nanogui: Performance hints?
Subject:
Re: [nanogui] Performance hints?
From:
"Greg Haerr" ####@####.####
Date:
27 Nov 2007 20:17:47 +0000
Message-Id: <100f01c83132$8013db90$0300a8c0@RDP>
> it is spending about 35% of the cpu time in a small loop copying memory in
> linear16_drawhorzline().
That's pretty interesting. Is just drawhorzline, or is there
significant time being spent in other low-level draw routines?
I don't recall why the memsetw is not in use, perhaps there
wasn't a memsetw in the C library for the systems at the
time. I would suggest that you uncomment it and see where
the next bottleneck is. We should also be using Duff's loop
unrolling in many places.
The blit routine is another major area that could be sped up,
its a bit of a longer discussion, since there are emulation
layers upstairs in engine/devdraw.c, including GdArea and
GdAreaInternal that should be combined with GdBlit
and the two or three low level routines there now.
> I am trying to draw to an off screen buffer (640x640x16bpp) and then
flush it to screen using GrArea(). Maybe there is a better way of doing it?
It would be better to use GrCopyArea in this case. That allows all
bits to stay on the server. GrArea usually is used with GrReadArea
or when the bits are in the client process and need to be moved
to the server.
Regards,
Greg
