
File name
Commit message
Commit date
File name
Commit message
Commit date
File name
Commit message
Commit date
File name
Commit message
Commit date
import bisect from "./bisect.js";
export default function(objects) {
var indexesByArc = {}, // arc index -> array of object indexes
neighbors = objects.map(function() { return []; });
function line(arcs, i) {
arcs.forEach(function(a) {
if (a < 0) a = ~a;
var o = indexesByArc[a];
if (o) o.push(i);
else indexesByArc[a] = [i];
});
}
function polygon(arcs, i) {
arcs.forEach(function(arc) { line(arc, i); });
}
function geometry(o, i) {
if (o.type === "GeometryCollection") o.geometries.forEach(function(o) { geometry(o, i); });
else if (o.type in geometryType) geometryType[o.type](o.arcs, i);
}
var geometryType = {
LineString: line,
MultiLineString: polygon,
Polygon: polygon,
MultiPolygon: function(arcs, i) { arcs.forEach(function(arc) { polygon(arc, i); }); }
};
objects.forEach(geometry);
for (var i in indexesByArc) {
for (var indexes = indexesByArc[i], m = indexes.length, j = 0; j < m; ++j) {
for (var k = j + 1; k < m; ++k) {
var ij = indexes[j], ik = indexes[k], n;
if ((n = neighbors[ij])[i = bisect(n, ik)] !== ik) n.splice(i, 0, ik);
if ((n = neighbors[ik])[i = bisect(n, ij)] !== ij) n.splice(i, 0, ij);
}
}
}
return neighbors;
}