On Thu, Mar 27, 2014 at 11:35 AM, Jose Fonseca <jfons...@vmware.com> wrote: > > > ----- Original Message ----- >> On Wed, Mar 26, 2014 at 4:30 AM, Roland Scheidegger <srol...@vmware.com> >> wrote: >> > Am 26.03.2014 03:29, schrieb Marek Olšák: >> >> My reasoning was that it would be better to specify a raw clear value >> >> and clear value size for buffers, which are always untyped, and >> >> pipe_color_union for textures, which are always typed, so that drivers >> >> can easily implement the texture clearing on top of >> >> pipe_context::clear. >> >> >> >> I also suggested that clear_render_target and clear_depth_stencil >> >> should be removed in favor of a new function clear_texture(pipe, >> >> resource, level, box, pipe_color_union). For depth-stencil, we can >> >> assume that the first component of the clear color is a floating-point >> >> depth value and the second component is an unsigned integer stencil >> >> value. >> > This could not clear only depth or stencil, though. >> > Clear is just a mess why couldn't the apis agree a bit more what is >> > useful... >> > So d3d10 can only clear render target / depth stencil views, meaning >> > your resrouces need the bind_render_target flag (not that drivers >> > actually usually enforce this for rendering since it breaks mesa state >> > tracker in a couple of places due to this being not required in general >> > and hard to guess in GL). You cannot clear only parts (or rather, you >> > can clear individual layers and such by creating a different view, but >> > not specify coords). You can however clear only depth or stencil. >> > And you cannot clear buffers (well you can if you make them render >> > target bindable but this has severe limitations and isn't something >> > you'd do just so you can clear them). >> > GL OTOH doesn't require the resources to be renderable for clearing to >> > work, doesn't allow to clear only depth/stencil but does allow a box. >> > There's also another problem with the proposed parameters for d3d10, the >> > format of the resource could be different to that you'd actually want to >> > use for clearing (for typeless resources). >> >> Adding the format parameter is not a problem. It would also allow >> depth-only or stencil-clear by setting Z24X8 or X24S8, respectively. >> >> Regarding non-renderable textures, well, RGB9_E5 is the only >> non-renderable GL format on Radeon and we could easily clear that as >> R32_UINT. Radeon drivers already change texture formats to support >> fully-accelerated resource_copy_region and they will do so for >> clearing as well. You can always use a software fallback if you have >> no other option. >> >> Some of the GL 4.x stuff will be a bigger mess, and there are also fun >> things like GL_ARB_bindless_texture. > > Having a clear_resource, with all necessary parameters so it can superceed > clear_render/depth_stencil view, seems a sensible thing to do FWIW.
Just to clarify -- is this a vote against my current implementation of ARB_clear_buffer_object acceleration (which adds a ->clear_buffer call), or a comment on how you'd like to see ARB_clear_texture acceleration implemented? If the latter, I'm concerned that there will be drivers that can clear RT's but not random textures. This shouldn't be an issue for nv50/nvc0, but I'm much less familiar with what else is out there. FWIW, the way that'd be done on nv50/nvc0 is by cheating -- there are actually a bunch of formats that can be used for texturing but not rendering. But the clear mechanism is just a glorified memset, so we can fake the formats as long as they're the right number of bytes. -ilia _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
