Share the Cesium ports between the app and conformance renderers

The frame, draw, camera, query and capture ports move out of the
conformance scene renderer into src/render/cesium/ports.js, unchanged.
The app's transitional renderer, now src/render/cesium/appRenderer.js,
builds the same ports over the full viewer; it still leaves out globe,
whenSettled and setTime, which would misreport photoreal tiles and stop
the app clock.

Disposing the ports now settles a pending renderOnce and detaches the
draw sets, so a model that loads after destroy is destroyed rather than
added to a destroyed collection. A viewer whose ports fail to build is
destroyed with its credits.

Checked in a browser: the app boots with one credits element, and all
eleven conformance scenes match their references exactly.

scripts/format-scope.json

@@ -671,7 +671,7 @@
   "src/services/application.js",
   "src/services/requests.js",
   "src/app/scene.js",
-  "src/app/renderer.test.mjs",
+  "src/render/cesium/appRenderer.test.mjs",
   "src/render/noCesiumOutsideRender.test.mjs",
   "src/render/cesiumAllowList.json",
   "src/geo/geo.test.mjs",

scripts/package-boundaries.json

@@ -2421,7 +2421,8 @@
       "src/app/layers/traffic.js",
       "src/app/operations.js",
       "src/app/scene.js",
-      "src/app/renderer.js",
+      "src/render/cesium/appRenderer.js",
+      "src/render/cesium/ports.js",
       "src/render/contract/index.js",
       "src/sources/sourceSlot.js",
       "src/app/sources.js",

src/app/scene.js

@@ -1,7 +1,10 @@
 import { createApplicationOperations } from './operations.js';
 import * as Cesium from 'cesium';
 import { installTrackpadPinchZoom } from '../app/viewer.js';
-import { cesiumRenderer, cesiumViewerOf } from './renderer.js';
+import {
+  cesiumRenderer,
+  cesiumViewerOf,
+} from '../render/cesium/appRenderer.js';
 import { registerDataCredits } from '../data/dataCredits.js';
 import { configureCreditKeyboardAccess } from '../creditKeyboard.js';
 import { MapStackController } from '../mapStackController.js';

src/render/cesium/appRenderer.js

@@ -1,23 +1,30 @@
 /**
- * @module app/renderer
+ * @module render/cesium/appRenderer
  * @description The application's default renderer plugin: today's Cesium
  * viewer, set up exactly as before, behind the contract's `RendererPlugin`
  * (`src/render/contract/renderer.d.ts`).
  *
- * The renderer it makes is transitional: it has only the members it really
+ * The renderer it makes is transitional. Its ports are the shared Cesium
- * has, and the contract's ports arrive one layer family at a time (phase 2
+ * ports (`ports.js`), the ones the conformance renderer is checked with,
- * of the renderer plan); `checkRendererShape` lists what is still missing.
+ * less the members that would not be true of the application yet: the
+ * globe (it draws photoreal tiles the port does not know), `whenSettled`
+ * (it would not wait for them) and `frame.setTime` (it would stop the
+ * application's clock). Those arrive with the layer families that need
+ * them (phase 2 of the renderer plan); `checkRendererShape` lists what is
+ * still missing.
  * Until a family is ported, its code reaches the Cesium viewer through
  * `cesiumViewerOf`, never through a renderer member, so no engine type
  * crosses the contract and each call marks code still to port.
  */
-import { CONTRACT_VERSION } from '../render/contract/index.js';
+import { createApplicationViewer } from '../../app/viewer.js';
-import { createApplicationViewer } from './viewer.js';
+import { CONTRACT_VERSION } from '../contract/index.js';
+import { createCesiumPorts } from './ports.js';
 
 /**
  * The members a transitional renderer has today.
- * @typedef {Pick<import('../render/contract/renderer').Renderer,
+ * @typedef {Pick<import('../contract/renderer').Renderer,
- *   'id' | 'contractVersion' | 'capabilities' | 'canvas' | 'resize' | 'destroy'>}
+ *   'id' | 'contractVersion' | 'capabilities' | 'canvas' | 'frame' | 'draw'
+ *   | 'camera' | 'query' | 'capture' | 'resize' | 'destroy'>}
  *   TransitionalRenderer
  */
 
@@ -75,22 +82,31 @@ export function createCesiumRendererPlugin({
       creditContainer.id = 'cesium-credits';
       document.body.appendChild(creditContainer);
       let viewer;
+      let ports;
       try {
         viewer = createViewer({ container, creditContainer });
+        ports = createCesiumPorts(viewer);
       } catch (error) {
+        if (viewer && !viewer.isDestroyed()) viewer.destroy();
         creditContainer.remove();
         throw error;
       }
       const renderer = Object.freeze({
         id: 'cesium',
         contractVersion: CONTRACT_VERSION,
-        capabilities: new ReadonlySet(),
+        capabilities: new ReadonlySet(['models']),
         canvas: viewer.canvas,
+        frame: ports.frame,
+        draw: ports.draw,
+        camera: ports.camera,
+        query: ports.query,
+        capture: ports.capture,
         resize() {
           viewer.resize();
         },
         destroy() {
           try {
+            ports.dispose();
             if (!viewer.isDestroyed()) viewer.destroy();
           } finally {
             creditContainer.remove();

src/render/cesium/appRenderer.test.mjs

@@ -1,15 +1,13 @@
 import assert from 'node:assert/strict';
 import test from 'node:test';
-import {
+import * as Cesium from 'cesium';
-  CONTRACT_VERSION,
+import { CONTRACT_VERSION, checkRendererShape } from '../contract/index.js';
-  checkRendererShape,
-} from '../render/contract/index.js';
 import {
   ReadonlySet,
   cesiumRenderer,
   cesiumViewerOf,
   createCesiumRendererPlugin,
-} from './renderer.js';
+} from './appRenderer.js';
 
 /** A document with just a body, recording what is attached. */
 function fakeDocument() {
@@ -32,9 +30,29 @@ function fakeDocument() {
   };
 }
 
+/** A Cesium event: listeners added, and removed by the returned function. */
+function fakeEvent(listeners) {
+  return {
+    addEventListener(cb) {
+      listeners.add(cb);
+      return () => listeners.delete(cb);
+    },
+  };
+}
+
 function fakeViewer(log, { failDestroy = false } = {}) {
   let destroyed = false;
+  const listeners = new Set();
   return {
+    listeners,
+    scene: {
+      camera: {},
+      primitives: { add() {}, remove() {} },
+      requestRender() {},
+      preUpdate: fakeEvent(listeners),
+      preRender: fakeEvent(listeners),
+      postRender: fakeEvent(listeners),
+    },
     canvas: { tag: 'canvas' },
     resize: () => log.push('resize'),
     isDestroyed: () => destroyed,
@@ -64,10 +82,12 @@ test('the plugin wraps the viewer it is given, behind the accessor only', async
   withDocument(t, doc);
   const log = [];
   let given;
+  let viewer;
   const plugin = createCesiumRendererPlugin({
     createViewer(options) {
       given = options;
-      return fakeViewer(log);
+      viewer = fakeViewer(log);
+      return viewer;
     },
   });
   const container = { tag: 'container' };
@@ -94,14 +114,65 @@ test('the plugin wraps the viewer it is given, behind the accessor only', async
   assert.ok(!('viewer' in renderer), 'no engine object is a member');
   assert.equal(cesiumViewerOf(renderer).canvas, renderer.canvas);
 
+  assert.ok(viewer.listeners.size > 0, 'the ports follow the frame phases');
+  assert.equal(typeof renderer.draw.icons, 'function');
+  assert.ok(renderer.capabilities.has('models'), 'draw.models is declared');
+
   renderer.resize();
   renderer.destroy();
+  assert.equal(viewer.listeners.size, 0, 'and stop on destroy');
   assert.deepEqual(log, ['resize', 'destroy']);
   assert.deepEqual(doc.children, [], 'credits leave with the renderer');
   renderer.destroy();
   assert.deepEqual(log, ['resize', 'destroy'], 'destroying twice is safe');
 });
 
+test('work pending at destroy settles and lets go of the scene', async (t) => {
+  withDocument(t, fakeDocument());
+  const viewers = [];
+  const plugin = createCesiumRendererPlugin({
+    createViewer: () => {
+      const viewer = fakeViewer([]);
+      viewers.push(viewer);
+      return viewer;
+    },
+  });
+
+  const renderer = await plugin.create({ container: {} });
+  const rendered = renderer.frame.renderOnce();
+  renderer.destroy();
+  await rendered;
+  assert.equal(viewers[0].listeners.size, 0, 'no one-shot render stays');
+  await renderer.frame.renderOnce();
+
+  // A model that finishes loading after destroy is destroyed, not added.
+  const load = Promise.withResolvers();
+  const saved = Cesium.Model.fromGltfAsync;
+  Cesium.Model.fromGltfAsync = () => load.promise;
+  t.after(() => {
+    Cesium.Model.fromGltfAsync = saved;
+  });
+  const again = await plugin.create({ container: {} });
+  again.draw.models({ id: 'm' }).set([
+    {
+      id: 'a',
+      url: 'a.glb',
+      pos: { lon: 0, lat: 0, height: 0 },
+      orientation: { heading: 0, pitch: 0, roll: 0 },
+    },
+  ]);
+  again.destroy();
+  let destroyed = false;
+  load.resolve({
+    destroy: () => (destroyed = true),
+    readyEvent: fakeEvent(new Set()),
+    errorEvent: fakeEvent(new Set()),
+  });
+  await load.promise;
+  await new Promise((resolve) => setImmediate(resolve));
+  assert.ok(destroyed, 'the late model is destroyed');
+});
+
 test('the credits leave even when the viewer fails to destroy', async (t) => {
   const doc = fakeDocument();
   withDocument(t, doc);
@@ -151,7 +222,7 @@ test('an aborted creation builds nothing', async (t) => {
   assert.deepEqual(doc.children, []);
 });
 
-test('the transitional renderer lacks exactly the ports still to come', async (t) => {
+test('the transitional renderer lacks exactly the members still to come', async (t) => {
   withDocument(t, fakeDocument());
   const renderer = await createCesiumRendererPlugin({
     createViewer: () => fakeViewer([]),
@@ -174,9 +245,9 @@ test('only renderers this plugin made reach a Cesium viewer', () => {
 });
 
 test('the application refuses a renderer it cannot run on, and destroys it', async (t) => {
-  const { createApplicationScene } = await import('./scene.js');
+  const { createApplicationScene } = await import('../../app/scene.js');
   const { createApplicationRequestServices } =
-    await import('../services/requests.js');
+    await import('../../services/requests.js');
   const destroyed = [];
   const deferred = [];
   const plugin = {
@@ -218,18 +289,69 @@ test('the application refuses a renderer it cannot run on, and destroys it', asy
 });
 
 const EXPECTED_MISSING = [
-  'camera',
+  'camera.cancelFlight',
-  'capture',
+  'camera.controls',
-  'credits',
+  'camera.controls.coast',
-  'draw',
+  'camera.controls.coast.drag',
-  'effects',
+  'camera.controls.coast.zoom',
-  'frame',
+  'camera.controls.collision',
-  'globe',
+  'camera.controls.enableRotate',
-  'input',
+  'camera.controls.enableTilt',
-  'on',
+  'camera.controls.enableZoom',
-  'quality',
+  'camera.controls.enabled',
-  'query',
+  'camera.controls.maxDistance',
-  'readPixels',
+  'camera.controls.minDistance',
-  'releaseUnused',
+  'camera.controls.pitchRange',
-  'whenSettled',
+  'camera.controls.suspend',
-].map((member) => `renderer.${member} is missing`);
+  'camera.controls.zoomFactor',
+  'camera.controls.zoomInputs',
+  'camera.flyTo',
+  'camera.flyToBounds',
+  'camera.flying',
+  'camera.follow',
+  'camera.followFramed',
+  'camera.followOffset',
+  'camera.followOffset.get',
+  'camera.followOffset.set',
+  'camera.followed',
+  'camera.look',
+  'camera.lookAt',
+  'camera.matrices',
+  'camera.move',
+  'camera.on',
+  'camera.onCommand',
+  'camera.release',
+  'camera.rotateAround',
+  'camera.setFov',
+  'camera.viewRectangle',
+  'camera.zoom',
+  'draw.atlas',
+  'draw.clampState',
+  'draw.on',
+  'frame.diagnostics',
+  'frame.holdContinuous',
+  'frame.mode',
+  'frame.setTargetFps',
+  'frame.setTime',
+  'frame.suspend',
+  'query.clampToSurface',
+  'query.drillPick',
+  'query.isOccluded',
+  'query.pickGlobe',
+  'query.pickPosition',
+  'query.pickRay',
+  'query.projectMany',
+  'query.rayCast',
+  'query.sampleHeight',
+  'query.sampleHeightNow',
+  'query.sampleHeightNowMany',
+  'renderer.credits',
+  'renderer.effects',
+  'renderer.globe',
+  'renderer.input',
+  'renderer.on',
+  'renderer.quality',
+  'renderer.readPixels',
+  'renderer.releaseUnused',
+  'renderer.whenSettled',
+].map((member) => `${member} is missing`);

src/render/cesium/ports.js

@@ -0,0 +1,575 @@
+/**
+ * @module render/cesium/ports
+ * @description The Cesium renderer's contract ports, built over a Cesium
+ * widget or viewer someone else made and configured: frame phases, the
+ * draw sets, `setView` and the pose, picks and projection, and capture.
+ * Building them changes nothing in the scene; only calls do.
+ *
+ * The conformance renderer (`sceneRenderer.js`) and the application's
+ * renderer (`appRenderer.js`) both use them, so what conformance
+ * checks is what the application runs. Members a port does not have are
+ * absent, never stubbed.
+ */
+import * as Cesium from 'cesium';
+
+/** The contract's colour as Cesium's. */
+export function toColor(color, alpha = 1) {
+  if (color === undefined || color === null)
+    return Cesium.Color.WHITE.withAlpha(alpha);
+  const c =
+    typeof color === 'string'
+      ? Cesium.Color.fromCssColorString(color)
+      : new Cesium.Color(color[0], color[1], color[2], color[3] ?? 1);
+  return c.withAlpha(c.alpha * alpha);
+}
+
+/** An image reference as something a billboard takes. */
+export function toImage(image) {
+  if (typeof image === 'string') return image;
+  if (image?.svg)
+    return `data:image/svg+xml;charset=utf-8,${encodeURIComponent(image.svg)}`;
+  if (image?.canvas) return image.canvas;
+  throw new Error('the Cesium renderer takes URL, SVG and canvas images only');
+}
+
+/** A contract position as ECEF. */
+export function toCartesian(pos) {
+  if ('x' in pos) return new Cesium.Cartesian3(pos.x, pos.y, pos.z);
+  return Cesium.Cartesian3.fromDegrees(pos.lon, pos.lat, pos.height ?? 0);
+}
+
+const ANCHORS = {
+  center: Cesium.VerticalOrigin.CENTER,
+  bottom: Cesium.VerticalOrigin.BOTTOM,
+  top: Cesium.VerticalOrigin.TOP,
+};
+
+/**
+ * @param {object} widget A Cesium `CesiumWidget` or `Viewer`.
+ */
+export function createCesiumPorts(widget) {
+  const scene = widget.scene;
+  const camera = scene.camera;
+  const sets = new Map();
+
+  const frameListeners = { preUpdate: [], preRender: [], postRender: [] };
+  let frames = 0;
+  const onPhase = (phase) => (_scene, time) => {
+    if (frameListeners[phase].length === 0) return;
+    const t = {
+      frame: frames,
+      time: Cesium.JulianDate.toDate(
+        time ?? widget.clock.currentTime,
+      ).getTime(),
+      now: performance.now(),
+      dt: 1 / 60,
+      rendering: phase !== 'preUpdate',
+    };
+    for (const cb of frameListeners[phase].slice()) cb(t);
+  };
+  let disposed = false;
+  const removers = [
+    scene.preUpdate.addEventListener(() => (frames += 1)),
+    scene.preUpdate.addEventListener(onPhase('preUpdate')),
+    scene.preRender.addEventListener(onPhase('preRender')),
+    scene.postRender.addEventListener(onPhase('postRender')),
+  ];
+
+  // Pending one-shot renders; disposal settles them rather than leave them
+  // attached to a scene that will not render again.
+  const pendingRenders = new Set();
+  function nextPostRender() {
+    if (disposed) return Promise.resolve();
+    return new Promise((resolve) => {
+      const done = () => {
+        off();
+        pendingRenders.delete(done);
+        resolve();
+      };
+      const off = scene.postRender.addEventListener(done);
+      pendingRenders.add(done);
+      scene.requestRender();
+    });
+  }
+
+  const frame = {
+    on(phase, cb) {
+      frameListeners[phase].push(cb);
+      return () => {
+        const i = frameListeners[phase].indexOf(cb);
+        if (i >= 0) frameListeners[phase].splice(i, 1);
+      };
+    },
+    requestRender: () => scene.requestRender(),
+    renderNow: () => scene.render(widget.clock.currentTime),
+    renderOnce: () => nextPostRender(),
+    time: () => Cesium.JulianDate.toDate(widget.clock.currentTime).getTime(),
+  };
+
+  // --- Draw ------------------------------------------------------------------
+
+  function makeSet(kind, spec, build) {
+    if (sets.has(spec.id)) throw new Error(`a set with id ${spec.id} is live`);
+    const items = new Map();
+    const listeners = { ready: [] };
+    const record = { kind, spec, items, listeners, host: null, rebuild: null };
+    const handle = {
+      id: spec.id,
+      set(list) {
+        items.clear();
+        for (const item of list) items.set(item.id, item);
+        build(record);
+        scene.requestRender();
+      },
+      upsert(list) {
+        for (const item of list) items.set(item.id, item);
+        build(record);
+        scene.requestRender();
+      },
+      remove(ids) {
+        for (const id of ids) items.delete(id);
+        build(record);
+        scene.requestRender();
+      },
+      clear() {
+        items.clear();
+        build(record);
+        scene.requestRender();
+      },
+      setOptions(options) {
+        Object.assign(spec, options);
+        if (record.host) record.host.show = spec.show !== false;
+        scene.requestRender();
+      },
+      size: () => items.size,
+      get show() {
+        return spec.show !== false;
+      },
+      set show(value) {
+        spec.show = value;
+        if (record.host) record.host.show = value;
+        scene.requestRender();
+      },
+      on(event, cb) {
+        listeners[event]?.push(cb);
+        return () => {
+          const list = listeners[event];
+          const i = list?.indexOf(cb) ?? -1;
+          if (i >= 0) list.splice(i, 1);
+        };
+      },
+      dispose() {
+        if (record.host && !record.host.isDestroyed?.())
+          scene.primitives.remove(record.host);
+        record.host = null;
+        // A newer set under the same id is not this handle's to remove.
+        if (sets.get(spec.id) === record) sets.delete(spec.id);
+        scene.requestRender();
+      },
+    };
+    sets.set(spec.id, record);
+    return handle;
+  }
+
+  const pickId = (record, item) => ({
+    set: record.spec.id,
+    id: item.id,
+    meta: item.meta,
+  });
+
+  function replaceHost(record, host) {
+    if (record.host) scene.primitives.remove(record.host);
+    record.host = host;
+    host.show = record.spec.show !== false;
+    scene.primitives.add(host);
+  }
+
+  function buildIcons(record) {
+    const host = new Cesium.BillboardCollection({ scene });
+    for (const item of record.items.values()) {
+      const position = toCartesian(item.pos);
+      const options = {
+        position,
+        image: toImage(item.image),
+        width: item.size[0] * (item.scale ?? 1),
+        height: item.size[1] * (item.scale ?? 1),
+        color: toColor(item.color, item.alpha ?? 1),
+        verticalOrigin: ANCHORS[item.anchor ?? 'center'],
+        disableDepthTestDistance: item.disableDepthTest ?? 0,
+        show: item.show !== false,
+        id: pickId(record, item),
+      };
+      if (item.rotationMode === 'screen') options.rotation = item.rotation ?? 0;
+      if (item.rotationMode === 'course') {
+        const enu = Cesium.Transforms.eastNorthUpToFixedFrame(position);
+        options.alignedAxis = Cesium.Matrix4.multiplyByPointAsVector(
+          enu,
+          Cesium.Cartesian3.UNIT_Y,
+          new Cesium.Cartesian3(),
+        );
+        options.rotation = -Cesium.Math.toRadians(item.course ?? 0);
+      }
+      host.add(options);
+    }
+    replaceHost(record, host);
+  }
+
+  function buildPoints(record) {
+    const host = new Cesium.PointPrimitiveCollection();
+    for (const item of record.items.values())
+      host.add({
+        position: toCartesian(item.pos),
+        pixelSize: item.pixelSize,
+        color: toColor(item.color),
+        outlineColor: toColor(item.outlineColor ?? [0, 0, 0, 0]),
+        outlineWidth: item.outlineWidth ?? 0,
+        disableDepthTestDistance: item.disableDepthTest ?? 0,
+        show: item.show !== false,
+        id: pickId(record, item),
+      });
+    replaceHost(record, host);
+  }
+
+  function lineMaterial(style) {
+    switch (style.kind) {
+      case 'solid':
+        return Cesium.Material.fromType('Color', {
+          color: toColor(style.color),
+        });
+      case 'glow':
+        return Cesium.Material.fromType('PolylineGlow', {
+          color: toColor(style.color),
+          glowPower: style.power,
+          taperPower: style.taper ?? 1,
+        });
+      case 'dash':
+        return Cesium.Material.fromType('PolylineDash', {
+          color: toColor(style.color),
+          gapColor: toColor(style.gapColor ?? [0, 0, 0, 0]),
+          dashLength: style.length,
+          ...(style.pattern16 !== undefined
+            ? { dashPattern: style.pattern16 }
+            : {}),
+        });
+      case 'arrow':
+        return Cesium.Material.fromType('PolylineArrow', {
+          color: toColor(style.color),
+        });
+      default:
+        throw new Error(`the Cesium renderer has no ${style.kind} lines`);
+    }
+  }
+
+  function linePositions(item) {
+    const flat = item.positions instanceof Float64Array;
+    const points = [];
+    const n = flat ? item.positions.length / 3 : item.positions.length;
+    for (let i = 0; i < n; i++)
+      points.push(
+        flat
+          ? new Cesium.Cartesian3(
+              item.positions[i * 3],
+              item.positions[i * 3 + 1],
+              item.positions[i * 3 + 2],
+            )
+          : toCartesian(item.positions[i]),
+      );
+    if (item.mode !== 'geodesic') return points;
+    const dense = [];
+    for (let i = 0; i + 1 < points.length; i++) {
+      const a = Cesium.Cartographic.fromCartesian(points[i]);
+      const b = Cesium.Cartographic.fromCartesian(points[i + 1]);
+      const geodesic = new Cesium.EllipsoidGeodesic(a, b);
+      for (let k = 0; k < 64; k++) {
+        const s = k / 64;
+        const at = geodesic.interpolateUsingFraction(s);
+        dense.push(
+          Cesium.Cartesian3.fromRadians(
+            at.longitude,
+            at.latitude,
+            a.height + (b.height - a.height) * s,
+          ),
+        );
+      }
+    }
+    dense.push(points.at(-1));
+    return dense;
+  }
+
+  function buildLines(record) {
+    const host = new Cesium.PolylineCollection();
+    for (const item of record.items.values()) {
+      if (item.mode === 'draped')
+        throw new Error('the Cesium renderer has no draped lines');
+      host.add({
+        positions: linePositions(item),
+        width: item.widthPx,
+        material: lineMaterial(item.style),
+        show: item.show !== false,
+        id: pickId(record, item),
+      });
+    }
+    replaceHost(record, host);
+  }
+
+  const heightOf = (pos) =>
+    'x' in pos
+      ? Cesium.Cartographic.fromCartesian(toCartesian(pos)).height
+      : (pos.height ?? 0);
+
+  function shapeGeometry(item) {
+    const g = item.geometry;
+    const extrudedHeight = item.extrudeHeight;
+    switch (g.kind) {
+      case 'polygon': {
+        const [outer, ...holes] = g.rings.map((ring) => ring.map(toCartesian));
+        const hierarchy = new Cesium.PolygonHierarchy(
+          outer,
+          holes.map((h) => new Cesium.PolygonHierarchy(h)),
+        );
+        return {
+          fill: new Cesium.PolygonGeometry({
+            polygonHierarchy: hierarchy,
+            height: g.perPositionHeight ? undefined : heightOf(g.rings[0][0]),
+            extrudedHeight,
+            perPositionHeight: g.perPositionHeight,
+          }),
+          ring: outer,
+        };
+      }
+      case 'ellipse':
+        return {
+          fill: new Cesium.EllipseGeometry({
+            center: toCartesian(g.center),
+            semiMajorAxis: g.semiMajor,
+            semiMinorAxis: g.semiMinor,
+            rotation: g.rotation ?? 0,
+            height: heightOf(g.center),
+            extrudedHeight,
+          }),
+        };
+      case 'rectangle':
+        return {
+          fill: new Cesium.RectangleGeometry({
+            rectangle: Cesium.Rectangle.fromDegrees(
+              g.rect.west,
+              g.rect.south,
+              g.rect.east,
+              g.rect.north,
+            ),
+            height: g.height ?? 0,
+            extrudedHeight,
+          }),
+        };
+      case 'box': {
+        const d = g.dimensions;
+        return {
+          fill: Cesium.BoxGeometry.fromDimensions({
+            dimensions: new Cesium.Cartesian3(d.x, d.y, d.z),
+          }),
+          modelMatrix: Cesium.Transforms.eastNorthUpToFixedFrame(
+            toCartesian(g.center),
+          ),
+        };
+      }
+      default:
+        throw new Error(`the Cesium renderer has no ${g.kind} shapes`);
+    }
+  }
+
+  function buildShapes(record) {
+    const host = new Cesium.PrimitiveCollection();
+    const outlines = new Cesium.PolylineCollection();
+    for (const item of record.items.values()) {
+      if (item.show === false) continue;
+      if (
+        item.fill &&
+        typeof item.fill === 'object' &&
+        !Array.isArray(item.fill)
+      )
+        throw new Error('the Cesium renderer fills shapes with colours only');
+      const shape = shapeGeometry(item);
+      const id = pickId(record, item);
+      const solid =
+        item.extrudeHeight !== undefined || item.geometry.kind === 'box';
+      if (item.fill && !item.outlineOnly) {
+        const color = toColor(item.fill);
+        host.add(
+          new Cesium.Primitive({
+            geometryInstances: new Cesium.GeometryInstance({
+              geometry: shape.fill,
+              modelMatrix: shape.modelMatrix,
+              attributes: {
+                color: Cesium.ColorGeometryInstanceAttribute.fromColor(color),
+              },
+              id,
+            }),
+            appearance: new Cesium.PerInstanceColorAppearance({
+              translucent: color.alpha < 1,
+              closed: solid,
+              // Flat shapes unlit: lit, their two triangles shade apart.
+              flat: !solid,
+            }),
+            asynchronous: false,
+          }),
+        );
+      }
+      if (item.outline && shape.ring)
+        outlines.add({
+          positions: [...shape.ring, shape.ring[0]],
+          width: item.outlineWidth ?? 1,
+          material: Cesium.Material.fromType('Color', {
+            color: toColor(item.outline),
+          }),
+          id,
+        });
+    }
+    host.add(outlines);
+    replaceHost(record, host);
+  }
+
+  function buildModels(record) {
+    const host = new Cesium.PrimitiveCollection();
+    replaceHost(record, host);
+    // A model counts as loading until it is ready or fails, not when added;
+    // each model settles once, and a failure is kept for `whenSettled`.
+    host.loading = record.items.size;
+    host.failed = 0;
+    for (const item of record.items.values()) {
+      let settled = false;
+      const settle = (failed) => {
+        if (settled) return;
+        settled = true;
+        host.loading -= 1;
+        if (failed) host.failed += 1;
+        scene.requestRender();
+      };
+      const o = item.orientation;
+      const modelMatrix = Cesium.Transforms.headingPitchRollToFixedFrame(
+        toCartesian(item.pos),
+        new Cesium.HeadingPitchRoll(o.heading, o.pitch, o.roll),
+      );
+      Cesium.Model.fromGltfAsync({
+        url: item.url,
+        modelMatrix,
+        scale: item.scale ?? 1,
+        minimumPixelSize: item.minPixelSize ?? 0,
+        // All textures before ready, so a settled capture is the whole model.
+        incrementallyLoadTextures: false,
+        id: pickId(record, item),
+      }).then(
+        (model) => {
+          // Rebuilt, disposed, or the renderer is gone.
+          if (record.host !== host || host.isDestroyed())
+            return model.destroy();
+          host.add(model);
+          model.readyEvent.addEventListener(() => {
+            settle(false);
+            for (const cb of record.listeners.ready.slice()) cb(item.id);
+          });
+          model.errorEvent.addEventListener(() => settle(true));
+          scene.requestRender();
+        },
+        () => settle(true),
+      );
+    }
+  }
+
+  const draw = {
+    icons: (spec) => makeSet('icons', { ...spec }, buildIcons),
+    points: (spec) => makeSet('points', { ...spec }, buildPoints),
+    lines: (spec) => makeSet('lines', { ...spec }, buildLines),
+    shapes: (spec) => makeSet('shapes', { ...spec }, buildShapes),
+    models: (spec) => makeSet('models', { ...spec }, buildModels),
+  };
+
+  const cameraPort = {
+    setView(spec) {
+      const d = spec.destination;
+      if (d && 'rect' in d)
+        throw new Error('the Cesium renderer takes position destinations only');
+      const o = spec.orientation ?? {};
+      camera.setView({
+        ...(d ? { destination: toCartesian(d) } : {}),
+        orientation: {
+          heading: o.heading ?? 0,
+          pitch: o.pitch ?? -Math.PI / 2,
+          roll: o.roll ?? 0,
+        },
+      });
+      scene.requestRender();
+    },
+    pose() {
+      const v = (c) => ({ x: c.x, y: c.y, z: c.z });
+      return {
+        position: v(camera.positionWC),
+        direction: v(camera.directionWC),
+        up: v(camera.upWC),
+        right: v(camera.rightWC),
+        heading: camera.heading,
+        pitch: camera.pitch,
+        roll: camera.roll,
+        height: camera.positionCartographic.height,
+        fovy: camera.frustum.fovy,
+        aspectRatio: camera.frustum.aspectRatio,
+        near: camera.frustum.near,
+        far: camera.frustum.far,
+        frameIsIdentity: Cesium.Matrix4.equals(
+          camera.transform,
+          Cesium.Matrix4.IDENTITY,
+        ),
+      };
+    },
+  };
+
+  const query = {
+    pick(x, y) {
+      const picked = scene.pick(new Cesium.Cartesian2(x, y));
+      const id = picked?.id;
+      return id && typeof id.set === 'string'
+        ? { ...id, surface: false }
+        : null;
+    },
+    project(position) {
+      const s = Cesium.SceneTransforms.worldToWindowCoordinates(
+        scene,
+        toCartesian(position),
+      );
+      return s ? { x: s.x, y: s.y } : null;
+    },
+    pickEllipsoid(x, y) {
+      const c = camera.pickEllipsoid(new Cesium.Cartesian2(x, y));
+      return c ? { x: c.x, y: c.y, z: c.z } : null;
+    },
+  };
+
+  async function capture({ type = 'png' } = {}) {
+    scene.render(widget.clock.currentTime);
+    return new Promise((resolve) =>
+      scene.canvas.toBlob(resolve, `image/${type}`),
+    );
+  }
+
+  /** The live model sets, for a renderer's own `whenSettled`. */
+  const modelSets = () =>
+    [...sets.values()].filter((r) => r.kind === 'models' && r.host);
+
+  return {
+    frame,
+    draw,
+    camera: cameraPort,
+    query,
+    capture,
+    modelSets,
+    nextPostRender,
+    /** Detach from the scene; the widget's owner destroys the widget. */
+    dispose() {
+      disposed = true;
+      for (const off of removers) off();
+      for (const done of [...pendingRenders]) done();
+      // Late model loads find no host and destroy themselves.
+      for (const record of sets.values()) record.host = null;
+      sets.clear();
+    },
+  };
+}

src/render/cesium/sceneRenderer.js

@@ -6,11 +6,18 @@
  * phases, settling and capture. The `/dev/conformance/` page draws the
  * scenes with it to make and check the visual references.
  *
+ * Its ports are `ports.js`'s, which the application's renderer shares;
+ * this factory adds the conformance widget, its fixed settings and the
+ * bare-globe and sky members.
+ *
  * It is not yet the whole Cesium renderer: each later migration adds the
  * members its layer family needs, until it passes the whole suite.
  * Members it does not have are absent, never stubbed.
  */
 import * as Cesium from 'cesium';
+import { createCesiumPorts } from './ports.js';
+
+export { toCartesian, toColor, toImage } from './ports.js';
 
 const SKY_DEFAULTS = Object.freeze({
   atmosphere: false,
@@ -22,38 +29,6 @@ const SKY_DEFAULTS = Object.freeze({
   lighting: false,
 });
 
-/** The contract's colour as Cesium's. */
-export function toColor(color, alpha = 1) {
-  if (color === undefined || color === null)
-    return Cesium.Color.WHITE.withAlpha(alpha);
-  const c =
-    typeof color === 'string'
-      ? Cesium.Color.fromCssColorString(color)
-      : new Cesium.Color(color[0], color[1], color[2], color[3] ?? 1);
-  return c.withAlpha(c.alpha * alpha);
-}
-
-/** An image reference as something a billboard takes. */
-export function toImage(image) {
-  if (typeof image === 'string') return image;
-  if (image?.svg)
-    return `data:image/svg+xml;charset=utf-8,${encodeURIComponent(image.svg)}`;
-  if (image?.canvas) return image.canvas;
-  throw new Error('the scene renderer takes URL, SVG and canvas images only');
-}
-
-/** A contract position as ECEF. */
-export function toCartesian(pos) {
-  if ('x' in pos) return new Cesium.Cartesian3(pos.x, pos.y, pos.z);
-  return Cesium.Cartesian3.fromDegrees(pos.lon, pos.lat, pos.height ?? 0);
-}
-
-const ANCHORS = {
-  center: Cesium.VerticalOrigin.CENTER,
-  bottom: Cesium.VerticalOrigin.BOTTOM,
-  top: Cesium.VerticalOrigin.TOP,
-};
-
 /**
  * @param {{container: HTMLElement, msaa?: number}} options
  * @returns {Promise<object>} A renderer with the members listed above.
@@ -72,7 +47,6 @@ export async function createCesiumSceneRenderer({ container, msaa = 4 }) {
     contextOptions: { webgl: { preserveDrawingBuffer: true } },
   });
   const scene = widget.scene;
-  const camera = scene.camera;
   // A fixed time, so lighting is the same in every capture.
   widget.clock.shouldAnimate = false;
   widget.clock.currentTime = Cesium.JulianDate.fromIso8601(
@@ -85,7 +59,6 @@ export async function createCesiumSceneRenderer({ container, msaa = 4 }) {
   if (scene.sun) scene.sun.show = false;
   if (scene.moon) scene.moon.show = false;
 
-  const sets = new Map();
   const sky = { ...SKY_DEFAULTS };
   const capabilities = new Set(['models']);
 
@@ -98,49 +71,9 @@ export async function createCesiumSceneRenderer({ container, msaa = 4 }) {
     scene.requestRender();
   }
 
-  const frameListeners = { preUpdate: [], preRender: [], postRender: [] };
+  const ports = createCesiumPorts(widget);
-  let frames = 0;
-  const onPhase = (phase) => (_scene, time) => {
-    const t = {
-      frame: frames,
-      time: Cesium.JulianDate.toDate(
-        time ?? widget.clock.currentTime,
-      ).getTime(),
-      now: performance.now(),
-      dt: 1 / 60,
-      rendering: phase !== 'preUpdate',
-    };
-    for (const cb of frameListeners[phase].slice()) cb(t);
-  };
-  const removers = [
-    scene.preUpdate.addEventListener(() => (frames += 1)),
-    scene.preUpdate.addEventListener(onPhase('preUpdate')),
-    scene.preRender.addEventListener(onPhase('preRender')),
-    scene.postRender.addEventListener(onPhase('postRender')),
-  ];
-
-  function nextPostRender() {
-    return new Promise((resolve) => {
-      const off = scene.postRender.addEventListener(() => {
-        off();
-        resolve();
-      });
-      scene.requestRender();
-    });
-  }
-
   const frame = {
-    on(phase, cb) {
+    ...ports.frame,
-      frameListeners[phase].push(cb);
-      return () => {
-        const i = frameListeners[phase].indexOf(cb);
-        if (i >= 0) frameListeners[phase].splice(i, 1);
-      };
-    },
-    requestRender: () => scene.requestRender(),
-    renderNow: () => scene.render(widget.clock.currentTime),
-    renderOnce: () => nextPostRender(),
-    time: () => Cesium.JulianDate.toDate(widget.clock.currentTime).getTime(),
     setTime(ms) {
       widget.clock.currentTime = Cesium.JulianDate.fromDate(new Date(ms));
       widget.clock.shouldAnimate = false;
@@ -148,382 +81,7 @@ export async function createCesiumSceneRenderer({ container, msaa = 4 }) {
     },
   };
 
-  // --- Draw ------------------------------------------------------------------
+  // --- Globe -----------------------------------------------------------------
-
-  function makeSet(kind, spec, build) {
-    if (sets.has(spec.id)) throw new Error(`a set with id ${spec.id} is live`);
-    const items = new Map();
-    const listeners = { ready: [] };
-    const record = { kind, spec, items, listeners, host: null, rebuild: null };
-    const handle = {
-      id: spec.id,
-      set(list) {
-        items.clear();
-        for (const item of list) items.set(item.id, item);
-        build(record);
-        scene.requestRender();
-      },
-      upsert(list) {
-        for (const item of list) items.set(item.id, item);
-        build(record);
-        scene.requestRender();
-      },
-      remove(ids) {
-        for (const id of ids) items.delete(id);
-        build(record);
-        scene.requestRender();
-      },
-      clear() {
-        items.clear();
-        build(record);
-        scene.requestRender();
-      },
-      setOptions(options) {
-        Object.assign(spec, options);
-        if (record.host) record.host.show = spec.show !== false;
-        scene.requestRender();
-      },
-      size: () => items.size,
-      get show() {
-        return spec.show !== false;
-      },
-      set show(value) {
-        spec.show = value;
-        if (record.host) record.host.show = value;
-        scene.requestRender();
-      },
-      on(event, cb) {
-        listeners[event]?.push(cb);
-        return () => {
-          const list = listeners[event];
-          const i = list?.indexOf(cb) ?? -1;
-          if (i >= 0) list.splice(i, 1);
-        };
-      },
-      dispose() {
-        if (record.host && !record.host.isDestroyed?.())
-          scene.primitives.remove(record.host);
-        record.host = null;
-        // A newer set under the same id is not this handle's to remove.
-        if (sets.get(spec.id) === record) sets.delete(spec.id);
-        scene.requestRender();
-      },
-    };
-    sets.set(spec.id, record);
-    return handle;
-  }
-
-  const pickId = (record, item) => ({
-    set: record.spec.id,
-    id: item.id,
-    meta: item.meta,
-  });
-
-  function replaceHost(record, host) {
-    if (record.host) scene.primitives.remove(record.host);
-    record.host = host;
-    host.show = record.spec.show !== false;
-    scene.primitives.add(host);
-  }
-
-  function buildIcons(record) {
-    const host = new Cesium.BillboardCollection({ scene });
-    for (const item of record.items.values()) {
-      const position = toCartesian(item.pos);
-      const options = {
-        position,
-        image: toImage(item.image),
-        width: item.size[0] * (item.scale ?? 1),
-        height: item.size[1] * (item.scale ?? 1),
-        color: toColor(item.color, item.alpha ?? 1),
-        verticalOrigin: ANCHORS[item.anchor ?? 'center'],
-        disableDepthTestDistance: item.disableDepthTest ?? 0,
-        show: item.show !== false,
-        id: pickId(record, item),
-      };
-      if (item.rotationMode === 'screen') options.rotation = item.rotation ?? 0;
-      if (item.rotationMode === 'course') {
-        const enu = Cesium.Transforms.eastNorthUpToFixedFrame(position);
-        options.alignedAxis = Cesium.Matrix4.multiplyByPointAsVector(
-          enu,
-          Cesium.Cartesian3.UNIT_Y,
-          new Cesium.Cartesian3(),
-        );
-        options.rotation = -Cesium.Math.toRadians(item.course ?? 0);
-      }
-      host.add(options);
-    }
-    replaceHost(record, host);
-  }
-
-  function buildPoints(record) {
-    const host = new Cesium.PointPrimitiveCollection();
-    for (const item of record.items.values())
-      host.add({
-        position: toCartesian(item.pos),
-        pixelSize: item.pixelSize,
-        color: toColor(item.color),
-        outlineColor: toColor(item.outlineColor ?? [0, 0, 0, 0]),
-        outlineWidth: item.outlineWidth ?? 0,
-        disableDepthTestDistance: item.disableDepthTest ?? 0,
-        show: item.show !== false,
-        id: pickId(record, item),
-      });
-    replaceHost(record, host);
-  }
-
-  function lineMaterial(style) {
-    switch (style.kind) {
-      case 'solid':
-        return Cesium.Material.fromType('Color', {
-          color: toColor(style.color),
-        });
-      case 'glow':
-        return Cesium.Material.fromType('PolylineGlow', {
-          color: toColor(style.color),
-          glowPower: style.power,
-          taperPower: style.taper ?? 1,
-        });
-      case 'dash':
-        return Cesium.Material.fromType('PolylineDash', {
-          color: toColor(style.color),
-          gapColor: toColor(style.gapColor ?? [0, 0, 0, 0]),
-          dashLength: style.length,
-          ...(style.pattern16 !== undefined
-            ? { dashPattern: style.pattern16 }
-            : {}),
-        });
-      case 'arrow':
-        return Cesium.Material.fromType('PolylineArrow', {
-          color: toColor(style.color),
-        });
-      default:
-        throw new Error(`the scene renderer has no ${style.kind} lines`);
-    }
-  }
-
-  function linePositions(item) {
-    const flat = item.positions instanceof Float64Array;
-    const points = [];
-    const n = flat ? item.positions.length / 3 : item.positions.length;
-    for (let i = 0; i < n; i++)
-      points.push(
-        flat
-          ? new Cesium.Cartesian3(
-              item.positions[i * 3],
-              item.positions[i * 3 + 1],
-              item.positions[i * 3 + 2],
-            )
-          : toCartesian(item.positions[i]),
-      );
-    if (item.mode !== 'geodesic') return points;
-    const dense = [];
-    for (let i = 0; i + 1 < points.length; i++) {
-      const a = Cesium.Cartographic.fromCartesian(points[i]);
-      const b = Cesium.Cartographic.fromCartesian(points[i + 1]);
-      const geodesic = new Cesium.EllipsoidGeodesic(a, b);
-      for (let k = 0; k < 64; k++) {
-        const s = k / 64;
-        const at = geodesic.interpolateUsingFraction(s);
-        dense.push(
-          Cesium.Cartesian3.fromRadians(
-            at.longitude,
-            at.latitude,
-            a.height + (b.height - a.height) * s,
-          ),
-        );
-      }
-    }
-    dense.push(points.at(-1));
-    return dense;
-  }
-
-  function buildLines(record) {
-    const host = new Cesium.PolylineCollection();
-    for (const item of record.items.values()) {
-      if (item.mode === 'draped')
-        throw new Error('the scene renderer has no draped lines');
-      host.add({
-        positions: linePositions(item),
-        width: item.widthPx,
-        material: lineMaterial(item.style),
-        show: item.show !== false,
-        id: pickId(record, item),
-      });
-    }
-    replaceHost(record, host);
-  }
-
-  const heightOf = (pos) =>
-    'x' in pos
-      ? Cesium.Cartographic.fromCartesian(toCartesian(pos)).height
-      : (pos.height ?? 0);
-
-  function shapeGeometry(item) {
-    const g = item.geometry;
-    const extrudedHeight = item.extrudeHeight;
-    switch (g.kind) {
-      case 'polygon': {
-        const [outer, ...holes] = g.rings.map((ring) => ring.map(toCartesian));
-        const hierarchy = new Cesium.PolygonHierarchy(
-          outer,
-          holes.map((h) => new Cesium.PolygonHierarchy(h)),
-        );
-        return {
-          fill: new Cesium.PolygonGeometry({
-            polygonHierarchy: hierarchy,
-            height: g.perPositionHeight ? undefined : heightOf(g.rings[0][0]),
-            extrudedHeight,
-            perPositionHeight: g.perPositionHeight,
-          }),
-          ring: outer,
-        };
-      }
-      case 'ellipse':
-        return {
-          fill: new Cesium.EllipseGeometry({
-            center: toCartesian(g.center),
-            semiMajorAxis: g.semiMajor,
-            semiMinorAxis: g.semiMinor,
-            rotation: g.rotation ?? 0,
-            height: heightOf(g.center),
-            extrudedHeight,
-          }),
-        };
-      case 'rectangle':
-        return {
-          fill: new Cesium.RectangleGeometry({
-            rectangle: Cesium.Rectangle.fromDegrees(
-              g.rect.west,
-              g.rect.south,
-              g.rect.east,
-              g.rect.north,
-            ),
-            height: g.height ?? 0,
-            extrudedHeight,
-          }),
-        };
-      case 'box': {
-        const d = g.dimensions;
-        return {
-          fill: Cesium.BoxGeometry.fromDimensions({
-            dimensions: new Cesium.Cartesian3(d.x, d.y, d.z),
-          }),
-          modelMatrix: Cesium.Transforms.eastNorthUpToFixedFrame(
-            toCartesian(g.center),
-          ),
-        };
-      }
-      default:
-        throw new Error(`the scene renderer has no ${g.kind} shapes`);
-    }
-  }
-
-  function buildShapes(record) {
-    const host = new Cesium.PrimitiveCollection();
-    const outlines = new Cesium.PolylineCollection();
-    for (const item of record.items.values()) {
-      if (item.show === false) continue;
-      if (
-        item.fill &&
-        typeof item.fill === 'object' &&
-        !Array.isArray(item.fill)
-      )
-        throw new Error('the scene renderer fills shapes with colours only');
-      const shape = shapeGeometry(item);
-      const id = pickId(record, item);
-      const solid =
-        item.extrudeHeight !== undefined || item.geometry.kind === 'box';
-      if (item.fill && !item.outlineOnly) {
-        const color = toColor(item.fill);
-        host.add(
-          new Cesium.Primitive({
-            geometryInstances: new Cesium.GeometryInstance({
-              geometry: shape.fill,
-              modelMatrix: shape.modelMatrix,
-              attributes: {
-                color: Cesium.ColorGeometryInstanceAttribute.fromColor(color),
-              },
-              id,
-            }),
-            appearance: new Cesium.PerInstanceColorAppearance({
-              translucent: color.alpha < 1,
-              closed: solid,
-              // Flat shapes unlit: lit, their two triangles shade apart.
-              flat: !solid,
-            }),
-            asynchronous: false,
-          }),
-        );
-      }
-      if (item.outline && shape.ring)
-        outlines.add({
-          positions: [...shape.ring, shape.ring[0]],
-          width: item.outlineWidth ?? 1,
-          material: Cesium.Material.fromType('Color', {
-            color: toColor(item.outline),
-          }),
-          id,
-        });
-    }
-    host.add(outlines);
-    replaceHost(record, host);
-  }
-
-  function buildModels(record) {
-    const host = new Cesium.PrimitiveCollection();
-    replaceHost(record, host);
-    // A model counts as loading until it is ready or fails, not when added;
-    // each model settles once, and a failure is kept for `whenSettled`.
-    host.loading = record.items.size;
-    host.failed = 0;
-    for (const item of record.items.values()) {
-      let settled = false;
-      const settle = (failed) => {
-        if (settled) return;
-        settled = true;
-        host.loading -= 1;
-        if (failed) host.failed += 1;
-        scene.requestRender();
-      };
-      const o = item.orientation;
-      const modelMatrix = Cesium.Transforms.headingPitchRollToFixedFrame(
-        toCartesian(item.pos),
-        new Cesium.HeadingPitchRoll(o.heading, o.pitch, o.roll),
-      );
-      Cesium.Model.fromGltfAsync({
-        url: item.url,
-        modelMatrix,
-        scale: item.scale ?? 1,
-        minimumPixelSize: item.minPixelSize ?? 0,
-        // All textures before ready, so a settled capture is the whole model.
-        incrementallyLoadTextures: false,
-        id: pickId(record, item),
-      }).then(
-        (model) => {
-          if (record.host !== host) return model.destroy();
-          host.add(model);
-          model.readyEvent.addEventListener(() => {
-            settle(false);
-            for (const cb of record.listeners.ready.slice()) cb(item.id);
-          });
-          model.errorEvent.addEventListener(() => settle(true));
-          scene.requestRender();
-        },
-        () => settle(true),
-      );
-    }
-  }
-
-  const draw = {
-    icons: (spec) => makeSet('icons', { ...spec }, buildIcons),
-    points: (spec) => makeSet('points', { ...spec }, buildPoints),
-    lines: (spec) => makeSet('lines', { ...spec }, buildLines),
-    shapes: (spec) => makeSet('shapes', { ...spec }, buildShapes),
-    models: (spec) => makeSet('models', { ...spec }, buildModels),
-  };
-
-  // --- Globe, camera, query --------------------------------------------------
 
   const globe = {
     async setBase(base) {
@@ -549,75 +107,14 @@ export async function createCesiumSceneRenderer({ container, msaa = 4 }) {
     isSettled: () => scene.globe.tilesLoaded,
   };
 
-  const cameraPort = {
-    setView(spec) {
-      const d = spec.destination;
-      if (d && 'rect' in d)
-        throw new Error('the scene renderer takes position destinations only');
-      const o = spec.orientation ?? {};
-      camera.setView({
-        ...(d ? { destination: toCartesian(d) } : {}),
-        orientation: {
-          heading: o.heading ?? 0,
-          pitch: o.pitch ?? -Math.PI / 2,
-          roll: o.roll ?? 0,
-        },
-      });
-      scene.requestRender();
-    },
-    pose() {
-      const v = (c) => ({ x: c.x, y: c.y, z: c.z });
-      return {
-        position: v(camera.positionWC),
-        direction: v(camera.directionWC),
-        up: v(camera.upWC),
-        right: v(camera.rightWC),
-        heading: camera.heading,
-        pitch: camera.pitch,
-        roll: camera.roll,
-        height: camera.positionCartographic.height,
-        fovy: camera.frustum.fovy,
-        aspectRatio: camera.frustum.aspectRatio,
-        near: camera.frustum.near,
-        far: camera.frustum.far,
-        frameIsIdentity: Cesium.Matrix4.equals(
-          camera.transform,
-          Cesium.Matrix4.IDENTITY,
-        ),
-      };
-    },
-  };
-
-  const query = {
-    pick(x, y) {
-      const picked = scene.pick(new Cesium.Cartesian2(x, y));
-      const id = picked?.id;
-      return id && typeof id.set === 'string'
-        ? { ...id, surface: false }
-        : null;
-    },
-    project(position) {
-      const s = Cesium.SceneTransforms.worldToWindowCoordinates(
-        scene,
-        toCartesian(position),
-      );
-      return s ? { x: s.x, y: s.y } : null;
-    },
-    pickEllipsoid(x, y) {
-      const c = camera.pickEllipsoid(new Cesium.Cartesian2(x, y));
-      return c ? { x: c.x, y: c.y, z: c.z } : null;
-    },
-  };
-
   // --- Renderer --------------------------------------------------------------
 
   async function whenSettled({ timeoutMs = 20000 } = {}) {
-    const models = () =>
+    const models = ports.modelSets;
-      [...sets.values()].filter((r) => r.kind === 'models' && r.host);
     const end = performance.now() + timeoutMs;
     let quiet = 0;
     while (performance.now() < end) {
-      await nextPostRender();
+      await ports.nextPostRender();
       if (models().some((r) => r.host.failed > 0))
         return { state: 'failed', blockers: ['models'] };
       const loading = models().some((r) => r.host.loading > 0);
@@ -637,19 +134,14 @@ export async function createCesiumSceneRenderer({ container, msaa = 4 }) {
     canvas: scene.canvas,
     frame,
     globe,
-    draw,
+    draw: ports.draw,
-    camera: cameraPort,
+    camera: ports.camera,
-    query,
+    query: ports.query,
-    async capture({ type = 'png' } = {}) {
+    capture: ports.capture,
-      scene.render(widget.clock.currentTime);
-      return new Promise((resolve) =>
-        scene.canvas.toBlob(resolve, `image/${type}`),
-      );
-    },
     whenSettled,
     resize: () => widget.resize(),
     destroy() {
-      for (const off of removers) off();
+      ports.dispose();
       widget.destroy();
     },
   };