Am 02.02.2017 um 16:40 schrieb Brian Paul: > On 02/02/2017 08:13 AM, Roland Scheidegger wrote: >> Am 02.02.2017 um 16:00 schrieb Roland Scheidegger: >>> Am 02.02.2017 um 09:11 schrieb Andrew A.: >>>> Thank you for the help! It was indeed an incomplete texture issue. >>>> Setting the MIN/MAG filters to GL_NEAREST ended up resolving it. >>>> >>>> I did have one other question -- why is this considered a silent >>>> non-error condition? >>> I did put quotation marks around that :-). >>> Incomplete textures have been like that since day one in OpenGL (or >>> rather, since GL got support for textures). Not considered an error, you >>> just get all black, even though really everybody would consider that an >>> error in practice... > > Actually, the original fixed-function pipeline expected to get white > texture samples from incomplete textures and I remember a screen saver > from many, many years ago that depended on that behavior. Wow that's really crazy...
> > But yes, with GLSL, sampling an incomplete texture returns black. > > FWIW, GL 1.0 had textures, but not texture objects. Ahh right my bad, even with nice internal format support of 1,2,3,4 :-). I somehow thought it was a 1.1 feature. So that incomplete behavior was indeed there since day 1 (I think the all-white behavior was due to pretending like texture mapping was disabled in this case?). Roland > > >>> Maybe it's because this error is only detectable at draw command time, >>> and there weren't really any errors which got detected (and returned as >>> such) with draw commands then (just invalid parameters of draw itself). >>> Albeit this is no longer the case now. But really I have no idea... And >>> yes it is annoying and sometimes makes for interesting debugging >>> (especially since some vendors don't actually implement it as literal as >>> the spec says in cases the filters don't matter and don't even warn >>> about it...). >> >> I forgot to mention, mesa can warn about this - >> MESA_DEBUG=incomplete_tex should do it with a debug build. Maybe though >> this should always be logged through KHR_debug (especially since in >> contrast to incomplete fbos, there's just no way to query it from GL), >> I'm not familiar with that part... > > That's a good idea. I may look into it if I have spare time. > > -Brian > > _______________________________________________ mesa-dev mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/mesa-dev
