new gamemode - keep the base [source included!]

[GeneralDisarray]

Try posting the new code - the old one didn't disable/restore glBlend state but that might not be relevant anymore. Would also be good if you could post more screenshots + closeups of a few example glitches, seems there's a bit of detail behind the blocky patches but I can't see well enough. The fact that those glitches are apparently in screen (post-transform) space *and* related to models (which are obviously in world space) is fairly confusing.

Also try calling the cylinder code at the end of frame rendering (ie after all other GL code is done), at that point it really shouldn't mess up anything. Fairly weird, given that your GL code really doesn't do anything fancy at all.