Brian Paul wrote on 2010-02-04 22:07: > michal wrote: > >> Brian Paul wrote on 2010-02-03 17:58: >> >>> Keith Whitwell wrote: >>> >>> >>>>>> Michal, >>>>>> >>>>>> why do you need this for linear interpolator and not perspective? I >>>>>> think d3d mobile let you disable perspective correct texturing, but it >>>>>> is always enabled for normal d3d. >>>>>> >>>>>> >>>>>> >>>>> I could not think of a use case that uses perspective and cylindrical >>>>> interpolation at the same time. If you think it's valid, we can >>>>> implement cylindrical wrapping for perspective interpolator, but then I >>>>> am not sure how exactly it should be done, i.e. should we divide and >>>>> then wrap or the opposite? >>>>> >>>>> >>>> Is there some way we can figure out what DX9 does here? Maybe a quick >>>> test? >>>> >>>> >>> I suspect cylindrical wrapping would be done after the divide. >>> >>> >>> >> A quick test shows it is legal to have perspective and cylindrical >> interpolation. In fact, I see no difference between projected and >> non-projected version with REF device -- both are perspective correct. >> >> I think I am stuck at this point and need further help. I am trying to >> modify tri_persp_coeff() in softpipe in a similar manner to >> tri_linear_coeff(), but all I get are lousy rendering artifacts. If we >> need do cylindrical wrapping after divide, it must be done as part of >> shader interpolator, but the only place where we have enough information >> to do wrapping is in primitive setup. >> > > Do you have a patch relative to gallium-cylindrical-wrap? I'll take a > look. > > Brian,
I have no half-working patch for you, sorry. I tried a few approaches, but they were nonsensical. The linear coeff calculation is simple: calculate distance between two coordinates, and if it's greater than 0.5, apply wrapping by adjusting the distance. However, for the perspective correct coeffs, we divide early by position.w before calculating the distance, and so my approach that worked for linear fails here. I am either not comprehending the math here (why do we divide the second time in interpolator, for instance?) or we need to put more information into struct tgsi_interp_coef so that the interpolator code has enough information to do wrapping on its own without help of primitive setup. ------------------------------------------------------------------------------ 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
