Microsoft Foundation Classes (mfc.hlp) (Table of Contents; Topic list)
CRgn::CombineRgn
CRgn                                        Up Contents Index Back
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  int CombineRgn( CRgn* pRgn1, CRgn* pRgn2, int nCombineMode );
 
  Parameter      Description
 
  <pRgn1>        Identifies an existing region.
 
  <pRgn2>        Identifies an existing region.
 
  <nCombineMode> Specifies the operation to be performed when combining
                 the two source regions. It can be any one of the
                 following values:
 
                 Value      Meaning
 
                 RGN_AND    Uses overlapping areas of both regions
                            (intersection).
 
                 RGN_COPY   Creates a copy of region 1 (identified by
                            <pRgn1>).
 
                 RGN_DIFF   Creates a region consisting of the areas of
                            region 1 (identified by <pRgn1>) that are not
                            part of region 2 (identified by <pRgn2>).
 
                 RGN_OR     Combines both regions in their entirety
                            (union).
 
                 RGN_XOR    Combines both regions but removes overlapping
                            areas.
 
  Remarks
 
  Creates a new GDI region by combining two existing regions. The regions
  are combined as specified by <nCombineMode>.
 
  The two specified regions are combined, and the resulting region handle
  is stored in the CRgn object. Thus, whatever region is stored in the
  CRgn object is replaced by the combined region.
 
  NOTE: Use CopyRgn to simply copy one region into another region.
 
  Return Value
 
  Specifies the type of the resulting region. It can be one of the
  following values:
 
  Value           Meaning
 
  COMPLEXREGION   New region has overlapping borders.
 
  ERROR           No new region created.
 
  NULLREGION      New region is empty.
 
  SIMPLEREGION    New region has no overlapping borders.
 
  See Also
 
  CRgn::CopyRgn, ::CombineRgn
 
 
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