Not that uncommon back in the day. Even Doom on PC didn't use floating-point; instead relying on fixed point.
This set me reminiscing about the x87 series FP co-processors. Nice nostalgia break waiting for a build to finish, thanks!
Yes, and what few people know, is that x86 co-processors in general really only had to stick to the hardware interface given by Intel. What they actually did with that was up to the co-processor. Best known case in point were the Weitek math co-processors which were not actually machine code compatible with the Intel x87s.
Modern Vintage Gamer made a video[1] about this a few days ago
Re:The Polygons of Doom: PSX
by badsectoracula on Friday March 27, 2020 @08:47AM
(#22702411)
Note that the video had several errors: https://www.reddit.com/r/Games/comments/fnl0o1/why_playstati...
Re:The Polygons of Doom: PSX
by dangerbird2 on Friday March 27, 2020 @09:38AM
(#22702704)
I was going to link that video, especially considering regarding the problem of affine texture mapping. MVG discussed the common workaround in PSX: tesselating flat surfaces so the perspective distortion is minimized. I was surprised to see in OP's article that the PSX-Doom devs took a completely different approach of drawing a polygon for each scanline to emulate the PC-Doom's raymarching line-renderer.
Re:The Polygons of Doom: PSX
by GrantSolar on Friday March 27, 2020 @02:58AM
(#22700883)
This lead to some interesting issues when porting PC to PlayStation
https://www.gamasutra.com/view/feature/132500/dirty_coding_t...
Re:The Polygons of Doom: PSX
by Waterluvian on Friday March 27, 2020 @07:56AM
(#22702129)
Is this why geometries loved to jiggle and dance?
That's why I was so surprised! I've heard of early PCs omitting floating-point, but it seems crazy for a platform designed specifically for games, for precisely this kind of reason.
That's not the reason, though.
Re:The Polygons of Doom: PSX
by noisem4ker on Friday March 27, 2020 @08:03AM
(#22702161)
It seems so. A recent video about the graphical quirks of the PlayStation:
Why PlayStation 1 Graphics Warped and Wobbled so much https://youtu.be/x8TO-nrUtSI
Re:The Polygons of Doom: PSX
by badsectoracula on Friday March 27, 2020 @08:48AM
(#22702424)
The reasons mentioned in the video have nothing to do with the warping and wobbling, see what i wrote on Reddit about it: https://www.reddit.com/r/Games/comments/fnl0o1/why_playstati...
Re:The Polygons of Doom: PSX
by ReactiveJelly on Friday March 27, 2020 @09:10AM
(#22702539)
Yep. 16 bits isn't enough precision for 3D no matter how you use it.
When you get up to 32 or 64 bits, fixed and float are both very good.
Re:The Polygons of Doom: PSX
by alexisread on Friday March 27, 2020 @06:22AM
(#22701650)
Yes, though the affine texture mapping is not the only solution, just the easiest/ best conceptually at the time.
There's a port of Quake II to the Atari Falcon which has an interesting take on this lack of FP. See if interested:
http://www.atari-forum.com/viewtopic.php?f=68&t=26775&sid=78...
Wow!