Microsoft Foundation Classes (mfc.hlp) (
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CRgn::CreatePolygonRgn
◄CRgn► ◄Up► ◄Contents► ◄Index► ◄Back►
──Microsoft Foundation Classes──────────────────────────────────────────────
BOOL CreatePolygonRgn( LPPOINT lpPoints, int nCount, int nMode );
Parameter Description
<lpPoints> Points to an array of POINT structures or an array of CPoint
objects. Each structure specifies the x- and y-coordinate of
one vertex of the polygon.
<nCount> Specifies the number of POINT structures or CPoint objects
in the array pointed to by <lpPoints>.
<nMode> Specifies the filling mode for the region. This parameter
may be either ALTERNATE or WINDING.
Remarks
Creates a polygonal region. The system closes the polygon automatically,
if necessary, by drawing a line from the last vertex to the first. The
resulting region is stored in the CRgn object.
When the polygon-filling mode is ALTERNATE, the system fills the area
between odd-numbered and even-numbered polygon sides on each scan line.
That is, the system fills the area between the first and second side,
between the third and fourth side, and so on.
When the polygon-filling mode is WINDING, the system uses the direction
in which a figure was drawn to determine whether to fill an area. Each
line segment in a polygon is drawn in either a clockwise or a
counterclockwise direction. Whenever an imaginary line drawn from an
enclosed area to the outside of a figure passes through a clockwise line
segment, a count is incremented. When the line passes through a
counterclockwise line segment, the count is decremented. The area is
filled if the count is nonzero when the line reaches the outside of the
figure.
Return Value
TRUE if the operation succeeded; otherwise FALSE.
See Also
◄CRgn::CreatePolyPolygonRgn►, ◄::CreatePolygonRgn►
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