On 06/16/2011 08:01 AM, Alex Deucher wrote: > On Wed, Jun 15, 2011 at 9:09 PM, Chad Versace <c...@chad-versace.us> wrote: >> If a renderbuffer wraps multiple renderbuffers, then Unwrapped points to >> the them. >> >> For example, if hardware requires separate depth and stencil buffers >> (X8_Z24 and S8), then glRenderbufferStorage(GL_DEPTH24_STENCIL8) may >> create a fake S8_Z24 renderbuffer for which Unwrapped[BUFFER_DEPTH] and >> Unwrapped[BUFFER_STENCIL] point to the real X8_Z24 and S8 renderbuffers. >> > > FWIW, evergreen and newer chips only support separate stencil and > depth, so we had a similar issue. We ended up using > GL_ARB_shader_stencil_export to implement writes to the stencil. > Start of the thread: > http://lists.freedesktop.org/archives/mesa-dev/2010-September/003318.html > > Alex
The thread mentions some strange behaviour on r600: > so on r600g, the only way to directly write to the stencil is via the > shader, using a transfer would require an extra step to flush the DS > buffer I've observed mysterious behaviour when writing to intel's stencil buffer through a memory mapped pointer. It's seems that the hardware fails to recognize that the writes ever occurred. (Writes via rendering work fine). I still need to investigate the problem further, but perhaps GL_ARB_shader_stencil_export is what the intel driver needs to work around this problem. Thanks for pointing this out. -- Chad Versace c...@chad-versace.us _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev