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fixatan2(3)			Allegro	manual			   fixatan2(3)

NAME
       fixatan2	 -  Fixed  point  version of the libc atan2() routine. Allegro
       game programming	library.

SYNOPSIS
       #include	<allegro.h>

       fixed fixatan2(fixed y, fixed x);

DESCRIPTION
       This is a fixed point version of	the libc atan2() routine. It  computes
       the arc tangent of `y / x', but the signs of both arguments are used to
       determine the quadrant of the result, and `x' is	permitted to be	 zero.
       This function is	useful to convert Cartesian coordinates	to polar coor-
       dinates.	 Example:

	  fixed	result;

	  /* Sets `result' to binary angle 64. */
	  result = fixatan2(itofix(1), 0);
	  /* Sets `result' to binary angle -109. */
	  result = fixatan2(itofix(-1),	itofix(-2));
	  /* Fails the assert. */
	  result = fixatan2(0, 0);
	  ASSERT(!errno);

RETURN VALUE
       Returns the arc tangent of `y / x' in fixed point binary	format	angle,
       from  `-128'  to	 `128'.	If both	`x' and	`y' are	zero, returns zero and
       sets `errno' to EDOM.

SEE ALSO
       , exlights(3), exspline(3)

Allegro				 version 4.4.3			   fixatan2(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | SEE ALSO

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