al_rumble_haptic - Allegro 5 API

       Uploads  a  simple  rumble  effect  to  the haptic device and starts playback immediately.  The parameter
       intensity is a relative magnitude between 0.0 and 1.0 that determines the intensity of the rumble effect.
       The duration determines the duration of the effect in seconds.

       You must also pass in a pointer to a user allocated ALLEGRO_HAPTIC_EFFECT_ID(3alleg5).  It it is stored a
       reference to be used to control  playback  of  the  effect.   Returns  true  if  the  rumble  effect  was
       successfully uploaded and started, false if not.

       In   case   false   is   returned,   the   rumble   effect   will   be   automatically   released  as  if
       al_release_haptic_effect(3alleg5) had been called, so there is no need to call it again manually in  this
       case.   However,  if true is returned, it is necessary to call al_release_haptic_effect(3alleg5) when the
       effect isn’t needed anymore, to prevent the amount of available effects on the haptic device from running
       out.

       al_rumble_haptic - Allegro 5 API

       5.1.8

              [UnstableAPI]: Perhaps could be simplified due to limited support for all  the  exposed  features
              across all of the platforms.  Awaiting feedback from users.

Allegro reference manual                                                               al_rumble_haptic(3alleg5)

              #include <allegro5/allegro.h>

              bool al_rumble_haptic(ALLEGRO_HAPTIC *hap,
                 double intensity, double duration, ALLEGRO_HAPTIC_EFFECT_ID *id)