Bernard Leclerc (bleclerc++at++cae.ca)
Fri, 15 Nov 1996 11:09:24 -0500
These days, I'm spending most of my time interpreting statistics collected
from a multichannels/multipipes application. Since the beginning of this
exercise, I had difficulty interpreting the value "frame" in the top
portion of the display.
If I understand correctly the meaning of "frame", it represents the time
spent between the call to pfFrame() in the APP stage and the moment the
corresponding frame is completed in the DRAW stage.
Typically, I'm using the APP_CULL_DRAW model. The value "frame" should
correspond to sum of the APP, CULL and the portion of the DRAW spent
drawing this frame in a particular channel.
The following diagram illustrates what, I think, is the time measured by
"frame". The asterisk represents the call to pfFrame().
|----------|----------|----------|
APP ....*...
CULL .......
DRAW .....
<======= frame =======>
Here the value "frame", computed after the frame is completely rendered,
should be
frame = pfGetTime() - pfGetFrameTimeStamp()
Is this correct?
I would appreciate if Sharon, Michael or Remi could comment on this:
a) The time measured by "frame" does not include the time spent
between pfSync() and pfFrame().
b) The time measured by "frame" includes the DRAW time for the
channel plus some time necessary to flush the pipe.
Thanks in advance to the Performer team for taking the time to comment on
the subject.
Regards.
--
Bernard Leclerc CAE Electronics Ltd., 8585 Cote De Liesse
Technical Leader Saint-Laurent, Quebec, Canada, H4L-4X4
3-D Graphics Applications tel: +1 514 341 2000 extension 2275
bleclerc++at++cae.ca fax: +1 514 340 5496
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