private TD.Image DrawGrid()
{
// Skip drawing if viewport not sized yet
if (_viewport.GetImageSize().IsEmpty())
{
return(null);
}
// Create image
var image = new TD.Image(_viewport);
// Update drawer items: pos, visibility,.. (according to collected update flags)
#if USE_PERF
_perfUpdateItems.Start();
#endif
_gridDrawer.UpdateItems();
_gridDrawer.UpdateCursorItem();
#if USE_PERF
_perfUpdateItems.Stop();
#endif
// Draw items as image elements
#if USE_PERF
_perfDrawItems.Start();
#endif
_gridDrawer.DrawGrid(image);
#if USE_PERF
_perfDrawItems.Stop();
#endif
return(image);
}