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Hi
I send almost the same message as the one below yesterday from BeOS, but
it seems it never arrived, so I'm rewriting it (this time from XP, heh):
As you may have noticed, I fixed a small bug on BeOS that caused high
flickering when using page flipping and sound. As I expected that was a
synchronization issue, namely it was caused by a hack I added when
dealing with an old problem that made the lib not to work properly on
SMP machines. I removed the hack, page flipping then worked ok again,
but I was fearing about the SMP problem... Luckly some BeOS people I
contacted tested it on their SMP systems and it seems they had no
problems at all :)
Anyway, while trying to catch the bug, I noticed the timer retrace
syncer is fixed to 70 Hz. This caused bad behaviours on PCs whose gfx
cards didn't support waiting for the vertical retrace, as these then use
the timer retracer... The problem is that by default these guys have the
screen set at 60 Hz (I'm talking about under BeOS, where the refresh
rate is always fixed to 60 Hz in fullscreen mode; that's a limit of the
current Be API), while the timer retracer always runs at 70 Hz, thus
causing bad synchronization...
So I changed the timer retracer to run at 60 Hz by default, which IMO is
also much more standard compliant than 70 Hz (also VESA runs at 60 Hz by
default). If this is an issue for anyone, please reply to this message
so we'll discuss it, and eventually I'll restore the old frequency. If
it's ok I'll also update the docs (Elias pointed me out that allegro.txt
says 70 Hz), so let me know!
--
Angelo Mottola
lillo@xxxxxxxxxx