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. Marek _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
