From d872ca6f320cc545eb7b890fd0e1134c54a3ad9d Mon Sep 17 00:00:00 2001
From: que01 <que01@foxmail.com>
Date: Mon, 27 Jul 2026 14:00:49 +0800
Subject: [PATCH] Make vehicle following opt-in

---
 scripts/build-area.js | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/scripts/build-area.js b/scripts/build-area.js
index cd53a28..0961ac1 100755
--- a/scripts/build-area.js
+++ b/scripts/build-area.js
@@ -496,6 +496,7 @@ function cesiumPreviewHtml(glbName, metadataName, routeName, areaId) {
   <div id="cesiumContainer"></div>
   <div id="controls">
     <button id="toggleCruise">Pause</button>
+    <button id="toggleFollow">Follow</button>
     <label>Speed <input id="speedControl" type="range" min="2" max="22" step="1" value="8"></label>
     <span id="speedLabel">8 m/s</span>
   </div>
@@ -503,6 +504,7 @@ function cesiumPreviewHtml(glbName, metadataName, routeName, areaId) {
   <script>
     const statusEl = document.getElementById("status");
     const toggleCruise = document.getElementById("toggleCruise");
+    const toggleFollow = document.getElementById("toggleFollow");
     const speedControl = document.getElementById("speedControl");
     const speedLabel = document.getElementById("speedLabel");
     Cesium.Ion.defaultAccessToken = "";
@@ -626,7 +628,15 @@ function cesiumPreviewHtml(glbName, metadataName, routeName, areaId) {
         viewer.clock.multiplier = value / speed;
         speedLabel.textContent = value + " m/s";
       });
-      viewer.trackedEntity = vehicle;
+      toggleFollow.addEventListener("click", () => {
+        if (viewer.trackedEntity === vehicle) {
+          viewer.trackedEntity = undefined;
+          toggleFollow.textContent = "Follow";
+        } else {
+          viewer.trackedEntity = vehicle;
+          toggleFollow.textContent = "Free";
+        }
+      });
       return { segment, vehicle };
     }