fix: 修正 Cesium 巡航车道中心对齐

scripts/lib/turn-lane-arrows.js

@@ -2,6 +2,7 @@
 
 const fs = require("fs");
 const path = require("path");
+const { laneCenterline } = require("./lane-geometry");
 
 const ASSET_MANIFEST = path.resolve(__dirname, "..", "..", "assets", "lane-icons", "manifest.json");
 const LANE_WIDTH_METERS = 3.2;
@@ -262,23 +263,6 @@ function closestPointOnSegment(point, start, end, meters) {
   return [start[0] + ratio * (end[0] - start[0]), start[1] + ratio * (end[1] - start[1])];
 }
 
-function laneCenterline(lane) {
-  const ring = lane?.geometry?.type === "Polygon" ? lane.geometry.coordinates?.[0] : null;
-  // A straight osm2streets Driving lane is commonly a closed quadrilateral:
-  // four distinct vertices plus the repeated closing vertex. Its opposing
-  // edges still provide the same two-point centerline as longer lane shapes.
-  if (!ring || ring.length < 5) return null;
-  // osm2streets Driving polygons are ordered along one boundary then back
-  // along the other. Midpoints of paired vertices form the rendered lane axis.
-  const vertices = ring.slice(0, -1);
-  const half = vertices.length / 2;
-  if (!Number.isInteger(half) || half < 2) return null;
-  return vertices.slice(0, half).map((point, index) => [
-    (point[0] + vertices[vertices.length - 1 - index][0]) / 2,
-    (point[1] + vertices[vertices.length - 1 - index][1]) / 2,
-  ]);
-}
-
 function axisForLane(ordered, meters) {
   return normalizeMetersVector(subtractPoint(ordered[0], ordered[1]), meters);
 }