debian man page for fixacos

fixacos(3alleg4)						  Allegro manual						  fixacos(3alleg4)

NAME
       fixacos - Fixed point inverse cosine lookup table. Allegro game programming library.

SYNOPSIS
       #include <allegro.h>

       fixed fixacos(fixed x);

DESCRIPTION
       This function finds the inverse cosine of a value using a lookup table. The input value must be a fixed point radian. The inverse cosine is
       defined only in the domain from `-1' to `1'. Outside of this input range, the function will set `errno' to EDOM and return zero. Example:

	  fixed result;

	  /* Sets `result' to binary angle 128. */
	  result = fixacos(itofix(-1));

RETURN VALUE
       Returns the inverse sine of a fixed point value, measured as fixed point binary format angle, or zero if the input was out  of  range.  All
       return values of this function will be in the range `0' to `128'.

SEE ALSO
Allegro 							   version 4.4.2						  fixacos(3alleg4)