public bool CanPush(Direction direction)
{
if (CellContents == null) //如果内容为空
{
return(false); //不能推一个空的无内容的方块
}
Cell neighbour = //获取邻近的方块
Level[Location.GetAdjacentLocation(direction)];
return(neighbour != null && neighbour.CanEnter);
}
public bool TryPushContents(Direction direction)
{
if (!CanPush(direction))//判断指定的方向是否可以推动
{
return(false);
}
Cell neighbour = //得到邻近的方格
Level[Location.GetAdjacentLocation(direction)];
neighbour.TrySetContents(CellContents);//设置邻近方格的内容
return(true);
}
/// <summary>
/// 使用特定的Jump对象进行跳转移动
/// </summary>
/// <param name="jump">指定如何移动的Jump对象</param>
internal bool DoMove(Jump jump)
{
bool result = false; //初始化结果值
if (jump.Undo) //如果为撤消跳转
{
lock (moveLock) //使用线程同步对象锁定线程
{ //遍历移动路径
for (int i = jump.Route.Length - 1; i >= 0; i--)
{ //获得要移动的邻近的相反的方向
Location moveLocation = Location.GetAdjacentLocation
(jump.Route[i].Direction.GetOppositeDirection());
//得到目标Cell对象实例
Cell toCell = Level[moveLocation];
if (!toCell.TrySetContents(this)) //尝试设置方块内容
{ //如果放置失败，抛出异常
throw new SokobanException("不能到达指定的路径.");
}
}
MoveCount -= jump.Route.Length;//减少移动步骤
result = true;
}
}
else
{ //使用ThreadPool接收的WaitCallback创建线程执行代码
WaitCallback callback = delegate
{
#region 匿名Jump方法.
lock (moveLock)
{ //使用SearchPathFinder查找最短移动路径
SearchPathFinder searchPathFinder =
new SearchPathFinder(Cell, jump.Destination);
if (searchPathFinder.TryFindPath()) //查找最短目标路径
{ //遍历结果路径
for (int i = 0; i < searchPathFinder.Route.Length; i++)
{
Move move = searchPathFinder.Route[i]; //得到路径中的Move对象
/* 休眠线程指定的时长*/
Thread.Sleep(stepDelay);
Location moveLocation = //获取移动的邻近位置
Location.GetAdjacentLocation(move.Direction);
Cell toCell = Level[moveLocation]; //得到目标Cell
if (!toCell.TrySetContents(this)) //设置目标Cell内容
{ //如果无法到达，则抛出异常
throw new SokobanException("不能到达指定的路径.");
}
MoveCount++;//增加移动步长
}
/* 设置用于撤消跳转的Jump对象*/
Jump newMove = new Jump(searchPathFinder.Route)
{
Undo = true
};
moves.Push(newMove);//将对象压入堆栈
result = true;
}
}
#endregion
};//将callback放入线程池，在后台执行跳转操作
ThreadPool.QueueUserWorkItem(callback);
}
return(result);//返回执行结果
}
/// <summary>
/// Attempt to relocate to the another cell
/// using the route in the specified <see cref="Push"/> instance.
/// </summary>
/// <param name="push">The push.</param>
/// <returns><code>true</code> if the move succeeded,
/// <code>false</code> otherwise.</returns>
internal bool DoMove(Push push)
{
bool result = false;
if (push.Undo)
{
lock (moveLock)
{
for (int i = push.Route.Length - 1; i >= 0; i--)
{
Move move = push.Route[i];
Location moveLocation = Location.GetAdjacentLocation(push.Route[i].Direction.GetOppositeDirection());
Cell toCell = Level[moveLocation];
Cell fromCell = this.Cell;
if (!toCell.TrySetContents(this))
{
throw new SokobanException("Unable to follow route.");
}
if (move.PushedContents != null)
{
if (!fromCell.TrySetContents(move.PushedContents))
{
throw new SokobanException("Unable to undo set contents.");
}
}
}
MoveCount -= push.Route.Length;
result = true;
}
}
else
{
WaitCallback callback = delegate(object state)
{
#region Anonymous Push method.
lock (moveLock)
{
PushPathFinder pathFinder = new PushPathFinder(Cell, push.Desrination);
if (pathFinder.TryFindPath())
{
for (int i = 0; i < pathFinder.Route.Length; i++)
{
Move move = pathFinder.Route[i];
/* Sleep for the stepDelay period. */
Thread.Sleep(stepDelay);
Location moveLocation = Location.GetAdjacentLocation(move.Direction);
Cell toCell = Level[moveLocation];
if (!toCell.CanEnter && toCell.CellContents is Treasure)
{
move.PushedContents = toCell.CellContents;
if (!toCell.TryPushContents(move.Direction))
{
throw new SokobanException("Unable to push contents.");
}
}
if (!toCell.TrySetContents(this))
{
throw new SokobanException("Unable to follow route.");
}
MoveCount++;
}
/* Set the undo item. */
Push newMove = new Push(pathFinder.Route)
{
Undo = true
};
moves.Push(newMove);
result = true;
}
}
#endregion
};
ThreadPool.QueueUserWorkItem(callback);
}
return(result);
}
internal bool DoMoveAux(Move move) //单步移动操作辅助方法
{
bool result = false; //初始化返回值
Location moveLocation = Location. //得到指定方向的邻近的一个位置
GetAdjacentLocation(move.Direction);
if (Level.InBounds(moveLocation)) //判断位置是否在游戏区域内部
{
Cell toCell = Level[moveLocation]; //得到要移动位置的Cell对象
Cell fromCell = Level[Location]; //得到来源位置的Cell对象
CellContents toCellContents = toCell.CellContents; //获取移动位置的内容
if (toCell.CanEnter) //如果目标Cell允许设置内容
{ //如果不是撤消操作而是一个标准移动
if (!move.Undo)
{ //设置目标Cell的方块内容
result = toCell.TrySetContents(this);
if (result)
{
Move newMove = //为撤消操作指定相反的方向以备撤消
new Move(move.Direction.GetOppositeDirection())
{
Undo = true
};
moves.Push(newMove); //向撤消堆栈中插入Move
MoveCount++; //移动次数增加
}
}
//如果是撤消移动操作的话
else if (move.PushedContents != null) //如果角色推动的内容存在
{ //设置目标方块的推动内容
toCell.TrySetContents(this);
//然后向源方块设置推动的内容，因为单步移动操作
result = fromCell.TrySetContents(move.PushedContents);
if (result)
{ //移动次数减少
MoveCount--;
}
}
else
{ /* 如果没有推动内容，直接设置目标方块内容 */
result = toCell.TrySetContents(this);
if (result)
{ //移动次数减少
MoveCount--;
}
}
}//如果目标方块有内容，则先将目标方块内容推动到邻近方块
else if (toCell.TryPushContents(move.Direction))
{ //如果不为撤消操作
if (!move.Undo)
{
Move newMove = //实例化Move，并指定推动的内容以便撤消
new Move(move.Direction.GetOppositeDirection())
{
Undo = true, PushedContents = toCellContents
};
moves.Push(newMove);//压入撤消堆栈
}
//设置目标方块的内容
result = toCell.TrySetContents(this);
if (result)
{ //移动次数增加
MoveCount++;
}
}
}
return(result);//返回最终操作结果
}
