Tone.js/Tone/event/Event.js
2017-04-25 23:08:57 -04:00

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11 KiB
JavaScript

define(["Tone/core/Tone", "Tone/core/Transport", "Tone/type/Type", "Tone/core/TimelineState"], function (Tone) {
"use strict";
/**
* @class Tone.Event abstracts away Tone.Transport.schedule and provides a schedulable
* callback for a single or repeatable events along the timeline.
*
* @extends {Tone}
* @param {function} callback The callback to invoke at the time.
* @param {*} value The value or values which should be passed to
* the callback function on invocation.
* @example
* var chord = new Tone.Event(function(time, chord){
* //the chord as well as the exact time of the event
* //are passed in as arguments to the callback function
* }, ["D4", "E4", "F4"]);
* //start the chord at the beginning of the transport timeline
* chord.start();
* //loop it every measure for 8 measures
* chord.loop = 8;
* chord.loopEnd = "1m";
*/
Tone.Event = function(){
var options = Tone.defaults(arguments, ["callback", "value"], Tone.Event);
Tone.call(this);
/**
* Loop value
* @type {Boolean|Positive}
* @private
*/
this._loop = options.loop;
/**
* The callback to invoke.
* @type {Function}
*/
this.callback = options.callback;
/**
* The value which is passed to the
* callback function.
* @type {*}
* @private
*/
this.value = options.value;
/**
* When the note is scheduled to start.
* @type {Number}
* @private
*/
this._loopStart = this.toTicks(options.loopStart);
/**
* When the note is scheduled to start.
* @type {Number}
* @private
*/
this._loopEnd = this.toTicks(options.loopEnd);
/**
* Tracks the scheduled events
* @type {Tone.TimelineState}
* @private
*/
this._state = new Tone.TimelineState(Tone.State.Stopped);
/**
* The playback speed of the note. A speed of 1
* is no change.
* @private
* @type {Positive}
*/
this._playbackRate = 1;
/**
* A delay time from when the event is scheduled to start
* @type {Ticks}
* @private
*/
this._startOffset = 0;
/**
* private holder of probability value
* @type {NormalRange}
* @private
*/
this._probability = options.probability;
/**
* the amount of variation from the
* given time.
* @type {Boolean|Time}
* @private
*/
this._humanize = options.humanize;
/**
* If mute is true, the callback won't be
* invoked.
* @type {Boolean}
*/
this.mute = options.mute;
//set the initial values
this.playbackRate = options.playbackRate;
};
Tone.extend(Tone.Event);
/**
* The default values
* @type {Object}
* @const
*/
Tone.Event.defaults = {
"callback" : Tone.noOp,
"loop" : false,
"loopEnd" : "1m",
"loopStart" : 0,
"playbackRate" : 1,
"value" : null,
"probability" : 1,
"mute" : false,
"humanize" : false,
};
/**
* Reschedule all of the events along the timeline
* with the updated values.
* @param {Time} after Only reschedules events after the given time.
* @return {Tone.Event} this
* @private
*/
Tone.Event.prototype._rescheduleEvents = function(after){
//if no argument is given, schedules all of the events
after = this.defaultArg(after, -1);
this._state.forEachFrom(after, function(event){
var duration;
if (event.state === Tone.State.Started){
if (!this.isUndef(event.id)){
Tone.Transport.clear(event.id);
}
var startTick = event.time + Math.round(this.startOffset / this._playbackRate);
if (this._loop){
duration = Infinity;
if (this.isNumber(this._loop)){
duration = (this._loop) * this._getLoopDuration();
}
var nextEvent = this._state.getAfter(startTick);
if (nextEvent !== null){
duration = Math.min(duration, nextEvent.time - startTick);
}
if (duration !== Infinity){
//schedule a stop since it's finite duration
this._state.setStateAtTime(Tone.State.Stopped, startTick + duration + 1);
duration = Tone.Time(duration, "i");
}
var interval = Tone.Time(this._getLoopDuration(), "i");
event.id = Tone.Transport.scheduleRepeat(this._tick.bind(this), interval, Tone.TransportTime(startTick, "i"), duration);
} else {
event.id = Tone.Transport.schedule(this._tick.bind(this), startTick + "i");
}
}
}.bind(this));
return this;
};
/**
* Returns the playback state of the note, either "started" or "stopped".
* @type {String}
* @readOnly
* @memberOf Tone.Event#
* @name state
*/
Object.defineProperty(Tone.Event.prototype, "state", {
get : function(){
return this._state.getValueAtTime(Tone.Transport.ticks);
}
});
/**
* The start from the scheduled start time
* @type {Ticks}
* @memberOf Tone.Event#
* @name startOffset
* @private
*/
Object.defineProperty(Tone.Event.prototype, "startOffset", {
get : function(){
return this._startOffset;
},
set : function(offset){
this._startOffset = offset;
}
});
/**
* The probability of the notes being triggered.
* @memberOf Tone.Event#
* @type {NormalRange}
* @name probability
*/
Object.defineProperty(Tone.Event.prototype, "probability", {
get : function(){
return this._probability;
},
set : function(prob){
this._probability = prob;
}
});
/**
* If set to true, will apply small random variation
* to the callback time. If the value is given as a time, it will randomize
* by that amount.
* @example
* event.humanize = true;
* @type {Boolean|Time}
* @name humanize
*/
Object.defineProperty(Tone.Event.prototype, "humanize", {
get : function(){
return this._humanize;
},
set : function(variation){
this._humanize = variation;
}
});
/**
* Start the note at the given time.
* @param {TimelinePosition} time When the note should start.
* @return {Tone.Event} this
*/
Tone.Event.prototype.start = function(time){
time = this.toTicks(time);
if (this._state.getValueAtTime(time) === Tone.State.Stopped){
this._state.add({
"state" : Tone.State.Started,
"time" : time,
"id" : undefined,
});
this._rescheduleEvents(time);
}
return this;
};
/**
* Stop the Event at the given time.
* @param {TimelinePosition} time When the note should stop.
* @return {Tone.Event} this
*/
Tone.Event.prototype.stop = function(time){
this.cancel(time);
time = this.toTicks(time);
if (this._state.getValueAtTime(time) === Tone.State.Started){
this._state.setStateAtTime(Tone.State.Stopped, time);
var previousEvent = this._state.getBefore(time);
var reschedulTime = time;
if (previousEvent !== null){
reschedulTime = previousEvent.time;
}
this._rescheduleEvents(reschedulTime);
}
return this;
};
/**
* Cancel all scheduled events greater than or equal to the given time
* @param {TimelinePosition} [time=0] The time after which events will be cancel.
* @return {Tone.Event} this
*/
Tone.Event.prototype.cancel = function(time){
time = this.defaultArg(time, -Infinity);
time = this.toTicks(time);
this._state.forEachFrom(time, function(event){
Tone.Transport.clear(event.id);
});
this._state.cancel(time);
return this;
};
/**
* The callback function invoker. Also
* checks if the Event is done playing
* @param {Number} time The time of the event in seconds
* @private
*/
Tone.Event.prototype._tick = function(time){
if (!this.mute && this._state.getValueAtTime(Tone.Transport.ticks) === Tone.State.Started){
if (this.probability < 1 && Math.random() > this.probability){
return;
}
if (this.humanize){
var variation = 0.02;
if (!this.isBoolean(this.humanize)){
variation = this.toSeconds(this.humanize);
}
time += (Math.random() * 2 - 1) * variation;
}
this.callback(time, this.value);
}
};
/**
* Get the duration of the loop.
* @return {Ticks}
* @private
*/
Tone.Event.prototype._getLoopDuration = function(){
return Math.round((this._loopEnd - this._loopStart) / this._playbackRate);
};
/**
* If the note should loop or not
* between Tone.Event.loopStart and
* Tone.Event.loopEnd. An integer
* value corresponds to the number of
* loops the Event does after it starts.
* @memberOf Tone.Event#
* @type {Boolean|Positive}
* @name loop
*/
Object.defineProperty(Tone.Event.prototype, "loop", {
get : function(){
return this._loop;
},
set : function(loop){
this._loop = loop;
this._rescheduleEvents();
}
});
/**
* The playback rate of the note. Defaults to 1.
* @memberOf Tone.Event#
* @type {Positive}
* @name playbackRate
* @example
* note.loop = true;
* //repeat the note twice as fast
* note.playbackRate = 2;
*/
Object.defineProperty(Tone.Event.prototype, "playbackRate", {
get : function(){
return this._playbackRate;
},
set : function(rate){
this._playbackRate = rate;
this._rescheduleEvents();
}
});
/**
* The loopEnd point is the time the event will loop
* if Tone.Event.loop is true.
* @memberOf Tone.Event#
* @type {TransportTime}
* @name loopEnd
*/
Object.defineProperty(Tone.Event.prototype, "loopEnd", {
get : function(){
return Tone.TransportTime(this._loopEnd, "i").toNotation();
},
set : function(loopEnd){
this._loopEnd = this.toTicks(loopEnd);
if (this._loop){
this._rescheduleEvents();
}
}
});
/**
* The time when the loop should start.
* @memberOf Tone.Event#
* @type {TransportTime}
* @name loopStart
*/
Object.defineProperty(Tone.Event.prototype, "loopStart", {
get : function(){
return Tone.TransportTime(this._loopStart, "i").toNotation();
},
set : function(loopStart){
this._loopStart = this.toTicks(loopStart);
if (this._loop){
this._rescheduleEvents();
}
}
});
/**
* The current progress of the loop interval.
* Returns 0 if the event is not started yet or
* it is not set to loop.
* @memberOf Tone.Event#
* @type {NormalRange}
* @name progress
* @readOnly
*/
Object.defineProperty(Tone.Event.prototype, "progress", {
get : function(){
if (this._loop){
var ticks = Tone.Transport.ticks;
var lastEvent = this._state.get(ticks);
if (lastEvent !== null && lastEvent.state === Tone.State.Started){
var loopDuration = this._getLoopDuration();
var progress = (ticks - lastEvent.time) % loopDuration;
return progress / loopDuration;
} else {
return 0;
}
} else {
return 0;
}
}
});
/**
* Clean up
* @return {Tone.Event} this
*/
Tone.Event.prototype.dispose = function(){
this.cancel();
this._state.dispose();
this._state = null;
this.callback = null;
this.value = null;
};
return Tone.Event;
});