Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
fixasin(3)			Allegro	manual			    fixasin(3)

NAME
       fixasin	- Fixed	point inverse sine lookup table. Allegro game program-
       ming 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 de-
       fined 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(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | SEE ALSO

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=fixasin&sektion=3&manpath=FreeBSD+12.0-RELEASE+and+Ports>

home | help