On Tue, Feb 2, 2010 at 1:16 PM, Luca Barbieri <l...@luca-barbieri.com> wrote: >> Personally I'm >> going to take a break from this thread, spend a couple of days looking >> at i965, etc, to see what can be done to improve things there, and >> maybe come back with an alternate proposal. > > Yes, I think that the most important step is to precisely determine > how both hardware (and especially the newer cards you mentioned) works > and how shader APIs (especially DirectX) are defined. >
On AMD r6xx and newer asics, the hardware provides 8 bit semantic ids that are used for vertex fetches and shader to shader routing. See: http://www.x.org/docs/AMD/R6xx_R7xx_3D.pdf pages 10-11, 16-17 The driver can define the ids to whatever it wants and then data will be routed based on those ids. E.g., #define POSITION 1 #define COLOR0 2 #define TEXCOORD0 3 etc. then in your fetch shader: vfetch POSITION vfetch TEXCOORD0 vfetch COLOR0 and in your vs output: export COLOR0 export TEXCOORD0 export POSITION and in your ps inputs: input TEXCOORD0 input COLOR0 etc. The ordering doesn't matter all routing is done by semantic id. There's no need to recompile your vertex shaders or pixel shaders, you just adjust the fetch shader and sematic exports/imports state accordingly. The current r600 classic mesa driver just uses a hardcoded mapping right now, but it would make sense to use semantic ids in the gallium driver. Alex > Once the workings of both are known and agreed upon, the best solution > should be hopefully be clear. > > In addition to looking at hardware such as i965, it would be awesome > to find some clear and unambiguous documentation on DirectX shader > semantics. and agree on its interpretation. > > ------------------------------------------------------------------------------ > The Planet: dedicated and managed hosting, cloud storage, colocation > Stay online with enterprise data centers and the best network in the business > Choose flexible plans and management services without long-term contracts > Personal 24x7 support from experience hosting pros just a phone call away. > http://p.sf.net/sfu/theplanet-com > _______________________________________________ > Mesa3d-dev mailing list > Mesa3d-dev@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/mesa3d-dev > ------------------------------------------------------------------------------ The Planet: dedicated and managed hosting, cloud storage, colocation Stay online with enterprise data centers and the best network in the business Choose flexible plans and management services without long-term contracts Personal 24x7 support from experience hosting pros just a phone call away. http://p.sf.net/sfu/theplanet-com _______________________________________________ Mesa3d-dev mailing list Mesa3d-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
