NAME¶
SDL::Time - An SDL Perl extension for managing timers
CATEGORY¶
Core
SYNOPSIS¶
use warnings;
use strict;
use threads;
use threads::shared;
use SDL::Time;
package foo;
use SDL ':all';
SDL::init(SDL_INIT_TIMER);
my $tick :shared = 0;
sub ticker { $tick++; warn $tick; return 100; }
package main;
my $id = SDL::Time::add_timer(100, 'foo::ticker');
sleep(2);
SDL::Time::remove_timer($id);
METHODS¶
add_timer¶
my $id = SDL::Timer::add_timer( $ms_interval, $callback );
This runs in a separate thread and a cloned Perl thread. "threads" and
"threads::shared" must be used to share any variables the timer
uses.
The $callback function, specified with a string of the function's name, will be
called after the milliseconds of $interval have elapsed. The actual delay may
be longer than specified depending on the underlying OS. The callback function
is passed the current timer interval as well as the $interval parameter and
should return the next timer interval. If the return value from the callback
is 0, the timer is cancelled; otherwise, the timer will continue to run.
The timer callback function may run in a different thread to your main program,
so it shouldn't call any functions from within itself. You may call
SDL::push_event, however.
"SDL::Time::add_timer" returns the identifier value of the generated
timer or undef on error.
Note: You must initialize ("SDL::init") the timer subsystem to
use this function.
remove_timer¶
SDL::Timer::remove_timer( $id );
The other way to cancel a timer is to use "SDL::Time::remove_timer" on
the $id of a timer. This ID is the return value of the
"SDL::Time::add_timer" function.
"SDL::Time::remove_timer" returns 0 on success or "-1" on
error.
AUTHORS¶
See "AUTHORS" in SDL.