//定义点的结构体

function point(){

 this.x=0;

 this.y=0;

}

//计算一个点是否在多边形里,参数:点,多边形数组 


function PointInPoly(pt, poly) {

    for (var c = false, i = -1, l = poly.length, j = l - 1; ++i < l; j = i)

        ((poly[i].y <= pt.y && pt.y < poly[j].y) || (poly[j].y <= pt.y && pt.y < poly[i].y))

        && (pt.x < (poly[j].x - poly[i].x) * (pt.y - poly[i].y) / (poly[j].y - poly[i].y) + poly[i].x)

        && (c = !c);

    return c;

}

//调用

var pt=new point();

pt.x=34.32812720562833;

pt.y=108.93115997314453;

//这里的下x，y坐标是多边形的顺时针的拐角节点来排序的

var _poly=[{x:1.1,y:1.1},{x:3,y:1},{x:6,y:4},{x:2,y:10},{x:1.1,y:1.1}];

var xx=PointInPoly(pt,_poly);

alert(xx);