On Tue, 23 Mar 2004 08:16:49 -0800 (PST) Alex Deucher <[EMAIL PROTECTED]> wrote:
> > --- Felix K_hling <[EMAIL PROTECTED]> wrote: [snip] > > Anyway, the reason is that accelerated 3D rendering only works with > > tiled memory but the front buffer is linear. > > > > Software fallbacks draw to tiled surfaces, which map linear or tiled > > memory. If I understand it correctly it shouldn't make any difference > > whether the underlying memory is linear or tiled (as long as the > > tiled > > surface registers are setup correctly). > > That's my understanding as well, but I could be wrong. Also, tiling > the front buffer results in lower performance. I'm not sure why. It > might have just been due to the way the code was initially architected. > your changes to the 3d driver may have fixed that. Don't know which changes that would be. The only thing where the tiling of the front buffer would make a difference for normal double buffered rendering is on buffer swaps. The swapping didn't change. So possibly blitting to a linear frame buffer is faster than blitting to a tiled one. Anyway, from Keith's comments about double-buffered visuals where the app switches between rendering to front and back buffer, it sounds like we really want to have a tiled front buffer. > > > > > It seems that the front buffer surface uses a different line pitch > > than > > the back buffer. I don't know why that is. Alex, can this be changed > > easily or would it require big changes in the 2D driver? > > The pitch is different because of alignment requirements. I think I > tried changing the front pitch to match the others and it didn't seem > to break anything as I recall, so perhaps we can get away with it. If it really needs a different pitch it shouldn't be too hard to adjust savagespan.c. > Unfortunately, tiling of the front buffer broke when I ported S3's > changes to Tim's code. I'm not sure what the problem is as the set up > is pretty much identical. I never really dug into it too much since > linear seemed to work fine for most things. However, back when we were > using S3's driver and tiling worked, drawing to the front buffer was > still broken (looked the same whether the front buffer was tiled or > not). > > Alex > [snip] ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click -- _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
