Release God's Eye View as open source

src/data/cctvGizmo.test.mjs

@@ -0,0 +1,88 @@
+// src/data/cctvGizmo.test.mjs — pure drag math for the CCTV calibration gizmo
+// documented in docs/CURRENT-STATE.md.
+//
+// Locks:
+//   - closestParamOnAxis returns the metre-parameter along the AXIS of the
+//     point nearest the mouse ray (the workhorse for arrow/range drags), and
+//     refuses near-parallel configurations instead of exploding;
+//   - rayPlaneIntersect refuses grazing rays (|dir·normal| < 0.08 — spec §5
+//     precision guard) and behind-origin hits;
+//   - ringAngle/signedAngleDelta give quadrant-correct, wrap-safe angles for
+//     the heading/pitch ring drags.
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import * as Cesium from 'cesium';
+import {
+  closestParamOnAxis,
+  rayPlaneIntersect,
+  ringAngle,
+  signedAngleDelta,
+} from './cctvGizmo.js';
+
+const c3 = (x, y, z) => new Cesium.Cartesian3(x, y, z);
+
+test('closestParamOnAxis: perpendicular ray hits the axis at its own offset', () => {
+  // Axis along +X from origin. Ray shooting straight down (-Z) from (10, 0, 5):
+  // nearest axis point is x=10 → t=10.
+  const t = closestParamOnAxis(c3(10, 0, 5), c3(0, 0, -1), c3(0, 0, 0), c3(1, 0, 0));
+  assert.ok(Math.abs(t - 10) < 1e-9, `expected 10, got ${t}`);
+});
+
+test('closestParamOnAxis: skew ray resolves to the geometric closest point', () => {
+  // Axis +X. Ray from (0, 10, 0) toward (1, -1, 0)/√2 passes closest to the
+  // axis around x=10 (it reaches y=0 at x=10).
+  const dir = Cesium.Cartesian3.normalize(c3(1, -1, 0), new Cesium.Cartesian3());
+  const t = closestParamOnAxis(c3(0, 10, 0), dir, c3(0, 0, 0), c3(1, 0, 0));
+  assert.ok(Math.abs(t - 10) < 1e-6, `expected ~10, got ${t}`);
+});
+
+test('closestParamOnAxis: axis origin offset shifts the parameter', () => {
+  const t = closestParamOnAxis(c3(10, 0, 5), c3(0, 0, -1), c3(4, 0, 0), c3(1, 0, 0));
+  assert.ok(Math.abs(t - 6) < 1e-9, `expected 6, got ${t}`);
+});
+
+test('closestParamOnAxis: near-parallel ray/axis returns null', () => {
+  assert.equal(closestParamOnAxis(c3(0, 1, 0), c3(1, 0, 0), c3(0, 0, 0), c3(1, 0, 0)), null);
+  const nearly = Cesium.Cartesian3.normalize(c3(1, 1e-9, 0), new Cesium.Cartesian3());
+  assert.equal(closestParamOnAxis(c3(0, 1, 0), nearly, c3(0, 0, 0), c3(1, 0, 0)), null);
+});
+
+test('rayPlaneIntersect: straight-on hit lands at the expected point', () => {
+  const hit = rayPlaneIntersect(c3(0, 0, 10), c3(0, 0, -1), c3(0, 0, 0), c3(0, 0, 1));
+  assert.ok(hit, 'expected a hit');
+  assert.ok(Cesium.Cartesian3.distance(hit, c3(0, 0, 0)) < 1e-9);
+});
+
+test('rayPlaneIntersect: oblique hit resolves correctly', () => {
+  const dir = Cesium.Cartesian3.normalize(c3(1, 0, -1), new Cesium.Cartesian3());
+  const hit = rayPlaneIntersect(c3(0, 0, 5), dir, c3(0, 0, 0), c3(0, 0, 1));
+  assert.ok(hit);
+  assert.ok(Cesium.Cartesian3.distance(hit, c3(5, 0, 0)) < 1e-9, `got ${hit}`);
+});
+
+test('rayPlaneIntersect: grazing ray (|dir·n| < 0.08) returns null', () => {
+  // dir almost in-plane: z component 0.05 < 0.08 threshold.
+  const dir = Cesium.Cartesian3.normalize(c3(1, 0, -0.05), new Cesium.Cartesian3());
+  assert.equal(rayPlaneIntersect(c3(0, 0, 5), dir, c3(0, 0, 0), c3(0, 0, 1)), null);
+});
+
+test('rayPlaneIntersect: plane behind the ray origin returns null', () => {
+  assert.equal(rayPlaneIntersect(c3(0, 0, 10), c3(0, 0, 1), c3(0, 0, 0), c3(0, 0, 1)), null);
+});
+
+test('ringAngle: quadrant sweep in the (basisA, basisB) frame', () => {
+  const center = c3(0, 0, 0);
+  const a = c3(1, 0, 0);
+  const b = c3(0, 1, 0);
+  assert.ok(Math.abs(ringAngle(c3(5, 0, 0), center, a, b) - 0) < 1e-9);
+  assert.ok(Math.abs(ringAngle(c3(0, 5, 0), center, a, b) - Math.PI / 2) < 1e-9);
+  assert.ok(Math.abs(Math.abs(ringAngle(c3(-5, 0, 0), center, a, b)) - Math.PI) < 1e-9);
+  assert.ok(Math.abs(ringAngle(c3(0, -5, 0), center, a, b) + Math.PI / 2) < 1e-9);
+});
+
+test('signedAngleDelta: shortest-path wrap', () => {
+  const d2r = (d) => (d * Math.PI) / 180;
+  assert.ok(Math.abs(signedAngleDelta(d2r(170), d2r(-170)) - d2r(20)) < 1e-9);
+  assert.ok(Math.abs(signedAngleDelta(d2r(-170), d2r(170)) - d2r(-20)) < 1e-9);
+  assert.ok(Math.abs(signedAngleDelta(d2r(10), d2r(30)) - d2r(20)) < 1e-9);
+});