Ask a parked Navara globe for no frames and guard parked engines in the switch gate

The Navara look stopped requesting frames once its globe is parked. scripts/qa-app-once.mjs now fails if anything moves a parked engine's camera or asks it to draw (its own resume aside).

scripts/qa-app-once.mjs

@@ -166,9 +166,51 @@ try {
   report.uiBefore = uiBefore;
 
   const sequence = ['navara', 'cesium', 'navara', 'cesium', 'navara', 'cesium'];
+  // Dev guard: once an engine is parked, nothing may move its camera or
+  // ask it to draw until it is attached again (its own resume aside).
+  await page.evaluate(() => {
+    window.__qaParkedCalls = [];
+    window.__qaWatchParked = (engine) => {
+      if (!engine || engine.__qaWatched) return;
+      engine.__qaWatched = true;
+      const watch = (owner, names, label) => {
+        for (const name of names) {
+          const original = owner[name];
+          if (typeof original !== 'function') continue;
+          owner[name] = function (...args) {
+            const parked = window.__godsEyeView?.engine !== engine;
+            const resume = name === 'request' && args[0] === 'engine-resume';
+            if (parked && !resume && !window.__qaSwitching)
+              window.__qaParkedCalls.push({
+                call: `${engine.kind}.${label}.${name}`,
+                reason: typeof args[0] === 'string' ? args[0] : null,
+                stack: new Error().stack.split('\n').slice(2, 6).join(' | '),
+              });
+            return original.apply(this, args);
+          };
+        }
+      };
+      watch(
+        engine.camera,
+        ['setView', 'flyTo', 'lookAt', 'flyToBoundingSphere', 'release'],
+        'camera',
+      );
+      watch(engine.render, ['request', 'setContinuous'], 'render');
+    };
+    window.__qaWatchParked(window.__godsEyeView.engine);
+  });
   for (const kind of sequence) {
     const started = Date.now();
+    // The switch itself parks and resumes engines; only the time an engine
+    // sits parked is watched.
+    await page.evaluate(() => {
+      window.__qaSwitching = true;
+    });
     await switchEngine(page, kind);
+    await page.evaluate(() => {
+      window.__qaSwitching = false;
+      window.__qaWatchParked(window.__godsEyeView.engine);
+    });
     const state = await readSession(page);
     const ui = await readUi(page);
     if (kind === 'navara')
@@ -251,6 +293,12 @@ try {
     'each switch detaches once and attaches once',
     after.counters,
   );
+  report.parkedEngineCalls = await page.evaluate(() => window.__qaParkedCalls);
+  check(
+    report.parkedEngineCalls.length === 0,
+    'a parked engine had its camera moved or a frame requested',
+    report.parkedEngineCalls,
+  );
   check(
     after.counters?.applications === 1,
     'the application must be created once',

src/globe/navara/index.js

@@ -114,6 +114,8 @@ export async function createNavaraGlobe({
   let look;
   let removeLook = null;
   let removePostSampling = null;
+  // Parked for a switch back: its render loop is off (setRenderLoop).
+  let parked = false;
   try {
     view = new ThreeView(navaraViewOptions({ container, canvas, pixelRatio }));
     const plugin = new DefaultPlugin();
@@ -165,7 +167,9 @@ export async function createNavaraGlobe({
       camera.moveEnd.addEventListener(() => {
         moving = false;
         readGround();
-        engine.render.request('navara-look');
+        // A parked globe (setRenderLoop(false)) draws nothing: its camera
+        // settling asks for no frame.
+        if (!parked) engine.render.request('navara-look');
       }),
       // After the engine's camera sync: before the first frame the camera
       // has no position yet (camera.height() throws).
@@ -188,7 +192,8 @@ export async function createNavaraGlobe({
             ground,
             placed ? lookPlace : null,
             landscape,
-          )
+          ) &&
+          !parked
         )
           engine.render.request('navara-look');
       }),
@@ -219,7 +224,10 @@ export async function createNavaraGlobe({
       look.resetDaylight();
       engine.render.request('restored-daylight');
     },
-    setRenderLoop: (enabled) => setRenderLoopEnabled(view, enabled),
+    setRenderLoop: (enabled) => {
+      parked = !enabled;
+      setRenderLoopEnabled(view, enabled);
+    },
     destroy() {
       if (destroyed) return;
       destroyed = true;