Mon, 04 Dec 2000 Dominique Biesmans wrote:> > -----Original Message-----
From: Mattias Engdeg?rd [mailto:f91-men at nada.kth.se]
[snip]
Speaking of which, since filled polygons are frequently accelerated,
I was considering adding it to the SDL API for post-1.2, along with
drawing line segments. Nothing decided yet though
Filled polygons are often accelerated, yes, but only in a 3D context. I’m
wondering how things API wise will evolve when 3D stuff is pulled in…
Unless you’d layer everything on top of a 3D API (e.g. blitting a surface
would be done by drawing a textured quad), I think it will be hard
(impossible?) to offer hw accelerated polys & lines in a portable way …
3D is where serious work is spent on APIs and fast drivers - the rest is “just
for buttons and text”, and no one seems to care enough to even make sure that
there is a real API for 2D acceleration. Many cards have great 2D
acceleration, but I have yet to see a single API/driver combo that takes
advantage of more than a fraction of it.
“Ok, so 3D acceleration is widely available and supported; lets use that
instead!” Yeah, but… 3D APIs are meant for 3D, and the same goes for the
hardware. On a practical level, that means you have to deal with power-of-two
texture sizes, no “clean” way of passing 2D geometry to the card and similar
limitations. Sure, a 2D API on top of a 3D API is doable, but most existing 2D
APIs do things that are not compatible with 3D APIs, and they do things in ways
that are not suitable for 3D APIs from an efficiency POV.
Still, I’m interested in a serious accelerated 2D API (for games, mainly),
and I’m thinking about ways to build it on top of OpenGL. I’d be interested in
discussing design issues, experiences, ideas etc, although I can’t say when
I’ll be able to put serious hacking time into this project.
To begin somewhere, here’s what I’m looking for, basically:
* Speed
* Sub-pixel accurate sprites and scrolling
* High quality rendering w/ rotation and other transformations
* Speed
* Fast blending and transparency
* Massive parallax scrolling fields
* Speed
* 16 and 24 bit color
* Speed
Basically, I want to get a little bit closer to what 2D graphics should be
today, considering what 3D looks like. (Look at Quake III Arena on a decent
machine, and then have a look at the majority of 2D games, including those that
requrire massive CPU for smooth animation. Something is wrong here…)
Of course, this should be done using a nice API that lends itself to h/w
acceleration (using OpenGL, Glide, …, or dedicated drivers), as well as
software rasterizing engines. 
//David
…- M A I A -------------------------------------------------.
| Multimedia Application Integration Architecture |
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