fixtan man page

fixtan — Fixed point tangent of binary angles. Allegro game programming library.

Synopsis

#include <allegro.h>

fixed fixtan(fixed x);

Description

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

fixed angle, res_a, res_b;
float dif;

angle = itofix(37);
/* Prove that tan(angle) == sin(angle) / cos(angle). */
res_a = fixdiv(fixsin(angle), fixcos(angle));
res_b = fixtan(angle);
dif = fixtof(fixsub(res_a, res_b));
allegro_message("Precision error: %f\n", dif);

Return Value

Returns the tangent of a fixed point binary format angle. The return value will be in radians.

Info

version 4.4.2 Allegro Allegro manual