[SDL] 2D Accelerated Hardware Support?

[hayward at slothmud.org]

>>Most of the more common video cards are supported via. hardware
>>acceleration in 2D.  In fact, most 2D accel was available before 3D
>>accel was available for a particular card.
>
>Unless you are running SDL + Linux, of course.

Not exactly true.  For the longest time, X has had XAA acceleration.
Sure - you could run svgalib GL quake under linux, but thats a single
video card.  During that time there was already quite a bit of work done
on making use of video card acceleration.  And this has *nothing* todo
with DGA 1.0.  Theres more about video card acceleration than just DGA, I
believe.

Belew, you describe the conditions to get DGA 2.0.  While DGA gives you
better acceleration, it doesn't mean you aren't using acceleration if you
aren't using DGA.  Do some research into X11 XAA.  Read the documentation
for XFree86 3.X,  you'll find specifications describing which chipsets
are supported, which ones are supported with XAA acceleration, etc.

>X11 acceleration != SDL acceleration. If you want 2D acceleration under
>Linux, all of the following conditions must be fulfilled:
>
>1) XFree86 4.0 or later
>2) video hardware supported by XFree 4.0 (a limited set right now)
>3) video hardware for which XFree supports DGA2 (a further subset of 2)
>4) SDL must be configured to take advantage of DGA2
>5) root privileges!
>6) you don't expect anything but rectangular blits/fills or colourkeyed
>   blits to be accelerated