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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 deter-
     mine the quadrant of the result, and `x' is  permitted  to  be  zero.  This
     function  is  useful to convert Cartesian coordinates to polar coordinates.
     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  `er-
     rno' to EDOM.

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

Allegro 			  version 4.4.3 		     fixatan2(3)

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