On Wed, Jul 16, 2014 at 10:17 AM, Michel Dänzer <mic...@daenzer.net> wrote: > On 16.07.2014 00:07, Marek Olšák wrote: >> On Tue, Jul 15, 2014 at 11:53 AM, Michel Dänzer <mic...@daenzer.net> wrote: >>> On 13.07.2014 01:35, Marek Olšák wrote: >>>> >>>> Border colors have been broken if texturing from multiple shader stages is >>>> used. This patch doesn't change that. >>> >>> [...] >>> >>>> +/* Upload border colors and update the pointers in resource descriptors. >>>> + * There can only be 4096 border colors per context. >>>> + * >>>> + * XXX: This is broken if sampler states are bound to multiple shader >>>> stages, >>>> + * because TA_BC_BASE_ADDR is shared by all of them and we overwrite >>>> it >>>> + * for stages which were set earlier. This is also broken for >>>> + * fine-grained sampler state updates. >>>> + */ >>> >>> I don't think that's accurate, as the BO for storing the border colours >>> is per-context, not per-shader-stage. >> >> Ah yes. The problem only occurs when the BO is reallocated. Consider this: >> >> set_sampler_states(SHADER_VERTEX) >> // This sets TA_BC_BASE_ADDR and sets the border color pointers >> // in the sampler descriptors. The pointers are relative to the base >> address. >> >> set_sampler_states(SHADER_FRAGMENT) >> // If the buffer is reallocated, TA_BC_BASE_ADDR is changed. >> // All border color pointers for fragment sampler states are set and valid. >> // All border color pointers for vertex sampler states are now invalid, >> // because TA_BC_BASE_ADDR has been changed. >> >> The reallocation can also happen halfway through setting up border >> colors, e.g. you set border colors 0,1,2,3, then you have to >> reallocate, and then you set border colors 4,5,6,7, so the first four >> border color pointers end up being incorrect, because the previous >> buffer has been thrown away. > > Exactly, except in that case border colours 4,5,6,7 won't work properly > either, because their values are written to the old buffer, because the > border_color_table pointer isn't updated when reallocating the BO. > > >> I think the proper solution would be to update all border colors for >> all bound sampler states again when the buffer is reallocated. Also, >> to prevent frequent reallocations, we can check if the current border >> color pointer in a sampler state is still valid and if it is, we can >> skip the upload. > > Sounds good, are you going to give this a shot?
Yes, but not in this patch. For now, I'll just change the comment to "this code is very broken". Marek _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
