This commit is contained in:
Eric Rosenbaum 2017-11-07 15:21:47 -05:00
parent 9bd48e8761
commit 112bb55b9b

View file

@ -4,6 +4,10 @@ const Clone = require('../util/clone');
const Cast = require('../util/cast');
const MathUtil = require('../util/math-util');
/**
* An array of drum names, used in the play drum block.
* @type {string[]}
*/
const drumNames = [
'Snare Drum',
'Bass Drum',
@ -25,6 +29,10 @@ const drumNames = [
'Open Cuica'
];
/**
* An array of instrument names, used in the set instrument block.
* @type {string[]}
*/
const instrumentNames = [
'Piano',
'Electric Piano',
@ -66,7 +74,13 @@ class Scratch3MusicBlocks {
this.instrumentMenu = this._buildMenu(instrumentNames);
}
buildMenu (names) {
/**
* Build a menu using an array of strings.
* Used for creating the drum and instrument menus.
* @param {string[]} names - An array of names.
* @return {array} - An array of objects with text and value properties, for constructing a block menu.
* @private
*/
_buildMenu (names) {
const menu = [];
for (let i = 0; i < names.length; i++) {
@ -232,6 +246,14 @@ class Scratch3MusicBlocks {
};
}
/**
* Play a drum sound for some number of beats.
* @param {object} args - the block arguments.
* @param {object} util - utility object provided by the runtime.
* @property {int} DRUM - the number of the drum to play.
* @property {number} BEATS - the duration in beats of the drum sound.
* @return {Promise} - a promise which will resolve at the end of the duration.
*/
playDrumForBeats (args, util) {
let drum = Cast.toNumber(args.DRUM);
drum -= 1; // drums are one-indexed
@ -243,6 +265,13 @@ class Scratch3MusicBlocks {
return util.target.audioPlayer.playDrumForBeats(drum, beats);
}
/**
* Rest for some number of beats.
* @param {object} args - the block arguments.
* @param {object} util - utility object provided by the runtime.
* @property {number} BEATS - the duration in beats of the rest.
* @return {Promise} - a promise which will resolve at the end of the duration.
*/
restForBeats (args) {
let beats = Cast.toNumber(args.BEATS);
beats = this._clampBeats(beats);
@ -250,6 +279,14 @@ class Scratch3MusicBlocks {
return this.runtime.audioEngine.waitForBeats(beats);
}
/**
* Play a note using the current musical instrument for some number of beats.
* @param {object} args - the block arguments.
* @param {object} util - utility object provided by the runtime.
* @property {number} NOTE - the pitch of the note to play, interpreted as a MIDI note number.
* @property {number} BEATS - the duration in beats of the note.
* @return {Promise} - a promise which will resolve at the end of the duration.
*/
playNoteForBeats (args, util) {
let note = Cast.toNumber(args.NOTE);
note = MathUtil.clamp(note, Scratch3MusicBlocks.MIDI_NOTE_RANGE.min, Scratch3MusicBlocks.MIDI_NOTE_RANGE.max);
@ -261,6 +298,13 @@ class Scratch3MusicBlocks {
return this.runtime.audioEngine.playNoteForBeatsWithInstAndVol(note, beats, inst, 100);
}
/**
* Select an instrument for playing notes.
* @param {object} args - the block arguments.
* @param {object} util - utility object provided by the runtime.
* @property {int} INSTRUMENT - the number of the instrument to select.
* @return {Promise} - a promise which will resolve once the instrument has loaded.
*/
setInstrument (args, util) {
const musicState = this._getMusicState(util.target);
let instNum = Cast.toNumber(args.INSTRUMENT);
@ -271,15 +315,31 @@ class Scratch3MusicBlocks {
return this.runtime.audioEngine.instrumentPlayer.loadInstrument(musicState.currentInstrument);
}
/**
* Clamp a duration in beats to the allowed min and max duration.
* @param {number} beats - a duration in beats.
* @return {number} - the clamped duration.
* @private
*/
_clampBeats (beats) {
return MathUtil.clamp(beats, Scratch3MusicBlocks.BEAT_RANGE.min, Scratch3MusicBlocks.BEAT_RANGE.max);
}
/**
* Set the current tempo to a new value.
* @param {object} args - the block arguments.
* @property {number} TEMPO - the tempo, in beats per minute.
*/
setTempo (args) {
const tempo = Cast.toNumber(args.TEMPO);
this._updateTempo(tempo);
}
/**
* Change the current tempo by some amount.
* @param {object} args - the block arguments.
* @property {number} TEMPO - the amount to change the tempo, in beats per minute.
*/
changeTempo (args) {
const change = Cast.toNumber(args.TEMPO);
if (typeof this.runtime.audioEngine === 'undefined') return;
@ -287,12 +347,21 @@ class Scratch3MusicBlocks {
this._updateTempo(tempo);
}
/**
* Update the current tempo, clamping it to the min and max allowable range.
* @param {number} tempo - the tempo to set, in beats per minute.
* @private
*/
_updateTempo (tempo) {
tempo = MathUtil.clamp(tempo, Scratch3MusicBlocks.TEMPO_RANGE.min, Scratch3MusicBlocks.TEMPO_RANGE.max);
if (typeof this.runtime.audioEngine === 'undefined') return;
this.runtime.audioEngine.setTempo(tempo);
}
/**
* Get the current tempo.
* @return {number} - the current tempo, in beats per minute.
*/
getTempo () {
if (typeof this.runtime.audioEngine === 'undefined') return;
return this.runtime.audioEngine.currentTempo;