Re: [Chromium-dev] CR_SUPPRESS_SWAP_BIT

[Brian P. <br...@tu...>]

Karl Rasche wrote:
> 
> as i recall, the setting of the CR_SUPPRESS_SWAP_BIT (for
> handling the multiple clears with sort-first & readback) was taken out
> some time ago.

It's still there.  You might have this confused with the SINGLE_CLEAR
bit I had defined for glClear().  I took that out because it didn't
work as well as I'd hoped.


> was it ever put back in? i've just added a config option for the readback
> spu here.. maybe i've overlooked something (as i haven't really been
> keeping up with code changes lately).

is defined in cr/include/cr_applications.h
The crSwapBuffers(GLint window, GLint flags) function accepts it
in the flags parameter.

It's documented in the parallel applications section and is used by
the psubmit.c demo.  Basically, for a sort-last configuration you
only want one of the submitters to really send a SwapBuffers to the
final rendering SPU; but the other submitters still need to indicate
end-of-frame so the readback SPU can do it's thing.

Calling crSwapBuffers(win, CR_SUPPRESS_SWAP_BIT) tells the readback
SPU that this is the end of the frame (send the color and Z values)
but don't send a SwapBuffers to the downstream render SPU.

-Brian