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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 | 37x 37x 37x 37x 37x 37x 37x 9x 9x 258x 224x 224x 224x 224x 201x 201x 201x 201x 201x 201x 201x 201x 224x 224x 2x 2x 224x 202x 224x 224x 3x 2x 2x 2x 2x 2x 2x 1x 1x 2x 2x 2x 1x 1x | import { loadData } from "./loader.js";
/**
* Base class for audio components that load and play back sample buffers
* (e.g. disc drive noise, cassette relay clicks).
*
* Provides: gain node setup, sample loading, one-shot playback, and
* gain-based mute/unmute. Subclasses add domain-specific behaviour.
*/
export class SamplePlayer {
constructor(context, destination, volume) {
this.context = context;
this.volume = volume;
this.sounds = {};
this.gain = context.createGain();
this.gain.gain.value = volume;
this.gain.connect(destination);
// Prevent older Safari from GC-ing in-flight AudioBufferSourceNodes.
this.playing = [];
}
/**
* Load a map of {name: path} into decoded AudioBuffers stored in this.sounds.
*/
async loadSounds(pathMap) {
const entries = Object.entries(pathMap);
const decoded = await Promise.all(
entries.map(async ([, path]) => {
const data = await loadData(path);
// Safari doesn't support the promise form of decodeAudioData.
return new Promise((resolve, reject) => {
this.context.decodeAudioData(
data.buffer,
(buf) => resolve(buf),
(err) => reject(err),
);
});
}),
);
for (let i = 0; i < entries.length; i++) {
this.sounds[entries[i][0]] = decoded[i];
}
}
/**
* Fire-and-forget: play a buffer once, return its duration.
*/
oneShot(sound) {
this.startSound(sound);
return sound.duration;
}
/**
* Start `sound` at `when` on the audio clock (now if 0), `offset` seconds in, for
* `duration` seconds (the rest of it if undefined), with `fadeSeconds` of fade at each
* end so a cut into the middle of it does not click. Returns the source, or null when
* the context is not running.
*/
startSound(sound, { when = 0, offset = 0, duration, fadeSeconds = 0 } = {}) {
if (this.context.state !== "running") return null;
const source = this.context.createBufferSource();
source.buffer = sound;
let into = this.gain;
if (fadeSeconds > 0 && duration !== undefined) {
const fade = this.context.createGain();
const start = when || this.context.currentTime;
fade.gain.setValueAtTime(0, start);
fade.gain.linearRampToValueAtTime(1, start + fadeSeconds);
fade.gain.setValueAtTime(1, start + duration - fadeSeconds);
fade.gain.linearRampToValueAtTime(0, start + duration);
fade.connect(this.gain);
into = fade;
}
source.connect(into);
source.onended = () => {
this.playing = this.playing.filter((s) => s !== source);
if (into !== this.gain) into.disconnect();
};
if (duration === undefined) source.start(when, offset);
else source.start(when, offset, duration);
this.playing.push(source);
return source;
}
/**
* Play a buffer, optionally looping. Returns a Promise that resolves
* with the source node (if looping) or when playback ends (if not).
*/
play(sound, loop) {
if (this.context.state !== "running") return Promise.reject();
return new Promise((resolve) => {
const source = this.context.createBufferSource();
source.loop = !!loop;
source.buffer = sound;
source.connect(this.gain);
source.onended = () => {
this.playing = this.playing.filter((s) => s !== source);
Eif (!source.loop) resolve();
};
source.start();
this.playing.push(source);
if (source.loop) resolve(source);
});
}
mute() {
this.gain.gain.value = 0;
}
unmute() {
this.gain.gain.value = this.volume;
}
}
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