103 lines
3.9 KiB
JavaScript
103 lines
3.9 KiB
JavaScript
"use strict";
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function parseOsm(xml) {
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const boundsMatch = xml.match(/<bounds\b([^>]*)\/?\s*>/);
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const boundsAttrs = boundsMatch ? xmlAttrs(boundsMatch[1]) : {};
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const candidateBounds = {
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minLon: Number(boundsAttrs.minlon), minLat: Number(boundsAttrs.minlat),
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maxLon: Number(boundsAttrs.maxlon), maxLat: Number(boundsAttrs.maxlat),
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};
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const bounds = Object.values(candidateBounds).every(Number.isFinite) ? candidateBounds : null;
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const nodes = new Map();
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const trafficSignalControls = [];
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const nodePattern = /<node\b([^>]*?)(?:\/>|>([\s\S]*?)<\/node>)/g;
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for (const match of xml.matchAll(nodePattern)) {
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const attrs = xmlAttrs(match[1]);
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if (attrs.action === "delete" || !attrs.id || attrs.lon === undefined || attrs.lat === undefined) continue;
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const coordinate = [Number(attrs.lon), Number(attrs.lat)];
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if (!coordinate.every(Number.isFinite)) continue;
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nodes.set(attrs.id, coordinate);
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const tags = parseTags(match[2] || "");
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if (tags.highway === "traffic_signals") {
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trafficSignalControls.push({ id: attrs.id, longitude: coordinate[0], latitude: coordinate[1], tags });
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}
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}
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const ways = [];
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for (const match of xml.matchAll(/<way\b([^>]*)>([\s\S]*?)<\/way>/g)) {
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const attrs = xmlAttrs(match[1]);
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if (attrs.action === "delete") continue;
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const body = match[2];
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const refs = [];
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for (const ndMatch of body.matchAll(/<nd\b([^>]*)\/?\s*>/g)) {
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const ref = xmlAttrs(ndMatch[1]).ref;
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if (ref && nodes.has(ref)) refs.push(ref);
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}
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if (refs.length >= 2) ways.push({ id: attrs.id || `way-${ways.length + 1}`, refs, tags: parseTags(body) });
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}
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for (const control of trafficSignalControls) {
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const arms = [];
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for (const way of ways) {
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if (!isMotorRoad(way.tags)) continue;
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for (let index = 0; index < way.refs.length; index += 1) {
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if (way.refs[index] !== control.id) continue;
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for (const neighborIndex of [index - 1, index + 1]) {
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const neighbor = way.refs[neighborIndex];
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if (!neighbor || !nodes.has(neighbor)) continue;
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const neighborPoint = nodes.get(neighbor);
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arms.push({
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headingDegrees: headingBetween(control, neighborPoint),
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wayId: String(way.id),
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neighborNodeId: String(neighbor),
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});
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}
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}
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}
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control.arms = dedupeHeadings(arms);
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control.junctionType = control.arms.length === 3 ? "T" : control.arms.length === 4 ? "cross" : "other";
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}
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return { bounds, nodes, ways, trafficSignalControls };
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}
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function isMotorRoad(tags) {
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const highway = tags.highway || "";
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return highway && tags.area !== "yes" && !new Set([
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"footway", "path", "pedestrian", "steps", "cycleway", "service", "track",
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"bridleway", "corridor", "elevator", "platform", "construction",
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]).has(highway);
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}
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function headingBetween(from, to) {
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const latitude = (from.latitude + to[1]) / 2 * Math.PI / 180;
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return Math.atan2((to[0] - from.longitude) * Math.cos(latitude), to[1] - from.latitude) * 180 / Math.PI;
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}
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function dedupeHeadings(arms) {
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const normalized = (value) => ((value % 360) + 360) % 360;
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const distance = (a, b) => Math.abs(((a - b + 540) % 360) - 180);
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const result = [];
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for (const arm of arms) {
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arm.headingDegrees = normalized(arm.headingDegrees);
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if (!result.some((other) => distance(other.headingDegrees, arm.headingDegrees) <= 25)) result.push(arm);
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}
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return result.sort((a, b) => a.headingDegrees - b.headingDegrees);
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}
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function xmlAttrs(text) {
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const attrs = {};
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for (const match of text.matchAll(/([:\w-]+)\s*=\s*(?:"([^"]*)"|'([^']*)')/g)) {
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attrs[match[1]] = match[2] !== undefined ? match[2] : match[3];
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}
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return attrs;
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}
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function parseTags(body) {
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const tags = {};
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for (const match of body.matchAll(/<tag\b([^>]*)\/?\s*>/g)) {
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const tag = xmlAttrs(match[1]);
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if (tag.k) tags[tag.k] = tag.v || "";
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}
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return tags;
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}
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module.exports = { parseOsm };
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