For shadow mapping, for each light source taken into account, you will have to render the scene as seen from the light source. You can probably render directly to texture, but it's still a full render pass for each light. You will do a special render only giving you depth information -> shadow map. Then you have to merge all the shadow maps created that way with the regular scene in another render pass. Now I have to render shadow maps for all objects whos shadows are visible, and do that for the lights that affect each object most. That can easily amount to several dozen light sources. Level 1 of D2:CS alone contains 135 lights!
I cannot pull this off either, as you have to project the shadow maps so that they look right if seen from the actual viewer position, and I don't know how to do it, and cannot figure it from the tutorials and documents I've read (you may guess it: I have tried to get shadow mapping into D2X-XL). They all refer to OpenGL and GLU calls, and I'd need the basic 3D math explained first. I am constantly so tired that I just cannot think enough. I also don't know how to merge multiple shadow maps with the scene. There is no really good OpenGL course on the inet I'd know of that would teach such enhanced things, and I cannot pull it together from information bits and pieces and OpenGL references (which are poor as hell as far as I know them), because they don't even tell you what all the stuff is actually good for. You have to know the answers already. Oh yeah, and for the kind of light sources in D2, you'd need to implement hyperbolic (I think that was the term) shadow mapping to make it look good.
D2X-XL eats too much of my time, and yields too little for what I put in it.
I'd need someone who really knows how to code such stuff and would be willing to poke around in D2X-XL a little, with my support where needed. If Chris would take a look in D2X-XL and simply fix the stuff I would be more than happy ... but I doubt he would.
Oh well, I have a life at last.