Question

我试图弄清楚是否有可能检测到两个Google地图圈（标记周围）相交或相互碰撞。

我想要完成的是，如果两个圆相交，我想举起一个事件。我不确定这是否可行。

Answer 1

计算圆心之间的距离，如果它小于两个圆的半径之和，则它们相交。

Answer 2

以下是一些可以检测两个圆是否相交的JavaScript

 var e = Math;         // shortcut for the mathematical function 
 var D2R = e.PI/180.0; // value used for converting degrees to radians

 Number.prototype.toRadians = function() {
   return this * D2R;
 };

 function distance(lat0,lng0,lat1,lng1){

   // convert degrees to radians
   var rlat0 = lat0.toRadians();
   var rlng0 = lng0.toRadians();
   var rlat1 = lat1.toRadians();
   var rlng1 = lng1.toRadians();

   // calculate the differences for both latitude and longitude (the deltas)
   var Δlat=(rlat1-rlat0);
   var Δlng=(rlng1-rlng0);

   // calculate the great use haversine formula to calculate great-circle distance between two points
   var a = e.pow(e.sin(Δlat/2),2) + e.pow(e.sin(Δlng/2),2)*e.cos(rlat0)*e.cos(rlat1);
   var c = 2*e.asin(e.sqrt(a));
   var d = c * 6378137;  // multiply by the radius of the great-circle (average radius of the earth in meters)

   return d;
 }

  function hasIntersections(circle0,circle1){
    var center0 = circle0.getCenter();
    var center1 = circle1.getCenter();

    var maxDist = circle0.getRadius()+circle1.getRadius();
    var actualDist = distance(center0.lat(),center0.lng(),center1.lat(),center1.lng());

    return maxDist>=actualDist;
  }

只需使用对您圈子的引用来调用hasIntersections即可。这是一个示例，显示几乎触摸的两个圆（返回false），如果在c1中将零更改为1，则它们将触摸（返回true）。

    map = new google.maps.Map(document.getElementById('map'), {
      center: {lat: 41.081301, lng: -98.214219},
      zoom: 25
    });

    var c0 = new google.maps.Circle({
        strokeOpacity: .1,
        strokeWeight: 1,
        fillColor: '#0000FF',
        fillOpacity: .2,
        map: map,
        center: {lat:41.082953, lng:  -98.215285},
        radius: 200
      });

    var c1 =new google.maps.Circle({
        strokeOpacity: .1,
        strokeWeight: 1,
        fillColor: '#FF0000',
        fillOpacity: .2,
        map: map,
        center: {lat:41.081070, lng: -98.214027},
        radius: 34.692866520
      });
      console.log(hasIntersections(c1,c0));

Google Maps API Circle相交检测

2 个答案: