Scenegraph rewrite

[joevenzon]

I've started adding support for data-driven rendering setup. My goal is to get it working kind of like rendermonkey, but with text configuration files. It's mostly done now but I haven't reimplemented all of the normal shader paths yet, so the following things aren't working:
* shadows
* dynamic reflections
* bloom
* "ultra" lighting mode

These are known issues and I'll fix them shortly, I just wanted to get my code committed. The new way this is set up is really cool, you can edit a text file to change how the renderer is setup and then hit F8 to reload it and all of the shaders and BAM instantly see changes. Very cool.

[NaN]

This is so cool. I love it. Found the explanation for the parameters in graphics_config.h and the available draw layers in drawable_container.h. We need a readme for this thingy.

[NaN]

What do you think about exposing the drawable parameters(decal, lit, is2d, partial_transparency, ...) and make drawable layers scriptable?

Edit:
Then separate it from vdrift and you've got a fast, lightweight graphics engine. Just kidding.

[joevenzon]

Yeah, I think i'll add info about the file format in comments at the top of it once it stabilizes.

The drawable layers are very performance sensitive, so I'd have to think about how to do that. My goal is to make it as easy as possible to use the VDrift graphics engine in other projects (because I do this all the time for little experiments). Also I want to start fiddling with different deferred rendering setups, and being able to do that at runtime is handy.

[joevenzon]

I think we could emulate texture vertex color blending
...
Does it make sense to use texture combiners? I think they have been deprecated in OpenGL 3.0. I just want to avoid doing it in software.

I've got this working for the non-shader path in R2745.

[NaN]

Nice! I can start replacing the body??.png textures.

The camera is broken for non-shader path. The position and orientation are OK. It is using an offset orthographic cam (maybe from shadows).

[joevenzon]

Oops, fixed in R2748.

[joevenzon]

As I'm rewriting the FBO system to handle multiple render targets (needed for deferred rendering) I've removed sky.cpp from the SConscript to avoid compilation errors... just a heads up.