public void Move(ScreenDrawingSurface surface, Point location)
{
if (!held) return;
Point pos = new Point(location.X / surface.Screen.Tileset.TileSize, location.Y / surface.Screen.Tileset.TileSize);
if (pos == currentTilePos) return; // don't keep drawing on the same spot
Draw(surface, pos.X, pos.Y);
}