al_fixtan(3) al_fixtan(3)

al_fixtan - Allegro 5 API

#include <allegro5/allegro.h>
al_fixed al_fixtan(al_fixed x);

This function finds the tangent of a value using a lookup table. The input value must be a fixed point binary angle.


al_fixed angle, res_a, res_b;
float dif;
angle = al_itofix(37);
/* Prove that tan(angle) == sin(angle) / cos(angle). */
res_a = al_fixdiv(al_fixsin(angle), al_fixcos(angle));
res_b = al_fixtan(angle);
dif = al_fixtof(al_fixsub(res_a, res_b));
printf("Precision error: %f\n", dif);

Returns the tangent of a fixed point binary format angle as a fixed point value.

Allegro reference manual