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.