node-red-contrib-tak-registration
Version:
A Node-RED node to register to TAK and to help wrap files as datapackages to send to TAK
63 lines (56 loc) • 1.9 kB
JavaScript
import join from "./join.js";
// Given an extracted (pre-)topology, cuts (or rotates) arcs so that all shared
// point sequences are identified. The topology can then be subsequently deduped
// to remove exact duplicate arcs.
export default function(topology) {
var junctions = join(topology),
coordinates = topology.coordinates,
lines = topology.lines,
rings = topology.rings,
next,
i, n;
for (i = 0, n = lines.length; i < n; ++i) {
var line = lines[i],
lineMid = line[0],
lineEnd = line[1];
while (++lineMid < lineEnd) {
if (junctions.has(coordinates[lineMid])) {
next = {0: lineMid, 1: line[1]};
line[1] = lineMid;
line = line.next = next;
}
}
}
for (i = 0, n = rings.length; i < n; ++i) {
var ring = rings[i],
ringStart = ring[0],
ringMid = ringStart,
ringEnd = ring[1],
ringFixed = junctions.has(coordinates[ringStart]);
while (++ringMid < ringEnd) {
if (junctions.has(coordinates[ringMid])) {
if (ringFixed) {
next = {0: ringMid, 1: ring[1]};
ring[1] = ringMid;
ring = ring.next = next;
} else { // For the first junction, we can rotate rather than cut.
rotateArray(coordinates, ringStart, ringEnd, ringEnd - ringMid);
coordinates[ringEnd] = coordinates[ringStart];
ringFixed = true;
ringMid = ringStart; // restart; we may have skipped junctions
}
}
}
}
return topology;
}
function rotateArray(array, start, end, offset) {
reverse(array, start, end);
reverse(array, start, start + offset);
reverse(array, start + offset, end);
}
function reverse(array, start, end) {
for (var mid = start + ((end-- - start) >> 1), t; start < mid; ++start, --end) {
t = array[start], array[start] = array[end], array[end] = t;
}
}