On Fri, 28 Jan 2005 09:51:25 +0100, Jacek Rosik <[EMAIL PROTECTED]> wrote: > Hi, > > I have some questions about r200 depth tiling. Generally I'm also > interested in r100 tiling too, but currently i work on r200. > > First of all in functions r200_mba_z16|32 from r200_span.c frontPitch > offset is used. Is it intentional or just because depthOffset is also > the same? Maybe it should be depthOffset? > > Depth tiles on r200 are 32x16 or 64x16, depending on FB depth, right? > > I don't quite follow third line before last? Can someone enlighten me? > > TIA. > > Generally if one could explain tiling a bit for me I would be grateful. > What I'm trying to do is to is to modify depthOffset to be as close to > top-left corner of viewport as possible and modify. I this possible with > shared depth buffer. This means that each 3D window would have different > depthOffset but pointing to the same shared buffer. >
There are several good descriptions in the dri-devel archives, but it basically works like this: the framebuffer is divided up into fixed size (1024 bytes for example, so 16 bpp tiles would be 16x32x2 bytes or 24 bpp would be 16x16x4 bytes) tiles. The tiles take better advantage of GPU caches and can speed up rendering as you only have to update effected tiles. However, when you are dealing with tiles, you usually have to deal with full tiles so you need to pad your buffers accordingly so that you don't have any partial tiles. Hope that helps, Alex > Best, > -- > Jacek Rosik <[EMAIL PROTECTED]> > ------------------------------------------------------- This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting Tool for open source databases. Create drag-&-drop reports. Save time by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc. Download a FREE copy at http://www.intelliview.com/go/osdn_nl -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
