private void UpdateSelectionPanel()
{
int ox = -90;
int oy = -76;
int px = (int)Math.Round(SelectedMarker.ScreenPos.X, MidpointRounding.AwayFromZero) + ox;
int py = (int)Math.Round(SelectedMarker.ScreenPos.Y, MidpointRounding.AwayFromZero) + oy;
int sx = SelectionPanel.Width;
int sy = SelectionPanel.Height;
SelectionPanel.SetBounds(px, py, sx, sy);
}