fix(missions): throttle hover picks and clear stale cursors

docs/CURRENT-STATE.md

@@ -1,5 +1,7 @@
 # God's Eye View Current State
 
+Mission hover picking is limited to one drill-pick per 120 ms and suppressed during camera movement, hidden tabs, disabled layers, and pointer-owned tools. Motion, hiding, disable, and destroy clear the cursor. Click selection keeps its full overlap-aware drill-pick behavior.
+
 Shared distance checks use `src/geoDistance.js` with `{ lat, lon }` points and
 the IUGG mean spherical Earth radius, 6371.0088 km. `greatCircleKm` is
 canonical; `greatCircleMeters` is its exact metre conversion. Missing,

src/layers/launches/hover.test.mjs

@@ -0,0 +1,91 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { Event } from 'cesium';
+import { createLaunchHover } from './lifecycle.js';
+
+test('mission hover throttles, clears on motion/hidden, and releases listeners', () => {
+  let at = 0,
+    picks = 0,
+    enabled = true;
+  const listeners = new Set();
+  const doc = {
+    hidden: false,
+    addEventListener: (_n, fn) => listeners.add(fn),
+    removeEventListener: (_n, fn) => listeners.delete(fn),
+  };
+  const viewer = {
+    camera: { moveStart: new Event(), moveEnd: new Event() },
+    scene: {
+      canvas: { style: {} },
+      drillPick() {
+        picks++;
+        return [{ id: 'launch' }];
+      },
+    },
+  };
+  const hover = createLaunchHover({
+    viewer,
+    enabled: () => enabled,
+    entityLaunchId: (id) => id === 'launch',
+    now: () => at,
+    documentRef: doc,
+    pointerFree: () => true,
+  });
+  for (at = 0; at < 120; at++) hover.move({ endPosition: {} });
+  assert.equal(picks, 1);
+  assert.equal(viewer.scene.canvas.style.cursor, 'pointer');
+  hover.move({ endPosition: {} });
+  assert.equal(picks, 2);
+  viewer.camera.moveStart.raiseEvent();
+  at = 500;
+  hover.move({ endPosition: {} });
+  assert.equal(picks, 2);
+  assert.equal(viewer.scene.canvas.style.cursor, '');
+  viewer.camera.moveEnd.raiseEvent();
+  hover.move({ endPosition: {} });
+  assert.equal(picks, 3);
+  doc.hidden = true;
+  for (const fn of listeners) fn();
+  hover.move({ endPosition: {} });
+  assert.equal(picks, 3);
+  assert.equal(viewer.scene.canvas.style.cursor, '');
+  doc.hidden = false;
+  enabled = false;
+  hover.move({ endPosition: {} });
+  assert.equal(picks, 3);
+  hover.destroy();
+  assert.equal(listeners.size, 0);
+  assert.equal(viewer.camera.moveStart.numberOfListeners, 0);
+  assert.equal(viewer.camera.moveEnd.numberOfListeners, 0);
+});
+
+test('mission hover preserves the cursor of a pointer-owning tool', () => {
+  let free = true,
+    picks = 0;
+  const viewer = {
+    camera: { moveStart: new Event(), moveEnd: new Event() },
+    scene: {
+      canvas: { style: { cursor: '' } },
+      drillPick() {
+        picks++;
+        return [{ id: 'launch' }];
+      },
+    },
+  };
+  const hover = createLaunchHover({
+    viewer,
+    enabled: () => true,
+    entityLaunchId: () => true,
+    documentRef: null,
+    pointerFree: () => free,
+  });
+  hover.move({ endPosition: {} });
+  assert.equal(viewer.scene.canvas.style.cursor, 'pointer');
+  free = false;
+  viewer.scene.canvas.style.cursor = 'crosshair';
+  hover.move({ endPosition: {} });
+  viewer.camera.moveStart.raiseEvent();
+  hover.destroy();
+  assert.equal(picks, 1);
+  assert.equal(viewer.scene.canvas.style.cursor, 'crosshair');
+});

src/layers/launches/lifecycle.js

@@ -1,6 +1,75 @@
 import * as Cesium from 'cesium';
 import { isPointerFree } from '../../data/inputOwnership.js';
 
+/** Bound hover picking independently of precise click selection. */
+export function createLaunchHover({
+  viewer,
+  enabled,
+  entityLaunchId,
+  now = () => performance.now(),
+  documentRef = globalThis.document,
+  pointerFree = isPointerFree,
+}) {
+  let moving = false;
+  let lastPick = -Infinity;
+  let ownsCursor = false;
+  const clearCursor = () => {
+    if (ownsCursor && viewer.scene.canvas.style.cursor === 'pointer')
+      viewer.scene.canvas.style.cursor = '';
+    ownsCursor = false;
+  };
+  const reset = () => {
+    clearCursor();
+    lastPick = -Infinity;
+  };
+  const start = () => {
+    moving = true;
+    reset();
+  };
+  const end = () => {
+    moving = false;
+    reset();
+  };
+  const visibility = () => {
+    if (documentRef?.hidden || documentRef?.visibilityState === 'hidden')
+      reset();
+  };
+  const removeStart = viewer.camera?.moveStart?.addEventListener(start);
+  const removeEnd = viewer.camera?.moveEnd?.addEventListener(end);
+  documentRef?.addEventListener?.('visibilitychange', visibility);
+  return {
+    move(movement) {
+      if (
+        !enabled() ||
+        moving ||
+        documentRef?.hidden ||
+        documentRef?.visibilityState === 'hidden' ||
+        !pointerFree()
+      ) {
+        reset();
+        return;
+      }
+      const at = now();
+      if (at - lastPick < 120) return;
+      lastPick = at;
+      const found = viewer.scene
+        .drillPick(movement.endPosition, 12)
+        .some((picked) => entityLaunchId(picked?.id));
+      if (found) {
+        viewer.scene.canvas.style.cursor = 'pointer';
+        ownsCursor = true;
+      } else clearCursor();
+    },
+    reset,
+    destroy() {
+      reset();
+      removeStart?.();
+      removeEnd?.();
+      documentRef?.removeEventListener?.('visibilitychange', visibility);
+    },
+  };
+}
+
 export function createLifecycle({
   state: layerState,
   services,
@@ -8,6 +77,7 @@ export function createLifecycle({
   source,
 }) {
   const { holdContinuousRender, releaseContinuousRender } = services.render;
+  let hover = null;
 
   const methods = {
     init(viewer) {
@@ -45,14 +115,15 @@ export function createLifecycle({
       layerState._moveHandler = new Cesium.ScreenSpaceEventHandler(
         viewer.scene.canvas,
       );
-      layerState._moveHandler.setInputAction((movement) => {
-        if (!layerState._enabled || !layerState._dataSource?.show) return;
-        const missionEntity = viewer.scene
-          .drillPick(movement.endPosition, 12)
-          .map((picked) => picked?.id)
-          .find((candidate) => parts.selection.entityLaunchId(candidate));
-        viewer.scene.canvas.style.cursor = missionEntity ? 'pointer' : '';
-      }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);
+      hover = createLaunchHover({
+        viewer,
+        enabled: () => layerState._enabled && layerState._dataSource?.show,
+        entityLaunchId: parts.selection.entityLaunchId,
+      });
+      layerState._moveHandler.setInputAction(
+        hover.move,
+        Cesium.ScreenSpaceEventType.MOUSE_MOVE,
+      );
       // Apply horizon visibility before Cesium traverses and picks the scene.
       // A postRender write is one frame late and can remain visibly stale when
       // request-on-demand rendering stops after a globe camera move.
@@ -100,6 +171,7 @@ export function createLifecycle({
     },
 
     async disable() {
+      hover?.reset();
       layerState._sourceController.abort();
       layerState._enabled = false;
       releaseContinuousRender('rocket-launches');
@@ -122,6 +194,8 @@ export function createLifecycle({
     },
 
     async destroy(viewer) {
+      hover?.destroy();
+      hover = null;
       layerState._sourceController.abort();
       releaseContinuousRender('rocket-launches'); // direct-destroy path (perf wave 2 fix)
       layerState._enabled = false;