al_fixtorad_r - Allegro 5 API

       This constant gives a ratio which can be used to convert a fixed point number in binary angle format to a
       fixed point number in radians.

       Example:

              al_fixed rad_angle, binary_angle;

              /* Set the binary angle to 90 degrees. */
              binary_angle = 64;

              /* Now convert to radians (about 1.57). */
              rad_angle = al_fixmul(binary_angle, al_fixtorad_r);

       al_fixtorad_r - Allegro 5 API

al_fixmul(3alleg5), al_radtofix_r(3alleg5).

Allegro reference manual                                                                  al_fixtorad_r(3alleg5)

              #include <allegro5/allegro.h>

              const al_fixed al_fixtorad_r = (al_fixed)1608;