JS中实现A*算法寻路

来源：互联网发布：文化创新的例子知乎编辑：程序博客网时间：2024/06/09 19:32

强人写的，看后无语

written by hjjboy

email:tianmashuangyi@163.com

qq:156809986

var closelist=new Array(),openlist=new Array();

var gw=10,gh=10,gwh=14;

var p_start=new Array(2),p_end=new Array(2);

var s_path,n_path="";

var num,bg,flag=0;

var w=30,h=20;

function GetRound(pos){

var a=new Array();

a[0]=(pos[0]+1)+","+(pos[1]-1);

a[1]=(pos[0]+1)+","+pos[1];

a[2]=(pos[0]+1)+","+(pos[1]+1);

a[3]=pos[0]+","+(pos[1]+1);

a[4]=(pos[0]-1)+","+(pos[1]+1);

a[5]=(pos[0]-1)+","+pos[1];

a[6]=(pos[0]-1)+","+(pos[1]-1);

a[7]=pos[0]+","+(pos[1]-1);

return a;

}

function GetF(arr){

var t,G,H,F;

for(var i=0;i<arr.length;i++){

t=arr[i].split(",");

t[0]=parseInt(t[0]);t[1]=parseInt(t[1]);

if(IsOutScreen([t[0],t[1]])||IsPass(arr[i])||InClose([t[0],t[1]])||IsStart([t[0],t[1]])||!IsInTurn([t[0],t[1]]))

continue;

if((t[0]-s_path[3][0])*(t[1]-s_path[3][1])!=0)

G=s_path[1]+gwh;

else

G=s_path[1]+gw;

if(InOpen([t[0],t[1]])){

if(G<openlist[num][1]){

openlist[num][0]=(G+openlist[num][2]);

openlist[num][1]=G;

openlist[num][4]=s_path[3];

}

else{G=openlist[num][1];}

}

else{

H=(Math.abs(p_end[0]-t[0])+Math.abs(p_end[1]-t[1]))*gw;

F=G+H;

arr[i]=new Array();

arr[i][0]=F;arr[i][1]=G;arr[i][2]=H;arr[i][3]=[t[0],t[1]];arr[i][4]=s_path[3];

openlist[openlist.length]=arr[i];

}

if(maptt.rows[t[1]].cells[t[0]].style.backgroundColor!="#cccccc"&&maptt.rows[t[1]].cells[t[0]].style.backgroundColor!="#0000ff"&&maptt.rows[t[1]].cells[t[0]].style.backgroundColor!="#ff0000"&&maptt.rows[t[1]].cells[t[0]].style.backgroundColor!="#00ff00")

{

maptt.rows[t[1]].cells[t[0]].style.backgroundColor="#FF00FF";

//maptt.rows[t[1]].cells[t[0]].innerHTML="<font color=white>"+G+"</font>";

}

function IsStart(arr){

if(arr[0]==p_start[0]&&arr[1]==p_start[1])

return true;

return false;

}

function IsInTurn(arr){

if(arr[0]>s_path[3][0]){

if(arr[1]>s_path[3][1]){

if(IsPass((arr[0]-1)+","+arr[1])||IsPass(arr[0]+","+(arr[1]-1)))

return false;

}

else if(arr[1]<s_path[3][1]){

if(IsPass((arr[0]-1)+","+arr[1])||IsPass(arr[0]+","+(arr[1]+1)))

return false;

}

else if(arr[0]<s_path[3][0]){

if(arr[1]>s_path[3][1]){

if(IsPass((arr[0]+1)+","+arr[1])||IsPass(arr[0]+","+(arr[1]-1)))

return false;

}

else if(arr[1]<s_path[3][1]){

if(IsPass((arr[0]+1)+","+arr[1])||IsPass(arr[0]+","+(arr[1]+1)))

return false;

}

return true;

}

function IsOutScreen(arr){

if(arr[0]<0||arr[1]<0||arr[0]>(w-1)||arr[1]>(h-1))

return true;

return false;

}

function InOpen(arr){

var bool=false;

for(var i=0;i<openlist.length;i++){

if(arr[0]==openlist[i][3][0]&&arr[1]==openlist[i][3][1]){

bool=true;num=i;break;}

}

return bool;

}

function InClose(arr){

var bool=false;

for(var i=0;i<closelist.length;i++){

if((arr[0]==closelist[i][3][0])&&(arr[1]==closelist[i][3][1])){

bool=true;break;}

}

return bool;

}

function IsPass(pos){

if((";"+n_path+";").indexOf(";"+pos+";")!=-1)

return true;

return false;

}

function Sort(arr){

var temp;

for(var i=0;i<arr.length;i++){

if(arr.length==1)break;

if(arr[i][0]<=arr[i+1][0]){

temp=arr[i];

arr[i]=arr[i+1];

arr[i+1]=temp;

}

if((i+1)==(arr.length-1))

break;

}

function main(){

GetF(GetRound(s_path[3]));

Sort(openlist);

s_path=openlist[openlist.length-1];

closelist[closelist.length]=s_path;

openlist[openlist.length-1]=null;

if(openlist.length==0){alert("找不到路径");return;}

openlist.length=openlist.length-1;

if((s_path[3][0]==p_end[0])&&(s_path[3][1]==p_end[1])){

getPath();

}

else{maptt.rows[s_path[3][1]].cells[s_path[3][0]].style.backgroundColor="#00ff00";setTimeout("main()",100);}

}

function getPath(){

var str="";

var t=closelist[closelist.length-1][4];

while(1){

str+=t.join(",")+";";

maptt.rows[t[1]].cells[t[0]].style.backgroundColor="#ffff00";

for(var i=0;i<closelist.length;i++){

if(closelist[i][3][0]==t[0]&&closelist[i][3][1]==t[1])

t=closelist[i][4];

}

if(t[0]==p_start[0]&&t[1]==p_start[1])

break;

}

alert(str);

}

function setPos(){

var h=(Math.abs(p_end[0]-p_start[0])+Math.abs(p_end[1]-p_start[1]))*gw;

s_path=[h,0,h,p_start,p_start];

}

function set(id,arr){

switch(id){

case 1:

p_start=arr;

maptt.rows[arr[1]].cells[arr[0]].style.backgroundColor="#ff0000";break;

case 2:

p_end=arr;maptt.rows[arr[1]].cells[arr[0]].style.backgroundColor="#0000ff";break;

case 3:

n_path+=arr.join(",")+";";maptt.rows[arr[1]].cells[arr[0]].style.backgroundColor="#cccccc";break;

default:

break;

}

function setflag(id){flag=id;}

</script>

for(var i=0;i<h;i++){

document.write("<tr>");

for(var j=0;j<w;j++){

document.write('<td onclick="set(flag,['+j+','+i+']);" bgcolor="#ffffff" width="20" height="20"></td>');

}

document.write("</tr>");

}

</script>

</table>

<a href='javascript:setflag(3);'>设置障碍点</a><br>

</body>

</html>