Как правильно переносить картинку мышкой внутри формы

void __fastcall TForm1::Image3MouseDown(TObject *Sender, TMouseButton Button, TShiftState Shift,
          int X, int Y)
{
    this->x = X;
    this->y = Y;
    Image2->BeginDrag(false);
}
//---------------------------------------------------------------------------
 
void __fastcall TForm1::Image3DragOver(TObject *Sender, TObject *Source, int X, int Y,
          TDragState State, bool &Accept)
{
    this->Image2->Left += X-this->x;
    this->Image2->Top += Y-this->y;
 
    this->Image3->Left += X-this->x;
    this->Image3->Top += Y-this->y;
 
    this->login_edit->Left += X-this->x;
    this->login_edit->Top += Y-this->y;
 
    this->pass_edit->Left += X-this->x;
    this->pass_edit->Top += Y-this->y;
   //   Accept = true;
}
//---------------------------------------------------------------------------
 
 
void __fastcall TForm1::Image3DragDrop(TObject *Sender, TObject *Source, int X, int Y)
{
    if (this->Image2->Top < 0)
    {
        this->Image2->Top = 1;
        this->Image3->Top = 1;
 
        this->login_edit->Top = this->Image3->Top+46;
        this->pass_edit->Top = this->login_edit->Top+41;
    }
 
    if (this->Image2->Top > this->ClientHeight-this->Image2->Height)
    {
        this->Image2->Top = this->ClientHeight-this->Image2->Height-1;
        this->Image3->Top = this->ClientHeight-this->Image2->Height-1;
 
        this->login_edit->Top = this->Image3->Top+46;
        this->pass_edit->Top = this->login_edit->Top+41;
    }
}
//---------------------------------------------------------------------------

DoubleBuffered = true;

TBitmap *buff = new TBitmap;
    
int img2_x = this->Image2->Left+X-this->x;
int img2_y = this->Image2->Top+Y-this->y;
    
int img3_x = this->Image3->Left+X-this->x;
int img3_y = this->Image3->Top+Y-this->y;
    
buff->Canvas->Draw(img2_x,img2_y,this->Image2);

Image2->Canvas->Draw(x,y,Bitmap);