Display a TopoJSON file on a Map.

100% © OpenStreetMap contributors.
index.js
import TopoJSON from 'ol/format/TopoJSON.js';
import OSM from 'ol/source/OSM.js';
import { Fill, Stroke, Style } from 'ol/style.js';

import { MapControls } from 'three/examples/jsm/controls/MapControls.js';
import { CSS2DObject } from 'three/examples/jsm/renderers/CSS2DRenderer.js';

import ColorLayer from '@giro3d/giro3d/core/layer/ColorLayer.js';
import Extent from '@giro3d/giro3d/core/geographic/Extent.js';
import Instance from '@giro3d/giro3d/core/Instance.js';
import Map from '@giro3d/giro3d/entities/Map.js';
import VectorSource from '@giro3d/giro3d/sources/VectorSource.js';
import Inspector from '@giro3d/giro3d/gui/Inspector.js';
import TiledImageSource from '@giro3d/giro3d/sources/TiledImageSource.js';
import Coordinates from '@giro3d/giro3d/core/geographic/Coordinates.js';

Instance.registerCRS(
    'EPSG:30174',
    '+proj=tmerc +lat_0=26 +lon_0=142 +k=0.9999 +x_0=0 +y_0=0 +ellps=bessel +towgs84=-146.414,507.337,680.507,0,0,0,0 +units=m +no_defs +type=crs',
);

// Defines geographic extent: CRS, min/max X, min/max Y
const extent = new Extent(
    'EPSG:30174',
    -201012.900985493,
    -198191.63799031873,
    1066954.2964232096,
    1071890.8856167798,
);

// `viewerDiv` will contain Giro3D' rendering area (the canvas element)
const viewerDiv = document.getElementById('viewerDiv');

// Creates a Giro3D instance
const instance = new Instance(viewerDiv, {
    crs: extent.crs(),
});

// Instanciates camera
const center = extent.centerAsVector2();
instance.camera.camera3D.position.set(center.x, center.y - 1, 2000);

// Instanciates controls
const controls = new MapControls(instance.camera.camera3D, instance.domElement);
controls.enableDamping = true;
controls.dampingFactor = 0.25;

instance.useTHREEControls(controls);

// target
controls.target.set(center.x, center.y, 0);

// Adds layers in a map

const map = new Map('planar', { extent, backgroundColor: '#135D66' });
instance.add(map);

const buildingsStyle = feature => {
    const highlight = feature.get('highlight');
    const stroke = highlight
        ? new Stroke({
              color: 'white',
              width: 2,
          })
        : undefined;

    return new Style({
        zIndex: highlight ? 1 : 0,
        fill: new Fill({
            color: highlight ? 'green' : 'red',
        }),
        stroke,
    });
};

const buildingsLayer = new ColorLayer({
    name: 'Buildings',
    extent,
    source: new VectorSource({
        format: new TopoJSON(),
        data: 'https://3d.oslandia.com/giro3d/vectors/tokyo_buildings.topojson',
        dataProjection: 'EPSG:4326',
        style: buildingsStyle,
    }),
});

// Create the OpenStreetMap color layer using an OpenLayers source.
// See https://openlayers.org/en/latest/apidoc/module-ol_source_OSM-OSM.html
// for more informations.
const osm = new ColorLayer({
    name: 'osm',
    source: new TiledImageSource({ source: new OSM() }),
    extent,
});

map.addLayer(osm);
map.addLayer(buildingsLayer);

const labelElement = document.createElement('span');
labelElement.classList = 'badge rounded-pill text-bg-light';
labelElement.style.marginTop = '2rem';
const label = new CSS2DObject(labelElement);

label.visible = false;
instance.add(label);

let previousFeature;

function pickFeatures(mouseEvent) {
    const pickResult = instance.pickObjectsAt(mouseEvent, {
        radius: 0,
    });

    const picked = pickResult.at(0);

    previousFeature?.set('highlight', false);

    function resetPickedFeatures() {
        previousFeature = null;
        if (label.visible) {
            instance.notifyChange(map);
            label.visible = false;
        }
    }

    if (picked) {
        const { x, y } = picked.point;
        const features = buildingsLayer.getVectorFeaturesAtCoordinate(
            new Coordinates(instance.referenceCrs, x, y),
        );

        if (features.length > 0) {
            const firstFeature = features[0];

            firstFeature.set('highlight', true);

            previousFeature = firstFeature;

            instance.notifyChange(map);
            label.position.set(x, y, 100);
            label.visible = true;
            label.element.innerText = firstFeature.get('osm_id');
            label.updateMatrixWorld(true);
        } else {
            resetPickedFeatures();
        }
    } else {
        resetPickedFeatures();
    }
}

instance.domElement.addEventListener('mousemove', pickFeatures);
Inspector.attach(document.getElementById('panelDiv'), instance);
instance.domElement.addEventListener('dblclick', e => console.log(instance.pickObjectsAt(e)));

instance.notifyChange(map);
index.html
<!doctype html>
<html lang="en">
    <head>
        <title>TopoJSON</title>
        <meta charset="UTF-8" />
        <meta name="name" content="ol_vector_topojson" />
        <meta name="description" content="Display a TopoJSON file on a Map." />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />

        <link rel="icon" href="https://giro3d.org/images/favicon.svg" />
        <link href="https://giro3d.org/assets/bootstrap-custom.css" rel="stylesheet" />
        <script src="https://giro3d.org/assets/bootstrap.bundle.min.js"></script>
        <link
            rel="stylesheet"
            type="text/css"
            href="https://giro3d.org/latest/css/example.css"
        />

        
    </head>

    <body>
        <div id="viewerDiv" class="m-0 p-0 w-100 h-100"></div>
        <div id="panelDiv" class="position-absolute top-0 start-0 mh-100 overflow-auto"></div>

        

        <script type="module" src="index.js"></script>
        <script>
            /* activate popovers */
            const popoverTriggerList = [].slice.call(
                document.querySelectorAll('[data-bs-toggle="popover"]'),
            );
            popoverTriggerList.map(
                // bootstrap is used as script in the template, disable warning about undef
                // eslint-disable-next-line no-undef
                popoverTriggerEl =>
                    new bootstrap.Popover(popoverTriggerEl, {
                        trigger: 'hover',
                        placement: 'left',
                        content: document.getElementById(
                            popoverTriggerEl.getAttribute('data-bs-content'),
                        ).innerHTML,
                        html: true,
                    }),
            );
        </script>
    </body>
</html>
package.json
{
    "name": "ol_vector_topojson",
    "dependencies": {
        "@giro3d/giro3d": "0.37.2"
    },
    "devDependencies": {
        "vite": "^3.2.3"
    },
    "scripts": {
        "start": "vite",
        "build": "vite build"
    }
}