CombineRgn

CombineRgn

The CombineRgn function combines two regions and stores the result in a third region. The two regions are combined according to the specified mode.

int CombineRgn(

HRGN hrgnDest,	// handle to destination region
HRGN hrgnSrc1,	// handle to source region
HRGN hrgnSrc2,	// handle to source region
int fnCombineMode	// region combining mode
);

Parameters

hrgnDest

Identifies a new region with dimensions defined by combining two other regions. (This region must exist before CombineRgn is called.)

hrgnSrc1

Identifies the first of two regions to be combined.

hrgnSrc2

Identifies the second of two regions to be combined.

fnCombineMode

Specifies a mode indicating how the two regions will be combined. This parameter can be one of the following values:

Value	Description
RGN_AND	Creates the intersection of the two combined regions.
RGN_COPY	Creates a copy of the region identified by hrgnSrc1.
RGN_DIFF	Combines the parts of hrgnSrc1 that are not part of hrgnSrc2.
RGN_OR	Creates the union of two combined regions.
RGN_XOR	Creates the union of two combined regions except for any overlapping areas.

Return Values

The return value specifies the type of the resulting region. It can be one of the following values:

Value	Meaning
NULLREGION	The region is empty.
SIMPLEREGION	The region is a single rectangle.
COMPLEXREGION	The region is more than a single rectangle.
ERROR	No region is created.

Remarks

The three regions need not be distinct. For example, the hrgnSrc1 parameter can equal the hrgnDest parameter.