As some of you may know Descent source code has been released since 1998. I decided I wanted to play around with it, but since my coding skills are limited, especially in C I'm putting a disclaimer that I have used AI assistance here. Still, the build I have now is working fine for me in DOSBOX, but I don't know enough of the minute details of the game to tell if there are other issues. Disclaimer: I did this patch for my own use as I want to use the original DOS version of Descent and not one of the modern source ports. It was not with initial intent to release, but I got so good results that I thought others may have a usecase for it.

This requires Descent registered fully patched to 1.5 version gamefiles.

FPS LIMITER
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-maxfps <N> Frame rate cap (5-150)
Descent has an issue with running too fast on quicker CPUs. To prevent this, set a limit you desire. Recommended 60 or 70 (depending on monitor)
You can see your FPS during gameplay with -showfps flag

PHYSICS FIX for Homing missile
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- Homing missile tracking decoupled from framerate
- Updates at ~30Hz regardless of render FPS (to match the "community standard" with behaviour at around 30 fps)
- Staggered per-missile for smooth visual appearance
- Original behavior preserved at <= 30 FPS

Cockpit HUD in 640x400 SVGA
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- Scales up the cockpit HUD from 320x200 to also work in 640x400 (-640x400 flag)
- Uses the hi-res fonts from D2

BENCHMARK MODE
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-benchmark (captures avg/min/1% low FPS during demo playback, writes BENCH.LOG in the game directory)

1DESCENT BENCHMARK RESULTS
2========================
3
4Frames: 3058
5Total time: 95.90 sec
6
7Average FPS: 31.89
8Minimum FPS: 7.36
91% low FPS:  16.86
10
11Average frametime: 31.35 ms
12Worst frametime:   135.78 ms
131% low frametime:  59.31 ms
14
15Renderer: Software

In DOSBOX-X I sometimes notice sound clipping when playing demos, especially if CPU cycles is set high. I did some testing to the mixer and buffer, but I'm not 100% if it's making an effect, but I left it in there.
- Volume clamping to prevent mixer overflow/clipping
- Higher sample rate (22050 Hz) and larger DMA buffer (8192)

As the source is being compiled with Open Watcom 2.0 I added /5r to optimization for Pentium CPUs.