@loaders.gl/mvt
Version:
Loader for Mapbox Vector Tiles
53 lines • 1.73 kB
JavaScript
// loaders.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors
// Forked from https://github.com/mapbox/geojson-vt under compatible ISC license
export function createProtoFeature(id, type, geometry, tags) {
const feature = {
// eslint-disable-next-line
id: id == null ? null : id,
type,
simplifiedType: undefined, // TODO
geometry,
tags,
minX: Infinity,
minY: Infinity,
maxX: -Infinity,
maxY: -Infinity
};
// TODO break out into separate function
switch (type) {
case 'Point':
case 'MultiPoint':
case 'LineString':
calcLineBBox(feature, geometry);
break;
case 'MultiLineString':
for (const line of geometry) {
calcLineBBox(feature, line);
}
break;
case 'Polygon':
// the outer ring (ie [0]) contains all inner rings
calcLineBBox(feature, geometry[0]);
break;
case 'MultiPolygon':
for (const polygon of geometry) {
// the outer ring (ie [0]) contains all inner rings
calcLineBBox(feature, polygon[0]);
}
break;
default:
throw new Error(String(type));
}
return feature;
}
function calcLineBBox(feature, geometry) {
for (let i = 0; i < geometry.length; i += 3) {
feature.minX = Math.min(feature.minX, geometry[i]);
feature.minY = Math.min(feature.minY, geometry[i + 1]);
feature.maxX = Math.max(feature.maxX, geometry[i]);
feature.maxY = Math.max(feature.maxY, geometry[i + 1]);
}
}
//# sourceMappingURL=proto-feature.js.map