Feat: setup audio component

packages/core/src/asset/AssetType.ts

@@ -51,6 +51,10 @@ export enum AssetType {
   Font = "Font",
   /** Source Font, include ttf、 otf and woff. */
   SourceFont = "SourceFont",
+  /** AudioClip, inclue ogg, wav and mp3 */
+  Audio = "Audio",
   /** Project asset. */
   Project = "project"
 }
+
+

packages/core/src/audio/AudioClip.ts

@@ -0,0 +1,67 @@
+import { Engine } from "../Engine";
+import { ReferResource } from "../asset/ReferResource";
+import { AudioManager } from "./AudioManager";
+
+/**
+ * Audio Clip
+ */
+export class AudioClip extends ReferResource {
+  /** @internal */
+  _context: AudioContext;
+  private _audioBuffer: AudioBuffer | null = null;
+
+  /**
+   * Name of clip.
+   */
+  name: string;
+
+  /**
+   * Number of discrete audio channels.
+   */
+  get channels(): number {
+    return this._audioBuffer.numberOfChannels;
+  }
+
+  /**
+   * Sample rate, in samples per second.
+   */
+  get sampleRate(): number {
+    return this._audioBuffer.sampleRate;
+  }
+
+  /**
+   * Duration, in seconds.
+   */
+  get duration(): Readonly<number> {
+    return this._audioBuffer.duration;
+  }
+
+  /**
+   * Get the clip's audio buffer.
+   */
+  getAudioSource(): AudioBuffer {
+    return this._audioBuffer;
+  }
+
+  /**
+   * Set audio buffer for the clip.
+   */
+  setAudioSource(value: AudioBuffer): void {
+    this._audioBuffer = value;
+  }
+
+  constructor(engine: Engine, name: string = "") {
+    super(engine);
+    this.name = name;
+    this._context = AudioManager.context;
+  }
+
+  /**
+   * @internal
+   */
+  protected override _onDestroy(): void {
+    super._onDestroy();
+    this._audioBuffer = null;
+    this.name = null;
+  }
+}

packages/core/src/audio/AudioManager.ts

@@ -0,0 +1,50 @@
+/**
+ * @internal
+ * Audio Manager
+ */
+export class AudioManager {
+  private static _context: AudioContext;
+  private static _gainNode: 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);
+      window.document.addEventListener("touchend", AudioManager._unlock, true);
+      window.document.addEventListener("touchstart", AudioManager._unlock, true);
+    }
+    return AudioManager._context;
+  }
+
+  /**
+   * Audio GainNode.
+   */
+  static get gainNode(): GainNode {
+    if (!AudioManager._gainNode) {
+      const gain = AudioManager.context.createGain();
+      gain.connect(AudioManager.context.destination);
+      AudioManager._gainNode = gain;
+    }
+    return AudioManager._gainNode;
+  }
+
+  private static _unlock(): void {
+    if (AudioManager._unlocked) {
+      return;
+    }
+    AudioManager._context.resume().then(() => {
+      if (AudioManager._context.state === "running") {
+        window.document.removeEventListener("pointerdown", AudioManager._unlock, true);
+        window.document.removeEventListener("touchend", AudioManager._unlock, true);
+        window.document.removeEventListener("touchstart", AudioManager._unlock, true);
+        AudioManager._unlocked = true;
+      }
+    });
+  }
+}

packages/core/src/audio/AudioSource.ts

@@ -0,0 +1,264 @@
+import { Component } from "../Component";
+import { Entity } from "../Entity";
+import { AudioClip } from "./AudioClip";
+import { AudioManager } from "./AudioManager";
+import { deepClone, ignoreClone } from "../clone/CloneManager";
+
+/**
+ * Audio Source Component
+ */
+export class AudioSource extends Component {
+  @ignoreClone
+  private _isPlaying: boolean = false;
+
+  @ignoreClone
+  private _clip: AudioClip;
+  @deepClone
+  private _gainNode: GainNode;
+  @ignoreClone
+  private _sourceNode: AudioBufferSourceNode | null = null;
+
+  @deepClone
+  private _pausedTime: number = -1;
+  @ignoreClone
+  private _absoluteStartTime: number = -1;
+
+  @deepClone
+  private _volume: number = 1;
+  @deepClone
+  private _lastVolume: number = 1;
+  @deepClone
+  private _playbackRate: number = 1;
+  @deepClone
+  private _loop: boolean = false;
+
+  /** If set to true, the audio component automatically begins to play on startup. */
+  playOnEnabled: boolean = true;
+
+  /**
+   * The audio cilp to play.
+   */
+  get clip(): AudioClip {
+    return this._clip;
+  }
+
+  set clip(value: AudioClip) {
+    const lastClip = this._clip;
+    if (lastClip !== value) {
+      lastClip && lastClip._addReferCount(-1);
+      this._clip = value;
+
+      if (this.playOnEnabled && this.enabled) {
+        this.play();
+      }
+    }
+  }
+
+  /**
+   * Whether the clip playing right now (Read Only).
+   */
+  get isPlaying(): boolean {
+    return this._isPlaying;
+  }
+
+  /**
+   * The volume of the audio source. 1.0 is origin volume.
+   */
+  get volume(): number {
+    return this._volume;
+  }
+
+  set volume(value: number) {
+    this._volume = value;
+    if (this._isPlaying) {
+      this._gainNode.gain.setValueAtTime(value, AudioManager.context.currentTime);
+    }
+  }
+
+  /**
+   * The playback rate of the audio source, 1.0 is normal playback speed.
+   */
+  get playbackRate(): number {
+    return this._playbackRate;
+  }
+
+  set playbackRate(value: number) {
+    this._playbackRate = value;
+    if (this._isPlaying) {
+      this._sourceNode.playbackRate.value = this._playbackRate;
+    }
+  }
+
+  /**
+   * Mutes / Unmutes the AudioSource.
+   * Mute sets volume as 0, Un-Mute restore volume.
+   */
+  get mute(): boolean {
+    return this.volume === 0;
+  }
+
+  set mute(value: boolean) {
+    if (value) {
+      this._lastVolume = this.volume;
+      this.volume = 0;
+    } else {
+      this.volume = this._lastVolume;
+    }
+  }
+
+  /**
+   * Whether the audio clip looping. Default false.
+   */
+  get loop(): boolean {
+    return this._loop;
+  }
+
+  set loop(value: boolean) {
+    if (value !== this._loop) {
+      this._loop = value;
+
+      if (this._isPlaying) {
+        this._sourceNode.loop = this._loop;
+      }
+    }
+  }
+
+  /**
+   * Playback position in seconds.
+   */
+  get time(): number {
+    if (this._isPlaying) {
+      return this._pausedTime > 0
+        ? this.engine.time.elapsedTime - this._absoluteStartTime + this._pausedTime
+        : this.engine.time.elapsedTime - this._absoluteStartTime;
+    } else {
+      return this._pausedTime > 0 ? this._pausedTime : 0;
+    }
+  }
+
+  /**
+   * Plays the clip.
+   */
+  play(): void {
+    if (!this._canPlay()) return;
+    if (this._isPlaying) return;
+    this._initSourceNode();
+    this._startPlayback(this._pausedTime > 0 ? this._pausedTime : 0);
+
+    this._pausedTime = -1;
+    this._isPlaying = true;
+  }
+
+  /**
+   * Stops playing the clip.
+   */
+  stop(): void {
+    if (this._isPlaying) {
+      this._clearSourceNode();
+
+      this._isPlaying = false;
+      this._pausedTime = -1;
+      this._absoluteStartTime = -1;
+    }
+  }
+
+  /**
+   * Pauses playing the clip.
+   */
+  pause(): void {
+    if (this._isPlaying) {
+      this._clearSourceNode();
+
+      this._isPlaying = false;
+      this._pausedTime = this.time;
+    }
+  }
+
+  /** @internal */
+  constructor(entity: Entity) {
+    super(entity);
+    this._onPlayEnd = this._onPlayEnd.bind(this);
+
+    this._gainNode = AudioManager.context.createGain();
+    this._gainNode.connect(AudioManager.gainNode);
+  }
+
+  /**
+   * @internal
+   */
+  override _onEnable(): void {
+    this.playOnEnabled && this.play();
+  }
+
+  /**
+   * @internal
+   */
+  override _onDisable(): void {
+    this.pause();
+  }
+
+  /**
+   * @internal
+   */
+  protected override _onDestroy(): void {
+    super._onDestroy();
+    if (this._clip) {
+      this._clip._addReferCount(-1);
+      this._clip = null;
+    }
+  }
+
+  private _onPlayEnd(): void {
+    this.stop();
+  }
+
+  private _initSourceNode(): void {
+    this._clearSourceNode();
+    this._sourceNode = AudioManager.context.createBufferSource();
+
+    const { _sourceNode: sourceNode } = this;
+    sourceNode.buffer = this._clip.getAudioSource();
+    sourceNode.onended = this._onPlayEnd;
+    sourceNode.playbackRate.value = this._playbackRate;
+    sourceNode.loop = this._loop;
+
+    this._gainNode.gain.setValueAtTime(this._volume, AudioManager.context.currentTime);
+    sourceNode.connect(this._gainNode);
+  }
+
+  private _clearSourceNode(): void {
+    if (!this._sourceNode) return;
+
+    this._sourceNode.stop();
+    this._sourceNode.disconnect();
+    this._sourceNode.onended = null;
+    this._sourceNode = null;
+  }
+
+  private _startPlayback(startTime: number): void {
+    this._sourceNode.start(0, startTime);
+    this._absoluteStartTime =
+      this._absoluteStartTime > 0 ? this.engine.time.elapsedTime - startTime : this.engine.time.elapsedTime;
+  }
+
+  private _canPlay(): boolean {
+    return this._isValidClip() && this._isAudioContextRunning();
+  }
+
+  private _isValidClip(): boolean {
+    if (!this._clip || this._clip.duration <= 0) {
+      return false;
+    }
+
+    return true;
+  }
+
+  private _isAudioContextRunning(): boolean {
+    if (AudioManager.context.state !== "running") {
+      console.warn("AudioContext is not running. User interaction required.");
+      return false;
+    }
+
+    return true;
+  }
+}

packages/core/src/audio/index.ts

@@ -0,0 +1,2 @@
+export { AudioClip } from "./AudioClip";
+export { AudioSource } from "./AudioSource";