GeoJSON feature & Mapbox segments
custom JSON format ???
{
"rows": [],
"props": {
"labelPoint": {
"x": 93.5,
"y": 68.0291
},
"type": "",
"fill": "#ffffff"
},
"_type": "",
"graphType": "Polygon",
"graph": {
"points": [
{
"x": 93.5,
"y": 2
},
{
"x": 182.4238,
"y": 52.4418
},
{
"x": 148.4579,
"y": 134.0582
},
{
"x": 38.5421,
"y": 134.0582
},
{
"x": 4.5762,
"y": 52.4418
}
],
"segments": [
{
"p1": {
"x": 93.5,
"y": 2
},
"p2": {
"x": 182.4238,
"y": 52.4418
},
"line": {
"k": 0.5672474635586874,
"b": -51.03763784273727,
"x": null
}
},
{
"p1": {
"x": 182.4238,
"y": 52.4418
},
"p2": {
"x": 148.4579,
"y": 134.0582
},
"line": {
"k": -2.4028923125840915,
"b": 490.7865466523778,
"x": null
}
},
{
"p1": {
"x": 148.4579,
"y": 134.0582
},
"p2": {
"x": 38.5421,
"y": 134.0582
},
"line": {
"k": 0,
"b": 134.0582,
"x": null
}
},
{
"p1": {
"x": 38.5421,
"y": 134.0582
},
"p2": {
"x": 4.5762,
"y": 52.4418
},
"line": {
"k": 2.402892312584092,
"b": 41.44568419915268,
"x": null
}
},
{
"p1": {
"x": 4.5762,
"y": 52.4418
},
"p2": {
"x": 93.5,
"y": 2
},
"line": {
"k": -0.5672474635586874,
"b": 55.03763784273727,
"x": null
}
}
],
"segmentNum": 0,
"middleLine": null,
"fill": "#ffffff"
},
"fill": "#ffffff"
}
geojson-segment
split a geojson file generated by togeojson into two-vertex chunks with properties
$ npm i -S @mapbox/geojson-segment
https://github.com/mapbox/geojson-segment
mapbox demo
https://docs.mapbox.com/mapbox-gl-js/example/data-driven-lines/
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Style lines with a data-driven property</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<script src="https://api.mapbox.com/mapbox-gl-js/v1.8.1/mapbox-gl.js"></script>
<link href="https://api.mapbox.com/mapbox-gl-js/v1.8.1/mapbox-gl.css" rel="stylesheet" />
<style>
body { margin: 0; padding: 0; }
#map { position: absolute; top: 0; bottom: 0; 100%; }
</style>
</head>
<body>
<div id="map"></div>
<script>
mapboxgl.accessToken = 'pk.eyJ1IjoieGdxZnJtcyIsImEiOiJjaXNtbmVrNWMwMW9lMnFteHJlN2M4NWU1In0.USVUsZvLCNUF1dNVuZsO5g';
var map = new mapboxgl.Map({
container: 'map',
style: 'mapbox://styles/mapbox/streets-v11',
center: [-122.48383155304096, 37.82882682974591],
zoom: 16
});
map.on('load', function() {
map.addSource('lines', {
'type': 'geojson',
'data': {
'type': 'FeatureCollection',
'features': [
{
'type': 'Feature',
'properties': {
'color': '#F7455D' // red
},
'geometry': {
'type': 'LineString',
'coordinates': [
[-122.4833858013153, 37.829607404976734],
[-122.4830961227417, 37.82932776098012],
[-122.4830746650696, 37.82932776098012],
[-122.48218417167662, 37.82889558180985],
[-122.48218417167662, 37.82890193740421],
[-122.48221099376678, 37.82868372835086],
[-122.4822163581848, 37.82868372835086],
[-122.48205006122589, 37.82801003030873]
]
}
},
{
'type': 'Feature',
'properties': {
'color': '#33C9EB' // blue
},
'geometry': {
'type': 'LineString',
'coordinates': [
[-122.48393028974533, 37.829471820141016],
[-122.48395174741744, 37.82940826466351],
[-122.48395174741744, 37.829412501697064],
[-122.48423874378203, 37.829357420242125],
[-122.48422533273697, 37.829361657278575],
[-122.48459815979002, 37.8293425906126],
[-122.48458743095398, 37.8293447091313],
[-122.4847564101219, 37.82932776098012],
[-122.48474299907684, 37.829331998018276],
[-122.4849334359169, 37.829298101706186],
[-122.48492807149889, 37.82930022022615],
[-122.48509705066681, 37.82920488676767],
[-122.48509168624878, 37.82920912381288],
[-122.48520433902739, 37.82905870855876],
[-122.48519897460936, 37.82905870855876],
[-122.4854403734207, 37.828594749716714],
[-122.48543500900269, 37.82860534241688],
[-122.48571664094925, 37.82808206121068],
[-122.48570591211319, 37.82809689109353],
[-122.4858346581459, 37.82797189627337],
[-122.48582661151886, 37.82797825194729],
[-122.4859634041786, 37.82788503534145],
[-122.48595803976059, 37.82788927246246],
[-122.48605459928514, 37.82786596829394]
]
}
}
]
}
});
map.addLayer({
'id': 'lines',
'type': 'line',
'source': 'lines',
'paint': {
'line-width': 3,
// Use a get expression (https://docs.mapbox.com/mapbox-gl-js/style-spec/#expressions-get)
// to set the line-color to a feature property value.
'line-color': ['get', 'color']
}
});
});
</script>
</body>
</html>
toFixed
x = "-100";
"-100"
"-100"
+x;
-100
x = -100;
-100
+x.toFixed(4);
-100
x = -100.000000001;
-100.000000001
+x.toFixed(4);
-100
x = 100.00111;
100.00111
+x.toFixed(4);
100.0011
x = -100.00111;
-100.00111
+x.toFixed(4);
-100.0011