Simple Ray Tracer
=================

"srt" is a simple ray tracer. Currently it only support rendering a scene
containing only spheres. The scene is setup using a CLI.

Building
--------
Building srt is as simple as:
   make

Render output selection
-----------------------
As default visual output a .tga file will be created which can be viewed by
any image viewer. The .tga file is created using the included ssil
(Small and Simle Image Library).

If you dont want the the included ssil to handle the visual output, you can
write your own code or use ssgl (Small and Simple Graphics Library) to
open a window with the rendered scene. See Makefile how to disable ssil and
use ssgl.

If you prefer writing your own code for a visual output you have the data for
the rendered scene available in the variable 'image'. The data in 'image' is
an array of pixels, starting with the pixel at the lower left corner and then
continuing with increasing x value. Each pixel is stored in three bytes
starting with the red component followed by the green and then the blue.

Scene setup
-----------
The scene can be configured through the CLI or the "scene.xml" file.
Use the command "help" in the CLI to get help.
The "scene.xml" uses the follow tags and attributes:
<scene>                                       - Begin Scene setup
  <camera>                                    - Begin Camera setup
    <data x="?" y="?" z="?"                   - Camera attributes,
          fov="?">                              x,y,z - Camera position
    </data>                                     fov   - Camera field of view
  </camera>                                   - End camera setup
  <sphere id="?">                             - Begin Sphere setup. Each sphere
                                                must have an unique "id". At the
                                                moment this can only be the number
                                                0,1 or 2.
    <data x="?" y="?" z="?"                   - Sphere attributes,
          radius="?"                            x,y,z - Sphere center
          r="?" g="?" b="?">                    radius - Sphere radius
    </data>                                     r,g,b - Sphere color
  </sphere>
</scene>                                      - End of scene setup.

Library dependencies
--------------------
- GNU C library, http://www.gnu.org/s/libc/
- GNU Readline library, http://tiswww.case.edu/php/chet/readline/rltop.html
- LibXML2, http://www.xmlsoft.org/