Provided by: allegro5-doc_5.2.6.0-1_all bug

NAME

       al_set_mouse_wheel_precision - Allegro 5 API

SYNOPSIS

              #include <allegro5/allegro.h>

              void al_set_mouse_wheel_precision(int precision)

DESCRIPTION

       Sets the precision of the mouse wheel (the z and w coordinates).  This precision manifests
       itself as a multiplier on the dz and dw fields in mouse events.  It also affects the z and
       w  fields of events and ALLEGRO_MOUSE_STATE(3alleg5), but not in a simple way if you alter
       the precision often, so it is  suggested  to  reset  those  axes  to  0  when  you  change
       precision.   Setting  this to a high value allows you to detect small changes in those two
       axes for some high precision mice.  A flexible way of using this precision is to set it to
       a  high  value  (120  is  likely sufficient for most, if not all, mice) and use a floating
       point dz and dw like so:

              al_set_mouse_wheel_precision(120);

              ALLEGRO_EVENT event;
              al_wait_for_event(event_queue, &event);
              if (event.type == ALLEGRO_EVENT_MOUSE_AXES) {
                double dz = (double)event.mouse.dz / al_get_mouse_wheel_precision();
                /* Use dz in some way... */
              }

       Precision is set to 1 by default.  It is impossible to set it to a  lower  precision  than
       that.

SINCE

       5.1.10

SEE ALSO

       al_get_mouse_wheel_precision(3alleg5)