Hi,
currently i am using a GForce 4 MX420 on win 2k. No i dont use a frame rate limiter and i do use SDL_Flip to swap the two surfaces in double buffering mode.
I’ve already tried to do this rectangle update thing. But when used in double buffering mode, the surface i am working with is 2 frames old. That means i would have to figure out the position of the ball 2 frames ago. So i have to skip using double buffering, and use UpdateRects ? Doesn’t SDL have this limitation that you can’t write on the surface you are displaying at the moment ?
The argument with 77Mb/sec seems clear to me. I just thought that in times of Quake III and so on, graphic cards should do 2d Blits just easily.
Bye,
Marc
Marc Essinger wrote:
Hi,currently i am using a GForce 4 MX420 on win 2k. No i dont use a
frame rate limiter and i do use SDL_Flip to swap the two surfaces in
double buffering mode. I’ve already tried to do this rectangle update
thing. But when used in double buffering mode, the surface i am
working with is 2 frames old. That means i would have to figure out
the position of the ball 2 frames ago. So i have to skip using double
buffering, and use UpdateRects ? Doesn’t SDL have this limitation
that you can’t write on the surface you are displaying at the moment
? The argument with 77Mb/sec seems clear to me. I just thought that in
times of Quake III and so on, graphic cards should do 2d Blits just
easily.Bye,Marc
If you set the video mode without double buffering, then SDL uses a
single backbuffer instead. Meaning the surface you’re blitting to this
frame is the exact same surface as last frame. 
And if it is possible to do that 77MB/s hardware-accelerated blit,
more power to you, but just imagine all the cool stuff you could do
using that bandwidth efficiently!
Hello!
But when used in double buffering mode, the surface i am working with
is 2 frames old.
I guess that’s not a problem, our brains are not so fast in computing
(but very good in averaging out such problems).
The argument with 77Mb/sec seems clear to me. I just thought that in times
of Quake III and so on, graphic cards should do 2d Blits just easily.
Graphic cards are Quake-optimized, not 2D-optimized.
So some people even do their 2D stuff (ab)using a 3D engine.
Ciao,
Eike