On 27.04.2010 18:29, José Fonseca wrote: > On Tue, 2010-04-27 at 08:59 -0700, Roland Scheidegger wrote: >> On 27.04.2010 17:32, Roland Scheidegger wrote: >>> On 27.04.2010 13:13, Dave Airlie wrote: >>>> Another trying to figure out gallium patch from me, >>>> >>>> This is in theory EXT_texture_swizzle support, r300g passes the glean >>>> test with this now. >>>> >>>> Some caveats in the patch (i.e. I'm not sure what exactly is correct >>>> state tracker behaviour wrt sampler views). >>> Dave, >>> >>> Basically looks good but I have some concerns. First, I think the >>> extension should not be announced unconditionally but rather based on a >>> cap bit. There's hw we care about which can't do this (i965, svga) and >>> it seems unreasonable to expect them to do workarounds just so this >>> extension can be always exposed. >>> Also, I think it won't work correctly if the pipe format itself has a >>> swizzle (which is different to rgba). There are really two swizzles >>> here, one coming from the extension the other inherited from the format, >>> and they need to be combined. Either in the driver or the state tracker, >>> I think it's underspecified right now but I think the swizzle parameter >>> should express the hardware view, hence the combining should take place >>> in the state tracker. (Also, for depth textures it should also take the >>> depth texture mode into account, but that might be out of the scope of >>> what you're trying to do.) >>> >>> Roland >> Actually right now the swizzle seems to represent only the "GL swizzle", >> not the format one (looking at the u_sampler_view_default_template). Not >> sure though if that's really the right design. In this case the driver >> would need to combine the format and extension swizzle. > > I think it is worthwhile to keep the format swizzle orthogonal to the > sampler view swizzles. It is actually more complex trying to describe > swizzles in terms of the packed vector, since they not always have > unambiguous meaning (bitmasks, subsampled formats, compressed textures). > > Jose
ok. Can we still express depth texture mode though in the sampler view swizzle? I guess it's not unreasonable to let drivers handle combining the swizzles, if necessary could use some util code (for the normal formats at least). Roland _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
