Tex-Engine

This page tells how to use "Tex-Engine" to obtain high quality image from Latex text.

Liu Xuefeng, xfliu.math[at]gmail.com, 2009/10/01.

1. Please try it first.

Click the image below, please.

On Start

2. How to use it?

The "Tex-Engine" is located on Google App Engine. You can call it by both "GET" and "POST" method.

http://tex-engine.appspot.com/?t=type&q=string

Specification of parameters:

The parameter type should be "file" or "link". If nothing is given, the default value "file" will be used.
"link": Tex-Engine will return a string as the image link. This is useful if you only want the link for the created image. You can call "Tex-Engine" from your code and get the image link.
"file": In this case, the Tex-Engine link above will correspond to the address of created PNG image file for given Latex text. A sample use is like below, where "%20" is the encoded char for empty space.
```
<img src="http://tex-engine.appspot.com/?t=file&q=I%20Love%20You" >      
```
The parameter string should be a text in Latex format. Please notice that if you call Tex-Engine by GET method, the sensitive characters in the URL should be removed. You can do it by calling Javascript functions:
```
encoded_string = escape(string).replace("+","%2B","g");
```
Or, using the following tool.

Another online encoding tool is available here: http://www.web-code.org/coding-tools/javascript-escape-unescape-converter-tool.html.

A demo page that uses "POST" method to call "Tex-Engine" is here: http://tex-engine.appspot.com/html/test.html

IMPORTANT: As there is a limit for the query string length, you can not call "Tex-Engine" by "GET" method with too long string.
If there happens to be error during the text processing, a lovely bee will appear.

3. What is running at background?

The program located at Google App Engine(GAE) is ready for processing the input Latex string. A cache scheme is also adopted, that is, if the input string has been processed previously, the "Tex-Engine" will redirect it to the corresponding link; otherwise, "Tex-Engine" processes the string and saved the image file in GAE. The link for image saved in GAE is like this:

http://tex-engine.appspot.com/get_img?id=1139

As it is impossible to install a Latex system on GAE, the code at GAE will call a third server with

system installed. The total structure of "Tex-Engine" is like this:

As the "

Server" is a rented server, there is a limit on the outcoming accesses. If you can supply stable server with

system installed, I will appreciate for that.

Supported by Google App Engine: http://code.google.com/intl/en/appengine/

Liu Xuefeng, xfliu.math[at]gmail.com, 2009/10/01.