CreatePolygonRgn

The CreatePolygonRgn function creates a polygonal region.

HRGN CreatePolygonRgn(
  CONST POINT *lppt,  // pointer to array of points
  int cPoints,        // number of points in array
  int fnPolyFillMode  // polygon-filling mode
);
 

Parameters

lppt

Pointer to an array of POINT structures that define the vertices of the polygon. The polygon is presumed closed. Each vertex can be specified only once.

cPoints

Specifies the number of points in the array.

fnPolyFillMode

Specifies the fill mode used to determine which pixels are in the region. This parameter can be one of the following values:

Value	Meaning
ALTERNATE	Selects alternate mode (fills area between odd-numbered and even-numbered polygon sides on each scan line).
WINDING	Selects winding mode (fills any region with a nonzero winding value).

For more information about these modes, see the SetPolyFillMode function.

Return Values

If the function succeeds, the return value is the handle to the region.

If the function fails, the return value is NULL.

Windows NT: To get extended error information, call GetLastError.

QuickInfo

  Windows NT: Requires version 3.1 or later.
  Windows: Requires Windows 95 or later.
  Windows CE: Unsupported.
  Header: Declared in wingdi.h.
  Import Library: Use gdi32.lib.

See Also

Regions Overview, Region Functions, CreatePolyPolygonRgn, DeleteObject, POINT, SelectObject, SetPolyFillMode