10 Jan
2013
10 Jan
'13
4:47 a.m.
On Jan 9, 2013, at 10:44 PM, Toby Thain wrote:
Well. EVERYTHING in software. Texture mapping, sprites,
polygon setup, geometry transforms, blitting (or, generally,
page-swapping). There was no hardware assist whatsoever
unless you count page-swapping (which you might, if you
worked on machines like the Macintosh which didn't have it).
What does DOOM
need, CPU power of graphics?
Texture mapping in software, so: CPU, since there is a bunch of stuff done per pixel, and
there are quite a lot of pixels. Then you need a framebuffer to render the pixels. Unless you had an SGI, this stuff really didn't
get exciting until RISC and PowerPC (Marathon, Halo 1...) and then hardware 3D, which soon
enough made it to the PC world.
Marathon was written for both 68K and PowerPC, and actually
performed pretty OK on a 25 MHz 68040. Halo 1 was WAY into
the 3D acceleration era; the original development was for
fast G3s running Rage 128 at a minimum, then quickly moved
to Xbox (PIII Celeron with third-gen NVIDIA graphics) once
Microsoft bought Bungie.
DOOM (which had an engine similar in complexity to Marathon)
ran OK on a 386 and pretty damn well on a 486, neither of
which was RISC in any sense. It was also never hardware
accelerated until iD open-sourced it and the community
modified it to be so, long after the engine had any real
relevance.
We are quickly moving away from what most people might
consider "vintage", though parts of this discussion are
well over 20 years old. To bring it back, maybe: I'm
rather curious about DOS extenders. I know DOOM and
Quake both used 32-bit extenders to gain access beyond the
limitations of real mode, but I've never been quite clear
on what those extenders actually DID. Surely there are
five or ten people overflowing with information on this
point here?
- Dave