turf-inside
Checks to see if a point is inside of a polygon. The polygon can be convex or concave. The function accepts any valid polygon or multipolygon and accounts for holes.
<!doctype html>
<html lang="en">
<head>
<link rel="stylesheet" href="https://rawcdn.githack.com/openlayers/openlayers.github.io/master/en/v5.3.0/css/ol.css" type="text/css">
<link rel="stylesheet" href="assets/css/styles.css" type="text/css">
<script src="//cdn.jsdelivr.net/npm/@turf/turf@5/turf.min.js"></script>
<script src="https://rawcdn.githack.com/openlayers/openlayers.github.io/master/en/v5.3.0/build/ol.js" type="text/javascript"></script>
<script src="assets/js/helpers.js"></script>
<title>Turf and OpenLayers 3 - Inside</title>
</head>
<body>
<div id="map" class="map"></div>
<button id="drawtoggle" data-toggle="false" type="button">
Activate/Desactivate drawing
</button>
<script type="text/javascript">
// Declare a source for points and drawing
var vectorSource = new ol.source.Vector();
var vectorSourceDrawing = new ol.source.Vector();
// Create a style function for coloring points
var pointStyles = (function() {
var defaultStyle = [
new ol.style.Style({
image: new ol.style.Circle({
stroke: new ol.style.Stroke({
color: 'white'
}),
fill: new ol.style.Fill({
color: '#1f6b75'
}),
radius: 4
})
})
];
var ruleStyle = [new ol.style.Style({
image: new ol.style.Circle({
stroke: new ol.style.Stroke({
color: 'white'
}),
fill: new ol.style.Fill({
color: 'red'
}),
radius: 5
})
})];
return function(feature, resolution) {
var isInside = feature.get('isInside');
if (isInside != undefined && isInside === true) {
return ruleStyle;
} else {
return defaultStyle;
}
};
})();
// Declare vector layers, one for points and the other for the drawing
var vectorLayer = new ol.layer.Vector({
source: vectorSource,
style: pointStyles
});
var vectorLayerDrawing = new ol.layer.Vector({
source: vectorSourceDrawing
});
// Instanciate a map and add layers
var map = new ol.Map({
target: 'map',
layers: [
new ol.layer.Tile({
source: new ol.source.OSM()
}),
vectorLayer,
vectorLayerDrawing
],
view: new ol.View({
center: ol.proj.fromLonLat([-1.5603, 47.2383]),
zoom: 11
})
});
// Generate and add random features
var newfeatures = (new ol.format.GeoJSON()).readFeatures(
turf.random('point', 50, {
bbox: ol.proj.transformExtent(map.getView().calculateExtent(map.getSize()), 'EPSG:3857', 'EPSG:4326')
}), {
featureProjection: 'EPSG:3857'
}
);
vectorSource.addFeatures(newfeatures);
// Create a button and bind a click function
var button = document.getElementById('drawtoggle');
var draw;
button.addEventListener('click', function(e) {
var toggleState = this.getAttribute('data-toggle');
// Some issues due to type. Can't use !toggleState to go back and forth
// between true and false (type not boolean but string)
// Remove drawing interaction if true
if (toggleState === 'true') {
this.setAttribute('data-toggle', 'false');
map.removeInteraction(draw);
} else {
this.setAttribute('data-toggle', 'true');
// Assign draw interaction (variable created before for scope reason)
draw = new ol.interaction.Draw({
source: vectorSourceDrawing,
type: 'Polygon'
});
// Bind event on the draw component
draw.on('drawend', function(e) {
// Remove immediately other features for demo purpose
vectorSourceDrawing.clear();
var formatDraw = new ol.format.GeoJSON();
var featureDraw = formatDraw.writeFeature(e.feature, {
featureProjection: 'EPSG:3857'
});
// Loop on features
vectorSource.getFeatures().forEach(function(el) {
var feat = formatDraw.writeFeature(el, {
featureProjection: 'EPSG:3857'
});
// Below function can be replaced with ol.extent.intersects
// if drawing a bounding box
var isInside = turf.inside(JSON.parse(feat), JSON.parse(featureDraw));
el.set('isInside', isInside);
});
});
// Add the interaction to the map
map.addInteraction(draw);
}
});
</script>
</body>
</html>