On Wed, Feb 3, 2010 at 4:42 AM, Luca Barbieri <l...@luca-barbieri.com> wrote: > I tested this on Windows, using nVidia driver 195 on nv40, and it > seems we are all partially wrong. > > SM3 does indeed allow semantics unrelated to hardware resources. > However, the semantic indices for any semantic type must be in the > range 0-15, or D3DX will report a compiler error during shader > compilation: > error X2000: syntax error : unexpected token 'dcl_texcoord16' > > This is further confirmed by the following lines in d3d9types.h: > #define MAXD3DDECLUSAGE D3DDECLUSAGE_SAMPLE > #define MAXD3DDECLUSAGEINDEX 15 > > I would guess that these two 4-bit values are combined into an 8-bit > value that is then passed directly to hardware like r600 which > supports 8-bit semantic indices in hardware. > Is this the case on Radeon? > > Is the 8-bit semantic table a feature of r300 too or only of r600+?
Only r600+. r3xx-r5xx is more basic. You basically set up a table based on the inputs and outputs. Order doesn't matter as long as the table is correct for the vs and ps you are using. See pages 258-261 for the vertex fetch setup and pages 197-199 for the vs to ps routing of the r5xx accel guide: http://www.x.org/docs/AMD/R5xx_Acceleration_v1.4.pdf Alex > > In light of this, it may make sense to do some range limitation ourselves too. > In particular, a good plan could be limiting all semantic indices to > 0-15, except GENERIC, which could support a 0-127 range. > This would allow to both directly take advantage of Radeon hardware, > and let drivers that need to remap in software do so with direct > lookup in a small array. > ------------------------------------------------------------------------------ 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
