public void RebuildLayerInfo()
{
// initialize the layer dictionary with only false values
for (int i = 0; i < _numberOfMapLayers; i++) {
if (i >= LayerFlags.Count) {
LayerFlags.Add(false);
}
}
if (LayerFlags.Count > _numberOfMapLayers) {
LayerFlags.RemoveRange(_numberOfMapLayers, LayerFlags.Count - _numberOfMapLayers);
}
}