public System.Drawing.Bitmap CreatePreviewBitmap(Display.DefinedViewportProjection definedViewportProjection, DisplayMode displayMode, System.Drawing.Size bitmapSize)
        {
            IntPtr ptr_rhino_dib = UnsafeNativeMethods.CRhinoInstanceDefinition_GetPreviewBitmap(m_doc.m_docId, m_index, (int)definedViewportProjection, (int)displayMode, bitmapSize.Width, bitmapSize.Height);

            if (IntPtr.Zero == ptr_rhino_dib)
            {
                return(null);
            }

            IntPtr hbitmap = UnsafeNativeMethods.CRhinoDib_Bitmap(ptr_rhino_dib);

            System.Drawing.Bitmap rc = null;
            if (IntPtr.Zero != hbitmap)
            {
                rc = System.Drawing.Image.FromHbitmap(hbitmap);
            }
            UnsafeNativeMethods.CRhinoDib_Delete(ptr_rhino_dib);
            return(rc);
        }
 public System.Drawing.Bitmap CreatePreviewBitmap(Display.DefinedViewportProjection definedViewportProjection, System.Drawing.Size bitmapSize)
 {
     return(CreatePreviewBitmap(definedViewportProjection, DisplayMode.Wireframe, bitmapSize));
 }