Align text in PHP GD

gistfile1.php

<?php

function textSize($size, $angle, $font, $text) {

	$f = imagettfbbox($size, $angle, $font, $text);

	return array(
		'height' => $f[1] - $f[5],
		'width' => $f[4] - $f[0]
	);

}

function text(&$im, $size, $angle, $y, $color, $font, $text, $align) {
	// Image/text sizes
	$imageSize = array(
		'height' => imagesy($im),
		'width' => imagesx($im)
	);
	$textSize = textSize($size, $angle, $font, $text);

	// Starting $x position
	switch(strtoupper($align)) {
		case 'R':
			$x = $imageSize['width'] - $textSize['width'];
			break;
		case 'C':
			$x = ($imageSize['width'] - $textSize['width']) / 2;
			break;
		default:
			$x = 0; // L
	}

	// Render
	imagettftext($im, $size, $angle, $x, $y, $color, $font, $text);

	return;
}

// Create a 300x150 image
$im = imagecreatetruecolor(300, 150);

// Colors
$black = imagecolorallocate($im, 0, 0, 0);
$white = imagecolorallocate($im, 255, 255, 255);

// Create black border
imagefilledrectangle($im, 1, 1, 297, 147, $white);

// Path to our font file
$font = './Arial.ttf';

// Write it
text($im, 10, 0, 30, $black, $font, $_GET['q'], 'c');

// Output to browser
header('Content-Type: image/png');

imagepng($im);
imagedestroy($im);