public HashSet <int> GetVisiableBlock(Camera mapCamera, HashSet <int> fillSet = null)
{
HashSet <int> ret = fillSet != null ? fillSet : new HashSet <int> ();
//地图的可见区域是一个四边形，因为当前摄像机是不能旋转的，所以只取左上和右下点
IntVector2 leftBottom = ScreenPosToMapCoord(mapCamera, new Vector2(0f, 0f));
IntVector2 leftTop = ScreenPosToMapCoord(mapCamera, new Vector2(0f, Screen.height));
IntVector2 rightTop = ScreenPosToMapCoord(mapCamera, new Vector2(Screen.width, Screen.height));
IntVector2 leftBottomBlock = MapDataManager.TileCoordToBlockCoord(leftBottom);
IntVector2 rightTopBlock = MapDataManager.TileCoordToBlockCoord(rightTop);
IntVector2 leftTopBlock = MapDataManager.TileCoordToBlockCoord(leftTop);
for (int i = leftTopBlock.x; i <= rightTopBlock.x; ++i)
{
for (int j = leftBottomBlock.y; j <= leftTopBlock.y; ++j)
{
ret.Add(MapDataManager.BlockCoordToBlockId(i, j));
}
}
return(ret);
}
