Tone.js/Tone/core/Offline.js
tambien ed71d8141b amd to es6 import/export
no longer using AMD (require.js) style imports, and beginning to move to es6 "import/export" statements everywhere.
2019-01-27 13:05:20 -05:00

75 lines
2.5 KiB
JavaScript

import Tone from "../core/Tone";
import "../core/Transport";
import "../core/Buffer";
import "../core/OfflineContext";
import "../core/Master";
/**
* Generate a buffer by rendering all of the Tone.js code within the callback using the OfflineAudioContext.
* The OfflineAudioContext is capable of rendering much faster than real time in many cases.
* The callback function also passes in an offline instance of Tone.Transport which can be used
* to schedule events along the Transport. **NOTE** OfflineAudioContext has the same restrictions
* as the AudioContext in that on certain platforms (like iOS) it must be invoked by an explicit
* user action like a click or tap.
* @param {Function} callback All Tone.js nodes which are created and scheduled within this callback are recorded into the output Buffer.
* @param {Time} duration the amount of time to record for.
* @return {Promise} The promise which is invoked with the Tone.Buffer of the recorded output.
* @example
* //render 2 seconds of the oscillator
* Tone.Offline(function(){
* //only nodes created in this callback will be recorded
* var oscillator = new Tone.Oscillator().toMaster().start(0)
* //schedule their events
* }, 2).then(function(buffer){
* //do something with the output buffer
* })
* @example
* //can also schedule events along the Transport
* //using the passed in Offline Transport
* Tone.Offline(function(Transport){
* var osc = new Tone.Oscillator().toMaster()
* Transport.schedule(function(time){
* osc.start(time).stop(time + 0.1)
* }, 1)
* Transport.start(0.2)
* }, 4).then(function(buffer){
* //do something with the output buffer
* })
*/
Tone.Offline = function(callback, duration){
//set the OfflineAudioContext
var sampleRate = Tone.context.sampleRate;
var originalContext = Tone.context;
var context = new Tone.OfflineContext(2, duration, sampleRate);
Tone.context = context;
//invoke the callback/scheduling
var response = callback(Tone.Transport);
//the return value
var ret = null;
if (response && Tone.isFunction(response.then)){
//wait for the promise to resolve
ret = response.then(function(){
//then render the audio
return context.render();
});
} else {
//process the audio
ret = context.render();
}
//return the original AudioContext
Tone.context = originalContext;
//return the audio
return ret.then(function(buffer){
//wrap it in a Tone.Buffer
return new Tone.Buffer(buffer);
});
};
export default Tone.Offline;