CreateEllipticRgn

The CreateEllipticRgn function creates an elliptical region.

HRGN CreateEllipticRgn(
  int nLeftRect,   // x-coord of the upper-left corner of the bounding rectangle
  int nTopRect,    // y-coord of the upper-left corner of the bounding rectangle
  int nRightRect,  // x-coord of the lower-right corner of the bounding rectangle
  int nBottomRect  // y-coord of the lower-right corner of the bounding rectangle
);
 

Parameters

nLeftRect

Specifies the x-coordinate of the upper-left corner of the bounding rectangle of the ellipse.

nTopRect

Specifies the y-coordinate of the upper-left corner of the bounding rectangle of the ellipse.

nRightRect

Specifies the x-coordinate of the lower-right corner of the bounding rectangle of the ellipse.

nBottomRect

Specifies the y-coordinate of the lower-right corner of the bounding rectangle of the ellipse.

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.

Remarks

A bounding rectangle defines the size, shape, and orientation of the region: The long sides of the rectangle define the length of the ellipse's major axis; the short sides define the length of the ellipse's minor axis; and the center of the rectangle defines the intersection of the major and minor axes.

The coordinates of the bounding rectangle are specified in logical units.

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, CreateEllipticRgnIndirect, DeleteObject, SelectObject