javascript A*算法 寻路算法 获取最短路径算法

Posted 2021-03-09 weihexin

  1 //A算法 自动寻路 路径
  2 class GetAutoPath{
  3 
  4     constructor(id, map, sPos, ePos, mapArr){
  5         //this.type = id.type;
  6         this.id = id;
  7         this.map = map;
  8         this.sPos = sPos;
  9         this.ePos = ePos;
 10         this.mapArr = mapArr;
 11         this.maxMach = 10000;
 12         this.openArr = [];
 13         this.closeArr = [];
 14         this.minPath = [];
 15         if(!this.isPath(this.sPos.x, this.sPos.y)){this.sPos = this.getNewDot(sPos, ePos);}
 16         if(!this.isPath(this.ePos.x, this.ePos.y)){this.ePos = this.getNewDot(ePos, sPos);}
 17         //console.log(this.mapArr);
 18         return this.run();
 19     }
 20     
 21     posts(txt, arr){//post消息
 22         //let id = this.id, sPos = this.sPos, ePos = this.ePos, arrs = arr || [];
 23         return {id:this.id, map:this.map, arr:arr || [], sPos:this.sPos, ePos:this.ePos, txt:txt}
 24     }
 25     
 26     isPath(x, y){//isPath = true 合法路径 = isBanPath === undefined
 27         let isPath = false, ym = this.mapArr.get(y), xm; //console.log(ym);  debugger;
 28         if(ym !== undefined){
 29             xm = ym.get(x);
 30             if(xm !== undefined){
 31                 if(xm.isBanPath === undefined){isPath = true;}
 32             }
 33         }
 34         //if(this.mapArr[y] !== undefined && this.mapArr[y][x] !== undefined && this.mapArr[y][x].isPath === 1){isPath = true;}
 35         return isPath;
 36     }
 37     
 38     getEqual(arr, x, y){//获取目标数组相同的坐标
 39         let isPos = false;
 40         if(arr.length === 0){
 41             isPos = false;
 42         }else{
 43             isPos = arr.some(function (o){return o.x === x && o.y === y;});
 44         }
 45         return isPos;
 46     }
 47 
 48     getDot(x, y){//获取周围8个方向坐标
 49         return [{x:x-1,y:y},{x:x+1,y:y},{x:x,y:y-1},{x:x,y:y+1},{x:x-1,y:y-1},{x:x+1,y:y+1},{x:x+1,y:y-1},{x:x-1,y:y+1}]
 50     }    
 51     
 52     getNewDot(setPos, pos){//重定义起点或终点
 53         let dot = setPos, pointDot, k, arr = [], arrs = [], g, end, maxMachT = 0;
 54         while(!end && maxMachT < this.maxMach){
 55             maxMachT++;
 56             pointDot = this.getDot(dot.x, dot.y);
 57             for(k in pointDot){
 58                 g = Math.round(Math.sqrt(Math.abs(pointDot[k].x - pos.x) + Math.abs(pointDot[k].y - pos.y)) * 100) / 100;
 59                 if(!this.isPath(pointDot[k].x, pointDot[k].y)){//不合法
 60                     arr.push({x:pointDot[k].x, y:pointDot[k].y, g:g});
 61                     arr.sort(function(a, b){return a.g - b.g;});
 62                 }else{//合法
 63                     arrs.push({x:pointDot[k].x, y:pointDot[k].y, g:g});
 64                     arrs.sort(function(a, b){return a.g - b.g;});
 65                 }
 66                 if(arrs.length > 0){end = true;}
 67             }
 68             dot = {x:arr[0].x, y:arr[0].y, g:arr[0].g}; arr = []; 
 69         }
 70         if(!arrs[0].x || !arrs[0].y){return this.posts("没有符合的坐标");}
 71         return {x:arrs[0].x, y:arrs[0].y};
 72     }
 73     
 74     run(){
 75         if(this.sPos.x === undefined || this.ePos.x === undefined){return this.posts("没有符合的坐标");}
 76         let sPos = this.sPos, ePos = this.ePos, point, key, i, newPoint, ger, gers, g, h, f, maxMachT = 0;
 77         this.openArr[0] = {x : sPos.x, y : sPos.y, f : 0, p : 0, ger : 0}
 78         while(this.openArr.length > 0){
 79             maxMachT++;
 80             point = this.openArr[0]; this.closeArr.push(point); this.openArr.splice(0,1);
 81             key = this.closeArr.length - 1;//设置当前节点
 82             newPoint = this.getDot(point.x, point.y);//获取周围点
 83             for(i in newPoint){//设置周围点
 84                 ger = Math.round(Math.sqrt(Math.abs(newPoint[i].x - point.x) + Math.abs(newPoint[i].y - point.y)) * 100) / 100;//到当前节点的曼哈顿距离,保留两位小数点
 85                 gers = ger + point.ger;
 86                 g = Math.round(gers * 100) / 100;
 87                 h = Math.abs(newPoint[i].x - ePos.x) + Math.abs(newPoint[i].y - ePos.y);
 88                 f = g + h;
 89                 if(this.isPath(newPoint[i].x, newPoint[i].y) && !this.getEqual(this.openArr, newPoint[i].x, newPoint[i].y) && !this.getEqual(this.closeArr, newPoint[i].x, newPoint[i].y)){this.openArr.push({x:newPoint[i].x, y:newPoint[i].y, f:f, p:key, ger:ger});}
 90             }
 91             this.openArr.sort(function(a, b){return a.f - b.f;});//排序
 92             if(this.getEqual(this.closeArr, ePos.x, ePos.y) || this.getEqual(this.openArr, ePos.x, ePos.y)){//end
 93                 this.minPath.unshift(this.closeArr[key]);
 94                 while(this.minPath.length > 0){
 95                     if(this.minPath[0].p == 0){return this.posts(‘success‘, this.minPath);}else{this.minPath.unshift(this.closeArr[this.minPath[0].p]);}
 96                 }
 97             }else if(maxMachT === this.maxMach){
 98                 return this.posts("没有符合的坐标");
 99             }
100         }
101         return this.posts("没有符合的坐标");
102     }
103     
104 }