More ray tracing

Yesterday I had free time for the first time in weeks!! So I worked a lot on the ray tracer...
All data structures are Python objects. However, all the ray calculation is currently done by a module written in C.
Something that is really cool, is that at the innermost loop of the ray calculation, I have a call to a python function, named "shader".  That call isn't really that expensive and it allows me to run python code at the main loop!! Not only that, the objects (for now only spheres) actually have a reference to the shader they want to use. So I can call basically any python function if I plug it into one of the spheres =)

For now, there is only one loop. The shaders will be in charge of running new loops to calculate lighting, make shadows, reflections, etc.. But for now they only fill the pixel with a determined color.

Here is a 600x300 image that took only 0.079 seconds to draw. It is noteworthy that most of that time was spent drawing pixels with the Python Image Library. A faster library will improve it a lot, and adding support for multiple processors will be easy.


They are two spheres of the same size, the green one is farther away from the eye. (The last image I posted had two spheres of different sizes with no perspective)