[2];
}
// convert to decimal and change luminosity
$rgb = "#";
for ($i = 0; $i < 3; $i++) {
$c = base_convert(substr($hex, $i * 2, 2), 16, 10);
echo $c . " - ";
$c = base_convert((round(min(max(0, floatval($c + ($c * $lum))),255))), 10, 16);
echo $c . " - ";
$rgb .= substr('00' . $c, strlen($c));
echo $rgb . " - ";
}
return $rgb;
}
echo ColorLuminance("#69c", 0) . "\n"; // returns "#6699cc"
/*echo ColorLuminance("6699CC", 0.2) . "\n";// "#7ab8f5" - 20% lighter
echo ColorLuminance("69C", -0.5) . "\n";// "#334d66" - 50% darker
echo ColorLuminance("000", 1) . "\n";// "#000000" - true black cannot be made lighter!*/
preferences:
35.23 ms | 402 KiB | 5 Q