debian man page for fixasin

fixasin(3alleg4)						  Allegro manual						  fixasin(3alleg4)

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
Allegro 							   version 4.4.2						  fixasin(3alleg4)