Webmaster in a Nutshell, Second Edition

Graphics Functions

The graphics functions in PHP can dynamically create a GIF image stream. This stream can either be sent directly to the browser or saved in a standard GIF file. The following example illustrates a number of these image functions:

Header("Content-type: image/gif");
if(!isset($s)) $s=11;
$size = imagettfbbox($s,0,"/fonts/TIMES.TTF",$text);
$dx = abs($size[2]-$size[0]);
$dy = abs($size[5]-$size[3]);
$xpad=9; $ypad=9;
$im = imagecreate($dx+$xpad,$dy+$ypad);
$blue = ImageColorAllocate($im, 0x2c,0x6D,0xAF);
$black = ImageColorAllocate($im, 0,0,0);
$white = ImageColorAllocate($im, 255,255,255);
ImageRectangle($im,0,0,$dx+$xpad-1,$dy+$ypad-1,$black);
ImageRectangle($im,0,0,$dx+$xpad,$dy+$ypad,$white); 
ImageTTFText($im, $s, 0, (int)($xpad/2)+1, $dy+(int)($ypad/2), 
             $black, "/fonts/TIMES.TTF", $text);
ImageTTFText($im, $s, 0, (int)($xpad/2), $dy+(int)($ypad/2)-1, 
             $white, "/fonts/TIMES.TTF", $text);
ImageGif($im);
ImageDestroy($im);

This example should be saved as a file named button.php3, for example, and then called as part of an HTML <IMG> tag like this:

<IMG SRC="button.php3?s=13&text=Help" >

This produces a blue-shaded button with white-shadowed text using a 13-point Times font.

Here are the graphics functions provided by PHP.

array getimagesize(string filename)

Get the size of a GIF, JPG, or PNG image

int imagearc(int im, int cx, int cy, int w, int h, int s, int e, int col)

Draw a partial ellipse

int imagechar(int im, int font, int x, int y, string c, int col)

Draw a character ...