float CaculateNodeCost(PlayerAtt player, PathFindNodeItem a, PathFindNodeItem b)
{
bool needClimb = false;
bool needJump = false;
if (b.Height - a.Height > grid.CanPathThrethhold)
{
needClimb = true;
}
else if (a.Height - b.Height > grid.CanPathThrethhold)
{
needJump = true;
}
float distance = getDistanceNodes(a, b);
float cost = distance / player.moveSpeed;
if (needClimb)
{
if (player.climbSpeed > 0.0f)
{
float climpcost = (b.Height - a.Height) / player.climbSpeed;
cost += climpcost;
}
else
{
cost = -1.0f;
}
}
if (needJump)
{
}
return(cost);
}
// 生成路径
void generatePath(PathFindNodeItem startNode, PathFindNodeItem endNode)
{
List <PathFindNodeItem> path = new List <PathFindNodeItem>();
if (endNode != null)
{
PathFindNodeItem temp = endNode;
while (temp != startNode)
{
path.Add(temp);
temp = temp.parent;
}
// 反转路径
path.Reverse();
}
// 更新路径
grid.updatePath(path);
}
// 获取两个节点之间的距离
float getDistanceNodes(PathFindNodeItem a, PathFindNodeItem b)
{
float ret;
float cntX = Mathf.Abs(a.x - b.x);
float cntY = Mathf.Abs(a.y - b.y);
// 判断到底是那个轴相差的距离更远
if (cntX > cntY)
{
ret = 14.14f * cntY + 10.0f * (cntX - cntY);
}
else
{
ret = 14.14f * cntX + 10.0f * (cntY - cntX);
}
float heightdiff = Mathf.Abs(b.Height - a.Height);
ret += heightdiff;
return(ret);
}
void Awake()
{
// 初始化格子
w = Mathf.RoundToInt(transform.localScale.x * 2);
h = Mathf.RoundToInt(transform.localScale.y * 2);
grid = new PathFindNodeItem[w, h];
WallRange = new GameObject("WallRange");
PathRange = new GameObject("PathRange");
// 将墙的信息写入格子中
for (int x = 0; x < w; x++)
{
for (int y = 0; y < h; y++)
{
Vector3 pos = new Vector3(x * 0.5f, y * 0.5f, 0);
// 通过节点中心发射圆形射线，检测当前位置是否可以行走
bool isWall = Physics.CheckSphere(pos, NodeRadius, WhatLayer);
// 构建一个节点
grid[x, y] = new PathFindNodeItem(isWall, pos, x, y);
if (isWall)
{
grid[x, y].Height = 3.0f;
}
// 如果是墙体，则画出不可行走的区域
if (isWall)
{
GameObject obj = GameObject.Instantiate(NodeWall, pos, Quaternion.identity) as GameObject;
obj.transform.SetParent(WallRange.transform);
}
else
{
// GameObject obj = GameObject.Instantiate( Node, pos, Quaternion.identity ) as GameObject;
// / obj.transform.SetParent( WallRange.transform );
}
}
}
}
// 取得周围的节点
public List <PathFindNodeItem> getNeibourhood(PathFindNodeItem node)
{
List <PathFindNodeItem> list = new List <PathFindNodeItem>();
for (int i = -1; i <= 1; i++)
{
for (int j = -1; j <= 1; j++)
{
// 如果是自己，则跳过
if (i == 0 && j == 0)
{
continue;
}
int x = node.x + i;
int y = node.y + j;
// 判断是否越界，如果没有，加到列表中
if (x < w && x >= 0 && y < h && y >= 0)
{
list.Add(grid[x, y]);
}
}
}
return(list);
}
// A*寻路
void FindingPath(PlayerAtt player, Vector3 s, Vector3 e)
{
PathFindNodeItem startNode = grid.getItem(s);
PathFindNodeItem endNode = grid.getItem(e);
List <PathFindNodeItem> openSet = new List <PathFindNodeItem>();
HashSet <PathFindNodeItem> closeSet = new HashSet <PathFindNodeItem>();
openSet.Add(startNode);
while (openSet.Count > 0)
{
PathFindNodeItem curNode = openSet[0];
for (int i = 0, max = openSet.Count; i < max; i++)
{
if (openSet[i].fCost <= curNode.fCost)
{
curNode = openSet[i];
}
}
openSet.Remove(curNode);
closeSet.Add(curNode);
// 找到的目标节点
if (curNode == endNode)
{
Debug.Log("cost is :" + curNode.gCost.ToString());
generatePath(startNode, endNode);
return;
}
// 判断周围节点，选择一个最优的节点
foreach (var item in grid.getNeibourhood(curNode))
{
// 如果是墙或者已经在关闭列表中
float neibourCost = CaculateNodeCost(player, curNode, item);
if (neibourCost == -1.0f || closeSet.Contains(item))
{
continue;
}
// 计算当前相领节点现开始节点距离
float newCost = curNode.gCost + neibourCost;
// 如果距离更小，或者原来不在开始列表中
if (newCost < item.gCost || !openSet.Contains(item))
{
// 更新与开始节点的距离
item.gCost = newCost;
// 更新与终点的距离
item.hCost = getDistanceNodes(item, endNode) / player.moveSpeed;
// 更新父节点为当前选定的节点
item.parent = curNode;
// 如果节点是新加入的，将它加入打开列表中
if (!openSet.Contains(item))
{
openSet.Add(item);
}
}
}
}
generatePath(startNode, null);
}