PHP: imageloadfont

Description

int imageloadfont ( string file )

imageloadfont() loads a user-defined bitmap font and returns an identifier for the font (that is always greater than 5, so it will not conflict with the built-in fonts). It returns FALSE in case of error.

The font file format is currently binary and architecture dependent. This means you should generate the font files on the same type of CPU as the machine you are running PHP on.

Tabela 1. Font file format

byte position	C data type	description
byte 0-3	int	number of characters in the font
byte 4-7	int	value of first character in the font (often 32 for space)
byte 8-11	int	pixel width of each character
byte 12-15	int	pixel height of each character
byte 16-	char	array with character data, one byte per pixel in each character, for a total of (ncharswidthheight) bytes.

Przykład 1. Using imageloadfont


<?php

$im = imagecreate(50, 20);

$black = imagecolorallocate($im, 0, 0, 0);

$white = imagecolorallocate($im, 255, 255, 255);

imagefilledrectangle($im, 0, 0, 49, 19, $white);

$font = imageloadfont("04b.gdf");

imagestring($im, $font, 0, 0, "Hello", $black);

imagepng($im);

?>

User Contributed Notes


Working under the assumption that the only 'architecture dependant' part of the font files is endianness, I wrote a quick and dirty Python script to convert between the two. It has only been tested on a single font on a single machine so don't bet your life on it working. All it does is swap the byte order of the first four ints.



#!/usr/bin/env python



f = open("myfont.gdf", "rb");

d = open("myconvertedfont.gdf", "wb");



for i in xrange(4):

        b = [f.read(1) for j in xrange(4)];

        b.reverse();

        d.write(''.join(b));



d.write(f.read());



I successfully used this script to convert anonymous.gdf, from one of the font links below, into something useable on Mac OS X.


Confirmation code generation for preventing automated registrations on a website.



Function arguments are:

$code - the code that you shall random generate

$location - relative location of the image that shall be generated

$fonts_dir - relative location for the GDF fonts directory



This function will create an image with the code given by you and will save it in the directory specified with the name formed by MD5 hash of the code.



You may insert as many font types in the fonts directory as you wish, with random names.



<?php

function generate_image($code, $location, $fonts_dir)

{

     $image  = imagecreate(150, 60);           

     imagecolorallocate($image, rand(0, 100), rand(100, 150), rand(150, 250));

     $fonts = scandir($fonts_dir);

     

     $max = count($fonts) - 2;

     

     $width = 10;

     for ($i = 0; $i <= strlen($code); $i++)

     {     

         $textcolor = imagecolorallocate($image, 255, 255, 255);

         $rand = rand(2, $max);

         $font = imageloadfont($fonts_dir."/".$fonts[$rand]);

         

         $fh = imagefontheight($font);

         $fw = imagefontwidth($font);



         imagechar($image, $font, $width, rand(10, 50 - $fh), $code[$i], $textcolor);     

          $width = $width + $fw;

        

     }

             

     imagejpeg($image, $location."/".md5($code).".jpg", 100);

     imagedestroy($image);       

    

     return $code;

     

}



?>