Aligning text horizontally and vertically with PHP GD

Let's draw text on 400x300 image as example.

Horizontal center align

$im = imagecreatetruecolor(400, 300);

$c_black = imageColorAllocate($im, 0,0,0);
$c_green = imageColorAllocate($im, 46,204,64);
$text = 'Hi';

$font = '/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf';
$p = imagettfbbox(40, 0, $font, $text);

imagettftext($im, 40, 0, (400 - $p[2])/2, 100, $c_green, $font, $text);
imagePng($im, '/tmp/image.png');

We use (400 - $p[2])/2 to calculate x coordinate so our text is centered horizontally. Open original or edit on Github.

Vertical and horizontal center align

$im = imagecreatetruecolor(400, 300);

$c_black = imageColorAllocate($im, 0,0,0);
$c_green = imageColorAllocate($im, 46,204,64);
$text = 'Hi';

$font = '/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf';
$p = imagettfbbox(40, 0, $font, $text);

imagettftext($im, 40, 0, (400 - $p[2])/2, (300 - $p[5])/2, $c_green, $font, $text);
imagePng($im, '/tmp/image.png');

We've used (400 - $p[2])/2to center align text horizontally and(300- $p[5])/2 to get y coordinate so our text is also centered vertically.

Open original or edit on Github.