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