bionic (3) fixacos.3alleg4.gz

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