/// <summary>
/// Get a region of tiles from a layer
/// </summary>
/// <param name="region"> Tile region </param>
/// <param name="layer"> Layer in context </param>
/// <returns> A region based from zero extracted from the layer </returns>
public WorldRegion GetLayerRegion(Rectangle region, int layer)
{
WorldLayer layerIn = GetLayer(layer);
WorldRegion regionOut = new WorldRegion(region.Width, region.Height);
for (int x = region.X, ox = 0; x < region.Right; x++, ox++)
{
for (int y = region.Y, oy = 0; y < region.Bottom; y++, oy++)
{
if (!PointInWorld(x, y))
{
regionOut[ox, oy] = null;
continue;
}
WorldTile i = layerIn[x, y];
regionOut[ox, oy] = i == null ? null : i.Clone();
}
}
return regionOut;
}
/// <summary>
/// Deletes all tiles in the selection rectangle
/// </summary>
public void DeleteSelection()
{
WorldRegion undoRegion = GetLayerRegion(selectionRectangle, SelectedLayer),
redoRegion = new WorldRegion(selectionRectangle.Width, selectionRectangle.Height);
for (int x = selectionRectangle.X; x < selectionRectangle.Right; x++)
{
for (int y = selectionRectangle.Y; y < selectionRectangle.Bottom; y++)
{
if (!PointInWorld(x, y))
continue;
SetTile(x, y, null, SelectedLayer);
}
}
History.Add(new HistoryItem(new TileChangesRegion(undoRegion, selectionRectangle.Location, SelectedLayer),
new TileChangesRegion(redoRegion, selectionRectangle.Location, SelectedLayer), applyDeletionChanges));
SelectionRectangle = Rectangle.Empty;
worldCanvas.Invalidate();
}