RE: [GD-Windows] More timer fun!
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From: Tom F. <to...@mu...> - 2002-09-03 10:57:36
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There's the fourth method that someone suggested - set up a silent sound of known length, and play it on your sound card. And have a notification at the end of each cycle. And now you have a medium-term calibrator for timeGetTime()'s slow drifts. Very very hacky, but suprisingly accurate, even on cheapo sound cards. Of course, many of them don't support notifications, so... Tom Forsyth - purely hypothetical Muckyfoot bloke. This email is the product of your deranged imagination, and does not in any way imply existence of the author. > -----Original Message----- > From: Jon Watte [mailto:hp...@mi...] > Sent: 02 September 2002 19:56 > To: Grills, Jeff; gam...@li... > Subject: RE: [GD-Windows] More timer fun! > > > > > and that we can apparently fix this within our games with > enough work, > > Microsoft should integrate fixes for this into their current and > > past OS's. > > QueryPerformanceCounter() is slow enough already (on the order of 1 > microsecond because of the bus transaction involved). Fixing it is > decidedly non-trivial, and, at a minimum, requires doubling the cost > of calling it. I think most people who use these functions would > rather not take the additional cost hit. > > RDTSC doesn't skip, that I've heard of. It's absolutely the right > thing to use for profiling and similar measurements. The only > weakness of it is that it may not measure wall-clock time accurately > on laptops (that use TimeStep CPUs). I'm prepared to live with that > on a local scale, and to use an unholy heuristic trio of > QPC/timeGetTime()/RDTSC for keeping track of wallclock time on a > global scale. > > Cheers, > > / h+ > > > > ------------------------------------------------------- > This sf.net email is sponsored by: OSDN - Tired of that same old > cell phone? Get a new here for FREE! > https://www.inphonic.com/r.asp?r=sourceforge1&refcode1=vs3390 > _______________________________________________ > Gamedevlists-windows mailing list > Gam...@li... > https://lists.sourceforge.net/lists/listinfo/gamedevlists-windows > Archives: > http://sourceforge.net/mailarchive/forum.php?forum_id=555 > |