# Direc­tory support/latexrender

LaTeX Rendering Class 0.8
Copyright (C) 2003/2004  Benjamin Zeiss <zeiss@math.uni-goettingen.de>
Maintained from version 0.7 by Steve Mayer
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LatexRender is a set of scripts that allows one to call LaTeX (or mimeTeX) from PHP programs;
in particular, this allows users to enter LaTeX commands in a forum and, on posting,
have it replaced by a suitable gif or png. LatexRender requires either LaTeX and
ImageMagick or mimeTeX to be installed. The open source PHP code was originally
designed for use with phpBB, but it can be adapted for use with other PHP programs.
Details and example installations are given at http://www.mayer.dial.pipex.com/tex.htm#latexrender

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class.latexrender.php
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This script prepares a simulated document then calls LaTeX and ImageMagick to output the image in
GIF or PNG format. (Imagemagick calls Ghostscript so ensure that is installed as well)

It requires the user to put in the paths of the executables, latex, dvips, convert and identify.

In Linux do "which latex", "which convert" and "which identify" to find the paths which could
well be the default given in the file. If they are not there they will need to be installed.
For Unix compatible systems (distributions commonly include LaTeX), a common LaTeX distribution
is teTeX available from http://www.tug.org/teTeX/
For Windows, MiKTeX can be found at http://www.miktex.org/
ImageMagick is at http://www.imagemagick.org/

For Windows the paths in class.latexrender.php must use \\ or / not just a single \. For example
var $_latex_path = "C:\\texmf\\miktex\\bin\\latex.exe"; or var$_latex_path = "C:/texmf/miktex/bin/latex.exe";

LatexRender uses a cache so that the same formula is not re-processed to minimise the load on the server.

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The scripts were originally written to work with phpBB forums but can easily be adapted for use
with other PHP programs.

PhpBB
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Full instructions on how to install for phpBB is given in the phpBB folder. All the necessary
files are in that folder: class.latexrender.php, index.php, phpbb_hook_1.php, phpbb_hook_2.php

Other programs
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The files can be found in the otherPHP folder.
For other PHP programs create a new folder called latexrender and inside this copy
a) the 2 files: latex.php and class.latexrender.php
b) two empty subfolders /tmp and /pictures which must be writeable by the scripts so may need to be chmod 777

In latex.php change the lines
$latexrender_path = "/home/domain_name/public_html/phpbb/latexrender";$latexrender_path_http = "/phpbb/latexrender";

In your program take the text that you wish to render. Surround any latex code
with the tags $$...$$. Suppose this is in the variable $latextext. For example:$latextext = "This is just text but $$\sqrt{2}$$ should be shown as an image and so should $$\frac {1}{2}$$";

Call latexrender with the 2 lines:

include_once('/full_path_here_to/latexrender/latex.php');
$latextext=latex_content($latextext);

latextext will now contain a link to the image in latexrender/pictures A simple working example is given in example.php. Copy this to the latexrender directory and then run the program. [There is also a more sophisticated demo in the demo folder - see readme.txt there for details] Instructions for installation on Simple Minds Forums are included courtesy of treo and Orstio. There's an attempt to improve vertical alignment at the cost of extra processing in the offset beta directory. Users may wish to experiment with this. Notes ----- 1. latex.php will show error codes 1-6 if there's a problem. The codes are explained in latex.php but their meaning is probably best not broadcast 2. If you use a WYSIWYG editor such as htmlArea http://www.interactivetools.com/products/htmlarea/ then you may need to remove some tags from the text to be converted. Uncomment the lines near the end of latex.php to do this. 3. The default is to use article.cls for LaTeX which is a common class but it only supports 10,11,12 point font sizes. For smaller (or larger fonts) in the image, install the extsizes package available from CTAN http://ctan.tug.org/. Add these files to a new extsizes directory in usr/share/texmf/tex/latex. Refresh the database using "texhash" command (if using teTeX) or MiKTex Options, Refresh Now (Windows) , Then in class.latexrender.php you can change var_font_size = 10; to var $_font_size = 8; 4. You can allow larger images and/or longer latex code by adjusting the default 500 in class.latexrender.php in the lines var$_xsize_limit = 500;
var $_ysize_limit = 500; var$_string_length_limit = 500;

5. You can make equation arrays and other code that starts with \begin, by prefacing them with 2 new lines.

6. Displayed formulae can be rendered using \displaystyle and < center > tag

7. Examples of conversions can be found in example.htm

8. Do protect programs like example.php. Opening up to everybody could soon fill up the pictures directory.
The files are small but lots of small files can take up precious space you may need.

9. Although the default size is set (see 3. above) you can resize a formula by using \mbox as in
\mbox{\huge\sqrt{2}} or \mbox{\footnotesize\sqrt{2}}

mimeTeX
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If you are unable to install LaTeX and ImageMagick (& Ghostscript) on your server then you can
try mimeTeX. This doesn't require any external programs but doesn't quite give the same standard
of output as LaTeX but is very acceptable. Full details in the mimetex folder.

Steve Mayer mayer@dial.pipex.com


## La­texRen­der – Use LaTeX in PHP pro­grams

La­texRen­der is a set of scripts that al­lows one to call from PHP pro­grams; in par­tic­u­lar, this al­lows users to en­ter com­mands in a fo­rum and, on post­ing, have it re­placed by a suit­able gif or png. La­texRen­der re­quires and ImageMag­ick to be in­stalled. The open source PHP code was orig­i­nally de­signed for use with ph­pBB, but it can be adapted for use with other PHP pro­grams. De­tails and ex­am­ple in­stal­la­tions may be found in the main­tainer's home page.

 Pack­age La­texRen­der Ver­sion 0.8 Li­censes GNU Gen­eral Public Li­cense Copy­right 2003, 2004 Ben­jamin Zeiss Main­tainer Steve MayerBen­jamin Zeiss (in­ac­tive) Topics CGI LaTeX See also mimetex