---
name: "al_fixtan"
section: "3"
platform: "linux"
package: "allegro"
version: "5.2.11.3-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/al_fixtan"
---

# al\_fixtan(3)

Allegro 5 API

## NAME

al\_fixtan - Allegro 5 API

## SYNOPSIS

-

  ```
  #include <allegro5/allegro.h>
  al_fixed al_fixtan(al_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:

-

  ```
  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);
  ```

## RETURN VALUE

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