+ wxCHECK_MSG( source, false, _T("wxMSWDCImpl::Blit(): NULL wxDC pointer") );
+
+ WXMICROWIN_CHECK_HDC_RET(false)
+
+ wxMSWDCImpl *implSrc = wxDynamicCast( source->GetImpl(), wxMSWDCImpl );
+ if ( !implSrc )
+ {
+ // TODO: Do we want to be able to blit from other DCs too?
+ return false;
+ }
+
+ const HDC hdcSrc = GetHdcOf(*implSrc);
+
+ // if either the source or destination has alpha channel, we must use
+ // AlphaBlt() as other function don't handle it correctly
+ const wxBitmap& bmpSrc = implSrc->GetSelectedBitmap();
+ if ( bmpSrc.IsOk() && (bmpSrc.HasAlpha() ||
+ (m_selectedBitmap.IsOk() && m_selectedBitmap.HasAlpha())) )
+ {
+ if ( AlphaBlt(GetHdc(), xdest, ydest, dstWidth, dstHeight,
+ xsrc, ysrc, srcWidth, srcHeight, hdcSrc, bmpSrc) )
+ return true;
+ }
+
+ wxMask *mask = NULL;
+ if ( useMask )
+ {
+ mask = bmpSrc.GetMask();
+
+ if ( !(bmpSrc.IsOk() && mask && mask->GetMaskBitmap()) )
+ {
+ // don't give assert here because this would break existing
+ // programs - just silently ignore useMask parameter
+ useMask = false;
+ }
+ }
+
+ if (xsrcMask == -1 && ysrcMask == -1)
+ {
+ xsrcMask = xsrc; ysrcMask = ysrc;
+ }
+
+ wxTextColoursChanger textCol(GetHdc(), *this);
+
+ DWORD dwRop;
+ switch (rop)
+ {
+ case wxXOR: dwRop = SRCINVERT; break;
+ case wxINVERT: dwRop = DSTINVERT; break;
+ case wxOR_REVERSE: dwRop = 0x00DD0228; break;
+ case wxAND_REVERSE: dwRop = SRCERASE; break;
+ case wxCLEAR: dwRop = BLACKNESS; break;
+ case wxSET: dwRop = WHITENESS; break;
+ case wxOR_INVERT: dwRop = MERGEPAINT; break;
+ case wxAND: dwRop = SRCAND; break;
+ case wxOR: dwRop = SRCPAINT; break;
+ case wxEQUIV: dwRop = 0x00990066; break;
+ case wxNAND: dwRop = 0x007700E6; break;
+ case wxAND_INVERT: dwRop = 0x00220326; break;
+ case wxCOPY: dwRop = SRCCOPY; break;
+ case wxNO_OP: dwRop = DSTCOPY; break;
+ case wxSRC_INVERT: dwRop = NOTSRCCOPY; break;
+ case wxNOR: dwRop = NOTSRCCOPY; break;
+ default:
+ wxFAIL_MSG( wxT("unsupported logical function") );
+ return false;
+ }
+
+ bool success = false;
+
+ if (useMask)
+ {
+#ifdef __WIN32__
+ // we want the part of the image corresponding to the mask to be
+ // transparent, so use "DSTCOPY" ROP for the mask points (the usual
+ // meaning of fg and bg is inverted which corresponds to wxWin notion
+ // of the mask which is also contrary to the Windows one)
+
+ // On some systems, MaskBlt succeeds yet is much much slower
+ // than the wxWidgets fall-back implementation. So we need
+ // to be able to switch this on and off at runtime.
+#if wxUSE_SYSTEM_OPTIONS
+ if (wxSystemOptions::GetOptionInt(wxT("no-maskblt")) == 0)