fixatan − Fixed point inverse tangent lookup table. Allegro game programming library.
#include <allegro.h>
fixed fixatan(fixed x);
This function finds the inverse tangent of a value using a lookup table. The input value must be a fixed point radian. The inverse tangent is the value whose tangent is ‘x’. Example:
fixed result;
/* Sets ‘result’ to binary angle 13. */
result = fixatan(ftofix(0.326));
Returns the inverse tangent of a fixed point value, measured as a fixed point binary format angle.