On 04/06/2015 08:33 AM, Pohjolainen, Topi wrote: > On Sun, Apr 05, 2015 at 08:22:13PM +0300, Pohjolainen, Topi wrote: >> On Sun, Apr 05, 2015 at 08:06:50PM +0300, Pohjolainen, Topi wrote: >>> On Sun, Apr 05, 2015 at 08:46:16AM -0400, Ilia Mirkin wrote: >>>> While this change is correct, the Intel guys will yell at you, because >>>> they're somehow misusing this in meta for Broadwell, s.t. this will >>>> cause crashes when blitting stencil. IMHO that's a problem that should >>>> be fixed in their driver and this can go on, but... it's also not my >>>> driver that's crashing -- they might feel differently :) >>> >>> As far as I can tell we only do: >>> >>> _mesa_TexParameteri(target, GL_DEPTH_STENCIL_TEXTURE_MODE, >>> GL_STENCIL_INDEX); >>> >>> which suppose to be the right thing to do - we select the stencil to be >>> sampled instead of depth. And this won't hit the path below. I made the >>> change locally and I'm now running piglit on broadwell. >>> >>> I noticed that _mesa_base_tex_format() is in turn used in >>> >>> src/mesa/drivers/common/meta_blit.c >>> >>> but we shouldn't go there with intel driver ever. On hardware older than >>> broadwell we don't use meta and the one used on broadwell and newer >>> is found in: >>> >>> src/mesa/drivers/dri/i965/brw_meta_stencil_blit.c >>> >>> But lets see what piglit says. >> >> Right you are. This is more subtle, we will hit it when we actually create >> a temporary texture out of the given read renderbuffer. It seems that this >> was hit first time when formats where adjusted and then Jason added the >> conditional using ARB_stencil_texturing (which is not right either). >> >> Really sorry that this is hindering your work now. I'll try to take a look >> at this tomorrow. > > So far I can't come up with other things than pure hacks. I'll explain > a little what happens in the "intel stencil meta blit". Like I said, the > driver creates a temporary texture out of the stencil attachment: > > const struct gl_renderbuffer_attachment *att = > &ctx->ReadBuffer->Attachment[BUFFER_STENCIL]; > struct gl_renderbuffer *rb = att->Renderbuffer; > struct gl_texture_object *tex_obj; > > ... > if (!_mesa_meta_bind_rb_as_tex_image(ctx, rb, &blit->tempTex, &tex_obj, > target)) { > > > This gets wound back to the driver, a call to > intel_bind_renderbuffer_tex_image() which in turn calls the core again. > > _mesa_init_teximage_fields(ctx, image, > rb->Width, rb->Height, 1, > 0, rb->InternalFormat, rb->Format); > > Here "rb->InternalFormat" is GL_STENCIL_INDEX that won't be accepted by > _mesa_base_tex_format() anymore without ARB_texture_stencil8. As most of > the texture image setting up logic takes place in the core, the boolean state > flag (brw_context::meta_in_progress) we have in intel driver is not much > help. It looks that we would need additional driver driven overriding. > But I don't like that at all.
On the platforms that use this path, don't we fake DEPTH_STENCIL textures by having separate depth and stencil surfaces? The implication being that all of the mechanism that does stencil texturing from DEPTH_STENCIL surfaces is the same as we would need to texture from STENCIL_INDEX8 surfaces. Wouldn't it be easier to just enable ARB_texture_stencil8 on those platforms? > I'll look into this some more, but any suggestions are welcome. > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev