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using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
public enum GridType
{
Normal,//正常
Obstacle,//障碍物
Start,//起点
End//终点
}
//为了格子排序 需要继承IComparable接口实现排序
public class MapGrid : IComparable//排序接口
{
public int x;//记录坐标
public int y;
public int f;//总消耗
public int g;//当前点到起点的消耗
public int h;//当前点到终点的消耗
public GridType type;//格子类型
public MapGrid fatherNode;//父节点
//排序
public int CompareTo(object obj) //排序比较方法 ICloneable的方法
{
//升序排序
MapGrid grid = (MapGrid)obj;
if (this.f < grid.f)
{
return -1; //升序
}
if (this.f > grid.f)
{
return 1; //降序
}
return 0;
}
}
public class AStar : MonoBehaviour
{
//格子大小
public int row = 5;
public int col = 10;
public int size = 70; //格子大小
public MapGrid[,] grids; //格子数组
public ArrayList openList; //开启列表
public ArrayList closeList; //结束列表
//开始,结束点位置
private int xStart = 2;
private int yStart = 1;
private int xEnd = 2;
private int yEnd = 5;
private Stack<string> fatherNodeLocation;
void Init()
{
grids = new MapGrid[row, col]; //初始化数组
for (int i = 0; i < row; i++)
{
for (int j = 0; j < col; j++)
{
grids[i, j] = new MapGrid();
grids[i, j].x = i;
grids[i, j].y = j; //初始化格子,记录格子坐标
}
}
grids[xStart, yStart].type = GridType.Start;
grids[xStart, yStart].h = Manhattan(xStart, yStart); //起点的 h 值
grids[xEnd, yEnd].type = GridType.End; //结束点
fatherNodeLocation = new Stack<string>();
//生成障碍物
for (int i = 1; i <= 3; i++)
{
grids[i, 3].type = GridType.Obstacle;
}
openList = new ArrayList();
openList.Add(grids[xStart, yStart]);
closeList = new ArrayList();
}
int Manhattan(int x, int y) //计算算法中的 h
{
return (int)(Mathf.Abs(xEnd - x) + Mathf.Abs(yEnd - y)) * 10;
}
// Use this for initialization
void Start()
{
Init();
}
void DrawGrid()
{
for (int i = 0; i < row; i++)
{
for (int j = 0; j < col; j++)
{
Color color = Color.yellow;
if (grids[i, j].type == GridType.Start)
{
color = Color.green;
}
else if (grids[i, j].type == GridType.End)
{
color = Color.red;
}
else if (grids[i, j].type == GridType.Obstacle) //障碍颜色
{
color = Color.blue;
}
else if (closeList.Contains(grids[i, j])) //关闭列表颜色 如果当前点包含在closList里
{
color = Color.yellow;
}
else { color = Color.gray; }
GUI.backgroundColor = color;
GUI.Button(new Rect(j * size, i * size, size, size), FGH(grids[i, j]));
}
}
}
//每个格子显示的内容
string FGH(MapGrid grid)
{
string str = "F" + grid.f + "\n";
str += "G" + grid.g + "\n";
str += "H" + grid.h + "\n";
str += "(" + grid.x + "," + grid.y + ")";
return str;
}
void OnGUI()
{
DrawGrid();
for (int i = 0; i < openList.Count; i++)
{
//生成一个空行,存放开启数组
GUI.Button(new Rect(i * size, (row + 1) * size, size, size), FGH((MapGrid)openList[i]));
}
//生成一个空行,存放关闭数组
for (int j = 0; j < closeList.Count; j++)
{
GUI.Button(new Rect(j * size, (row + 2) * size, size, size), FGH((MapGrid)closeList[j]));
}
if (GUI.Button(new Rect(col * size, size, size, size), "next"))
{
NextStep();//点击到下一步
}
}
void NextStep()
{
if (openList.Count == 0) //没有可走的点
{
print("Over !");
return;
}
MapGrid grid = (MapGrid)openList[0]; //取出openList数组中的第一个点
if (grid.type == GridType.End) //找到终点
{
print("Find");
ShowFatherNode(grid); //找节点//打印路线
return;
}
for (int i = -1; i <= 1; i++)
{
for (int j = -1; j <= 1; j++)
{
if (!(i == 0 && j == 0))
{
int x = grid.x + i;
int y = grid.y + j;
//x,y不超过边界,不是障碍物,不在closList里面
if (x >= 0 && x < row && y >= 0 && y < col && grids[x, y].type != GridType.Obstacle && !closeList.Contains(grids[x, y]))
{
//到起点的消耗
int g = grid.g + (int)(Mathf.Sqrt((Mathf.Abs(i) + Mathf.Abs(j))) * 10);
if (grids[x, y].g == 0 || grids[x, y].g > g)
{
grids[x, y].g = g;
grids[x, y].fatherNode = grid; //更新父节点
}
//到终点的消耗
grids[x, y].h = Manhattan(x, y);
grids[x, y].f = grids[x, y].g + grids[x, y].h;
if (!openList.Contains(grids[x,y]))
{
openList.Add(grids[x, y]); //如果没有则加入到openlist
}
openList.Sort(); //排序
}
}
}
}
//添加到关闭数组
closeList.Add(grid);
//从open数组删除
openList.Remove(grid);
}
//回溯法 递归父节点
void ShowFatherNode(MapGrid grid)
{
if (grid.fatherNode != null)
{
//print(grid.fatherNode.x + "," + grid.fatherNode.y);
string str = grid.fatherNode.x + "," + grid.fatherNode.y;
fatherNodeLocation.Push(str);
ShowFatherNode(grid.fatherNode);
}
if (fatherNodeLocation.Count!=0)
{
print(fatherNodeLocation.Pop());
}
}
}
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