debian man page for fixtan

fixtan(3alleg4) 						  Allegro manual						   fixtan(3alleg4)

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
", dif);

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

SEE ALSO
Allegro 							   version 4.4.2						   fixtan(3alleg4)