Feat: setup positional audio

packages/core/src/asset/AssetType.ts

@@ -48,5 +48,7 @@ export enum AssetType {
   /** Font. */
   Font = "Font",
   /** Source Font, include ttf、 otf and woff. */
-  SourceFont = "SourceFont"
+  SourceFont = "SourceFont",
+  /** AudioClip, inclue ogg, wav and mp3 */
+  Audio = "Audio"
 }

packages/core/src/audio/AudioClip.ts

@@ -0,0 +1,52 @@
+import { Engine } from "../Engine";
+import { ReferResource } from "../asset/ReferResource";
+
+/**
+ * Audio Clip
+ */
+export class AudioClip extends ReferResource {
+  /** the name of clip */
+  name: string;
+
+  private _audioBuffer: AudioBuffer;
+
+  /**
+   * the number of discrete audio channels
+   */
+  get channels(): Readonly<number> {
+    return this._audioBuffer.numberOfChannels;
+  }
+
+  /**
+   * the sample rate, in samples per second
+   */
+  get sampleRate(): Readonly<number> {
+    return this._audioBuffer.sampleRate;
+  }
+
+  /**
+   * the duration, in seconds
+   */
+  get duration(): Readonly<number> {
+    return this._audioBuffer.duration;
+  }
+
+  /**
+   * get the clip's audio buffer
+   */
+  getData(): AudioBuffer {
+    return this._audioBuffer;
+  }
+
+  /**
+   * set audio buffer for the clip
+   */
+  setData(value: AudioBuffer): void {
+    this._audioBuffer = value;
+  }
+
+  constructor(engine: Engine, name: string = null) {
+    super(engine);
+    this.name = name;
+  }
+}

packages/core/src/audio/AudioListener.ts

@@ -0,0 +1,66 @@
+import { Component } from "../Component";
+import { Entity } from "../Entity";
+import { TransformModifyFlags } from "../Transform";
+import { ignoreClone } from "../clone/CloneManager";
+import { AudioManager } from "./AudioManager";
+
+/**
+ * Audio Listener
+ * only one per scene
+ */
+export class AudioListener extends Component {
+  private _context: AudioContext;
+
+  /**
+   * @internal
+   */
+  constructor(entity: Entity) {
+    super(entity);
+    const gain = AudioManager.context.createGain();
+    gain.connect(AudioManager.context.destination);
+    AudioManager.listener = gain;
+
+    this._context = AudioManager.context;
+    this._onTransformChanged = this._onTransformChanged.bind(this);
+    this._registerEntityTransformListener();
+
+    this._setListenerPose();
+  }
+
+  /**
+   * @internal
+   */
+  @ignoreClone
+  protected _onTransformChanged(type: TransformModifyFlags) {
+    this._setListenerPose();
+  }
+
+  /**
+   * @internal
+   */
+  protected override _onDestroy(): void {
+    super._onDestroy();
+    AudioManager.listener = null;
+    this.entity.transform._updateFlagManager.removeListener(this._onTransformChanged);
+  }
+
+  private _registerEntityTransformListener() {
+    this.entity.transform._updateFlagManager.addListener(this._onTransformChanged);
+  }
+
+  private _setListenerPose() {
+    const { position, worldUp, worldForward } = this.entity.transform;
+    const { listener, currentTime } = this._context;
+
+    listener.positionX.setValueAtTime(position.x, currentTime);
+    listener.positionY.setValueAtTime(position.y, currentTime);
+    listener.positionZ.setValueAtTime(position.z, currentTime);
+
+    listener.upX.setValueAtTime(worldUp.x, currentTime);
+    listener.upY.setValueAtTime(worldUp.y, currentTime);
+    listener.upZ.setValueAtTime(worldUp.z, currentTime);
+
+    listener.forwardX.setValueAtTime(worldForward.x, currentTime);
+    listener.forwardY.setValueAtTime(worldForward.y, currentTime);
+  }
+}

packages/core/src/audio/AudioManager.ts

@@ -0,0 +1,48 @@
+/**
+ * @internal
+ * Audio Manager
+ */
+export class AudioManager {
+  /** @internal */
+  private static _context: AudioContext;
+  /** @internal */
+  private static _listener: GainNode;
+
+  private static _unlocked: boolean = false;
+
+  /**
+   * Audio context
+   */
+  static get context(): AudioContext {
+    if (!AudioManager._context) {
+      AudioManager._context = new window.AudioContext();
+    }
+    if (AudioManager._context.state !== "running") {
+      window.document.addEventListener("pointerdown", AudioManager._unlock, true);
+    }
+    return AudioManager._context;
+  }
+
+  /**
+   * Audio Listener. Can only have one listener in a Scene.
+   */
+  static get listener(): GainNode {
+    return AudioManager._listener;
+  }
+
+  static set listener(value: GainNode) {
+    AudioManager._listener = value;
+  }
+
+  private static _unlock(): void {
+    if (AudioManager._unlocked) {
+      return;
+    }
+    AudioManager._context.resume().then(() => {
+      if (AudioManager._context.state === "running") {
+        window.document.removeEventListener("pointerdown", AudioManager._unlock, true);
+        AudioManager._unlocked = true;
+      }
+    });
+  }
+}