The data in u_format.csv was migrated from p_format which was full of inconsistencies. I've fixed some of these but there are others which I haven't. Read the "pipe_format lookup table" thread of mesa3d-dev if you want to know the background.
I'll add more documentation to u_format.h. The gist is source channels come in a vector ordered from least significant bit -> highest significant bit. Jose On Mon, 2009-12-21 at 23:40 -0800, Marek Olšák wrote: > Hi, > > I noticed that gallium/auxiliary/util/u_format.csv contains some weird > swizzling, for example see this: > > $ grep zyxw u_format.csv > PIPE_FORMAT_A8R8G8B8_UNORM , arith , 1, 1, un8 , un8 , un8 , > un8 , zyxw, rgb > PIPE_FORMAT_A1R5G5B5_UNORM , arith , 1, 1, un5 , un5 , un5 , > un1 , zyxw, rgb > PIPE_FORMAT_A4R4G4B4_UNORM , arith , 1, 1, un4 , un4 , un4 , > un4 , zyxw, rgb > PIPE_FORMAT_A8B8G8R8_SNORM , arith , 1, 1, sn8 , sn8 , sn8 , > sn8 , zyxw, rgb > PIPE_FORMAT_B8G8R8A8_SRGB , arith , 1, 1, u8 , u8 , u8 , > u8 , zyxw, srgb > > It's hard to believe that ARGB, ABGR, and BGRA have the same > swizzling. Let's continue our journey: > > $ grep A8R8G8B8 u_format.csv > PIPE_FORMAT_A8R8G8B8_UNORM , arith , 1, 1, un8 , un8 , un8 , > un8 , zyxw, rgb > PIPE_FORMAT_A8R8G8B8_SRGB , arith , 1, 1, u8 , u8 , u8 , > u8 , wxyz, srgb > > Same formats, different swizzling? Also: > > $ grep B8G8R8A8 u_format.csv > PIPE_FORMAT_B8G8R8A8_UNORM , arith , 1, 1, un8 , un8 , un8 , > un8 , yzwx, rgb > PIPE_FORMAT_B8G8R8A8_SRGB , arith , 1, 1, u8 , u8 , u8 , > u8 , zyxw, srgb > > Same formats, different swizzling? I don't really get it. And there's > much more cases like these. Could someone tell me what the intended > order of channels should be? (or possibly propose a fix) The meaning > of the whole table is self-contradictory and it's definitely the > source of some r300g bugs. > > Marek ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Mesa3d-dev mailing list Mesa3d-dev@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
