fixtan(3) - Linux man page
Name
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);