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A*寻路算法(JavaScript实现)

程序员文章站 2024-03-16 22:52:58
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代码:
  
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title></title>
    <style>
        div{
            position: absolute;
            width: 50px;
            height: 50px;
            margin: 1px 1px;
            background-color: gray;
            border: 1px dashed #cccccc;
        }
        body{
            position: relative;
            font-family: "微软雅黑";


        }
        header,
        section
        {
            position: relative;
            margin: 0 auto;
            width: 998px;
        }

    </style>
</head>
<body>
    <header>
        <h1>A*寻路demo演示</h1>
        <table>
            <tr>
                <td>输入地图列数(最大15列):</td>
                <td><input id="rowInput" type="text"/></td>
            </tr>
            <tr>
                <td>请输入地图行数(最大15行):</td>
                <td><input id="colInput" type="text"></td>
            </tr>
            <tr>
                <td></td>
                <td><input id="createMapBtn" type="button" value="点击生成地图"/></td>
            </tr>
            <tr>
                <td id="prompt">test...</td>
                <td><input id="findPoint" type="button" value="开始寻路" style="display: none"/></td>
            </tr>


        </table>


    </header>

    <section id="main"></section>

    <script>
       function Point(){
           this.x=0;
           this.y=0;
           this.G=0;//G值 开始点 到当前点的移动量
           this.H=0;//H值 当前点移动目的地的移动量估算值
           this.father=null;
       };
       Point.prototype={
           Console:function(){
               console.log("x:"+this.x+" and y:"+this.y);
           },
           Init:function(x,y,father){
               this.x=x;
               this.y=y;
               this.father=father;
           }
       };
       function AStar(){
           //地图存放二维数组
           this.map=[];
           //行数
           this.rowCount=0;
           //列数
           this.colCount=0;
           //出发点
           this.startPoint=new Point();
           //终点
           this.endPoint=new Point();
           //存放Opint类的open数组
           this.openList=[];
           //存在Opint类的close数组
           this.closeList=[];
       };
       AStar.prototype={
           //是否为障碍物
           IsBar:function(x,y){
               if(this.map[x][y]==3){
                   console.log("bar...");
                   return true;
               }
               else{
                   console.log("no bar...")
                   return false;
               }
           },
           //当前坐标是否在OpenList
           IsInOpenList:function(x,y){
                for(var i=0;i<this.openList.length;i++){
                    if(this.openList[i].x==x&&this.openList[i].y==y){
                        return true;
                    }

                }
               return false;
           },
           //当前坐标是否在CloseList
           IsInCloseList:function(x,y){
               for(var i=0;i<this.closeList.length;i++){
                   if(this.closeList[i].x==x&&this.closeList[i].y==y){
                       return true;
                   }

               }
               return false;
           },
           //计算G值;(p是Point类)
           GetG:function(p){
               if(p.father==null){
                   return 0;
               }
               return p.father.G+1;
           },
           //计算H值
           GetH:function(p,pb){
               return Math.abs(p.x-pb.x)+Math.abs(p.y-pb.y);
           },
           //添加当前点的上下左右相邻的方格到Open列表中
           AddNeiToOpenList:function(curPoint){
               for(var x=curPoint.x-1;x<=curPoint.x+1;x++){
                    for(var y=curPoint.y-1;y<=curPoint.y+1;y++){
                        //排除自身以及超出下标的点
                        if((x>=0&&x<this.colCount&&y>=0&&y<this.rowCount)&&!(curPoint.x==x&&curPoint.y==y)){
                            //排除斜对角
                            if(Math.abs(x-curPoint.x)+Math.abs(y-curPoint.y)==1){
                                //不是障碍物且不在关闭列表中
                                if(this.IsBar(x,y)==false&&this.IsInCloseList(x,y)==false){
                                    //不存在Open列表
                                    if(this.IsInOpenList(x,y)==false){
                                        var point=new Point();
                                        point.x=x;
                                        point.y=y;
                                        point.father=curPoint;
                                        point.G=this.GetG(point);
                                        point.H=this.GetH(point,this.endPoint);
                                        this.openList.push(point);
                                    }
                                }
                            }
                        }
                    }
               }
           },
           //在openlist集合中获取G+H为最小的Point点
           GetMinFFromOpenList:function(){
               var minPoint=null;
               var index=0;
               for(var i=0;i<this.openList.length;i++){
                   if(minPoint==null||minPoint.G+minPoint.H>=this.openList[i].G+this.openList[i].H){
                       minPoint=this.openList[i];
                       index=i;
                   }
               }
               return{
                   minPoint:minPoint,
                   index:index
               }
           },

           GetPointFromOpenList:function(x,y){
               for(var i=0;i<this.openList.length;i++){
                   if(this.openList[i].x==x&&this.openList[i].y==y){
                       return this.openList[i];
                   }
               }
               return null;

           },
           //开始寻找节点
           FindPoint:function(){
               console.log(this);
               this.openList.push(this.startPoint);
               while(this.IsInOpenList(this.endPoint.x,this.endPoint.y)==false||this.openList.length==0){
                   var curPoint=this.GetMinFFromOpenList().minPoint;
                   console.log("curPoint:"+curPoint);
                   var index=this.GetMinFFromOpenList().index;
                   if(curPoint==null){
                       console.log("没有路");
                       return;
                   }
                   this.openList.splice(index,1);
                   this.closeList.push(curPoint);
                   this.AddNeiToOpenList(curPoint);
               }
               var p=this.GetPointFromOpenList(this.endPoint.x,this.endPoint.y);
               console.log(p+".....");
               while(p.father!=null){
                   p= p.father;
                   console.log("father..");
                   this.map[p.x][p.y]=4;
               }
               //把终结点也设置成4
               this.map[this.endPoint.x][this.endPoint.y]=4;
           },
           PrintMap:function(){

           }


       };
       //地图类    map数组保存数字标识 :0 默认 1 开始点 2 结束点 3 障碍物
       function Map(id){
           this.map=[];
           this.container=document.getElementById(id);
           this.colCount=0;
           this.rowCount=0;
       }
       Map.prototype={
           init:function(colCount,rowCount){
               this.colCount=colCount;
               this.rowCount=rowCount;
               for(var colIndex=0;colIndex<this.colCount;colIndex++){
                   this.map.push([]);
                   for(var rowIndex=0;rowIndex<this.rowCount;rowIndex++){
                       this.map[colIndex].push(0);
                   }
               }
           },
           drawMap:function(callback){
               for(var colIndex=0;colIndex<this.map.length;colIndex++){
                   for(var rowIndex=0;rowIndex<this.map[colIndex].length;rowIndex++){
                       var div=document.createElement("div");
                       div.style.top=colIndex*50+5+"px";
                       div.style.left=rowIndex*50+5+"px";
                       div.setAttribute("colIndex",colIndex);
                       div.setAttribute("rowIndex",rowIndex);
                       div.οnclick=callback;
                       this.container.appendChild(div);
                   }

               }

           },
           drawPoints:function(){
               var divs=this.container.children;
               console.log(divs.length);
               console.log(this.map);
               var timer=1000;
               for(var i=0;i<divs.length;i++){
                   var colIndex=divs[i].getAttribute("colIndex");
                   var rowIndex=divs[i].getAttribute("rowIndex");
                   if(this.map[colIndex][rowIndex]==4){
                       divs[i].style.backgroundColor="red";
                   }
               }
           },
           getPoint:function(colIndex,rowIndex){
               return this.map[colIndex][rowIndex];
           },
           setStartPoint:function(colIndex,rowIndex){
               this.map[colIndex][rowIndex]=1;
           },
           setEndPoint:function(colIndex,rowIndex){
               this.map[colIndex][rowIndex]=2;
           },
           setBarPoint:function(colIndex,rowIndex){
               this.map[colIndex][rowIndex]=3;
           },
           clearMap:function(){
               this.map.splice(0,this.map.length);
               this.container.innerHTML="";
           }

       }

       var rowInput=document.querySelector("#rowInput");
       var colInput=document.querySelector("#colInput");
       var createMapBtn=document.querySelector("#createMapBtn");
       var prompt=document.querySelector("#prompt");
       var findPoint=document.querySelector("#findPoint");
       var curMap=new Map("main");
       var state=0;//状态标识 0选择开始节点标识 1选择结束节点标识 2选择障碍物标识
       var aStar=new AStar();//寻路类

       createMapBtn.οnclick=function(){

           curMap.clearMap();
           curMap.init(colInput.value,rowInput.value);
           aStar.map=curMap.map;
           aStar.colCount=colInput.value;
           aStar.rowCount=rowInput.value;
           curMap.drawMap(function(){
                var colIndex=this.getAttribute("colIndex");
                var rowIndex=this.getAttribute("rowIndex");
                if(curMap.getPoint(colIndex,rowIndex)!=0){
                    return;
                }
                if(state==0){
                    this.style.backgroundColor="blue";
                    curMap.setStartPoint(colIndex,rowIndex);
                    aStar.startPoint.x=colIndex;
                    aStar.startPoint.y=rowIndex;
                    state=1;
                    prompt.innerHTML="请点击格子,设置终点";

                }else if(state==1){
                    this.style.backgroundColor="yellow";
                    curMap.setEndPoint(colIndex,rowIndex);
                    aStar.endPoint.x=colIndex;
                    aStar.endPoint.y=rowIndex;
                    prompt.innerHTML="请点击格子,设置障碍物";
                    console.log(findPoint);
                    findPoint.style.display="block";
                    state=2;
                }else if(state==2){
                    curMap.setBarPoint(colIndex,rowIndex);
                    this.style.backgroundColor="black";
                }
           });
           prompt.innerHTML="请点击格子,设置起始点";
       }
       findPoint.οnclick=function(){
           console.log(aStar.map);
           aStar.FindPoint();
           curMap.drawPoints();
       }

    </script>

</body>
</html>