radeonsi: fix texture gather on stencil textures

At least on VI, texture gather doesn't work with a 24_8 data format, so
use 8_8_8_8 and a modified swizzle instead.

A bit of background: When creating a GL_STENCIL_INDEX8 texture, we select
the X24S8 pipe format because we don't support stencil-only render targets
properly. With mip-mapping this can lead to a setup where the tiling is
incompatible with stencil texturing, and a flushed stencil texture is
used. For the flushed stencil, a literal X24S8 is used because there were
issues with an 8bpp DB->CB copy.

Longer term, it would be good if we could get away from these workarounds,
i.e. properly support an S8 format for stencil-only rendering and flushed
stencil. Since stencil texturing is somewhat rare, it's not a high
priority.

Fixes GL45-CTS.texture_cube_map_array.sampling.

Cc: 17.0 <mesa-stable@lists.freedesktop.org>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Acked-by: Edward O'Callaghan <funfunctor@folklore1984.net>
This commit is contained in:
Nicolai Hähnle 2017-01-18 09:28:47 +01:00
parent 905961452a
commit 3cd092c415
1 changed files with 16 additions and 2 deletions

View File

@ -1365,11 +1365,17 @@ static uint32_t si_translate_texformat(struct pipe_screen *screen,
case PIPE_FORMAT_Z16_UNORM:
return V_008F14_IMG_DATA_FORMAT_16;
case PIPE_FORMAT_X24S8_UINT:
case PIPE_FORMAT_S8X24_UINT:
/*
* Implemented as an 8_8_8_8 data format to fix texture
* gathers in stencil sampling. This affects at least
* GL45-CTS.texture_cube_map_array.sampling on VI.
*/
return V_008F14_IMG_DATA_FORMAT_8_8_8_8;
case PIPE_FORMAT_Z24X8_UNORM:
case PIPE_FORMAT_Z24_UNORM_S8_UINT:
return V_008F14_IMG_DATA_FORMAT_8_24;
case PIPE_FORMAT_X8Z24_UNORM:
case PIPE_FORMAT_S8X24_UINT:
case PIPE_FORMAT_S8_UINT_Z24_UNORM:
return V_008F14_IMG_DATA_FORMAT_24_8;
case PIPE_FORMAT_S8_UINT:
@ -2796,14 +2802,22 @@ si_make_texture_descriptor(struct si_screen *screen,
if (desc->colorspace == UTIL_FORMAT_COLORSPACE_ZS) {
const unsigned char swizzle_xxxx[4] = {0, 0, 0, 0};
const unsigned char swizzle_yyyy[4] = {1, 1, 1, 1};
const unsigned char swizzle_wwww[4] = {3, 3, 3, 3};
switch (pipe_format) {
case PIPE_FORMAT_S8_UINT_Z24_UNORM:
case PIPE_FORMAT_X24S8_UINT:
case PIPE_FORMAT_X32_S8X24_UINT:
case PIPE_FORMAT_X8Z24_UNORM:
util_format_compose_swizzles(swizzle_yyyy, state_swizzle, swizzle);
break;
case PIPE_FORMAT_X24S8_UINT:
/*
* X24S8 is implemented as an 8_8_8_8 data format, to
* fix texture gathers. This affects at least
* GL45-CTS.texture_cube_map_array.sampling on VI.
*/
util_format_compose_swizzles(swizzle_wwww, state_swizzle, swizzle);
break;
default:
util_format_compose_swizzles(swizzle_xxxx, state_swizzle, swizzle);
}