private void DoFindPath()
{
OpenStartNode();
while (!_openedList.isEmpty)
{
AStarEightDirectionsHeapNode currentNode = _openedList.GetMinimumCostNode();
if (IsDestination(currentNode))
{
break;
}
OpenNode(currentNode, Vector2.up);
OpenNode(currentNode, new Vector2(1, 1));
OpenNode(currentNode, Vector2.right);
OpenNode(currentNode, new Vector2(1, -1));
OpenNode(currentNode, Vector2.down);
OpenNode(currentNode, new Vector2(-1, -1));
OpenNode(currentNode, Vector2.left);
OpenNode(currentNode, new Vector2(-1, 1));
CloseNode(currentNode);
}
}
void OpenNode(AStarEightDirectionsHeapNode currentNode, Vector2 direction)
{
AStarEightDirectionsHeapNode 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
}
switch (newNode.state)
{
case AStarEightDirectionsNodeState.unopened:
DoOpenNode(currentNode, newNode);
break;
case AStarEightDirectionsNodeState.opened:
if (currentNode.startToCost < newNode.nextNode.startToCost) //如果新节点已经开了但从起点到指向的节点的成本比当前节点高
{
ReopenNode(currentNode, newNode);
}
break;
case AStarEightDirectionsNodeState.closed:
break;
}
}
public void Reset() //寻路开始时清空成本和指向
{
_state = AStarEightDirectionsNodeState.unopened;
_nextNode = null;
_startToCost = 0;
_toEndCost = 0;
_totalCost = 0;
}
void OpenStartNode()
{
AStarEightDirectionsHeapNode startNode = GetNode(_startPosition);
startNode.Open(_endPosition);
_openedList.Set(startNode);
}
public void Remove(AStarEightDirectionsHeapNode node)
{
var targetSubHeap = _heap.FindFirstThroughValue(node.totalCost);
targetSubHeap.RemoveFirstThroughObj(node);
if (targetSubHeap.Count == 0)
{
_heap.RemoveFirstThroughObj(targetSubHeap);
}
}
Color GetNodeColor(AStarEightDirectionsHeapNode 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);
}
public void Set(AStarEightDirectionsHeapNode node)
{
MinBinaryHeap <AStarEightDirectionsHeapNode> subHeap = _heap.FindFirstThroughValue(node.totalCost);
if (subHeap != null)
{
subHeap.SetNode(node, node.toEndCost);
}
else
{
subHeap = new MinBinaryHeap <AStarEightDirectionsHeapNode>();
subHeap.SetNode(node, node.toEndCost);
_heap.SetNode(subHeap, node.totalCost);
}
}
void DisplayPath()
{
AStarEightDirectionsHeapNode currentNode = _aStar.GetNode(_endPosition);
if (currentNode == null || currentNode.nextNode == null)
{
return;
}
while (currentNode.nextNode != null)
{
AddGreen(currentNode);
currentNode = currentNode.nextNode;
}
AddGreen(currentNode);
}
string GetDirectionText(AStarEightDirectionsHeapNode 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("←");
}
if (direction == new Vector2(-1, -1))
{
return("↙");
}
if (direction == new Vector2(-1, 1))
{
return("↖");
}
if (direction == new Vector2(1, -1))
{
return("↘");
}
if (direction == new Vector2(1, 1))
{
return("↗");
}
return("");
}
public void Pathfind_CanFind_NoObstacle()
{
AStarEightDirections aStar = new AStarEightDirections(7, 7);
Vector2 startPosition = new Vector2(0, 0);
Vector2 endPosition = new Vector2(6, 6);
aStar.FindPath(startPosition, endPosition);
/*
* 0 0 0 0 ↘ ↓ E
*
* 0 0 0 ↘ ↓ ↙ ←
*
* 0 0 ↘ ↓ ↙ ← ↖
*
* 0 ↘ ↓ ↙ ← ↖ 0
*
* ↘ ↓ ↙ ← ↖ 0 0
*
* ↓ ↙ ← ↖ 0 0 0
*
* S ← ↖ 0 0 0 0
*/
AStarEightDirectionsHeapNode[,] matrix = aStar.matrix;
AStarEightDirectionsHeapNode[,] nextNodes = new AStarEightDirectionsHeapNode[7, 7]
{
{ null, matrix[0, 0], matrix[1, 1], null, null, null, null },
{ matrix[0, 0], matrix[0, 0], matrix[1, 1], matrix[2, 2], null, null, null },
{ matrix[1, 1], matrix[1, 1], matrix[1, 1], matrix[2, 2], matrix[3, 3], null, null },
{ null, matrix[2, 2], matrix[2, 2], matrix[2, 2], matrix[3, 3], matrix[4, 4], null },
{ null, null, matrix[3, 3], matrix[3, 3], matrix[3, 3], matrix[4, 4], matrix[5, 5] },
{ null, null, null, matrix[4, 4], matrix[4, 4], matrix[4, 4], matrix[5, 5] },
{ null, null, null, null, matrix[5, 5], matrix[5, 5], matrix[5, 5] }
};
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 AStarEightDirections(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 AStarEightDirectionsHeapNode[width, height];
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
_matrix[x, y] = new AStarEightDirectionsHeapNode(x, y);
}
}
}
void MouseMiddleDown()
{
Vector2 position = GetMousePosition();
AStarEightDirectionsHeapNode node = _aStar.GetNode(position);
if (node == null)
{
return;
}
if (node.canThrough)
{
_aStar.SetObstacle(position);
}
else
{
_aStar.RemoveObstacle(position);
}
DoFindPath();
}
void ReopenNode(AStarEightDirectionsHeapNode currentNode, AStarEightDirectionsHeapNode openNode)
{
_openedList.Remove(openNode);
DoOpenNode(currentNode, openNode);
}
bool IsDestination(AStarEightDirectionsHeapNode currentNode)
{
return(currentNode == GetNode(_endPosition));
}
void AddGreen(AStarEightDirectionsHeapNode currentNode)
{
Vector2 position = currentNode.position;
_displayMatrix[(int)position.x, (int)position.y].GetComponentInChildren <Image>().color += Color.green;
}
void DoOpenNode(AStarEightDirectionsHeapNode currentNode, AStarEightDirectionsHeapNode openNode)
{
openNode.Open(currentNode, _endPosition);
_openedList.Set(openNode);
}
void CloseNode(AStarEightDirectionsHeapNode node)
{
_openedList.Remove(node);
node.Close();
}
void DisplayANode(AStarEightDirectionsHeapNode node, GameObject displayer, float maxStartToCost, float maxToEndCost)
{
displayer.GetComponentInChildren <Image>().color = GetNodeColor(node, maxStartToCost, maxToEndCost);
displayer.GetComponentInChildren <Text>().text = GetDirectionText(node);
}
public void Open(AStarEightDirectionsHeapNode nextNode, Vector2 destination)
{
_state = AStarEightDirectionsNodeState.opened;
_nextNode = nextNode;
ComputeCost(destination);
}
public AStarEightDirectionsHeapNode GetNode(AStarEightDirectionsHeapNode node, Vector2 direction)
{
return(GetNode(node.position + direction));
}
