Provided by: allegro5-doc_5.0.10-2_all bug

NAME

       al_fixmul - Allegro 5 API

SYNOPSIS

              #include <allegro5/allegro.h>

              al_fixed al_fixmul(al_fixed x, al_fixed y);

DESCRIPTION

       A  fixed  point  value  can be multiplied or divided by an integer with the normal * and /
       operators.  To multiply two fixed point values, though, you must use this function.

       If an overflow occurs, Allegro's errno will be set and the maximum possible value will  be
       returned, but errno is not cleared if the operation is successful.  This means that if you
       are  going  to  test  for  overflow  you  should  call  al_set_errno(0)   before   calling
       al_fixmul(3alleg5).

       Example:

                  al_fixed result;

                  /* This will put 30000 into `result'. */
                  result = al_fixmul(al_itofix(10), al_itofix(3000));

                  /* But this overflows, and sets errno. */
                  result = al_fixmul(al_itofix(100), al_itofix(3000));
                  assert(!al_get_errno());

RETURN VALUE

       Returns  the  clamped  result  of multiplying x by y, setting Allegro's errno to ERANGE if
       there was an overflow.

SEE ALSO

       al_fixadd(3alleg5), al_fixsub(3alleg5), al_fixdiv(3alleg5), al_get_errno(3alleg5).