NAME

       fixasin - Fixed point inverse sine lookup table. Allegro game programming library.

SYNOPSIS

       #include <allegro.h>

       fixed fixasin(fixed x);

DESCRIPTION

       This function finds the inverse sine of a value using a lookup table. The input value must
       be a fixed point value. The inverse sine 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:

          float angle;
          fixed val;

          /* Sets `val' to a right binary angle (`64'). */
          val = fixasin(itofix(1));
          /* Sets `angle' to 0.2405. */
          angle = fixtof(fixmul(fixasin(ftofix(0.238)), fixtorad_r));
          /* This will trigger the assert. */
          val = fixasin(ftofix(-1.09));
          ASSERT(!errno);

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 the range. All return values of this function will
       be in the range `-64' to `64'.

SEE ALSO