Include:
Prototype: short far _arc(short x1, short y1, short x2, short y2,
short x3, short y3, short x4, short y4);
short far _arc_wxy(struct _wxycoord pwxy1,
struct _wxycoord pwxy2,
struct _wxycoord pwxy3,
struct _wxycoord pwxy4);
Returns: a nonzero value if the arc is drawn successfully, or 0 if not.
See also: _ellipse, _lineto, _pie, _rectangle, _setcolor
The _arc functions draw elliptical arcs.
The _arc routine uses the view coordinate system. The center of the arc is
the center of the bounding rectangle defined by the points (x1, y1) and
(x2, y2). The arc starts at the point where it intersects the vector
defined by (x3, y3) and ends where it intersects the vector defined by
(x4, y4).
The _arc_wxy routine uses the real-world window coordinate system. The
center of the arc is the center of the bounding rectangle defined by the
window coordinate pairs pwxy1 and pwxy2. The arc starts at the point where
it intersects the vector defined by pwxy3, and ends where it intersects
the vector defined by pwxy4.
The _arc_wxy routine is implemented as a macro.
In both cases, the arc is drawn using the current color, moving in a
counterclockwise direction. Since an arc does not define a closed area, it
is not filled.
Return Value
The _arc and _arc_wxy functions return a nonzero value if the arc is
successfully drawn; otherwise, they return 0.