Merge pull request #951 from bilawalsidhu/fix/live-aircraft-initial-position

fix: start new live aircraft at their delayed display position

src/data/flights.test.mjs

@@ -168,6 +168,77 @@ test('nonempty OpenSky payload with zero usable rows cannot prove share target a
   }
 });
 
+test('a newly seen aircraft appears at its delayed position, not ahead of it', async () => {
+  // The fleet renders RENDER_DELAY_SEC behind real time, so a fresh contact's
+  // first displayed position is its fix projected back to that delayed time.
+  // Creating the billboard at the raw fix drew it ahead until the next fleet
+  // tick, which then jumped it back about one delay of travel.
+  const added = [];
+  const billboardCollection = {
+    show: false,
+    add(options) {
+      const billboard = { ...options };
+      added.push(billboard);
+      return billboard;
+    },
+    remove() {},
+  };
+  const viewer = { camera: { positionCartographic: null }, scene: {} };
+  _setTrackedFlightRefreshStateForTest({
+    icao24: 'seed00',
+    entity: null,
+    billboard: { show: false, position: Cesium.Cartesian3.fromDegrees(0, 0, 0) },
+    billboardCollection,
+    viewer,
+    meta: { rawLat: 0, rawLon: 0, onGround: false },
+    tracked: false,
+  });
+  const icao24 = 'fresh1';
+  const fixLon = -97.6;
+  const fixLat = 30.3;
+  const speedMps = 250;
+  const nowSec = Math.floor(Date.now() / 1000);
+  const realFetch = globalThis.fetch;
+  globalThis.fetch = async (url) => {
+    if (!String(url).startsWith('/api/flights')) {
+      return { ok: true, status: 200, json: async () => ({ ac: [] }) };
+    }
+    return {
+      ok: true,
+      status: 200,
+      headers: { get: () => null },
+      json: async () => ({
+        time: nowSec,
+        states: [[
+          icao24, 'NEW123 ', 'United States', nowSec - 2, nowSec - 2,
+          fixLon, fixLat, 10_668, false, speedMps, 90, 0, null, 10_700,
+          null, null, null, 5,
+        ]],
+      }),
+    };
+  };
+  try {
+    await flightsLayer.update(viewer);
+    const billboard = added.find((entry) => entry.id === icao24);
+    assert.ok(billboard, 'the new contact gets a billboard');
+    const shown = Cesium.Cartographic.fromCartesian(billboard.position);
+    const fix = Cesium.Cartesian3.fromDegrees(fixLon, fixLat, 10_700);
+    const behindM = Cesium.Cartesian3.distance(
+      Cesium.Cartesian3.fromRadians(shown.longitude, shown.latitude, 10_700),
+      fix,
+    );
+    // Eastbound, so the delayed position is west of the fix by the travel
+    // between the delayed time and the fix (about 28 s).
+    assert.ok(Cesium.Math.toDegrees(shown.longitude) < fixLon, 'drawn behind the fix');
+    assert.ok(
+      behindM > speedMps * 25 && behindM < speedMps * 31,
+      `expected about ${speedMps * 28} m behind the fix, got ${Math.round(behindM)} m`,
+    );
+  } finally {
+    globalThis.fetch = realFetch;
+  }
+});
+
 test('flights poll refreshes tracked callsign/FL/kts and marks a missed poll STALE', async () => {
   const icao24 = 'a1b2c3';
   const entity = { gevLabelModel: { title: 'OLD', details: [] } };

src/layers/flights/snapshotRenderer.js

@@ -179,8 +179,14 @@ export function createFlightSnapshotRenderer({
         // as the enrichment path — the class's GLB/scale may have changed.
         if (prevMeta?.klass !== meta.klass) rendering._syncModelToClass(icao24);
       } else {
+        // Start where the fleet pass will draw it: the fleet renders behind
+        // real time, so a fresh contact's displayed position is its fix
+        // projected back to that delayed time. Creating it at the raw fix drew
+        // it ahead until the next fleet tick snapped it back.
+        const displayed =
+          motion._deadReckon(icao24, new Cesium.Cartesian3()) || position;
         const bb = flightState._billboardCollection.add({
-          position,
+          position: displayed,
           image: aircraftIcon(rendering._iconKind(icao24, meta.klass)),
           width: isTracked ? 24 : 20,
           height: isTracked ? 24 : 20,

src/layers/military/index.js

@@ -33,6 +33,7 @@ export function createMilitaryFlightLayer({
     militaryRegistry: services.militaryRegistry,
     rendering: parts.rendering,
     tracking: parts.tracking,
+    motion: parts.motion,
     queries: parts.queries,
   });
   parts.ingestion = createIngestion({

src/layers/military/ownership.test.mjs

@@ -113,3 +113,101 @@ test('a normalized source can retain its stale reason without changing standalon
   assert.equal(layer.getStats().error, null);
   assert.equal(layer.getStats().stale, true);
 });
+
+test('a newly seen military contact appears at its delayed position, not ahead of it', async () => {
+  // The military fleet renders RENDER_DELAY_SEC behind real time, so a fresh
+  // contact's first displayed position is its fix projected back to that
+  // delayed time. Creating the billboard at the raw fix drew it ahead until
+  // the next fleet tick jumped it back.
+  const Cesium = await import('cesium');
+  const { RENDER_DELAY_SEC } = await import('./policy.js');
+  // The application's own scene services, as src/app/layers/militaryFlights.js
+  // composes them; only the surface samplers and registry are stubbed.
+  const supplied = {
+    picking: await import('../../data/pickRegistry.js'),
+    sprites: await import('../../data/spriteOrder.js'),
+    trails: await import('../../data/trailRenderer.js'),
+    aircraftPresentation: await import('../../data/tr3bRegistry.js'),
+    camera: await import('../../data/trackedCamera.js'),
+    labels: await import('../../data/detectionDraw.js'),
+    geoid: await import('../../data/geoid.js'),
+    focus: await import('../../data/focusDeemphasis.js'),
+    readout: await import('../../data/trackedReadout.js'),
+    context: await import('../../data/contextStore.js'),
+    render: await import('../../renderGovernor.js'),
+    recession: await import('../../data/aircraftRecession.js'),
+    groundFloor: await import('../../data/groundFloor.js'),
+    groundSnap: await import('../../data/groundSnap.js'),
+    meshFloor: { sampleMeshFloorCells: () => {} },
+    militaryRegistry: { registerMilitaryIcaos: () => {} },
+  };
+  const fixLon = -97.6;
+  const fixLat = 30.3;
+  const speedMps = 200;
+  const fixAgeMs = 2_000;
+  const nowMs = Date.now();
+  const layer = createMilitaryFlightLayer({
+    services: supplied,
+    source: {
+      label: 'Fixture aircraft',
+      async getSnapshot() {
+        return {
+          source: 'Fixture aircraft',
+          complete: true,
+          observedAtMs: nowMs,
+          records: [
+            {
+              id: 'ae0001',
+              latitude: fixLat,
+              longitude: fixLon,
+              onGround: false,
+              baroAltitudeM: 9_000,
+              courseDeg: 90,
+              speedMps,
+              positionTimeMs: nowMs - fixAgeMs,
+              contactTimeMs: nowMs - fixAgeMs,
+            },
+          ],
+        };
+      },
+    },
+  });
+  const added = [];
+  layer.testing._setTrackedMilitaryRefreshStateForTest({
+    icao24: 'seed00',
+    entity: null,
+    meta: { rawLat: 0, rawLon: 0, onGround: false },
+    billboard: {
+      show: false,
+      position: Cesium.Cartesian3.fromDegrees(0, 0, 0),
+    },
+    billboardCollection: {
+      show: false,
+      add(options) {
+        const billboard = { ...options };
+        added.push(billboard);
+        return billboard;
+      },
+      remove() {},
+    },
+    viewer: { camera: { positionCartographic: null }, scene: {} },
+    tracked: false,
+  });
+  await layer.update({ camera: { positionCartographic: null }, scene: {} });
+  const billboard = added.find((entry) => entry.id === 'ae0001');
+  assert.ok(billboard, 'the new contact gets a billboard');
+  const shown = Cesium.Cartographic.fromCartesian(billboard.position);
+  const behindM = Cesium.Cartesian3.distance(
+    Cesium.Cartesian3.fromRadians(shown.longitude, shown.latitude, 0),
+    Cesium.Cartesian3.fromDegrees(fixLon, fixLat, 0),
+  );
+  const expectedM = speedMps * (RENDER_DELAY_SEC - fixAgeMs / 1000);
+  assert.ok(
+    Cesium.Math.toDegrees(shown.longitude) < fixLon,
+    'drawn behind the fix',
+  );
+  assert.ok(
+    Math.abs(behindM - expectedM) < speedMps * 3,
+    `expected about ${Math.round(expectedM)} m behind the fix, got ${Math.round(behindM)} m`,
+  );
+});

src/layers/military/snapshotRenderer.js

@@ -23,6 +23,7 @@ export function createMilitarySnapshotRenderer({
   militaryRegistry,
   rendering,
   tracking,
+  motion,
   queries,
 }) {
   const { warmGroundFloor, cachedGroundFloor, GROUND_FLOOR_LIFT_M } =
@@ -142,8 +143,14 @@ export function createMilitarySnapshotRenderer({
         // Round 5: depth policy is uniform (always depth-test-free, see
         // _groundDepthDistance) — nothing to flip on landing/takeoff.
       } else {
+        // Start where the fleet pass will draw it: the fleet renders behind
+        // real time, so a fresh contact's displayed position is its fix
+        // projected back to that delayed time. Creating it at the raw fix drew
+        // it ahead until the next fleet tick snapped it back.
+        const displayed =
+          motion._deadReckon(icao24, new Cesium.Cartesian3()) || position;
         const bb = flightState._billboardCollection.add({
-          position,
+          position: displayed,
           image: aircraftIcon(rendering._iconKind(icao24, meta.klass)),
           width: isTracked ? 24 : 20,
           height: isTracked ? 24 : 20,