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read and set features in custom tileLoadFunction

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This commit is contained in:
mike-000
2020-04-17 00:01:28 +01:00
committed by GitHub
parent 7d2e367fd0
commit 71b866947f
1 changed files with 24 additions and 26 deletions
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50
examples/geojson-vt.js
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@@ -72,37 +72,35 @@ fetch(url)
extent: 4096,
debug: 1,
});
const vectorSource = new VectorTileSource({
format: new GeoJSON({
// Data returned from geojson-vt is in tile pixel units
dataProjection: new Projection({
code: 'TILE_PIXELS',
units: 'tile-pixels',
extent: [0, 0, 4096, 4096],
}),
const format = new GeoJSON({
// Data returned from geojson-vt is in tile pixel units
dataProjection: new Projection({
code: 'TILE_PIXELS',
units: 'tile-pixels',
extent: [0, 0, 4096, 4096],
}),
});
const vectorSource = new VectorTileSource({
tileUrlFunction: function (tileCoord) {
// Use the tile coordinate as a pseudo URL for caching purposes
return JSON.stringify(tileCoord);
},
});
// For tile loading obtain the GeoJSON for the tile coordinate
// before calling the default tileLoadFunction
const defaultTileLoadFunction = vectorSource.getTileLoadFunction();
vectorSource.setTileLoadFunction(function (tile, url) {
const tileCoord = JSON.parse(url);
const data = tileIndex.getTile(tileCoord[0], tileCoord[1], tileCoord[2]);
const geojson = JSON.stringify(
{
type: 'FeatureCollection',
features: data ? data.features : [],
},
replacer
);
defaultTileLoadFunction(
tile,
'data:application/json;charset=UTF-8,' + geojson
);
tileLoadFunction: function (tile, url) {
const tileCoord = JSON.parse(url);
const data = tileIndex.getTile(tileCoord[0], tileCoord[1], tileCoord[2]);
const geojson = JSON.stringify(
{
type: 'FeatureCollection',
features: data ? data.features : [],
},
replacer
);
const features = format.readFeatures(geojson, {
extent: vectorSource.getTileGrid().getTileCoordExtent(tileCoord),
featureProjection: map.getView().getProjection()
});
tile.setFeatures(features);
},
});
const vectorLayer = new VectorTileLayer({
source: vectorSource,