gistfile1.txt

<?php

/**
 * Convert color from hex in XXXXXX (eg. FFFFFF, 000000, FF0000) to array(R, G, B)
 * of integers (0-255).
 *
 * name: rgb2array
 * author: Yetty
 * @param $color hex in XXXXXX (eg. FFFFFF, 000000, FF0000)
 * @return string; array(R, G, B) of integers (0-255)
 */
function rgb2array($rgb) {
    return array(
        base_convert(substr($rgb, 0, 2), 16, 10),
        base_convert(substr($rgb, 2, 2), 16, 10),
        base_convert(substr($rgb, 4, 2), 16, 10),
    );
}

function square($canvasSize, $fgcolor, $bgcolor, $location, $size){

	// Output the header telling the browser this is a png image.
	header ('Content-type: image/png');

	// create the empty image.
	$im = imagecreatetruecolor($canvasSize, $canvasSize) or die('Cannot Initialize new GD image stream');
	
	$fg = rgb2array($fgcolor);
	$bg = rgb2array($bgcolor);

	/* Define the foreground and background colours and fill the image with the bacground colour.
	The foreground colour is passed as a parameter, the background colour is white */
	$fgcolor = imagecolorallocate($im, $fg[0], $fg[1], $fg[2]);
	$bgcolor = imagecolorallocate($im, $bg[0], $bg[1], $bg[2]);
	imagefill($im, 0, 0, $bgcolor);

	// Draw a rectangle. The upper left coordinate is 0,0. The lower right is size-1, size-1 since we started counting at 0.
	imagerectangle($im, $location[0], $canvasSize - $location[1] - $size, $location[0] + $size, $canvasSize - $location[1], $fgcolor);

	/* Write the image to standard out - in the case of the web server to the network to the browser
	and free up any memory used by the image */
	imagepng($im);
	imagedestroy($im);
}

square(200, "E00000", "000000", array(20, 20), 50);

?>