[SDL] Slow Framerates 3

[Corona688]

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!  :)