al_fixatan2(3)al_fixatan2(3)NAMEal_fixatan2 - Allegro 5 API
SYNOPSIS
#include <allegro5/allegro.h>
al_fixed al_fixatan2(al_fixed y, al_fixed x)
DESCRIPTION
This is a fixed point version of the libc atan2() routine. It computes
the arc tangent of y / x, but the signs of both arguments are used to
determine the quadrant of the result, and x is permitted to be zero.
This function is useful to convert Cartesian coordinates to polar coor‐
dinates.
Example:
al_fixed result;
/* Sets `result' to binary angle 64. */
result = al_fixatan2(al_itofix(1), 0);
/* Sets `result' to binary angle -109. */
result = al_fixatan2(al_itofix(-1), al_itofix(-2));
/* Fails the assert. */
result = al_fixatan2(0, 0);
assert(!al_get_errno());
RETURN VALUE
Returns the arc tangent of y / x in fixed point binary format angle,
from -128 to 128. If both x and y are zero, returns zero and sets
Allegro's errno to EDOM.
Allegro reference manualal_fixatan2(3)
