寻路效果.gif
代码实现
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
/// <summary>
/// 格子类型
/// </summary>
public enum ItemType
{
Normal,
Obsticle,
Start,
End
}
public class AStar : MonoBehaviour
{
/// <summary>
/// Item预设体
/// </summary>
public GameObject itemPrefab;
//起点终点坐标
public int startPointX = 1;
public int startPointY = 2;
public int endPointX = 10;
public int endPointY = 12;
//自定义偏移量
public float offset = 0.5f;
//障碍物出现的概率
public int obsticleScale = 60;
//地图格子的长宽
private int mapX;
private int mapY;
//地图偏移量
private float mapOffsetX;
private float mapOffsetY;
//格子数组
private Item[,] items;
/// <summary>
/// 开启列表（将所有计算过FGH值的格子存储）
/// </summary>
private List<Item> openList;
/// <summary>
/// 关闭列表（将被作为中心计算过的格子）
/// </summary>
private List<Item> closeList;
/// <summary>
/// 结果路径
/// </summary>
private Stack<Item> path;
void Awake()
{
openList = new List<Item>();
closeList = new List<Item>();
path = new Stack<Item>();
}
void Start()
{
MapReady();
AStarPathFinding();
}
/// <summary>
/// 地图准备
/// </summary>
void MapReady()
{
//计算地图长宽
mapX = (int)(transform.localScale.x * 20);
mapY = (int)(transform.localScale.z * 20);
//实例数组
items = new Item[mapX, mapY];
//计算地图偏移量
mapOffsetX = -transform.localScale.x * 10 / 2;
mapOffsetY = -transform.localScale.z * 10 / 2;
//生成格子
for (int i = 0; i < mapX; i++)
{
for (int j = 0; j < mapY; j++)
{
//获取当前格子
GameObject crtItem = Instantiate(itemPrefab,
new Vector3(i / 2f, 0, j / 2f) +
new Vector3(mapOffsetX + offset, 0,
mapOffsetY + offset),
Quaternion.identity);
//填充数组
items[i, j] = crtItem.GetComponent<Item>();
//设置坐标
items[i, j].SetItemXY(i, j);
//随机
int r = Random.Range(1, 101);
if (r <= obsticleScale)
{
//设置障碍物
items[i, j].SetItemType(ItemType.Obsticle);
}
}
}
//设置起点终点
items[startPointX, startPointY].SetItemType(ItemType.Start);
items[endPointX, endPointY].SetItemType(ItemType.End);
}
/// <summary>
/// A*寻路
/// </summary>
void AStarPathFinding()
{
//起点格子作为当前格子
Item currentItem = null;
//添加起点格子到开启列表
openList.Add(items[startPointX, startPointY]);
//循环遍历
while (openList.Count > 0)
{
//获取F值最小的格子作为当前格子
currentItem = openList[0];
//如果发现了终点
if (currentItem.GetItemType()
== ItemType.End)
{
//TODO:整理结果路径
GeneratePath(currentItem);
return;
}
//发现周围的格子
for (int i = -1; i <= 1; i++)
{
for (int j = -1; j <= 1; j++)
{
//越过当前格子
if (i == 0 && j == 0)
continue;
//被发现的格子坐标
int p = currentItem.GetItemX() + i;
int q = currentItem.GetItemY() + j;
if (p < 0 || q < 0 || p >= mapX
|| q >= mapY ||
items[p, q].GetItemType() == ItemType.Obsticle ||
closeList.Contains(items[p, q]))
{
continue;
}
//计算FGH
int g = currentItem.g + (int)(Mathf.Sqrt(i * i + j * j) * 10);
//如果该格子的g未被计算，或值太大，覆盖它
if (items[p, q].g == 0 || items[p, q].g > g)
{
items[p, q].g = g;
//设置发现者
items[p, q].parent = currentItem;
}
//曼哈顿计算h值
items[p, q].h = (Mathf.Abs(p - endPointX)
+ Mathf.Abs(q - endPointY)) * 10;
//计算F
items[p, q].f = items[p, q].g + items[p, q].h;
//添加到开启列表
openList.Add(items[p, q]);
}
}
//For循环结束
//移除当前格子从开启列表
openList.Remove(currentItem);
//放置到关闭列表
closeList.Add(currentItem);
//判断
if (openList.Count == 0)
Debug.Log("无法到达目标点！");
//排序
openList.Sort();
}
}
/// <summary>
/// 生成路径
/// </summary>
void GeneratePath(Item item)
{
if (item.parent != null)
{
//压栈
path.Push(item.parent);
//递归寻址
GeneratePath(item.parent);
}
else
{
//输出结果
StartCoroutine(ShowPath());
}
}
/// <summary>
/// 展示结果
/// </summary>
/// <param name="item">Item.</param>
IEnumerator ShowPath()
{
while (path.Count > 0)
{
//出栈
Item item = path.Pop();
if (item.GetItemType() != ItemType.Start)
{
//标记
item.SetColor(Color.black);
}
yield return new WaitForSeconds(0.2f);
}
}
void Update()
{
if (Input.GetKeyDown(KeyCode.Space))
{
UnityEngine.SceneManagement.SceneManager.LoadScene(0);
}
}
}
using UnityEngine;
using System.Collections;
using System.Collections.Generic;
public class Item : MonoBehaviour, System.IComparable
{
//格子类型
private ItemType itemType;
//格子坐标
private int x;
private int y;
//寻路估量代价值
public int f;
public int g;
public int h;
//当前格子的发现者
public Item parent;
private MeshRenderer meshRenderer;
void Awake()
{
meshRenderer = GetComponent<MeshRenderer>();
}
/// <summary>
/// 设置格子类型
/// </summary>
/// <param name="t">T.</param>
public void SetItemType(ItemType t)
{
//设置
itemType = t;
switch (t)
{
case ItemType.Start:
meshRenderer.material.color = Color.red;
break;
case ItemType.End:
meshRenderer.material.color = Color.green;
break;
case ItemType.Obsticle:
meshRenderer.material.color = Color.blue;
break;
default:
meshRenderer.material.color = Color.white;
break;
}
}
/// <summary>
/// 获取格子类型
/// </summary>
/// <returns>The item type.</returns>
public ItemType GetItemType()
{
return itemType;
}
public int GetItemX()
{
return x;
}
public int GetItemY()
{
return y;
}
/// <summary>
/// 设置坐标
/// </summary>
/// <param name="x">The x coordinate.</param>
/// <param name="y">The y coordinate.</param>
public void SetItemXY(int x, int y)
{
this.x = x;
this.y = y;
}
/// <summary>
/// 上色
/// </summary>
/// <param name="col">Col.</param>
public void SetColor(Color col)
{
meshRenderer.material.color = col;
}
/// <summary>
/// 排序规则
/// </summary>
/// <returns>The to.</returns>
/// <param name="obj">Object.</param>
public int CompareTo(object obj)
{
//新的Item
Item newItem = obj as Item;
if (newItem.f > this.f)
{
return -1;
}
else if (newItem.f < this.f)
{
return 1;
}
else
{
return 0;
}
}
}
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