CDC::SetPolyFillMode

Sets the polygon-filling mode.

int SetPolyFillMode(
   int nPolyFillMode 
);

Parameters

  • nPolyFillMode
    Specifies the new filling mode. This value may be either ALTERNATE or WINDING. The default mode set in Windows is ALTERNATE.

Return Value

The previous filling mode, if successful; otherwise 0.

Remarks

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. This mode is the default.

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.

Requirements

Header: afxwin.h

See Also

Reference

CDC Class

Hierarchy Chart

CDC::GetPolyFillMode

CDC::PolyPolygon

SetPolyFillMode

Other Resources

CDC Members