RGN_COPY, SetWindowRgn() - C++ Builder

 

private: // User declarations

        int form_Min(int x, int y);

        int r,margn;

        HRGN temp_RGN,temp_Ellipse;

        void init_Date();

public: // User declarations

        void rgn_Xor();

        void rgn_Or();

        void rgn_And();

        void rgn_Diff();

        __fastcall TForm1(TComponent* Owner);

};

int TForm1::form_Min(int x, int y)

{

 if(x<y)

  return x;

 else

  return y;

}

void TForm1::init_Date()

{

 temp_RGN=CreateRectRgn(0,0,Width,Height);

 r=form_Min(Height,Width);

 margn=Height-ClientHeight;

 temp_Ellipse=CreateEllipticRgn(0,margn,r,r);

}

void TForm1::rgn_Xor()

{

 init_Date();

 CombineRgn(temp_Ellipse,temp_RGN,temp_Ellipse,RGN_XOR);

 SetWindowRgn(Handle,temp_Ellipse,true);

}

void TForm1::rgn_Or()

{

 init_Date();

 CombineRgn(temp_Ellipse,temp_RGN,temp_Ellipse,RGN_OR);

 SetWindowRgn(Handle,temp_Ellipse,true);

}

void TForm1::rgn_And()

{

 init_Date();

 CombineRgn(temp_Ellipse,temp_RGN,temp_Ellipse,RGN_AND);

 SetWindowRgn(Handle,temp_Ellipse,true);

}

void TForm1::rgn_Diff()

{

 init_Date();

 CombineRgn(temp_Ellipse,temp_RGN,temp_Ellipse,RGN_DIFF);

 SetWindowRgn(Handle,temp_Ellipse,true);

}

__fastcall TForm1::TForm1(TComponent* Owner)

        : TForm(Owner)

{

}

//---------------------------------------------------------------------------

void __fastcall TForm1::Button1Click(TObject *Sender)

{

 rgn_Xor();

}

//---------------------------------------------------------------------------

void __fastcall TForm1::Button2Click(TObject *Sender)

{

  rgn_Or();

}

//---------------------------------------------------------------------------

void __fastcall TForm1::Button3Click(TObject *Sender)

{

 rgn_And();

}

//---------------------------------------------------------------------------

void __fastcall TForm1::Button4Click(TObject *Sender)

{

 rgn_Diff();

}