清除重複的點Point

function clearSamePoint(pt){
    var count = pt.length;
    for(var i = 0; i < (count - 1)){

        if(this.equal(pt[i].x,pt[i+1].x && this.equal(pt[i].y,pt[i+1].y))){
                pt.splice(i,1);//刪除這個相同的點
                count --;
                }else{
                i++;
                }
        }
        return pt;
}

function equal(num1,num2,tolerance){
        if(!tolerance){
                tolerance = 0.000001;
        }
        //兩點相減是否小於容限制   
    return Math.abs(num1 - num2) <= tolerance;

}