For the position, figure out your maximum absolute x, y, z values (loop over all your positions and do something like mx = max(mx, abs(vertex.x))). Then divide all your positions with this value and multiply with MAX_INT16 (or similar). You can now convert to a short, just be careful of rounding errors since this will quantize your positions. Just multiply with your scale (mx, my, mz) in the vertex program to convert back to unscaled space. And yeah, preprocessing is required for strips, but it can be done right where you create your geometry too (I do that for splines and tubes.)

I digged around a bit. You can use the fixed function pipeline and set glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, 1); GL will then light backfaces with your back material and reversed normals.

Ah, I was not aware of that.

It's also not recommended to use any Get command. The best you can do is probably to keep and set your matrices by your self. so restore is just another set. The matrix stack in general is also deprecated, the future proof way of setting them is using constants to your vertex program.

There are a lot of ways you can blend stuff together after blurring. The blend mode might scale against the background color/alpha.

You can do any blending that looks good. Regular add is common, another quite common is screen, which does not saturate as much. d = s1 + s2 - s1*s2 (assuming color is in the range [0, 1])

Another thing you might want to look at is materials. Implement one or several shading models efficiently (car paint, plastic). Learn about BRDF:s while doing so. Skinning is also quite often done in the vertex program so that might be something to look at.

@Ishan Sharma: Actually, a lot of game (engine) development is still don in C, or at least very C:ish C++. Nothing says that your C++ game will be better (or even better written) just because it's C++.

There seems to be quite some c# ports of box2d linked on the home page. box2d.org/links.html