Timer routines
- ALLEGRO_TIMER
- ALLEGRO_USECS_TO_SECS
- ALLEGRO_MSECS_TO_SECS
- ALLEGRO_BPS_TO_SECS
- ALLEGRO_BPM_TO_SECS
- al_create_timer
- al_start_timer
- al_resume_timer
- al_stop_timer
- al_get_timer_started
- al_destroy_timer
- al_get_timer_count
- al_set_timer_count
- al_add_timer_count
- al_get_timer_speed
- al_set_timer_speed
- al_get_timer_event_source
These functions are declared in the main Allegro header file:
#include <allegro5/allegro.h>ALLEGRO_TIMER
typedef struct ALLEGRO_TIMER ALLEGRO_TIMER;This is an abstract data type representing a timer object.
ALLEGRO_USECS_TO_SECS
#define ALLEGRO_USECS_TO_SECS(x) ((x) / 1000000.0)Convert microseconds to seconds.
ALLEGRO_MSECS_TO_SECS
#define ALLEGRO_MSECS_TO_SECS(x) ((x) / 1000.0)Convert milliseconds to seconds.
ALLEGRO_BPS_TO_SECS
#define ALLEGRO_BPS_TO_SECS(x) (1.0 / (x))Convert beats per second to seconds.
ALLEGRO_BPM_TO_SECS
#define ALLEGRO_BPM_TO_SECS(x) (60.0 / (x))Convert beats per minute to seconds.
al_create_timer
ALLEGRO_TIMER *al_create_timer(double speed_secs)Allocates and initializes a timer. If successful, a pointer to a new timer object is returned, otherwise NULL is returned. speed_secs is in seconds per "tick", and must be positive. The new timer is initially stopped.
Usage note: typical granularity is on the order of microseconds, but with some drivers might only be milliseconds.
See also: al_start_timer, al_destroy_timer
al_start_timer
void al_start_timer(ALLEGRO_TIMER *timer)Start the timer specified. From then, the timer's counter will increment at a constant rate, and it will begin generating events. Starting a timer that is already started does nothing. Starting a timer that was stopped will reset the timer's counter, effectively restarting the timer from the beginning.
See also: al_stop_timer, al_get_timer_started, al_resume_timer
al_resume_timer
void al_resume_timer(ALLEGRO_TIMER *timer)Resume the timer specified. From then, the timer's counter will increment at a constant rate, and it will begin generating events. Resuming a timer that is already started does nothing. Resuming a stopped timer will not reset the timer's counter (unlike al_start_timer).
See also: al_start_timer, al_stop_timer, al_get_timer_started
al_stop_timer
void al_stop_timer(ALLEGRO_TIMER *timer)Stop the timer specified. The timer's counter will stop incrementing and it will stop generating events. Stopping a timer that is already stopped does nothing.
See also: al_start_timer, al_get_timer_started, al_resume_timer
al_get_timer_started
bool al_get_timer_started(const ALLEGRO_TIMER *timer)Return true if the timer specified is currently started.
al_destroy_timer
void al_destroy_timer(ALLEGRO_TIMER *timer)Uninstall the timer specified. If the timer is started, it will automatically be stopped before uninstallation. It will also automatically unregister the timer with any event queues.
Does nothing if passed the NULL pointer.
See also: al_create_timer
al_get_timer_count
int64_t al_get_timer_count(const ALLEGRO_TIMER *timer)Return the timer's counter value. The timer can be started or stopped.
See also: al_set_timer_count
al_set_timer_count
void al_set_timer_count(ALLEGRO_TIMER *timer, int64_t new_count)Set the timer's counter value. The timer can be started or stopped. The count value may be positive or negative, but will always be incremented by +1 at each tick.
See also: al_get_timer_count, al_add_timer_count
al_add_timer_count
void al_add_timer_count(ALLEGRO_TIMER *timer, int64_t diff)Add diff to the timer's counter value. This is similar to writing:
al_set_timer_count(timer, al_get_timer_count(timer) + diff);except that the addition is performed atomically, so no ticks will be lost.
See also: al_set_timer_count
al_get_timer_speed
double al_get_timer_speed(const ALLEGRO_TIMER *timer)Return the timer's speed, in seconds. (The same value passed to al_create_timer or al_set_timer_speed.)
See also: al_set_timer_speed
al_set_timer_speed
void al_set_timer_speed(ALLEGRO_TIMER *timer, double new_speed_secs)Set the timer's speed, i.e. the rate at which its counter will be incremented when it is started. This can be done when the timer is started or stopped. If the timer is currently running, it is made to look as though the speed change occurred precisely at the last tick.
speed_secs has exactly the same meaning as with al_create_timer.
See also: al_get_timer_speed
al_get_timer_event_source
ALLEGRO_EVENT_SOURCE *al_get_timer_event_source(ALLEGRO_TIMER *timer)Retrieve the associated event source. Timers will generate events of type ALLEGRO_EVENT_TIMER.