/**
* Return a mix of $color1 and $color2 with given $weightPercentage (defaults to 50%)
*
* @param Node $color1
* @param Node $color2
* @param DimensionNode $weightPercentage
* @return ColorNode
* @link http://sass-lang.com
* @copyright 2006-2009 Hampton Catlin, Nathan Weizenbaum, and Chris Eppstein
*/
public function mix(Node $color1, Node $color2, DimensionNode $weightPercentage = null)
{
if (!$color1 instanceof ColorNode) {
return $color1;
} elseif (!$color2 instanceof ColorNode) {
return $color1;
}
if (!$weightPercentage) {
$weightPercentage = new DimensionNode(50);
}
$p = $weightPercentage->value / 100.0;
$w = $p * 2 - 1;
$a = $color1->getAlpha(true) - $color2->getAlpha(true);
$w1 = (($w * $a == -1 ? $w : ($w + $a) / (1 + $w * $a)) + 1) / 2;
$w2 = 1 - $w1;
$color1Rgb = $color1->getRGB();
$color2Rgb = $color2->getRGB();
$rgb = [$color1Rgb[0] * $w1 + $color2Rgb[0] * $w2, $color1Rgb[1] * $w1 + $color2Rgb[1] * $w2, $color1Rgb[2] * $w1 + $color2Rgb[2] * $w2];
$alpha = $color1->getAlpha(true) * $p + $color2->getAlpha(true) * (1 - $p);
return new ColorNode($rgb, $alpha);
}
