Create White Box around Text GD-Lib - php

Question

i want to add a white box around some text i add to an image via GD-Lib.
but i don't know how to do this best.
Here is my current code:
<?php
$textImg = imagecreatefromjpeg($tempImage);
$black = imagecolorallocate($textImg, 0, 0, 0);
$font = 'lib/verdana.ttf';
// Add the text
imagettftext($textImg, 20, 0, imagesx($textImg)*$textData['x']/100, imagesy($textImg)*$textData['y']/100, $black, $font, $textData['text']);
imagejpeg($textImg,$tempImage,$jpegQuality);
?>
I hope you can help me out.

Answer 1

You can use imagettfbbox() to get the coordinates of the bounding box by passing the same settings you use for the text itself (same text, font and size etc).
Once you have these coordinates you can use imagerectangle() to draw a border around the text, or you can use imagefilledrectangle() to draw a solid rectangle. Be sure to call it before you render the text with imagettftext()
A basic example is below but will need some tweaking as most of it is from memory and I suspect the $x and $y calculation could be done better as it probably doesn't work with varying canvas sizes as it is now. However, it demonstrates the principle.
// Set the content-type
header('Content-Type: image/png');
// Create the image
$im = imagecreatetruecolor(400, 30);
// Create some colors
$white = imagecolorallocate($im, 255, 255, 255);
$black = imagecolorallocate($im, 0, 0, 0);
imagefilledrectangle($im, 0, 0, 399, 29, $black);
// The text to draw
$text = 'Testing';
// Replace path by your own font path
$font = 'verdana.ttf';
// Add the text
$bbox = imagettfbbox(20, 0, $font, $text);
$x = $bbox[1] + (imagesx($im) / 2) - ($bbox[4]);
$y = $bbox[3] + (imagesy($im) / 2) - ($bbox[5]);
imagerectangle($im, 0, 0, $x, $y, $white);
imagettftext($im, 20, 0, 0, 20, $white, $font, $text);
// Using imagepng() results in clearer text compared with imagejpeg()
imagejpeg($im);
imagedestroy($im);