README

ShaderToy GLSL previewer
------------------------

This is a GLSL fragment shader previewer, specifically designed to be compatible
with fragment shaders written for ShaderToy (http://www.shadertoy.com).

Copyright (C) 2013 John Tsiombikas <nuclear@member.fsf.org>
This program is free software. Feel free to use it, modify it, redistribute it
(with or without modifications), under the terms of the GNU General Public
License version 3 or, at your option, any later version published by the Free
Software Foundation. See COPYING for details.

Usage instructions
------------------
The idea is that at some point you will be able to write a configuration file
(see example-shadertoy.conf) to specify paths containing shadertoy fragment
shaders. Then this program would show you a gallery of thumbnails or something
equivalent, and let you pick any one to view fullscreen.

At the moment however the usage is pretty rudimentary. You'll have to specify
the shader to load from the command line, as well as the ID of the texture you
wish to use in each one of the four sampler slots. The IDs are printed when the
program starts and loads textures during init, so run it once to see which is
which.

Example:
./shadertoy myshader.glsl -t 0 -t 12 -t 3

You will need to download the standard shadertoy data files (images, videos,
etc) from: https://www.dropbox.com/s/9k59bkzyoy7aakq/shadertoy_data.tar
which should be extracted in the shadertoy directory thus creating a data/
subdirectory with all the data.


Compiling
---------
To compile shadertoy you'll need the following libraries:
- GLUT (freeglut is a good choice: http://freeglut.sourceforge.net)
- GLEW (http://glew.sourceforge.net)
- imago2 (http://code.google.com/p/libimago/)
  which in turn needs: libpng, and jpeglib

If you have all the dependencies installed, just type make to compile.


TODO
----
- create a shader browser with live thumbnails
- allow interactive selection of the four sampler source datafiles.
- have a shader metadata file for each shader which will store the sampler
  source selection.
- add support for video and audio datafiles
- add the ability to load a shader directly from a shadertoy url