Cooper Yuan wrote: > I got it, thanks! Actually, in function st_init_clear(), if I set > bypass_vs_clip_and_viewport as 0, things get better. > > Another question is about the function clear_with_quad() provided by > state tracker, this function can clear color/depth buffer through a > quad, but driver's pipe->clear can also implement the operation by > filling a furface, which one is prefered?
pipe->clear() is only used to clear whole buffers. The clear_with_quad() path is used when scissoring is enabled and only part of the buffer is actually cleared (or when using colormasking). When a whole buffer is cleared, some optimizations can be made depending on the underlying rendering architecture. > Could you please tell me the difference between mesa/state tracker and > gallium/state tracker? The mesa/state_tracker/ could be moved under gallium/state_trackers/ (or it could go under src/mesa/drivers/). It just wound up where it is because it was the first state tracker. -Brian > > Cooper > On Tue, Aug 18, 2009 at 6:49 AM, Keith Whitwell <kei...@vmware.com > <mailto:kei...@vmware.com>> wrote: > > On Tue, 2009-08-18 at 05:25 -0700, Cooper Yuan wrote: > > Hi, > > > > Does bypass_vs_clip_and_viewport influence vertex fetch? > > I thought vertex transform engine is behind vertex shader, that > means, > > bypass_vs_clip_and_viewport will not impact vertex fetch. > > > > But when I debug glClear issue on r500 gallium driver, if driver > > disable VTE, the color data can't be fetched (position is correct), > > enabled VTE can fetch color data successfully. > > > > Could anyone give me clues? > > All this flag means is that the state tracker is sending you > pre-transfomed (ie window-space) vertex positions. If it sends you > vertex x,y == 100,300 then one corner of your triangle is at that pixel > coordinate. It's basically the same case as if you've used the draw > module to do software transformation within the driver. > > That said, I think we remove the remaining usage of this functionality > from the Mesa state tracker - it's a serious corner case for the > open-source drivers. > > Keith > > > > ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Mesa3d-dev mailing list Mesa3d-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
