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feat: add authenticated realtime presence

This commit is contained in:
2026-08-11 20:22:12 -07:00
parent 16dc85a6f8
commit 92ebf8abb5
20 changed files with 3746 additions and 1 deletions
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import {
isEntityPoseSnapshot,
isInterestCell,
validateClientRealtimeMessage,
validateServerRealtimeMessage,
} from "./protocol.ts";
import type {
EntityPoseSnapshot,
InterestCell,
JoinGrant,
JoinRequest,
ResumeGrant,
ResumeRequest,
ServerRealtimeMessage,
} from "./types.ts";
const MIN_SEND_INTERVAL_MS = 1_000 / 15;
const MAX_SEND_INTERVAL_MS = 1_000 / 10;
const UINT32_MAX = 4_294_967_295;
type Fetch = typeof globalThis.fetch;
type TimerHandle = ReturnType<typeof globalThis.setTimeout>;
export interface RealtimeClientTimers {
setTimeout(callback: () => void, delayMs: number): TimerHandle;
clearTimeout(handle: TimerHandle): void;
}
export interface RealtimeClientEndpoints {
join: string;
pose: string;
events: string;
leave: string;
}
export type RealtimeClientStatus =
| "idle"
| "joined"
| "streaming"
| "reconnecting"
| "left"
| "disposed";
export interface RealtimeClientState {
status: RealtimeClientStatus;
sessionId: string | null;
actorId: string;
interests: readonly InterestCell[];
serverEpoch: string | null;
lastReceivedSequence: number | null;
nextPoseSequence: number;
posePending: boolean;
subscribed: boolean;
reconnectAttempt: number;
}
export interface RealtimeSubscriptionCallbacks {
onMessage?(message: ServerRealtimeMessage): void;
onStateChange?(state: RealtimeClientState): void;
/** Receives protocol/parser errors without the untrusted payload or credentials. */
onMalformedEvent?(error: Error): void;
onError?(error: Error): void;
}
export interface RealtimeClientOptions {
actorId: string;
/**
* Optional SSO bearer, kept only in this closure and never placed in a URL.
* Omit it when the deployment uses an HttpOnly same-origin session cookie.
*/
accessToken?: string;
/**
* Preferred request adapter for hosted builds. Passing `authFetch` keeps SSO
* token lookup at request time and also supports HttpOnly cookie sessions.
*/
authenticatedFetch?: Fetch;
endpoints?: Partial<RealtimeClientEndpoints>;
fetch?: Fetch;
timers?: RealtimeClientTimers;
sendIntervalMs?: number;
reconnectBaseMs?: number;
reconnectMaximumMs?: number;
reconnectJitter?: number;
random?: () => number;
}
export interface RealtimeClient {
join(
interest: InterestCell | readonly InterestCell[],
entity: EntityPoseSnapshot,
): Promise<JoinGrant>;
publishPose(entity: EntityPoseSnapshot): void;
subscribe(callbacks: RealtimeSubscriptionCallbacks): () => void;
moveInterest(interest: InterestCell | readonly InterestCell[]): Promise<ResumeGrant>;
rejoin(): Promise<ResumeGrant>;
state(): RealtimeClientState;
leave(): Promise<void>;
dispose(): Promise<void>;
}
const DEFAULT_ENDPOINTS: RealtimeClientEndpoints = {
join: "/api/v1/realtime/join",
pose: "/api/v1/realtime/pose",
events: "/api/v1/realtime/events",
leave: "/api/v1/realtime/leave",
};
const DEFAULT_TIMERS: RealtimeClientTimers = {
setTimeout: (callback, delayMs) => globalThis.setTimeout(callback, delayMs),
clearTimeout: (handle) => globalThis.clearTimeout(handle),
};
function requireNonEmpty(value: string, name: string): void {
if (value.length === 0 || value.length > 256) throw new TypeError(`${name} must be 1-256 characters`);
}
function normalizeInterests(value: InterestCell | readonly InterestCell[]): readonly InterestCell[] {
const values = Array.isArray(value) ? value : [value];
if (values.length === 0 || values.length > 128 || !values.every(isInterestCell)) {
throw new TypeError("realtime interests are invalid");
}
return values.map((interest) => ({ ...interest }));
}
function errorFrom(reason: unknown, fallback: string): Error {
return reason instanceof Error ? reason : new Error(fallback);
}
function isTerminalStatus(status: RealtimeClientStatus): boolean {
return status === "disposed" || status === "left";
}
/**
* Browser transport for the server-authoritative realtime protocol.
*
* Streaming uses fetch + ReadableStream instead of EventSource. This permits a
* normal Authorization header and POST body, keeping both the access token and
* resume token out of URLs, referrers, history, and intermediary URL logs.
*/
export function createRealtimeClient(options: RealtimeClientOptions): RealtimeClient {
requireNonEmpty(options.actorId, "actorId");
if (options.accessToken !== undefined) requireNonEmpty(options.accessToken, "accessToken");
if (options.fetch && options.authenticatedFetch) {
throw new TypeError("provide either fetch or authenticatedFetch, not both");
}
const fetcher = options.authenticatedFetch ?? options.fetch ?? globalThis.fetch;
if (typeof fetcher !== "function") throw new TypeError("fetch is required");
const timers = options.timers ?? DEFAULT_TIMERS;
const endpoints = { ...DEFAULT_ENDPOINTS, ...options.endpoints };
for (const [name, endpoint] of Object.entries(endpoints)) requireNonEmpty(endpoint, `${name} endpoint`);
const sendIntervalMs = options.sendIntervalMs ?? MAX_SEND_INTERVAL_MS;
if (!Number.isFinite(sendIntervalMs) || sendIntervalMs < MIN_SEND_INTERVAL_MS || sendIntervalMs > MAX_SEND_INTERVAL_MS) {
throw new RangeError("sendIntervalMs must be between 66.67ms (15Hz) and 100ms (10Hz)");
}
const reconnectBaseMs = options.reconnectBaseMs ?? 500;
const reconnectMaximumMs = options.reconnectMaximumMs ?? 30_000;
const reconnectJitter = options.reconnectJitter ?? 0.2;
if (!Number.isFinite(reconnectBaseMs) || reconnectBaseMs <= 0) throw new RangeError("reconnectBaseMs must be positive");
if (!Number.isFinite(reconnectMaximumMs) || reconnectMaximumMs < reconnectBaseMs) {
throw new RangeError("reconnectMaximumMs must be at least reconnectBaseMs");
}
if (!Number.isFinite(reconnectJitter) || reconnectJitter < 0 || reconnectJitter > 1) {
throw new RangeError("reconnectJitter must be between zero and one");
}
const random = options.random ?? Math.random;
let status: RealtimeClientStatus = "idle";
let interests: readonly InterestCell[] = [];
let sessionId: string | null = null;
let serverEpoch: string | null = null;
let resumeToken: string | null = null;
let lastReceivedSequence: number | null = null;
let nextPoseSequence = 0;
let pendingPose: EntityPoseSnapshot | null = null;
let poseTimer: TimerHandle | null = null;
let reconnectTimer: TimerHandle | null = null;
let reconnectAttempt = 0;
let subscription: RealtimeSubscriptionCallbacks | null = null;
let streamAbort: AbortController | null = null;
// Resume rotates the credential. Do not race a pose against the first grant
// and send the token the server has just retired.
let streamReady = false;
let streamGeneration = 0;
// Scene changes can overtake join/resume HTTP calls. Only the newest
// transition may commit credentials or interest cells.
let transitionGeneration = 0;
let requestCounter = 0;
function snapshot(): RealtimeClientState {
return {
status,
sessionId,
actorId: options.actorId,
interests: interests.map((interest) => ({ ...interest })),
serverEpoch,
lastReceivedSequence,
nextPoseSequence,
posePending: pendingPose !== null,
subscribed: subscription !== null,
reconnectAttempt,
};
}
function changed(): void {
subscription?.onStateChange?.(snapshot());
}
function requestId(): string {
requestCounter += 1;
return `tera-client-${requestCounter}`;
}
function authHeaders(accept = "application/json"): HeadersInit {
const headers: Record<string, string> = {
Accept: accept,
"Content-Type": "application/json",
};
if (options.accessToken !== undefined) headers.Authorization = `Bearer ${options.accessToken}`;
return headers;
}
async function post(endpoint: string, body: unknown, accept?: string, signal?: AbortSignal): Promise<Response> {
return fetcher(endpoint, {
method: "POST",
credentials: "same-origin",
cache: "no-store",
redirect: "error",
headers: authHeaders(accept),
body: JSON.stringify(body),
signal,
});
}
async function json(response: Response): Promise<unknown> {
if (!response.ok) throw new Error(`realtime request failed (${response.status})`);
return response.json() as Promise<unknown>;
}
function cancelPose(): void {
if (poseTimer !== null) timers.clearTimeout(poseTimer);
poseTimer = null;
pendingPose = null;
}
function cancelStream(): void {
streamGeneration += 1;
streamAbort?.abort();
streamAbort = null;
streamReady = false;
if (reconnectTimer !== null) timers.clearTimeout(reconnectTimer);
reconnectTimer = null;
}
function acceptMessage(message: ServerRealtimeMessage): boolean {
if (serverEpoch !== null && "serverEpoch" in message && message.serverEpoch !== serverEpoch) {
subscription?.onMalformedEvent?.(new Error("realtime event belongs to a different server epoch"));
return false;
}
if (message.type === "pose-delta" || message.type === "membership-revoked") {
if (lastReceivedSequence !== null && message.sequence <= lastReceivedSequence) {
subscription?.onMalformedEvent?.(new Error("realtime event sequence is not monotonic"));
return false;
}
lastReceivedSequence = message.sequence;
} else if (message.type === "resume-grant") {
resumeToken = message.resumeToken;
serverEpoch = message.serverEpoch;
lastReceivedSequence = message.nextSequence === 0 ? 0 : message.nextSequence - 1;
streamReady = true;
status = "streaming";
}
reconnectAttempt = 0;
subscription?.onMessage?.(message);
if (message.type === "membership-revoked" && !message.reconnectAllowed) {
cancelStream();
status = "left";
resumeToken = null;
}
changed();
return true;
}
function parseEvent(data: string): void {
if (data.length === 0) return;
let raw: unknown;
try {
raw = JSON.parse(data);
} catch {
subscription?.onMalformedEvent?.(new Error("realtime event is not valid JSON"));
return;
}
const result = validateServerRealtimeMessage(raw);
if (!result.ok) {
subscription?.onMalformedEvent?.(new Error(result.error));
return;
}
acceptMessage(result.value);
}
async function readSse(response: Response, generation: number): Promise<void> {
if (!response.ok) throw new Error(`realtime stream failed (${response.status})`);
if (!response.body) throw new Error("realtime stream response has no body");
const reader = response.body.getReader();
const decoder = new TextDecoder();
let buffer = "";
let dataLines: string[] = [];
const line = (value: string): void => {
if (value === "") {
if (dataLines.length > 0) parseEvent(dataLines.join("\n"));
dataLines = [];
} else if (value.startsWith("data:")) {
dataLines.push(value.slice(5).replace(/^ /, ""));
}
};
try {
while (generation === streamGeneration) {
const chunk = await reader.read();
// An abort and an already-queued chunk may settle together. Never
// parse the old cell after another transition has won that race.
if (generation !== streamGeneration) break;
if (chunk.done) break;
buffer += decoder.decode(chunk.value, { stream: true }).replace(/\r\n/g, "\n").replace(/\r/g, "\n");
let newline = buffer.indexOf("\n");
while (newline >= 0) {
line(buffer.slice(0, newline));
buffer = buffer.slice(newline + 1);
newline = buffer.indexOf("\n");
}
}
if (generation !== streamGeneration) return;
buffer += decoder.decode();
if (buffer.length > 0) line(buffer);
if (dataLines.length > 0) parseEvent(dataLines.join("\n"));
} finally {
reader.releaseLock();
}
}
function reconnectDelay(): number {
const exponential = Math.min(reconnectMaximumMs, reconnectBaseMs * 2 ** reconnectAttempt);
const factor = 1 + (random() * 2 - 1) * reconnectJitter;
return Math.max(0, exponential * factor);
}
function scheduleReconnect(): void {
if (!subscription || status === "left" || status === "disposed" || reconnectTimer !== null) return;
status = "reconnecting";
const delay = reconnectDelay();
reconnectAttempt += 1;
changed();
reconnectTimer = timers.setTimeout(() => {
reconnectTimer = null;
void startStream();
}, delay);
}
async function startStream(): Promise<void> {
if (!subscription || !sessionId || !resumeToken || !serverEpoch || lastReceivedSequence === null) return;
cancelStream();
const generation = streamGeneration;
const abort = new AbortController();
streamAbort = abort;
const resume: ResumeRequest = {
type: "resume-request",
protocolVersion: 1,
requestId: requestId(),
sessionId,
resumeToken,
serverEpoch,
lastReceivedSequence,
interests,
};
if (!validateClientRealtimeMessage(resume).ok) throw new Error("realtime resume state is invalid");
try {
const response = await post(endpoints.events, resume, "text/event-stream", abort.signal);
if (generation !== streamGeneration) return;
await readSse(response, generation);
if (generation === streamGeneration) scheduleReconnect();
} catch (reason) {
if (generation !== streamGeneration || abort.signal.aborted) return;
subscription?.onError?.(errorFrom(reason, "realtime stream failed"));
scheduleReconnect();
}
}
async function sendPose(): Promise<void> {
poseTimer = null;
const pose = pendingPose;
pendingPose = null;
if (!pose || !sessionId || status === "left" || status === "disposed") return;
if (subscription && !streamReady) {
pendingPose = pose;
poseTimer = timers.setTimeout(() => void sendPose(), sendIntervalMs);
return;
}
try {
const response = await post(endpoints.pose, { sessionId, token: resumeToken, snapshot: pose });
if (!response.ok) throw new Error(`realtime pose request failed (${response.status})`);
} catch (reason) {
subscription?.onError?.(errorFrom(reason, "realtime pose request failed"));
}
changed();
}
async function join(interest: InterestCell | readonly InterestCell[], entity: EntityPoseSnapshot): Promise<JoinGrant> {
if (status === "disposed") throw new Error("realtime client is disposed");
const generation = ++transitionGeneration;
const nextInterests = normalizeInterests(interest);
if (!isEntityPoseSnapshot(entity)) throw new TypeError("realtime entity pose is invalid");
const request: JoinRequest = {
type: "join-request",
protocolVersion: 1,
requestId: requestId(),
actorId: options.actorId,
resumeToken,
lastReceivedSequence,
interests: nextInterests,
};
if (!validateClientRealtimeMessage(request).ok) throw new Error("realtime join request is invalid");
const parsed = validateServerRealtimeMessage(await json(await post(endpoints.join, { ...request, entity })));
if (!parsed.ok || parsed.value.type !== "join-grant") throw new Error("realtime join response is invalid");
const grant = parsed.value;
if (grant.actorId !== options.actorId || grant.requestId !== request.requestId) {
throw new Error("realtime join response identity does not match request");
}
if (generation !== transitionGeneration || isTerminalStatus(status)) {
// A superseded request can still have created a server session before
// the browser ignored its answer. Retire it without adopting its token.
void post(endpoints.leave, { sessionId: grant.sessionId, token: grant.resumeToken })
.catch(() => { /* normal idle expiry is the fallback */ });
throw new Error("realtime join was superseded");
}
interests = grant.interests.map((entry) => ({ ...entry }));
sessionId = grant.sessionId;
serverEpoch = grant.serverEpoch;
resumeToken = grant.resumeToken;
lastReceivedSequence = grant.nextSequence === 0 ? 0 : grant.nextSequence - 1;
nextPoseSequence = Math.max(entity.sequence + 1, grant.nextSequence);
status = "joined";
streamReady = subscription === null;
reconnectAttempt = 0;
changed();
if (subscription && lastReceivedSequence !== null) void startStream();
return grant;
}
function publishPose(entity: EntityPoseSnapshot): void {
if (!sessionId || status === "idle" || status === "left" || status === "disposed") {
throw new Error("realtime client must be joined before publishing a pose");
}
if (!isEntityPoseSnapshot(entity)) throw new TypeError("realtime entity pose is invalid");
if (nextPoseSequence > UINT32_MAX) throw new RangeError("realtime pose sequence exhausted");
const sequenced = { ...entity, sequence: nextPoseSequence } as EntityPoseSnapshot;
if (!isEntityPoseSnapshot(sequenced)) throw new TypeError("realtime entity pose is invalid");
nextPoseSequence += 1;
pendingPose = sequenced;
if (poseTimer === null) poseTimer = timers.setTimeout(() => void sendPose(), sendIntervalMs);
changed();
}
function subscribe(callbacks: RealtimeSubscriptionCallbacks): () => void {
if (status === "disposed") throw new Error("realtime client is disposed");
subscription = callbacks;
changed();
if (sessionId && lastReceivedSequence !== null) void startStream();
let active = true;
return () => {
if (!active || subscription !== callbacks) return;
active = false;
subscription = null;
cancelStream();
if (status === "streaming" || status === "reconnecting") status = sessionId ? "joined" : "idle";
};
}
async function resume(nextInterests: readonly InterestCell[]): Promise<ResumeGrant> {
if (status === "disposed") throw new Error("realtime client is disposed");
if (!sessionId || !resumeToken || !serverEpoch || lastReceivedSequence === null) {
throw new Error("realtime client has no resumable session");
}
const generation = ++transitionGeneration;
const expectedSessionId = sessionId;
const request: ResumeRequest = {
type: "resume-request",
protocolVersion: 1,
requestId: requestId(),
sessionId,
resumeToken,
serverEpoch,
lastReceivedSequence,
interests: nextInterests,
};
if (!validateClientRealtimeMessage(request).ok) throw new Error("realtime resume request is invalid");
// The old stream belongs to a different privacy and coordinate cell. Close
// it before the handoff request, not after its network round trip.
cancelStream();
status = "joined";
changed();
try {
const parsed = validateServerRealtimeMessage(await json(await post(endpoints.join, request)));
if (!parsed.ok || parsed.value.type !== "resume-grant") throw new Error("realtime resume response is invalid");
const grant = parsed.value;
if (grant.sessionId !== expectedSessionId || grant.requestId !== request.requestId) {
throw new Error("realtime resume response identity does not match request");
}
if (generation !== transitionGeneration || isTerminalStatus(status)) {
throw new Error("realtime resume was superseded");
}
interests = nextInterests.map((entry) => ({ ...entry }));
resumeToken = grant.resumeToken;
serverEpoch = grant.serverEpoch;
lastReceivedSequence = grant.nextSequence === 0 ? 0 : grant.nextSequence - 1;
streamReady = subscription === null;
reconnectAttempt = 0;
changed();
if (subscription && lastReceivedSequence !== null) void startStream();
return grant;
} catch (error) {
if (generation === transitionGeneration && !isTerminalStatus(status)) {
status = "joined";
changed();
}
throw error;
}
}
async function rejoin(): Promise<ResumeGrant> {
return resume(interests);
}
async function moveInterest(interest: InterestCell | readonly InterestCell[]): Promise<ResumeGrant> {
return resume(normalizeInterests(interest));
}
async function leave(): Promise<void> {
if (status === "disposed") return;
transitionGeneration += 1;
cancelPose();
cancelStream();
const leavingSession = sessionId;
const leavingToken = resumeToken;
status = "left";
sessionId = null;
serverEpoch = null;
resumeToken = null;
lastReceivedSequence = null;
reconnectAttempt = 0;
changed();
if (leavingSession && leavingToken) {
const response = await post(endpoints.leave, { sessionId: leavingSession, token: leavingToken });
if (!response.ok) throw new Error(`realtime leave request failed (${response.status})`);
}
}
async function dispose(): Promise<void> {
if (status === "disposed") return;
try {
await leave();
} finally {
subscription = null;
status = "disposed";
}
}
return { join, publishPose, subscribe, moveInterest, rejoin, state: snapshot, leave, dispose };
}
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@@ -8,4 +8,27 @@ export {
validateServerRealtimeMessage,
} from "./protocol.ts";
export { PoseInterpolationBuffer } from "./interpolation.ts";
export {
createRealtimeClient,
type RealtimeClient,
type RealtimeClientEndpoints,
type RealtimeClientOptions,
type RealtimeClientState,
type RealtimeClientStatus,
type RealtimeClientTimers,
type RealtimeSubscriptionCallbacks,
} from "./client.ts";
export {
createScenePeers,
scenePeerId,
type ScenePeers,
type ScenePeersOptions,
} from "./scenePeers.ts";
export {
createPresenceIndicator,
type PresenceConnectionState,
type PresenceIndicator,
type PresenceIndicatorOptions,
type PresenceIndicatorState,
} from "./presenceIndicator.ts";
export type * from "./types.ts";
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/** Small, identity-free hosted-presence status for a caller-owned container. */
export type PresenceConnectionState = "off" | "connecting" | "live" | "reconnecting" | "offline";
export interface PresenceIndicatorState {
signedIn: boolean;
connection: PresenceConnectionState;
/** Aggregate only. Individual peer identity never enters this adapter. */
nearbyPeerCount: number;
}
export interface PresenceIndicatorOptions {
container: HTMLElement;
onRetry?: () => void;
}
export interface PresenceIndicator {
root: HTMLElement;
update(state: PresenceIndicatorState): PresenceIndicatorState;
state(): PresenceIndicatorState;
dispose(): void;
}
const CONNECTIONS = new Set<PresenceConnectionState>([
"off", "connecting", "live", "reconnecting", "offline",
]);
function copy(state: PresenceIndicatorState): PresenceIndicatorState {
return { ...state };
}
function normalize(input: PresenceIndicatorState): PresenceIndicatorState {
if (!input || typeof input !== "object") throw new TypeError("presence indicator: invalid state");
if (typeof input.signedIn !== "boolean" || !CONNECTIONS.has(input.connection)) {
throw new TypeError("presence indicator: invalid connection state");
}
if (!Number.isSafeInteger(input.nearbyPeerCount) || input.nearbyPeerCount < 0 || input.nearbyPeerCount > 10_000) {
throw new RangeError("presence indicator: nearbyPeerCount must be an integer from 0 to 10000");
}
if (!input.signedIn) return { signedIn: false, connection: "off", nearbyPeerCount: 0 };
return {
signedIn: true,
connection: input.connection,
nearbyPeerCount: input.connection === "live" ? input.nearbyPeerCount : 0,
};
}
function label(state: PresenceIndicatorState): string {
if (!state.signedIn || state.connection === "off") return "Hosted presence is off.";
switch (state.connection) {
case "connecting": return "Hosted presence is connecting.";
case "reconnecting": return "Hosted presence is reconnecting.";
case "offline": return "Hosted presence is offline.";
case "live": {
const nearby = state.nearbyPeerCount === 1 ? "1 nearby peer" : `${state.nearbyPeerCount} nearby peers`;
return `Hosted presence is live · ${nearby}.`;
}
}
}
export function createPresenceIndicator(options: PresenceIndicatorOptions): PresenceIndicator {
if (!options.container || typeof options.container.append !== "function") {
throw new TypeError("presence indicator: container must be an HTMLElement");
}
if (options.onRetry !== undefined && typeof options.onRetry !== "function") {
throw new TypeError("presence indicator: onRetry must be a function");
}
const doc = options.container.ownerDocument;
const root = doc.createElement("div");
root.className = "tera-presence";
root.setAttribute("data-presence", "off");
const statusLine = doc.createElement("span");
statusLine.className = "tera-presence__status";
statusLine.setAttribute("role", "status");
statusLine.setAttribute("aria-live", "polite");
statusLine.setAttribute("aria-atomic", "true");
const retry = doc.createElement("button");
retry.type = "button";
retry.className = "tera-presence__retry";
retry.textContent = "Retry presence";
retry.hidden = true;
root.append(statusLine, retry);
options.container.append(root);
let current: PresenceIndicatorState = { signedIn: false, connection: "off", nearbyPeerCount: 0 };
let disposed = false;
let onRetry: (() => void) | null = options.onRetry ?? null;
function render(): void {
statusLine.textContent = label(current);
root.setAttribute("data-presence", current.connection);
retry.hidden = onRetry === null || !current.signedIn ||
(current.connection !== "offline" && current.connection !== "reconnecting");
}
retry.addEventListener("click", () => {
if (!disposed && !retry.hidden) onRetry?.();
});
render();
return {
root,
update(next) {
if (disposed) return copy(current);
current = normalize(next);
render();
return copy(current);
},
state: () => copy(current),
dispose() {
if (disposed) return;
disposed = true;
onRetry = null;
current = { signedIn: false, connection: "off", nearbyPeerCount: 0 };
root.remove();
},
};
}
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/**
* Three.js presentation for already-validated remote entity snapshots.
*
* Networking, trust, auth, and display names stay outside this module. It keeps
* only canonical protocol ids in a private Map, buffers authoritative motion,
* and gives each peer one stable, identity-free scene root. Procedural clones
* share four prototype resource sets for the lifetime of the adapter.
*/
import * as THREE from "three";
import {
buildCrow,
buildDog,
buildHumanoid,
cloneCrow,
cloneDog,
cloneHumanoid,
disposeCrow,
disposeDog,
disposeHumanoid,
poseCrowFlight,
poseDogAttention,
poseDogWalk,
poseHumanoid,
type CrowRig,
type DogRig,
type HumanoidRig,
} from "../assets/actors/index.ts";
import {
buildModelX,
cloneModelX,
disposeModelX,
setModelXSteering,
setModelXWheelRotation,
type ModelXRig,
} from "../assets/vehicles/index.ts";
import { PoseInterpolationBuffer } from "./interpolation.ts";
import { isEntityPoseSnapshot } from "./protocol.ts";
import type {
BufferedPoseSample,
EntityPoseSnapshot,
InterpolationOptions,
SpatialPose,
} from "./types.ts";
export interface ScenePeersOptions {
/** Geographic map projection. Returned X/Z are already scene units. */
project(lat: number, lng: number): readonly [number, number];
/** Terrain height in scene units at a geographic position. */
groundAt(lat: number, lng: number): number;
/** Converts geographic altitude metres and, by default, asset metres to scene units. */
geographicSceneUnitsPerMetre?: number;
/** Optional presentation exaggeration independent of geographic motion scale. */
geographicVisualScale?: number;
/** Local office/city metre scale. Defaults to direct 1 metre = 1 scene unit. */
localSceneUnitsPerMetre?: number;
/** Optional presentation scale independent of local coordinate scale. */
localVisualScale?: number;
interpolation?: InterpolationOptions;
/** Bounded nearby peer count. Defaults to 128, maximum 512. */
maximumPeers?: number;
}
export interface ScenePeers {
root: THREE.Group;
/** Add a new authoritative sample. Invalid/stale/over-capacity input returns false. */
upsert(snapshot: EntityPoseSnapshot): boolean;
/** Remove by canonical id from `scenePeerId`/`ids`. */
remove(id: string): boolean;
/** Apply interpolated state at authoritative server time; returns roots updated. */
tick(serverTimeMs: number): number;
ids(): readonly string[];
count(): number;
/** Interest reset: drops peers but retains shared prototype GPU resources. */
clear(): void;
dispose(): void;
}
type PeerVisual =
| { kind: "humanoid"; rig: HumanoidRig }
| { kind: "dog"; rig: DogRig }
| { kind: "crow"; rig: CrowRig }
| { kind: "model-x"; rig: ModelXRig };
interface Prototypes {
humanoid: HumanoidRig;
dog: DogRig;
crow: CrowRig;
vehicle: ModelXRig;
}
interface Peer {
readonly id: string;
readonly root: THREE.Group;
readonly buffer: PoseInterpolationBuffer;
visual: PeerVisual;
kind: EntityPoseSnapshot["kind"];
spaceKey: string;
latest: EntityPoseSnapshot;
lastSequence: number;
lastTimestampMs: number;
}
export function scenePeerId(snapshot: EntityPoseSnapshot): string {
return snapshot.entity === "actor" ? `actor:${snapshot.actorId}` : `vehicle:${snapshot.vehicleId}`;
}
function poseSpaceKey(pose: SpatialPose): string {
return pose.space === "geographic" ? "geographic" : `local:${JSON.stringify(pose.cell)}`;
}
function positive(value: number, name: string): number {
if (!(value > 0) || !Number.isFinite(value)) throw new RangeError(`${name} must be finite and positive`);
return value;
}
function resolveMaximumPeers(value: number | undefined): number {
const resolved = value ?? 128;
if (!Number.isInteger(resolved) || resolved < 1 || resolved > 512) {
throw new RangeError("maximumPeers must be an integer from 1 to 512");
}
return resolved;
}
function makePrototypes(): Prototypes {
const vehicle = buildModelX({ detail: "corridor", paint: 0x050607 });
vehicle.root.name = "generic-black-ev.prototype";
vehicle.root.userData.vehicleModel = "generic-black-ev";
return {
humanoid: buildHumanoid(),
dog: buildDog(),
crow: buildCrow(),
vehicle,
};
}
function cloneVisual(snapshot: EntityPoseSnapshot, prototypes: Prototypes): PeerVisual {
if (snapshot.entity === "vehicle") {
const rig = cloneModelX(prototypes.vehicle);
rig.root.name = "generic-black-ev";
rig.root.userData.vehicleModel = "generic-black-ev";
return { kind: "model-x", rig };
}
if (snapshot.kind === "dog") return { kind: "dog", rig: cloneDog(prototypes.dog) };
if (snapshot.kind === "crow") return { kind: "crow", rig: cloneCrow(prototypes.crow) };
return { kind: "humanoid", rig: cloneHumanoid(prototypes.humanoid) };
}
function visualRoot(visual: PeerVisual): THREE.Group {
return visual.rig.root;
}
function replaceVisual(peer: Peer, snapshot: EntityPoseSnapshot, prototypes: Prototypes): void {
visualRoot(peer.visual).removeFromParent();
peer.visual = cloneVisual(snapshot, prototypes);
peer.root.add(visualRoot(peer.visual));
peer.kind = snapshot.kind;
}
function animateActor(
visual: Exclude<PeerVisual, { kind: "model-x" }>,
sample: BufferedPoseSample,
): void {
const speed = Math.hypot(sample.velocity.xMps, sample.velocity.zMps);
const seconds = sample.timestampMs / 1_000;
if (visual.kind === "humanoid") {
poseHumanoid(visual.rig, {
walkPhase: seconds * Math.max(1.2, speed * 5.8),
stride: THREE.MathUtils.clamp(speed / 3.2, 0, 0.68),
});
} else if (visual.kind === "dog") {
poseDogWalk(
visual.rig,
seconds * Math.max(1.4, speed * 7.2),
THREE.MathUtils.clamp(speed / 4, 0, 0.68),
);
poseDogAttention(visual.rig, 0, seconds * 5);
} else {
poseCrowFlight(
visual.rig,
seconds * Math.max(3, speed * 1.5),
THREE.MathUtils.clamp(0.35 + speed / 14, 0.35, 1),
);
}
}
export function createScenePeers(options: ScenePeersOptions): ScenePeers {
if (typeof options.project !== "function" || typeof options.groundAt !== "function") {
throw new RangeError("scene peers require project and groundAt functions");
}
const geographicScale = positive(
options.geographicSceneUnitsPerMetre ?? 1,
"geographicSceneUnitsPerMetre",
);
const geographicVisualScale = positive(
options.geographicVisualScale ?? geographicScale,
"geographicVisualScale",
);
const localScale = positive(options.localSceneUnitsPerMetre ?? 1, "localSceneUnitsPerMetre");
const localVisualScale = positive(options.localVisualScale ?? localScale, "localVisualScale");
const limit = resolveMaximumPeers(options.maximumPeers);
const interpolation = { ...(options.interpolation ?? {}) };
const prototypes = makePrototypes();
const peers = new Map<string, Peer>();
const root = new THREE.Group();
root.name = "realtime-scene-peers";
root.userData.kind = "remote-presence";
let disposed = false;
function add(snapshot: EntityPoseSnapshot): Peer {
const visual = cloneVisual(snapshot, prototypes);
const peerRoot = new THREE.Group();
// IDs deliberately stay in the private Map, not names/userData inspected by render/debug tooling.
peerRoot.name = "remote-peer";
peerRoot.userData.entity = snapshot.entity;
peerRoot.userData.kind = snapshot.kind;
peerRoot.userData.forwardAxis = "-Z";
peerRoot.add(visualRoot(visual));
root.add(peerRoot);
const peer: Peer = {
id: scenePeerId(snapshot),
root: peerRoot,
buffer: new PoseInterpolationBuffer(interpolation),
visual,
kind: snapshot.kind,
spaceKey: poseSpaceKey(snapshot.pose),
latest: snapshot,
lastSequence: -1,
lastTimestampMs: -1,
};
peers.set(peer.id, peer);
return peer;
}
function apply(peer: Peer, sample: BufferedPoseSample): boolean {
const pose = sample.pose;
let visualScale: number;
if (pose.space === "geographic") {
const projected = options.project(pose.lat, pose.lng);
const ground = options.groundAt(pose.lat, pose.lng);
if (
projected.length < 2 ||
!Number.isFinite(projected[0]) ||
!Number.isFinite(projected[1]) ||
!Number.isFinite(ground)
) {
peer.root.visible = false;
return false;
}
peer.root.position.set(
projected[0],
ground + pose.altitudeM * geographicScale,
projected[1],
);
visualScale = geographicVisualScale;
} else {
peer.root.position.set(pose.xM * localScale, pose.yM * localScale, pose.zM * localScale);
visualScale = localVisualScale;
}
peer.root.visible = true;
peer.root.scale.setScalar(visualScale);
peer.root.rotation.order = "YXZ";
peer.root.rotation.set(
THREE.MathUtils.degToRad(pose.pitchDeg),
-THREE.MathUtils.degToRad(pose.headingDeg),
0,
);
if (peer.visual.kind === "model-x") {
const latest = peer.latest.entity === "vehicle" ? peer.latest : null;
if (latest) {
setModelXSteering(peer.visual.rig, latest.steering * 0.62);
// Simulation publishes positive travelled radians; the -Z-forward
// wheel geometry rolls forward with negative local-X rotation.
setModelXWheelRotation(peer.visual.rig, -latest.wheelRadians);
}
} else {
animateActor(peer.visual, sample);
}
return true;
}
return {
root,
upsert(snapshot) {
if (disposed || !isEntityPoseSnapshot(snapshot)) return false;
const id = scenePeerId(snapshot);
let peer = peers.get(id);
if (!peer) {
if (peers.size >= limit) return false;
peer = add(snapshot);
} else if (
snapshot.sequence <= peer.lastSequence ||
snapshot.timestampMs <= peer.lastTimestampMs
) {
return false;
}
if (peer.kind !== snapshot.kind) replaceVisual(peer, snapshot, prototypes);
const nextSpaceKey = poseSpaceKey(snapshot.pose);
if (nextSpaceKey !== peer.spaceKey) {
// Interest boundaries are not continuous coordinate frames. Resetting
// prevents a floor/city switch from interpolating through empty space.
peer.buffer.clear();
peer.spaceKey = nextSpaceKey;
}
if (!peer.buffer.push(snapshot)) {
// A failed first push must not consume bounded capacity.
if (peer.lastSequence < 0) {
peer.root.removeFromParent();
peers.delete(id);
}
return false;
}
peer.latest = snapshot;
peer.lastSequence = snapshot.sequence;
peer.lastTimestampMs = snapshot.timestampMs;
peer.root.userData.entity = snapshot.entity;
peer.root.userData.kind = snapshot.kind;
return true;
},
remove(id) {
if (disposed) return false;
const peer = peers.get(id);
if (!peer) return false;
peer.root.removeFromParent();
peer.buffer.clear();
peers.delete(id);
return true;
},
tick(serverTimeMs) {
if (disposed || !Number.isFinite(serverTimeMs)) return 0;
let updated = 0;
for (const peer of peers.values()) {
const sample = peer.buffer.sample(serverTimeMs);
if (sample && apply(peer, sample)) updated += 1;
}
return updated;
},
ids: () => [...peers.keys()],
count: () => peers.size,
clear() {
for (const peer of peers.values()) {
peer.root.removeFromParent();
peer.buffer.clear();
}
peers.clear();
},
dispose() {
if (disposed) return;
for (const peer of peers.values()) peer.root.removeFromParent();
peers.clear();
root.removeFromParent();
disposeHumanoid(prototypes.humanoid);
disposeDog(prototypes.dog);
disposeCrow(prototypes.crow);
disposeModelX(prototypes.vehicle);
disposed = true;
},
};
}