tinygpus VS DOOM-FX

- actual lookup table generation: https://github.com/sylefeb/tinygpus/blob/498be1b803d0950328a...

Sine tables are also very typical, for animating things on screen or plain

Very, very impressive works, both MRISC32 and FuryGPU (which I just learned about, love the idea of a FPGA-retro-GPU that could go in a modern computer!). It's hard to overstate the amount of passion, care and technical expertise that go into such projects.

I'm the author of 'q5k' (Quake viewer in 5K LUTs) and so I wanted to say Hi to my fellow Quake-on-FPGA enthusiasts. Thanks for the mention, and looking forward to the next steps of your projects!

PS: Q5k is of course much, much slower (runs on a small $10 ice40 up5k FPGA), and only a viewer. The renderer is custom using fixed-point only. Unlikely I'll be ever able to run the full game at any decent speed, but I'm surely going to try :) For anyone interested, here's the repo of q5k and doomchip-onice: https://github.com/sylefeb/tinygpus

I recently learned how Doom was ported to the SNES. It's quite impressive. The SNES hardware was nowhere near fast enough to do all the trig calculations needed for the game but cartridge based games had a trick up their sleeve: they could include actual hardware inside the cart that the game code could make use of. It was more expensive but if you expected to sell a boatload of copies, it could be worth it. However, even using extra hardware wasn't enough in this case. So they pre-calculated lookup tables for sine, cosine, tangent etc. for every angle at the necessary precision. They were helped by the fact that the game resolution in this case was fairly low.

If you're interested, you can peruse the C code that was used to generate the tables. Here's the file for sine/cosine:

https://github.com/RandalLinden/DOOM-FX/blob/master/source/m...

A Podcast Of Unnecessary Detail just did an episode talking about the SNES Doom port and how it used LUTs for trigonometry as the SNES didn't have a graphics processor.

https://festivalofthespokennerd.com/podcast/series-3-episode...

https://github.com/RandalLinden/DOOM-FX

Fun fact: Randy Linden, the original developer of the game, has posted the complete source on GitHub (https://github.com/RandalLinden/DOOM-FX) and then made some additional changes so that it could rebuild a byte-perfect copy of the original US ROM.

Looks like it does use BSP: https://github.com/RandalLinden/DOOM-FX/blob/master/source/rlbsp.a

Doom/FX for Super Nintendo with SuperFX GSU2A enhancement chip