Understanding classes

[j3rmain3]

i have to use a Color class to change the properties of a graph but i dont really understands graphs very well. I have read the Intro to Classes on the phpfreaks site but applying it to the class i have to use is what im ahving problems with.

Here is the class:

[code]
function Color($red, $green, $blue, $alpha = 0)
{
$this->red = (int)$red;
$this->green = (int)$green;
$this->blue = (int)$blue;
$this->alpha = (int)round($alpha * 127.0 / 255);

$this->gdColor = null;
}

/**
* Get GD color
*
* @access public
* @param $img GD image resource
*/

function getColor($img)
{
// Checks if color has already been allocated

if(!$this->gdColor)
{
if($this->alpha == 0 || !function_exists('imagecolorallocatealpha'))
$this->gdColor = imagecolorallocate($img, $this->red, $this->green, $this->blue);
else
$this->gdColor = imagecolorallocatealpha($img, $this->red, $this->green, $this->blue, $this->alpha);
}

// Returns GD color

return $this->gdColor;
}
}
[/code]

With the function underneath do i use as:

[b]$colour = new Color

$colour -> Color("255","0","0",$alpha);[/b]

[code]

function Color($red, $green, $blue, $alpha = 0)
{
$this->red = (int)$red;
$this->green = (int)$green;
$this->blue = (int)$blue;
$this->alpha = (int)round($alpha * 127.0 / 255);

$this->gdColor = null;
}
[/code]

Thanks
J3rmain£

[JasonLewis]

you have to add a class first....

here is what it should look like:

[code=php:0]
class Color {
var $red;
var $green;
var $blue;
var $alpha;
var $gdColor;
function makeColor($red, $blue, $green, $alpha=""){
$this->red = (int)$red;
$this->green = (int)$green;
$this->blue = (int)$blue;
$this->alpha = (int)round($alpha * 127.0 / 255);

$this->gdColor = null;
}

function getColor($img){
// Checks if color has already been allocated

if(!$this->gdColor){
if($this->alpha == 0 || !function_exists('imagecolorallocatealpha')){
$this->gdColor = imagecolorallocate($img, $this->red, $this->green, $this->blue);
}else{
$this->gdColor = imagecolorallocatealpha($img, $this->red, $this->green, $this->blue, $this->alpha);
}
}

// Returns GD color

return $this->gdColor;
}

} //end class
[/code]

then to call it:
[code=php:0]
$color = new Color;
$new_color = $color->("255","0","0",$alpha);
[/code]