gods-eye-view/src/ui/flyToDataSource.test.mjs

import test from 'node:test';
import assert from 'node:assert/strict';
import * as Cesium from 'cesium';
import { cancelCameraArrival } from '../data/cameraArrival.js';
import { dataSourcePoints, flyToDataSource } from './flyToDataSource.js';

function source() {
  const ds = new Cesium.CustomDataSource('t');
  ds.entities.add({
    position: Cesium.Cartesian3.fromDegrees(-122.4862, 37.7694, -2667),
    billboard: { heightReference: Cesium.HeightReference.CLAMP_TO_GROUND },
  });
  ds.entities.add({
    polyline: {
      positions: Cesium.Cartesian3.fromDegreesArray([
        -122.49, 37.77, -122.48, 37.771,
      ]),
    },
  });
  ds.entities.add({
    polygon: {
      hierarchy: Cesium.Cartesian3.fromDegreesArray([
        -122.5, 37.76, -122.49, 37.76, -122.49, 37.765,
      ]),
    },
  });
  return ds;
}

test('points come from positions, lines and polygons, as lon/lat only', () => {
  const points = dataSourcePoints(source());
  assert.equal(points.length, 6);
  assert.ok(Math.abs(points[0][0] + 122.4862) < 1e-6);
  assert.ok(Math.abs(points[0][1] - 37.7694) < 1e-6);
});

test('the camera frames the footprint at the surface, never a buried center', () => {
  const calls = [];
  const viewer = {
    camera: {
      heading: 0,
      flyToBoundingSphere: (sphere, options) => calls.push({ sphere, options }),
    },
    flyTo: () => calls.push('viewer.flyTo'),
  };
  assert.equal(flyToDataSource(viewer, source()), true);
  const center = Cesium.Cartographic.fromCartesian(calls[0].sphere.center);
  assert.ok(Math.abs(center.height) < 50, `center height ${center.height}`);
  assert.ok(calls[0].options.offset.range >= 800);
  assert.equal(
    typeof calls[0].options.complete,
    'function',
    'the ground guard runs on landing',
  );
  assert.equal(
    flyToDataSource(viewer, new Cesium.CustomDataSource('empty')),
    false,
  );
  assert.equal(
    calls.length,
    1,
    'empty sources never start deferred navigation',
  );
});

test('a very long track is framed without spreading it into a call', () => {
  // 400k vertices: `push(...line)` throws RangeError (too many arguments)
  // well below this; the walk keeps a bounded sample and both ends.
  const n = 400_000;
  const line = new Array(n);
  for (let i = 0; i < n; i++)
    line[i] = Cesium.Cartesian3.fromDegrees(-120 + (i / n) * 2, 40);
  const ds = new Cesium.CustomDataSource('long');
  ds.entities.add({ polyline: { positions: line } });
  ds.entities.add({ position: Cesium.Cartesian3.fromDegrees(-110, 41) });
  const points = dataSourcePoints(ds);
  assert.equal(points.length, n + 1, 'every vertex contributes to framing');
  const lons = points.map(([lon]) => lon);
  assert.ok(
    lons.reduce((a, b) => Math.min(a, b), Infinity) < -119.99 &&
      lons.reduce((a, b) => Math.max(a, b), -Infinity) > -110.01,
  );
  assert.ok(lons.some((lon) => Math.abs(lon - -118.000005) < 0.01));
});

test('framing includes a sparse interior outlier, walls and rotated overlays', () => {
  const ds = new Cesium.CustomDataSource('bounds');
  const line = Array.from({ length: 200031 }, () =>
    Cesium.Cartesian3.fromDegrees(0, 0),
  );
  line[12345] = Cesium.Cartesian3.fromDegrees(20, 10);
  ds.entities.add({ polyline: { positions: line } });
  ds.entities.add({
    wall: { positions: Cesium.Cartesian3.fromDegreesArray([30, 10, 31, 11]) },
  });
  ds.entities.add({
    rectangle: {
      coordinates: Cesium.Rectangle.fromDegrees(40, 0, 41, 1),
      rotation: Math.PI / 4,
    },
  });
  const points = dataSourcePoints(ds);
  assert.ok(points.some(([lon]) => Math.abs(lon - 20) < 1e-6));
  assert.ok(points.some(([lon]) => Math.abs(lon - 31) < 1e-6));
  assert.ok(points.some(([lon]) => lon > 41));
});

test('portrait framing accounts for FOV, high ground and symmetric extents', () => {
  const ds = new Cesium.CustomDataSource('view');
  ds.entities.add({
    polyline: {
      positions: Cesium.Cartesian3.fromDegreesArray([-105, 39, -104.9, 39]),
    },
  });
  const calls = [];
  const viewer = {
    scene: { globe: { getHeight: () => 2600 } },
    camera: {
      frustum: { fov: Math.PI / 3, aspectRatio: 390 / 844 },
      flyToBoundingSphere: (sphere, options) => calls.push({ sphere, options }),
    },
  };
  flyToDataSource(viewer, ds);
  assert.ok(
    Math.abs(
      Cesium.Cartographic.fromCartesian(calls[0].sphere.center).height - 2600,
    ) < 1e-6,
  );
  assert.equal(calls[0].options.offset.pitch, -Math.PI / 2);
  viewer.camera.frustum.aspectRatio = 16 / 9;
  flyToDataSource(viewer, ds);
  assert.ok(calls[0].options.offset.range > calls[1].options.offset.range);
  const symmetric = {
    entities: {
      values: [
        { position: { getValue: () => new Cesium.Cartesian3(6378137, 0, 0) } },
        { position: { getValue: () => new Cesium.Cartesian3(-6378137, 0, 0) } },
      ],
    },
  };
  assert.doesNotThrow(() => flyToDataSource(viewer, symmetric));
  assert.ok(Number.isFinite(calls.at(-1).options.offset.range));
  assert.doesNotThrow(() => calls.at(-1).options.complete());
  cancelCameraArrival(viewer);
});

test('non-finite positions and hidden features never enter the camera footprint', () => {
  const position = (p) => ({ position: { getValue: () => p } });
  const points = dataSourcePoints({
    entities: {
      values: [
        position(new Cesium.Cartesian3(NaN, 1, 2)),
        {
          ...position(Cesium.Cartesian3.fromDegrees(10, 10)),
          isShowing: false,
        },
        position(Cesium.Cartesian3.fromDegrees(20, 20)),
      ],
    },
  });
  assert.equal(points.length, 1);
  assert.ok(Math.abs(points[0][0] - 20) < 1e-6);
});