Dark coder:
I am totally aware of how to overlay without using a shader. I just didn't bother adding it because I felt the results showed enough. When I mentioned a shader, I was merely stating that the actual shadow calculations could be done with it. This method is merely a heavy distance check for every pixel (or two) of the screen, I'll clean it up and add light radius/falloff and multiple lights. It is actually an alpha map by nature, I just added the white pixels to make it more visible.
I'm suspecting that this "method" is what Doom3 and Fear (etc...) use. Now that I have understood it, I can go about trying to write a shader that will carry out these calculations on a dedicated GPU processor, freeing up the main processor of this hefty algorithm.
I'm guessing that even a low(-ish) res alpha image can yield alright results, relying on mip-mapping or other tricks to blur it a bit. I'm just sick of the Z-clashing and speed loss of the DBP built in vertex shader, and decided to go about the issue of shadows differently. I strongly believe that this method can work well in real-time, and on a personal level, it would keep DBP game making alive for me. People make too many comparisons with DBP and next-gen titles
so I thought cool shadows could re-vamp tho old DBP.
here is a quick screenie of what the shadows could end up looking like with the alpha overlayed on top.