[Mesa-dev] [PATCH] lp_build_lod_selector: Disable brilinear folding on explicit lod.

[Roland Scheidegger]

Does this fix the test because lp_build_brilinear_lod produces bogus 
values in this case or just because the test is strict about such 
filtering optimizations? In the latter case I'm not sure I really see 
much point.
I'm surprised it can actually pass in either case since we drop all but 
the first lod per quad values on the floor anyway so I think you will 
get neither the right filtering weights between mipmaps nor even the 
right mip levels (if the integer part of the lod isn't the same) for 
anything but the first texel per quad.

Roland

On 06/25/2012 05:50 PM, Olivier Galibert wrote:
> Brilinear folding must only be used if the log2 was computed with
> brilinear too.  Fixes fs-textureLod-miplevels.
>
> Signed-off-by: Olivier Galibert <galibert at pobox.com>
> ---
>   src/gallium/auxiliary/gallivm/lp_bld_sample.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample.c b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
> index d966788..9deda61 100644
> --- a/src/gallium/auxiliary/gallivm/lp_bld_sample.c
> +++ b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
> @@ -513,7 +513,7 @@ lp_build_lod_selector(struct lp_build_sample_context *bld,
>      }
>
>      if (mip_filter == PIPE_TEX_MIPFILTER_LINEAR) {
> -      if (!(gallivm_debug & GALLIVM_DEBUG_NO_BRILINEAR)) {
> +      if (!explicit_lod && !(gallivm_debug & GALLIVM_DEBUG_NO_BRILINEAR)) {
>            lp_build_brilinear_lod(float_bld, lod, BRILINEAR_FACTOR,
>                                   out_lod_ipart, out_lod_fpart);
>         }
>