<?

class Color {

    var $red;
    var $green;
    var $blue;

    function Color($red, $green, $blue) {
        $this->red = $red;
        $this->green = $green;
        $this->blue = $blue;
    }
    
    function add($color) {
            return new Color($color->red + $this->red, $color->green + $this->green, $color->blue + $this->blue);
    }

    function blend($color1, $color2) {
        return new Color(($color1->red + $color2->red)/2, ($color1->green + $color2->green)/2, ($color1->blue + $color2->blue)/2);
    }
    
    function changeBrightness($percent) {
        $this->red *= $percent;
        $this->green *= $percent;
        $this->blue *= $percent;
    
        if ($this->red > 255) $this->red = 255;
        if ($this->green > 255) $this->green = 255;
        if ($this->blue > 255) $this->blue = 255;
    }
    
    function difference($color) {
        $rDiff = $this->red - $color->red;
        $gDiff = $this->green - $color->green;    
        $bDiff = $this->blue - $color->blue;
        
        return new Color($rDiff, $gDiff, $bDiff);
    }
    
    function getAlphaColor($level) {
        $red = $level + $this->red;
        $green = $level + $this->green;
        $blue = $level + $this->blue;
    
        if ($red > 255) $red = 255;
        if ($green > 255) $green = 255;
        if ($blue > 255) $blue = 255;
        if ($red < 0) $red = 0;
        if ($green < 0) $green = 0;
        if ($blue < 0) $blue = 0;
        
        return array($red, $green, $blue);
    }
    
    function allocate($image) {
        return imagecolorallocate($image, $this->red, $this->green, $this->blue);
    }
}

?>