Hand tracking

tests/hand-aim.test.mjs

@@ -1,41 +1,58 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
 
-import { computePalmAimRay } from '../vr180player/xr/hand-aim.js';
+import {
+	beginPalmAimSelection,
+	computePalmAimRay,
+	createPalmAimLatch,
+	endPalmAimSelection,
+	getPalmAimSelectionRay,
+	recordStablePalmAimRay
+} from '../vr180player/xr/hand-aim.js';
 
 const wrist = { x: 0, y: 0, z: 0 };
 const middleMetacarpal = { x: 0, y: 0.1, z: 0 };
 const ringMetacarpal = { x: 0.025, y: 0.1, z: 0 };
+const straightAheadRay = {
+	direction: { x: 0, y: 0, z: -1 },
+	origin: { x: 0, y: 1.4, z: -0.04 }
+};
+const pinchedRay = {
+	direction: { x: 0.4, y: -0.2, z: -0.8 },
+	origin: { x: 0.04, y: 1.32, z: -0.03 }
+};
 
-test('computePalmAimRay points out from a right palm instead of following the index finger', () => {
+test('computePalmAimRay tilts a right palm ray toward the finger-forward axis', () => {
 	const ray = computePalmAimRay({
 		handedness: 'right',
-		indexMetacarpal: { x: -0.035, y: 0.1, z: 0 },
-		middleMetacarpal,
-		pinkyMetacarpal: { x: 0.055, y: 0.1, z: 0 },
-		ringMetacarpal,
+		indexMetacarpal: { x: -0.045, y: 0.1, z: 0 },
+		middleMetacarpal: { x: -0.015, y: 0.1, z: 0 },
+		pinkyMetacarpal: { x: 0.045, y: 0.1, z: 0 },
+		ringMetacarpal: { x: 0.015, y: 0.1, z: 0 },
 		wrist
 	});
 
 	assert.ok(ray);
 	assert.equal(Math.round(ray.direction.x * 1000) / 1000, 0);
-	assert.equal(Math.round(ray.direction.y * 1000) / 1000, 0);
-	assert.equal(Math.round(ray.direction.z * 1000) / 1000, -1);
-	assert.equal(Math.round(ray.origin.z * 1000) / 1000, -0.035);
+	assert.equal(Math.round(ray.direction.y * 1000) / 1000, 0.643);
+	assert.equal(Math.round(ray.direction.z * 1000) / 1000, -0.766);
+	assert.equal(Math.round(ray.origin.y * 1000) / 1000, 0.084);
+	assert.equal(Math.round(ray.origin.z * 1000) / 1000, -0.027);
 });
 
-test('computePalmAimRay flips the palm normal for a left hand', () => {
+test('computePalmAimRay flips the palm normal for a left hand while keeping forward tilt', () => {
 	const ray = computePalmAimRay({
 		handedness: 'left',
-		indexMetacarpal: { x: 0.035, y: 0.1, z: 0 },
-		middleMetacarpal,
-		pinkyMetacarpal: { x: -0.055, y: 0.1, z: 0 },
-		ringMetacarpal: { x: -0.025, y: 0.1, z: 0 },
+		indexMetacarpal: { x: 0.045, y: 0.1, z: 0 },
+		middleMetacarpal: { x: 0.015, y: 0.1, z: 0 },
+		pinkyMetacarpal: { x: -0.045, y: 0.1, z: 0 },
+		ringMetacarpal: { x: -0.015, y: 0.1, z: 0 },
 		wrist
 	});
 
 	assert.ok(ray);
-	assert.equal(Math.round(ray.direction.z * 1000) / 1000, -1);
+	assert.equal(Math.round(ray.direction.y * 1000) / 1000, 0.643);
+	assert.equal(Math.round(ray.direction.z * 1000) / 1000, -0.766);
 });
 
 test('computePalmAimRay returns null when palm joints cannot define a stable ray', () => {
@@ -47,3 +64,38 @@ test('computePalmAimRay returns null when palm joints cannot define a stable ray
 		wrist
 	}), null);
 });
+
+test('palm aim latch returns the latest fresh stable ray', () => {
+	const latch = createPalmAimLatch();
+
+	recordStablePalmAimRay(latch, straightAheadRay, 100);
+
+	assert.deepEqual(getPalmAimSelectionRay(latch, 120), straightAheadRay);
+	assert.equal(getPalmAimSelectionRay(latch, 500), null);
+});
+
+test('palm aim latch freezes the pre-selection ray while selecting', () => {
+	const latch = createPalmAimLatch();
+
+	recordStablePalmAimRay(latch, straightAheadRay, 100);
+	assert.deepEqual(beginPalmAimSelection(latch, 120), straightAheadRay);
+
+	recordStablePalmAimRay(latch, pinchedRay, 130);
+
+	assert.deepEqual(getPalmAimSelectionRay(latch, 140), straightAheadRay);
+	assert.deepEqual(getPalmAimSelectionRay(latch, 1000), straightAheadRay);
+
+	endPalmAimSelection(latch);
+	recordStablePalmAimRay(latch, pinchedRay, 150);
+
+	assert.deepEqual(getPalmAimSelectionRay(latch, 160), pinchedRay);
+});
+
+test('palm aim latch ignores stale rays when selection starts too late', () => {
+	const latch = createPalmAimLatch();
+
+	recordStablePalmAimRay(latch, straightAheadRay, 100);
+
+	assert.equal(beginPalmAimSelection(latch, 450), null);
+	assert.equal(getPalmAimSelectionRay(latch, 450), null);
+});