(Sega Saturn homebrew) Realtime gouraud lightning test (2018-05-16)

I wrote a little tool in C++ to convert 3D models (on the PC), generate the quads' normals and per-vertex normals in order to allow realtime gouraud shading lightning. The Saturn got a pretty nice gouraud shading implementation. I'm showing here a realtime gouraud shading test I did. I tested it on real hardware too and the VDP1 could keep up with 7 models onscreen at 60 fps (more than 650 drawn quads), while the CPU struggled a bit (but it ran fine at 30 fps). I think I will aim for 30 fps in Sonic Z-Treme and add nice effects (I'm not satisfied with the look of the older builds, even if it does run really smoothly). I still hope to make it out in time for SAGE 2018 with a new Sonic Z-Treme demo, but I still have so much to do that I start to think I won't have enough time. I might only make a really simple tech demo (kind of like what Sega did in 1996 with the boss engine demo). Running on SSF, using SGL/SBL and my own Z-TREME engine SDK. The models are all from Sonic R PC version, but I didn't fully texture map them (Tails' tails aren't texture mapped and Metal Sonic's shoes use one color only). There are also some issues with Tails' hair as it's only using 6 quads with no backface culling, so the normals on one side are pointing in the wrong direction (the only alternative is to put backface culling and make it 12 quads instead, but I won't do it for such a small detail).