string GetDirectionText(AstarBaseNode node)
{
if (node == null || node.nextNode == null)
{
return("");
}
Vector2 direction = node.nextNode.position - node.position;
if (direction == Vector2.up)
{
return("↑");
}
if (direction == Vector2.right)
{
return("→");
}
if (direction == Vector2.down)
{
return("↓");
}
if (direction == Vector2.left)
{
return("←");
}
return("");
}
public void FindPath(Vector2 startPosition, Vector2 endPosition)
{
if (!InMatrix(startPosition) || !InMatrix(endPosition) || !GetNode(startPosition).canThrough || !GetNode(endPosition).canThrough)
{
return;
}
ResetMatrix(_matrix.GetLength(0), _matrix.GetLength(1));
_openedList = new List <AstarBaseNode>();
_closedList = new List <AstarBaseNode>();
_startPosition = new Vector2((int)startPosition.x, (int)startPosition.y); //这步极其重要，一定要把起点终点的坐标进行精确，否则算成本的时候会出现不可预料的小数进而造成误差
_endPosition = new Vector2((int)endPosition.x, (int)endPosition.y);
_openedList.Add(GetNode(_startPosition)); //将起点加入开表
while (_openedList.Count > 0)
{
AstarBaseNode currentNode = GetMinimumCostNodeInOpenedList();
if (IsDestination(currentNode))
{
break;
}
OpenNode(currentNode, Vector2.up);
OpenNode(currentNode, Vector2.right);
OpenNode(currentNode, Vector2.down);
OpenNode(currentNode, Vector2.left);
CloseNode(currentNode);
}
}
public void Reset() //寻路开始时清空成本和指向
{
_nextNode = null;
_startToCost = 0;
_toEndCost = 0;
_totalCost = 0;
}
public void Pathfind_CantFind()
{
AStarBase aStar = new AStarBase(7, 7);
Vector2 startPosition = new Vector2(0, 0);
Vector2 endPosition = new Vector2(6, 6);
aStar.SetObstacle(new Vector2(0, 1));
aStar.SetObstacle(new Vector2(1, 1));
aStar.SetObstacle(new Vector2(2, 1));
aStar.SetObstacle(new Vector2(4, 1));
aStar.SetObstacle(new Vector2(4, 2));
aStar.SetObstacle(new Vector2(4, 3));
aStar.SetObstacle(new Vector2(5, 3));
aStar.SetObstacle(new Vector2(6, 3));
aStar.SetObstacle(new Vector2(1, 4));
aStar.SetObstacle(new Vector2(2, 4));
aStar.SetObstacle(new Vector2(3, 4));
aStar.SetObstacle(new Vector2(2, 5));
aStar.SetObstacle(new Vector2(0, 6));
aStar.SetObstacle(new Vector2(1, 6));
aStar.FindPath(startPosition, endPosition);
/*
* N N 0 0 0 0 E
*
* ↓ ← N 0 0 0 0
*
* ↓ N N N 0 0 0
*
* → → → ↓ N N N
*
* → → → ↓ N ↓ ←
*
* N N N ↓ N ↓ ←
*
* S ← ← ← ← ← ←
*/
AstarBaseNode[,] matrix = aStar.matrix;
AstarBaseNode[,] nextNodes = new AstarBaseNode[7, 7]
{
{ null, matrix[0, 0], matrix[1, 0], matrix[2, 0], matrix[3, 0], matrix[4, 0], matrix[5, 0] },
{ null, null, null, matrix[3, 0], null, matrix[5, 0], matrix[5, 1] },
{ matrix[1, 2], matrix[2, 2], matrix[3, 2], matrix[3, 1], null, matrix[5, 1], matrix[5, 2] },
{ matrix[1, 3], matrix[2, 3], matrix[3, 3], matrix[3, 2], null, null, null },
{ matrix[0, 3], null, null, null, null, null, null },
{ matrix[0, 4], matrix[0, 5], null, null, null, null, null },
{ null, null, null, null, null, null, null }
};
for (int x = 0; x < 7; x++)
{
for (int y = 0; y < 7; y++)
{
Assert.AreEqual(nextNodes[y, x], aStar.matrix[x, y].nextNode); //横y竖x，何等反人类，而且竟然严格符合了数组下标顺序：前面是第一层，后面是第二层
}
}
}
Color GetNodeColor(AstarBaseNode node, float maxStartToCost, float maxToEndCost)
{
if (!node.canThrough)
{
return(Color.black);
}
Color nodeRed = Color.red * node.startToCost / maxStartToCost;
Color nodeBlue = Color.blue * node.toEndCost / maxToEndCost;
return(nodeRed + nodeBlue + Color.gray * 0.5f);
}
void OpenNode(AstarBaseNode currentNode, Vector2 direction) //有缺陷，假设一个格子已经开了但有更低价的格子可以指向，缺少对这时候的处理，这个处理在后面几个里有
{
AstarBaseNode newNode = GetNode(currentNode, direction);
if (newNode == null || !newNode.canThrough)
{
return; //如果没获取到新节点或新节点不能通行则直接return
}
if (!_openedList.Contains(newNode) && !_closedList.Contains(newNode)) //不在开表里也不在闭表里，说明是未开启状态
{
DoOpenNode(currentNode, newNode);
}
}
void DisplayPath()
{
AstarBaseNode currentNode = _aStar.GetNode(_endPosition);
if (currentNode == null || currentNode.nextNode == null)
{
return;
}
while (currentNode.nextNode != null)
{
AddGreen(currentNode);
currentNode = currentNode.nextNode;
}
AddGreen(currentNode);
}
AstarBaseNode GetMinimumCostNodeInOpenedList()
{
AstarBaseNode minimumCostNode = _openedList[0];
foreach (AstarBaseNode currentNode in _openedList)
{
if (currentNode.totalCost < minimumCostNode.totalCost)
{
minimumCostNode = currentNode;
}
else if (currentNode.totalCost == minimumCostNode.totalCost && currentNode.toEndCost < minimumCostNode.toEndCost) //当前节点总成本和最小成本节点总成本相同，但距离终点更近的话
{
minimumCostNode = currentNode;
}
}
return(minimumCostNode);
}
public void Pathfind_CanFind_NoObstacle()
{
AStarBase aStar = new AStarBase(7, 7);
Vector2 startPosition = new Vector2(0, 0);
Vector2 endPosition = new Vector2(6, 6);
aStar.FindPath(startPosition, endPosition);
/*
* ↓ ← ← ← ← ← E
*
* ↓ ← ↑ ↑ ↑ ↑ 0
*
* ↓ ← 0 0 0 0 0
*
* ↓ ← 0 0 0 0 0
*
* ↓ ← 0 0 0 0 0
*
* ↓ ← 0 0 0 0 0
*
* S ← 0 0 0 0 0
*/
AstarBaseNode[,] matrix = aStar.matrix;
AstarBaseNode[,] nextNodes = new AstarBaseNode[7, 7]
{
{ null, matrix[0, 0], null, null, null, null, null },
{ matrix[0, 0], matrix[0, 1], null, null, null, null, null },
{ matrix[0, 1], matrix[0, 2], null, null, null, null, null },
{ matrix[0, 2], matrix[0, 3], null, null, null, null, null },
{ matrix[0, 3], matrix[0, 4], null, null, null, null, null },
{ matrix[0, 4], matrix[0, 5], matrix[2, 6], matrix[3, 6], matrix[4, 6], matrix[5, 6], null },
{ matrix[0, 5], matrix[0, 6], matrix[1, 6], matrix[2, 6], matrix[3, 6], matrix[4, 6], matrix[5, 6] }
};
for (int x = 0; x < 7; x++)
{
for (int y = 0; y < 7; y++)
{
Assert.AreEqual(nextNodes[y, x], aStar.matrix[x, y].nextNode); //二维数组赋值是按照横竖x的方式进行的，也就是说上面的矩阵写错了，要转置，这就是一个用 [y, x] 一个用 [x, y] 的原因
}
}
}
public AStarBase(int width, int height)
{
if (width < 0)
{
width = 0; //防止传入负数
}
if (height < 0)
{
height = 0; //防止传入负数
}
_matrix = new AstarBaseNode[width, height];
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
_matrix[x, y] = new AstarBaseNode(x, y);
}
}
}
void MouseMiddleDown()
{
Vector2 position = GetMousePosition();
AstarBaseNode node = _aStar.GetNode(position);
if (node == null)
{
return;
}
if (node.canThrough)
{
_aStar.SetObstacle(position);
}
else
{
_aStar.RemoveObstacle(position);
}
DoFindPath();
}
void DisplayANode(AstarBaseNode node, GameObject displayer, float maxStartToCost, float maxToEndCost)
{
displayer.GetComponentInChildren <Image>().color = GetNodeColor(node, maxStartToCost, maxToEndCost);
displayer.GetComponentInChildren <Text>().text = GetDirectionText(node);
}
public void Open(AstarBaseNode nextNode, Vector2 destination)
{
_nextNode = nextNode;
ComputeCost(destination);
}
public AstarBaseNode GetNode(AstarBaseNode node, Vector2 direction)
{
return(GetNode(node.position + direction));
}
void CloseNode(AstarBaseNode node)
{
_openedList.Remove(node);
_closedList.Add(node);
}
void DoOpenNode(AstarBaseNode currentNode, AstarBaseNode openNode)
{
openNode.Open(currentNode, _endPosition);
_openedList.Add(openNode);
}
bool IsDestination(AstarBaseNode currentNode)
{
return(currentNode == GetNode(_endPosition));
}
void AddGreen(AstarBaseNode currentNode)
{
Vector2 position = currentNode.position;
_displayMatrix[(int)position.x, (int)position.y].GetComponentInChildren <Image>().color += Color.green;
}
