PHP颜色渐变函数

该函数接收两个颜色值和渐变步数作为参数

函数的目的是在这两个颜色值之间计算出一系列中间颜色值。

function colorGradient($color1, $color2, $steps) {
    $colors = array();
    $r1 = hexdec(substr($color1, 0, 2));
    $g1 = hexdec(substr($color1, 2, 2));
    $b1 = hexdec(substr($color1, 4, 2));
	
    $r2 = hexdec(substr($color2, 0, 2));
    $g2 = hexdec(substr($color2, 2, 2));
    $b2 = hexdec(substr($color2, 4, 2));
	
    for ($i = 0; $i <= $steps; $i++) {
        $r = dechex(intval($r1 + ($r2 - $r1) * ($i / $steps)));
        $g = dechex(intval($g1 + ($g2 - $g1) * ($i / $steps)));
        $b = dechex(intval($b1 + ($b2 - $b1) * ($i / $steps)));
        $colors[] = strtoupper ( str_pad($r, 2, '0', STR_PAD_LEFT) . str_pad($g, 2, '0', STR_PAD_LEFT) . str_pad($b, 2, '0', STR_PAD_LEFT) );
    }
    return $colors;
}
//  $color1 = "FFFFFF"; $color2 = "000000"; $steps=19;
$gradientColors = colorGradient($color1, $color2, $steps);