refactoring: name factories consistently

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "wasa",
-	"version": "0.0.19",
+	"version": "0.0.20",
 	"description": "High level tooling for Web Audio API",
 	"main": "dist/wasa.js",
 	"scripts": {

src/common/utils.js

@@ -1,4 +1,3 @@
-
 import { times } from 'ramda'
 
 export const mandatory = (parameterName = '') => {
@@ -34,3 +33,4 @@ export const wrapNode = (audioNode = mandatory()) => ({
 		return { connect }
 	},
 })
+

src/constants/filter-types.js

@@ -1,3 +1,7 @@
+/**
+ * FilterTypes provides constants for filter type assignation
+ * @type {Object}
+ */
 export const FilterTypes = Object.freeze({
 	LOW_PASS: 'lowpass',
 	BAND_PASS: 'bandpass',

src/constants/wave-forms.js

@@ -1,3 +1,7 @@
+/**
+ * WaveForms provides a hash of constants for oscillator type assignation
+ * @type {Object}
+ */
 export const WaveForms = Object.freeze({
 	SQUARE: 'square',
 	SAWTOOTH: 'sawtooth',

src/core/note.js

@@ -1,11 +1,4 @@
-/**
- * note module exports a set of utility functions and constants for midi
- * to symbol and midi to frequency conversion
- * @module note
- */
-
 import { isNil } from 'ramda'
-
 /**
  * @typedef {Object} Note
  * @property {string} pitchClass - The pitch in chromatic scale (english notation)
@@ -51,7 +44,7 @@ export function symbolToMidi(pitchClass, octave) {
 /**
  * Computes the pitch class and octave for the given midi value
  * @param {number} midiValue - Octave value for note
- * @returns {module:note~Note}
+ * @returns {Note}
  */
 export function midiToSymbol(midiValue) {
 	const pitchClassIndex = (midiValue - (12 * 2)) % 12

src/core/sequencer.js

@@ -8,10 +8,9 @@ import { mandatory } from '../common/utils'
 /**
  * @function
  * @param audioContext
- * @returns {*}
- * @constructor
+ * @returns {Sequencer}
  */
-export const Sequencer = (audioContext = mandatory()) => {
+export const createSequencer = (audioContext = mandatory()) => {
 	/* time values */
 	let ticksPerQuarterNote = 4
 	let startTime = 0

src/core/sequencer.spec.js

@@ -1,17 +1,17 @@
 import test from 'ava'
 import sinon from 'sinon'
-import { Sequencer } from '.'
+import { createSequencer } from '.'
 import { AudioContextMock } from '../mock/audio-context.mock'
 
-test('Sequencer factory creates a sequencer object', (t) => {
+test('createSequencer factory creates a sequencer object', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	const sequencer = Sequencer(audioContext)
+	const sequencer = createSequencer(audioContext)
 	t.true(typeof sequencer === 'object')
 })
 
 test('Calling start triggers onStart handler', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	Sequencer(audioContext)
+	createSequencer(audioContext)
 		.onStart(() => {
 			t.pass()
 		})
@@ -20,38 +20,38 @@ test('Calling start triggers onStart handler', (t) => {
 
 test('Calling stop triggers onStop handler', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	Sequencer(audioContext)
+	createSequencer(audioContext)
 		.onStop(() => {
 			t.pass()
 		})
 		.start()
 		.stop()
 })
 
-test('Sequencer factory returns object with a loopMode getter and setter', (t) => {
+test('createSequencer factory returns object with a loopMode getter and setter', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	const sequencer = Sequencer(audioContext)
+	const sequencer = createSequencer(audioContext)
 	sequencer.setLoopMode(true)
 	t.is(true, sequencer.getLoopMode())
 })
 
-test('Sequencer factory returns object with a length getter and setter', (t) => {
+test('createSequencer factory returns object with a length getter and setter', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	const sequencer = Sequencer(audioContext)
+	const sequencer = createSequencer(audioContext)
 	sequencer.setLength(16)
 	t.is(16, sequencer.getLength())
 })
 
-test('Sequencer factory returns object with a division getter and setter', (t) => {
+test('createSequencer factory returns object with a division getter and setter', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	const sequencer = Sequencer(audioContext)
+	const sequencer = createSequencer(audioContext)
 	sequencer.setDivision(4)
 	t.is(4, sequencer.getDivision())
 })
 
-test('Sequencer factory returns object with a tempo getter and setter', (t) => {
+test('createSequencer factory returns object with a tempo getter and setter', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	const sequencer = Sequencer(audioContext)
+	const sequencer = createSequencer(audioContext)
 	sequencer.setTempo(120)
 	t.is(120, sequencer.getTempo())
 })

src/macros/effects/bit-crusher.js

@@ -0,0 +1,41 @@
+import * as R from 'ramda'
+
+export const createBitCrusher = (audioContext) => {
+	const bufferSize = 512
+	const scriptProcessor = audioContext.createScriptProcessor(bufferSize, 1, 1)
+	let bits = 16
+	let normFreq = 0.05
+	const step = 0.5 ** bits
+	let phaser = 0
+	let last = 0
+	scriptProcessor.onaudioprocess = (event) => {
+		const input = event.inputBuffer.getChannelData(0)
+		const output = event.outputBuffer.getChannelData(0)
+		R.times((i) => {
+			phaser += normFreq
+			if (phaser >= 1) {
+				phaser -= 1
+				last = step * Math.floor((input[i] / step) + 0.5)
+			}
+			output[i] = last
+		}, bufferSize)
+	}
+
+	return {
+		connect({ connect, getInput }) {
+			scriptProcessor.connect(getInput())
+			return { connect }
+		},
+		getInput() {
+			return scriptProcessor
+		},
+		setFrequencyValue(value) {
+			normFreq = value
+			return this
+		},
+		setBitsValue(value) {
+			bits = value
+			return this
+		},
+	}
+}

src/macros/effects/delay.js

@@ -1,4 +1,4 @@
-export const Delay = (audioContext) => {
+export const createDelay = (audioContext) => {
 	/* audio nodes */
 	const output = audioContext.createGain()
 	const filter = audioContext.createBiquadFilter()
@@ -38,10 +38,9 @@ export const Delay = (audioContext) => {
 		setDivisionValue(value) {
 			division = value
 			delayTimeSeconds = divisionToDelayTime(division, tempo)
-			const feedbackValue = feedback.gain.value
-			feedback.gain.value = 0
+			delay.disconnect(feedback)
 			delay.delayTime.value = delayTimeSeconds
-			feedback.gain.value = feedbackValue
+			delay.connect(feedback)
 			return this
 		},
 		getDivisionValue() {

src/macros/effects/delay.spec.js

@@ -1,55 +1,55 @@
 import test from 'ava'
 import sinon from 'sinon'
-import { Delay } from './delay'
+import { createDelay } from './delay'
 
 import { AudioContextMock } from '../../mock/audio-context.mock'
 
-test('Delay factory returns an object', (t) => {
+test('createDelay factory returns an object', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	const delay = Delay(audioContext)
+	const delay = createDelay(audioContext)
 	t.true(typeof delay === 'object')
 })
 
-test('Delay connect method returns an object with a connect method', (t) => {
+test('createDelay connect method returns an object with a connect method', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	const delay = Delay(audioContext)
+	const delay = createDelay(audioContext)
 	const nextInChain = {
 		getInput: () => audioContext.createGain(),
 		connect() {},
 	}
 	t.true(typeof delay.connect(nextInChain).connect === 'function')
 })
 
-test('Delay connect method returns an object with a getInput method', (t) => {
+test('createDelay connect method returns an object with a getInput method', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	const delay = Delay(audioContext)
+	const delay = createDelay(audioContext)
 	t.true(typeof delay.getInput() === 'object')
 })
 
-test('Delay factory returns object with a tempo getter and setter', (t) => {
+test('createDelay factory returns object with a tempo getter and setter', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	const delay = Delay(audioContext)
+	const delay = createDelay(audioContext)
 	delay.setTempoValue(120)
 	t.is(120, delay.getTempoValue())
 })
 
-test('Delay factory returns object with a division getter and setter', (t) => {
+test('createDelay factory returns object with a division getter and setter', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	const delay = Delay(audioContext)
+	const delay = createDelay(audioContext)
 	delay.setDivisionValue(4)
 	t.is(4, delay.getDivisionValue())
 })
 
-test('Delay factory returns object with a feedback getter and setter', (t) => {
+test('createDelay factory returns object with a feedback getter and setter', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	const delay = Delay(audioContext)
+	const delay = createDelay(audioContext)
 	delay.setFeedbackValue(0.8)
 	t.is(0.8, delay.getFeedbackValue())
 })
 
-test('Delay factory returns object with a frequency getter and setter', (t) => {
+test('createDelay factory returns object with a frequency getter and setter', (t) => {
 	const audioContext = AudioContextMock(sinon.sandbox.create())
-	const delay = Delay(audioContext)
+	const delay = createDelay(audioContext)
 	delay.setFrequencyValue(200)
 	t.is(200, delay.getFrequencyValue())
 })

src/macros/effects/distortion.js

@@ -1,28 +1,52 @@
-export const Distortion = (audioContext) => {
+import * as R from 'ramda'
+
+export const createDistortion = (audioContext) => {
 	const makeDistortionCurve = (amount) => {
-		const k = typeof amount === 'number' ? amount : 50
-		const nSamples = 44100
+		const { sampleRate } = audioContext
 		const curve = new Float32Array(44100)
 		const deg = Math.PI / 180
-		for (let i = 0; i < nSamples; i += 1) {
-			const x = (i * 2) / (nSamples - 1)
-			curve[i] = ((3 + k) * x * 20 * deg) / ((Math.PI + k) * Math.abs(x))
-		}
+		R.times((i) => {
+			const x = (i * 2) / (sampleRate - 1)
+			const a = (3 + amount) * x * 20 * deg
+			const b = Math.PI + (amount * Math.abs(x))
+			curve[i] = a / b
+		}, sampleRate)
 		return curve
 	}
+
+	const preGain = audioContext.createGain()
+	const postGain = audioContext.createGain()
 	const dist = audioContext.createWaveShaper()
-	dist.curve = makeDistortionCurve(100)
+	preGain.connect(dist).connect(postGain)
+	dist.curve = makeDistortionCurve(400)
+	dist.oversample = '4x'
+	preGain.gain.value = 50
+	postGain.gain.value = 1
 	return {
 		connect({ connect, getInput }) {
-			dist.connect(getInput())
-			return connect
+			postGain.connect(getInput())
+			return { connect }
 		},
 		getInput() {
-			return dist
+			return preGain
 		},
-		setCurve(amount) {
+		setCurveAmount(amount) {
 			dist.curve = makeDistortionCurve(amount)
 			return this
 		},
+		setPreGainValue(value) {
+			preGain.gain.value = value
+			return this
+		},
+		getPreGainValue() {
+			return preGain.gain.value
+		},
+		setPostGainValue(value) {
+			postGain.gain.value = value
+			return this
+		},
+		getPostGainValue() {
+			return postGain.gain.value
+		},
 	}
 }

src/macros/effects/noise-convolver.js

@@ -0,0 +1,24 @@
+import * as R from 'ramda'
+
+export const createNoiseConvolver = (audioContext) => {
+	const convolver = audioContext.createConvolver()
+	const bufferSize = audioContext.sampleRate
+	const buffer = audioContext.createBuffer(2, bufferSize / 2, bufferSize)
+	const left = buffer.getChannelData(0)
+	const right = buffer.getChannelData(1)
+	R.times((i) => {
+		left[i] = Math.random()
+		right[i] = Math.random()
+	}, buffer.length)
+	convolver.buffer = buffer
+
+	return {
+		connect({ connect, getInput }) {
+			convolver.connect(getInput())
+			return { connect }
+		},
+		getInput() {
+			return convolver
+		},
+	}
+}