.\" Generated by the Allegro makedoc utility
.TH fixacos 3alleg4 "version 4.4.3" "Allegro" "Allegro manual"
.SH NAME
fixacos \- Fixed point inverse cosine lookup table. Allegro game programming library.\&
.SH SYNOPSIS
.B #include <allegro.h>

.sp
.B fixed fixacos(fixed x);
.SH 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:

.nf
   fixed result;
   
   /* Sets `result' to binary angle 128. */
   result = fixacos(itofix(-1));
.fi
.SH "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'.

.SH SEE ALSO