Best way to measure milliseconds?

11-19-2007	#1 (permalink)
Alaric Linux Newbie Join Date: Jun 2006 Posts: 150	Best way to measure milliseconds? What is the best way to measure milliseconds in c++ in linux? I'm using Allegro for the game that I'm making, any ideas?
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11-19-2007	#2 (permalink)
wje_lf Linux Engineer Join Date: Sep 2007 Location: Mariposa Posts: 1,192	I don't know anything about Allegro, but does this do the trick for you? Code: man gettimeofday (Call it twice, subtract.) __________________ -- Bill Old age and treachery will overcome youth and skill.

11-19-2007	#3 (permalink)
Alaric Linux Newbie Join Date: Jun 2006 Posts: 150	hmm... now why was I thinking that that responded in seconds? Oh well, looks like it will work . Thanks!

11-19-2007	#4 (permalink)
wje_lf Linux Engineer Join Date: Sep 2007 Location: Mariposa Posts: 1,192	You might have been thinking of this: Code: man 2 time which, being only 32 bits wide, has its uses. __________________ -- Bill Old age and treachery will overcome youth and skill.

11-19-2007	#5 (permalink)
Alaric Linux Newbie Join Date: Jun 2006 Posts: 150	...wait, this only returns the time in microseconds and seconds, which would be fine if the timer didn't overflow every quarter of a second or whatever... Is there a way to get timeval->tv_usec in something larger? I'm trying to write a simple game, and I need to make sure that the player can only fire his gun every half a second... Here's my function so far. Code: timeval now; gettimeofday(&now); if(now.tv_usec-this->LastShot<PLAYERSHOTTIME) { return NULL; } this->LastShot=now.tv_usec; But right now, whenever the user fires right before the timer turns over, they can never fire again... Any other suggestions? p.s. How do I get those man pages? They've all given me page not found errors.

11-20-2007

#6 (permalink)

wje_lf

Linux Engineer

Join Date: Sep 2007

Location: Mariposa

Posts: 1,192

Let's answer the more important (by far) question first:

Quote:

How do I get those man pages? They've all given me page not found errors.

Hmmmm. Man pages missing from your computer? Google this:

Code:

Linux man gettimeofday

From the google search results, choose the man page layout that pleases you most.

When you've read the man page, you'll see that you're interested in not just the tv_usec field, but also the tv_sec field. Both of them together specify the time of day; it's customary for the tv_usec field not to exceed 999999.

Questions after reading the man page? Come back. :)

__________________
--
Bill

Old age and treachery will overcome youth and skill.