fixdiv

NAME

fixdiv − Fixed point division. Allegro game programming library.

SYNOPSIS

#include <allegro.h>

fixed fixdiv(fixed x, fixed y);

DESCRIPTION

A fixed point value can be divided by an integer with the normal ‘/’ operator. To divide two fixed point values, though, you must use this function. If a division by zero occurs, ‘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 division by zero you should set ‘errno=0’ before calling fixdiv(). Example:

fixed result;
/* This will put 0.06060 ‘result’. */
result = fixdiv(itofix(2), itofix(33));
/* This will put 0 into ‘result’. */
result = fixdiv(0, itofix(-30));
/* Sets ‘errno’ and puts -32768 into ‘result’. */
result = fixdiv(itofix(-100), itofix(0));
ASSERT(!errno); /* This will fail. */

RETURN VALUE

Returns the result of dividing ‘x’ by ‘y’. If ‘y’ is zero, returns the maximum possible fixed point value and sets ‘errno’ to ERANGE.

SEE ALSO

fixadd(3), fixsub(3), fixmul(3), exfixed(3)