Programming PHP

Example 9-7. Creating a dynamic button (continued)
$y = ( ImageSy($im) - $dy ) / 2 + $dy;
// draw text
$black = ImageColorAllocate($im,0,0,0);
ImageTTFText($im, $size, 0, $x, $y, $black, $font, $text);
header('Content-Type: image/png');
ImagePNG($im);
?>
In this case, the blank button (button.png) looks as shown in Figure 9-6.
Figure 9-6. Blank button
Note that if you are using GD 2.0.1, antialiased TrueType fonts work only if the
background image is indexed. If you are having problems with your text looking terrible,
load your background image into any image-editing tool and convert it from a
true color image to one with an 8-bit indexed palette. Alternatively, upgrade from
GD 2.0.1 to GD 2.0.2 or later.
The script in Example 9-7 can be called from a page like this:
This HTML generates the button shown in Figure 9-7.
Figure 9-7. Generated button
The + character in the URL is the encoded form of a space. Spaces are illegal in URLs
and must be encoded. Use PHP’s urlencode( ) function to encode your button
strings. For example: