[Mesa-dev] [PATCH] i965: Fix calculation of layers array length for isl_view

[Józef Kucia]

On Fri, Sep 7, 2018 at 6:44 PM Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>
> On Fri, Sep 7, 2018 at 12:35 PM, Józef Kucia <joseph.kucia at gmail.com> wrote:
> > On Fri, Sep 7, 2018 at 4:42 PM Danylo Piliaiev
> > <danylo.piliaiev at gmail.com> wrote:
> >
> >> @@ -1546,8 +1548,8 @@ update_image_surface(struct brw_context *brw,
> >>              .format = format,
> >>              .base_level = obj->MinLevel + u->Level,
> >>              .levels = 1,
> >> -            .base_array_layer = obj->MinLayer + u->_Layer,
> >> -            .array_len = num_layers,
> >> +            .base_array_layer = base_layer,
> >> +            .array_len = num_layers - base_layer,
> >>              .swizzle = ISL_SWIZZLE_IDENTITY,
> >>              .usage = ISL_SURF_USAGE_STORAGE_BIT,
> >>           };
> >
> > This sets the "array_len" to the number of layers remaining in the
> > original texture. Shouldn't it take into account the number of layers
> > in the GL texture view?
>
> Errr, right. Here is the logic in st/mesa, which I believe is correct.
> (But convoluted. Because there are so many bits to it.)
>
> https://cgit.freedesktop.org/mesa/mesa/tree/src/mesa/state_tracker/st_atom_image.c#n101

There is also view_num_layers in brw_update_texture_surface(). It
could be adapted.