Tone.js/Tone/source/Source.ts
2019-09-14 16:39:18 -04:00

309 lines
8.7 KiB
TypeScript

import { Volume } from "../component/channel/Volume";
import "../core/context/Destination";
import { Param } from "../core/context/Param";
import { OutputNode, ToneAudioNode, ToneAudioNodeOptions } from "../core/context/ToneAudioNode";
import { Decibels, Seconds, Time } from "../core/type/Units";
import { defaultArg } from "../core/util/Defaults";
import { noOp, readOnly } from "../core/util/Interface";
import { BasicPlaybackState, StateTimeline } from "../core/util/StateTimeline";
import { isUndef } from "../core/util/TypeCheck";
type onStopCallback = (source: Source<any>) => void;
export interface SourceOptions extends ToneAudioNodeOptions {
volume: Decibels;
mute: boolean;
onstop: onStopCallback;
}
/**
* Base class for sources. Sources have start/stop methods
* and the ability to be synced to the
* start/stop of this.context.transport.
*
* @example
* //Multiple state change events can be chained together,
* //but must be set in the correct order and with ascending times
*
* // OK
* state.start().stop("+0.2");
* // AND
* state.start().stop("+0.2").start("+0.4").stop("+0.7")
*
* // BAD
* state.stop("+0.2").start();
* // OR
* state.start("+0.3").stop("+0.2");
*
*/
export abstract class Source<Options extends SourceOptions> extends ToneAudioNode<Options> {
/**
* The output volume node
*/
private _volume: Volume;
/**
* The output note
*/
output: OutputNode;
/**
* Sources have no inputs
*/
input = undefined;
/**
* The volume of the output in decibels.
* @example
* source.volume.value = -6;
*/
volume: Param<Decibels>;
/**
* The callback to invoke when the source is stopped.
*/
onstop: onStopCallback;
/**
* Keep track of the scheduled state.
*/
protected _state: StateTimeline<{
duration?: Seconds;
offset?: Seconds;
/**
* Either the buffer is explicitly scheduled to end using the stop method,
* or it's implicitly ended when the buffer is over.
*/
implicitEnd?: boolean;
}> = new StateTimeline("stopped");
/**
* The synced `start` callback function from the transport
*/
protected _synced: boolean = false;
/**
* Keep track of all of the scheduled event ids
*/
private _scheduled: number[] = [];
/**
* Placeholder functions for syncing/unsyncing to transport
*/
private _syncedStart: (time: Seconds, offset: Seconds) => void = noOp;
private _syncedStop: (time: Seconds) => void = noOp;
constructor(options: SourceOptions) {
super(options);
this._state.memory = 100;
this._volume = this.output = new Volume({
context: this.context,
mute: options.mute,
volume: options.volume,
});
this.volume = this._volume.volume;
readOnly(this, "volume");
this.onstop = options.onstop;
}
static getDefaults(): SourceOptions {
return Object.assign(ToneAudioNode.getDefaults(), {
mute: false,
onstop: noOp,
volume: 0,
});
}
/**
* Returns the playback state of the source, either "started" or "stopped".
*/
get state(): BasicPlaybackState {
if (this._synced) {
if (this.context.transport.state === "started") {
return this._state.getValueAtTime(this.context.transport.seconds) as BasicPlaybackState;
} else {
return "stopped";
}
} else {
return this._state.getValueAtTime(this.now()) as BasicPlaybackState;
}
}
/**
* Mute the output.
* @example
* //mute the output
* source.mute = true;
*/
get mute(): boolean {
return this._volume.mute;
}
set mute(mute: boolean) {
this._volume.mute = mute;
}
// overwrite these functions
protected abstract _start(time: Time, offset?: Time, duration?: Time): void;
protected abstract _stop(time: Time): void;
abstract restart(time: Time, offset?: Time, duration?: Time): this;
/**
* Ensure that the scheduled time is not before the current time.
* Should only be used when scheduled unsynced.
*/
private _clampToCurrentTime(time: Seconds): Seconds {
if (this._synced) {
return time;
} else {
return Math.max(time, this.context.currentTime);
}
}
/**
* Start the source at the specified time. If no time is given,
* start the source now.
* @param time When the source should be started.
* @example
* source.start("+0.5"); //starts the source 0.5 seconds from now
*/
start(time?: Time, offset?: Time, duration?: Time): this {
let computedTime = isUndef(time) && this._synced ? this.context.transport.seconds : this.toSeconds(time);
computedTime = this._clampToCurrentTime(computedTime);
this.log("start", computedTime);
// if it's started, stop it and restart it
if (this._state.getValueAtTime(computedTime) === "started") {
this._state.cancel(computedTime);
this._state.setStateAtTime("started", computedTime);
this.restart(computedTime, offset, duration);
} else {
this._state.setStateAtTime("started", computedTime);
if (this._synced) {
// add the offset time to the event
const event = this._state.get(computedTime);
if (event) {
event.offset = this.toSeconds(defaultArg(offset, 0));
event.duration = duration ? this.toSeconds(duration) : undefined;
}
const sched = this.context.transport.schedule(t => {
this._start(t, offset, duration);
}, computedTime);
this._scheduled.push(sched);
// if it's already started
if (this.context.transport.state === "started") {
this._syncedStart(this.now(), this.context.transport.seconds);
}
} else {
this._start(computedTime, offset, duration);
}
}
return this;
}
/**
* Stop the source at the specified time. If no time is given,
* stop the source now.
* @param time When the source should be stopped.
* @example
* source.stop(); // stops the source immediately
*/
stop(time?: Time): this {
let computedTime = isUndef(time) && this._synced ? this.context.transport.seconds : this.toSeconds(time);
computedTime = this._clampToCurrentTime(computedTime);
this.log("stop", computedTime);
if (!this._synced) {
this._stop(computedTime);
} else {
const sched = this.context.transport.schedule(this._stop.bind(this), computedTime);
this._scheduled.push(sched);
}
this._state.cancel(computedTime);
this._state.setStateAtTime("stopped", computedTime);
return this;
}
/**
* Sync the source to the Transport so that all subsequent
* calls to `start` and `stop` are synced to the TransportTime
* instead of the AudioContext time.
*
* @example
* //sync the source so that it plays between 0 and 0.3 on the Transport's timeline
* source.sync().start(0).stop(0.3);
* //start the transport.
* this.context.transport.start();
*
* @example
* //start the transport with an offset and the sync'ed sources
* //will start in the correct position
* source.sync().start(0.1);
* //the source will be invoked with an offset of 0.4 = (0.5 - 0.1)
* this.context.transport.start("+0.5", 0.5);
*/
sync(): this {
if (!this._synced) {
this._synced = true;
this._syncedStart = (time, offset) => {
if (offset > 0) {
// get the playback state at that time
const stateEvent = this._state.get(offset);
// listen for start events which may occur in the middle of the sync'ed time
if (stateEvent && stateEvent.state === "started" && stateEvent.time !== offset) {
// get the offset
const startOffset = offset - this.toSeconds(stateEvent.time);
let duration;
if (stateEvent.duration) {
duration = this.toSeconds(stateEvent.duration) - startOffset;
}
this._start(time, this.toSeconds(stateEvent.offset) + startOffset, duration);
}
}
};
this._syncedStop = time => {
const seconds = this.context.transport.getSecondsAtTime(Math.max(time - this.sampleTime, 0));
if (this._state.getValueAtTime(seconds) === "started") {
this._stop(time);
}
};
this.context.transport.on("start", this._syncedStart);
this.context.transport.on("loopStart", this._syncedStart);
this.context.transport.on("stop", this._syncedStop);
this.context.transport.on("pause", this._syncedStop);
this.context.transport.on("loopEnd", this._syncedStop);
}
return this;
}
/**
* Unsync the source to the Transport. See Source.sync
*/
unsync(): this {
if (this._synced) {
this.context.transport.off("stop", this._syncedStop);
this.context.transport.off("pause", this._syncedStop);
this.context.transport.off("loopEnd", this._syncedStop);
this.context.transport.off("start", this._syncedStart);
this.context.transport.off("loopStart", this._syncedStart);
}
this._synced = false;
// clear all of the scheduled ids
this._scheduled.forEach(id => this.context.transport.clear(id));
this._scheduled = [];
this._state.cancel(0);
return this;
}
/**
* Clean up.
*/
dispose(): this {
super.dispose();
this.onstop = noOp;
this.unsync();
this._volume.dispose();
this._state.dispose();
return this;
}
}