The CreateRectRgn function creates a rectangular region.
HRGN CreateRectRgn( _In_ int nLeftRect, _In_ int nTopRect, _In_ int nRightRect, _In_ int nBottomRect );
- nLeftRect [in]
Specifies the x-coordinate of the upper-left corner of the region in logical units.
- nTopRect [in]
Specifies the y-coordinate of the upper-left corner of the region in logical units.
- nRightRect [in]
Specifies the x-coordinate of the lower-right corner of the region in logical units.
- nBottomRect [in]
Specifies the y-coordinate of the lower-right corner of the region in logical units.
If the function succeeds, the return value is the handle to the region.
If the function fails, the return value is NULL.
When you no longer need the HRGN object, call the DeleteObject function to delete it.
Region coordinates are represented as 27-bit signed integers.
Regions created by the Create<shape>Rgn methods (such as CreateRectRgn and CreatePolygonRgn) only include the interior of the shape; the shape's outline is excluded from the region. This means that any point on a line between two sequential vertices is not included in the region. If you were to call PtInRegion for such a point, it would return zero as the result.
For an example, see Drawing Markers.
Minimum supported client
|Windows 2000 Professional [desktop apps only]|
Minimum supported server
|Windows 2000 Server [desktop apps only]|
- Regions Overview
- Region Functions