d3.js-在谷歌地图上绘制站点和路径

var data = load_json()

main(data)

function main(json) {
        /*
        var m = d3.select('body').append('div')
                .style('width','100%')
                .style('height','100%')
                .style("margin",0)
                .style("padding",0)
                */
        
        var map = new google.maps.Map(d3.select("#map").node(), {
                zoom: 9,
                center: new google.maps.LatLng(44.391643516091975,23.159677682342053),
                mapTypeId: google.maps.MapTypeId.ROADMAP,//TERRAIN
                disableDefaultUI:false,
                navigationControl:false,
                mapTypeControl:false,
                scaleControl:false,
        });
        
        var overlay = new google.maps.OverlayView();
        overlay.onAdd = function() {                
                var olayer = this.getPanes().overlayLayer
                
                var projection = this.getProjection()
                var [width,height] = getMapDimension(map,projection)
                console.log(width,height)
                
                var layer = d3.select(olayer).append("svg")
                        .attr("class", "stations")
                        .attr('width',width)
                        .attr('height',height)
                        .attr('transform',`translate(${-width/2},${-height/2})`)
                        //.style('border','1px solid red')
                
                overlay.draw = function() {                     
                        draw_marker(map,layer,projection,json,width,height)
                }
        }
        // Bind our overlay to the map…
        overlay.setMap(map);
        //fit_screen(map,json.nodes,'lat','lng')
}

function getMapDimension(map,projection) {
        let bounds = map.getBounds();
    let ne = bounds.getNorthEast(),
        sw = bounds.getSouthWest(),
        center = bounds.getCenter();

        ne = coor2px(projection,{lat:ne.lat(), lng:ne.lng()},0,0)   
        sw = coor2px(projection,{lat:sw.lat(), lng:sw.lng()},0,0)
        var width = ne.x - sw.x
        var height = sw.y - ne.y
        if (height == 0) height = width
        return [width,height]
}

function fit_screen(map,data,lat,lng) {
        var lat_min = d3.min(data,d => d[lat])
        var lat_max = d3.max(data,d => d[lat])
        var lng_min = d3.min(data,d => d[lng])
        var lng_max = d3.max(data,d => d[lng])
        map.setCenter(new google.maps.LatLng(
                ((lat_max + lat_min) / 2.0),
                ((lng_max + lng_min) / 2.0)
        ));

        map.fitBounds(new google.maps.LatLngBounds(
                new google.maps.LatLng(lat_min, lng_min),//bottom left
                new google.maps.LatLng(lat_max, lng_max)//top right
        ));
        //map.setZoom(map.getZoom() + 1.8);
}

function draw_marker(map,layer,projection,json,width,height) {
    var markerLink = layer.selectAll(".link")
                .data(json.links)
                .join('line')
                .attr("class", "link")
        .attr("x1", d => {
                        var source = json.nodes[d.source]
                        var target = json.nodes[d.target]
                        d.src = coor2px(projection,source,width,height)
                        d.trg = coor2px(projection,target,width,height)
                        return d.src.x
                })
        .attr("y1", d => d.src.y)
        .attr("x2", d => d.trg.x)
        .attr("y2", d => d.trg.y)
                .attr("stroke-width",2)
                .attr("fill","none")
                .attr("stroke","blue")
        
    var marker = layer.selectAll(".marker")
                .data(json.nodes)
                .join("g")
                .attr('class','marker')
                .attr('transform',d => {
                        var p = coor2px(projection,d,width,height)
                        return `translate(${p.x},${p.y})`
                })

    marker.append("circle")
        .attr("r", 5)
                .attr('fill','red')

    marker.append("text")
        .attr("x", 7)
        .attr("y", 0)
        .attr("dy", ".37em")
        .text(function(d,i) {
                        return i;
        })
                .attr('font-size',30)
}

function coor2px(projection,d,width,height) {
        var p = new google.maps.LatLng(d.lat, d.lng);
        var p = projection.fromLatLngToDivPixel(p);
        return {x:p.x+width/2,y:p.y+height/2}
}       

function getwidth(){
   return window.innerWidth 
       || document.documentElement.clientWidth 
       || document.body.clientWidth 
       || 0;
}

function getheight(){
   return window.innerHeight 
       || document.documentElement.clientHeight 
       || document.body.clientHeight 
       || 0;
}


function load_json() {
  var jsonobj = {
    "directed": true,
    "graph": [],
    "nodes": [{
        "lat": 44.391643516091975,
        "lng": 23.159677682342053,
        "id": "1:a"
      },
      {
        "lat": 44.315988,
        "lng": 23.818359,
        "id": "a:a::"
      },
      {
        "lat": 44.29844994776969,
        "lng": 24.402314492323608,
        "id": "b:b"
      },
      {
        "lat": 44.351118152120485,
        "lng": 23.341791630955303,
        "id": "a:c"
      },
      {
        "lat": 44.889424527442685,
        "lng": 23.960970697645276,
        "id": "e:d"
      },
      {
        "lat": 43.46084400349923,
        "lng": 23.975774627524885,
        "id": "d:6104:1"
      },
      {
        "lat": 44.64680010013528,
        "lng": 23.20292820976948,
        "id": "c:6104:2"
      },
      {
        "lat": 44.40446080879215,
        "lng": 23.953536570796015,
        "id": "b:6104:3"
      },
      {
        "lat": 44.18593375168617,
        "lng": 23.769879901486856,
        "id": "af:6104:4"
      },
      {
        "lat": 44.09051846584001,
        "lng": 24.14130778735744,
        "id": "aaaa3bab:3d:7305"
      },
      {
        "lat": 44.66376251969314,
        "lng": 23.77379490100736,
        "id": "aaaa3bab:3d:5507"
      },
      {
        "lat": 44.6240449587762,
        "lng": 24.08347249542858,
        "id": "aaaa3bab:3d:6f06"
      },
      {
        "lat": 45.00138334367271,
        "lng": 24.092331272179138,
        "id": "aaaa3bab:3d:1306"
      },
      {
        "lat": 44.55033831045195,
        "lng": 24.312914121854526,
        "id": "aaaa3bab:3c:ef05"
      },
      {
        "lat": 44.74421652327631,
        "lng": 24.728457702115804,
        "id": "aaaa3bab:3c:ea03"
      },
      {
        "lat": 43.79401723931746,
        "lng": 23.77846416630604,
        "id": "aaaa3bab:3d:7200"
      },
      {
        "lat": 43.67351687345779,
        "lng": 23.00140978137842,
        "id": "aaaa3bab:3d:5d07"
      },
      {
        "lat": 43.87692500855015,
        "lng": 24.28543591328852,
        "id": "aaaa3bab:3d:550b"
      },
      {
        "lat": 44.28189405244278,
        "lng": 23.972410391551893,
        "id": "aaaa3bab:3d:2706"
      },
      {
        "lat": 43.94916218711252,
        "lng": 23.9733463072956,
        "id": "aaaa3bab:3d:2704"
      },
      {
        "lat": 44.61479884874806,
        "lng": 24.27581898293906,
        "id": "aaaa3bab:3d:2608"
      },
      {
        "lat": 44.92223011339065,
        "lng": 23.505887513934034,
        "id": "aaaa3bab:3d:6502"
      },
      {
        "lat": 44.20117807597118,
        "lng": 23.70555450810448,
        "id": "aaaa3bab:3d:2603"
      },
      {
        "lat": 43.547714841247966,
        "lng": 24.56985383484244,
        "id": "aaaa3bab:3d:2601"
      },
      {
        "lat": 43.92116991202797,
        "lng": 22.82805535024416,
        "id": "aaaa3bab:3d:5803"
      },
      {
        "lat": 44.56587414638437,
        "lng": 22.970799697228976,
        "id": "aaaa3bab:3d:7406"
      },
      {
        "lat": 44.10230727065641,
        "lng": 23.701204095342597,
        "id": "aaaa3bab:3d:7407"
      },
      {
        "lat": 45.25416535851712,
        "lng": 24.434312172789625,
        "id": "aaaa3bab:3d:7404"
      },
      {
        "lat": 44.91647619491961,
        "lng": 23.678252259828515,
        "id": "aaaa3bab:3d:7405"
      },
      {
        "lat": 45.03473433359779,
        "lng": 24.07596179597473,
        "id": "aaaa3bab:3d:7402"
      },
      {
        "lat": 45.16855171992733,
        "lng": 23.435986773864467,
        "id": "aaaa3bab:3d:7403"
      },
      {
        "lat": 44.553669079256146,
        "lng": 23.05123326220677,
        "id": "aaaa3bab:3d:7400"
      },
      {
        "lat": 43.32871087231798,
        "lng": 23.325707869122013,
        "id": "aaaa3bab:3d:5308"
      },
      {
        "lat": 43.40444516345915,
        "lng": 23.485798521785892,
        "id": "aaaa3bab:3c:f107"
      },
      {
        "lat": 43.9435337313432,
        "lng": 22.968285824722354,
        "id": "aaaa3bab:3d:7401"
      },
      {
        "lat": 44.74549949495889,
        "lng": 22.832034225254052,
        "id": "aaaa3bab:3d:7408"
      },
      {
        "lat": 44.34901730307382,
        "lng": 24.33506529636527,
        "id": "aaaa3bab:3d:7409"
      },
      {
        "lat": 43.53125851464172,
        "lng": 24.763229039168245,
        "id": "aaaa3bab:3d:6602"
      },
      {
        "lat": 44.155575603194634,
        "lng": 23.250881840942217,
        "id": "aaaa3bab:3c:e300"
      }
    ],
    "links": [{
        "source": 1,
        "target": 25
      },
      {
        "source": 1,
        "target": 26
      },
      {
        "source": 1,
        "target": 27
      },
      {
        "source": 1,
        "target": 28
      },
      {
        "source": 1,
        "target": 29
      },
      {
        "source": 1,
        "target": 30
      },
      {
        "source": 1,
        "target": 31
      },
      {
        "source": 1,
        "target": 34
      },
      {
        "source": 1,
        "target": 35
      },
      {
        "source": 1,
        "target": 36
      },
      {
        "source": 3,
        "target": 5
      },
      {
        "source": 3,
        "target": 6
      },
      {
        "source": 4,
        "target": 15
      },
      {
        "source": 4,
        "target": 9
      },
      {
        "source": 5,
        "target": 19
      },
      {
        "source": 5,
        "target": 23
      },
      {
        "source": 6,
        "target": 18
      },
      {
        "source": 6,
        "target": 20
      },
      {
        "source": 7,
        "target": 22
      },
      {
        "source": 8,
        "target": 37
      },
      {
        "source": 8,
        "target": 3
      },
      {
        "source": 10,
        "target": 11
      },
      {
        "source": 17,
        "target": 21
      }, {
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        "target": 13
      }, {
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        "target": 14
      }, {
        "source": 19,
        "target": 33
      }, {
        "source": 19,
        "target": 38
      }, {
        "source": 23,
        "target": 2
      }, {
        "source": 25,
        "target": 10
      }, {
        "source": 28,
        "target": 4
      }, {
        "source": 28,
        "target": 17
      }, {
        "source": 29,
        "target": 32
      }, {
        "source": 32,
        "target": 25
      }, {
        "source": 34,
        "target": 24
      }, {
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        "target": 8
      }, {
        "source": 35,
        "target": 16
      }, {
        "source": 37,
        "target": 7
      }, {
        "source": 37,
        "target": 12
      }
    ],
    "multigraph": false
  }

  return jsonobj
}

html,
    body,
    #map {
      width: 100%;
      height: 100%;
      margin: 0;
      padding: 0;
    }

<script src="https://unpkg.com/[email protected]/dist/d3.min.js"></script>
 <script type="text/javascript" src="http://maps.google.com/maps/api/js?&libraries=geometry"></script>     

<body>
<div id="map"></div>
</body>