I'm still working on this. I've been making progress with getting all of the input migrated over to SDL2 and whatnot. Joystick control is already ported over, and now I'm getting keyboard/mouse handling implemented.
This will require OpenGL 3.0, to answer everyone's question about that. This is because trying to support anything older with the planned features (such as shadows and replicating the software renderer's bright texture pixels for things like lights) would be a nightmare. The software renderer was gutted out because it's a nearly indecipherable mess of assembly. (There's C versions of most rendering functions, but not all, especially in Hellbender's case.)
In short, I'm working on it, it'll eventually be ready. When? Not sure. There's still a lot to do. The UI needs to be finished (since I'll be using an improved version of TV's old UI, rather than Fury3/Hellbender's MFC UI, which still needs to be gutted for portability reasons), I need to finish writing the new sound system, fix the many assorted bugs the thing has right now, and fix TV/Fury3 support. (Porting Hellbender broke the other two games since they are vastly different. I'll get it to a point where all 3 games can be run in the same executable, but first release may be hellbender-only.)
And yeah, I know I have mental / personal / health issues to deal with, I'm trying to get through it though.