tonegenerator - npm Package Compare versions

Comparing version 0.2.1 to 0.3.0

index.js

@@ -6,7 +6,48 @@ /*
  */
-function generateCycle(cycle, volume) {
+
+var shapes = {
+  sine: function (i, cycle, volume) {
+    // i / cycle => value between 0 and 1
+    // 0 = beginning of circly
+    // 0.25 Math.sin = 1
+    // 0.5 Math.sin = 0
+    // 0.75 Math.sin = -1
+    // 1 Math.sin = 1
+    return Math.min(volume * Math.sin((i/cycle) * Math.PI * 2), volume - 1);
+  },
+  triangle: function (i, cycle, volume) {
+    var halfCycle = cycle / 2
+    var level
+
+    if (i < halfCycle) {
+      level = (volume * 2) * (i / halfCycle) - volume;
+    } else {
+      i = i - halfCycle
+      level = -(volume * 2) * (i / halfCycle) + volume;
+    }
+
+    return Math.min(level, volume - 1);
+  },
+  saw: function (i, cycle, volume) {
+    return Math.min((volume * 2) * (i / cycle) - volume, volume - 1);
+  },
+  square: function (i, cycle, volume) {
+    if(i > cycle / 2) {
+      return volume - 1;
+    }
+
+    return -volume;
+  }
+}
+
+function generateCycle(cycle, volume, shape) {
   var data = [];
   var tmp;
+  var generator = typeof shape == 'function' ? shape : shapes[shape];
+  if (!generator) {
+    throw new Error('Invalid wave form: "' + shape + '" choose between: ' + Object.keys(shapes));
+  }
+
   for(var i = 0; i < cycle; i++) {
-    tmp = Math.min(volume * Math.sin((i/cycle) * Math.PI * 2), volume - 1)
+    tmp = generator(i, cycle, volume);
     data[i] = Math.round(tmp);
@@ -17,7 +58,9 @@ }
 
-module.exports = function(freq, lengthInSecs, volume, rate) {
-  freq = freq || 440;
-  rate = rate || 44100
-  lengthInSecs = lengthInSecs || 2.0;
-  volume = volume || 30
+function generateWaveForm(opts) {
+  opts = opts || {}
+  var freq = opts.freq || 440;
+  var rate = opts.rate || 44100
+  var lengthInSecs = opts.lengthInSecs || 2.0;
+  var volume = opts.volume || 30;
+  var shape = opts.shape || 'sine';
 
@@ -30,3 +73,3 @@ var cycle = Math.floor(rate/freq);
   for(var i = 0; i < cycles; i++) {
-    ret = ret.concat(generateCycle(cycle, volume));
+    ret = ret.concat(generateCycle(cycle, volume, shape));
   }
@@ -37,3 +80,17 @@
 
+module.exports = function() {
+  // to support both old interface and the new one:
+  var opts = arguments[0]
+  if (arguments.length > 1 && typeof opts === "number") {
+    opts = {}
+    opts.freq = arguments[0]
+    opts.lengthInSecs = arguments[1]
+    opts.volume = arguments[2]
+    opts.rate = arguments[3]
+  }
+
+  return generateWaveForm(opts)
+}
+
 module.exports.MAX_16 = 32768;
 module.exports.MAX_8 = 128;

package.json

 {
   "name": "tonegenerator",
   "description": "Generates a tone as raw PCM WAV data, so you can do operations on it",
-  "version": "0.2.1",
+  "version": "0.3.0",
   "scripts": {
@@ -6,0 +6,0 @@ "test": "node test.js",

README.md

 ToneGenerator for node.js
 ====
 
-This thing generates raw PCM data, specified by
-a frequency and length in seconds.
+This thing generates an array of numbers in waveforms. This waveform can be written into a wavefile as raw PCM data.
+It does not play the sounds. If you want to play sounds, make sure to read the examples on how to write wave files below.
 
@@ -10,13 +10,38 @@ ## Generating Tones:
 ```javascript
-tone(frequency, lengthInSeconds, volume = 30, sampleRate = 44100)
+var tone = require('tonegenerator')
+
+// New Interface! More options!!
+var tonedata = tone({
+  freq: 440,
+  lengthInSecs: 2.0,
+  volume: 30,
+  sampleRate: 44100,
+  shape: 'triangle'
+})
+
+// The old interface, still available for compatibility
+var tonedata = tone(frequency, lengthInSeconds, volume = 30, sampleRate = 44100)
 ```
 
+#### Using the new interface
+- **freq** frequency in hertz. *defaults to 440*
+- **lengthInSecs** controls the length of the array output together with the samplerate *defaults to 2.0*
+- **volume** controls max/min for the array values. If you intend to write 8-bit it should be less than or equal to tone.MAX_8, if 16 bit it should be less than or equal to tone.MAX_16. *defaults to 30*
+- **sampleRate** number of samples per second. Together with lengthInSecs, this define the length of the output array (lengthInSeccs * sampleRate). *defaults to 44100*
+- **shape** controls the wave shape. Options are *'triangle', 'square', 'sine', 'saw'*. You can also pass in a custom function, see the tests for an example of this. *defaults to 'sine'*
+
+#### Using the old interface
+The old interface takes four arguments: *freq, lengthInSecs, volume, sampleRate*.
 **volume** and **sampleRate** are optional, the default is shown above.
-**If you want to specify sampleRate, you have to specify volume!**
+**Shape is not available in the old interface. If you want to specify sampleRate, you have to specify volume!**
 
+#### Useful constants
+```javascript
+tone.MAX_8 // max volume to be used with 8-bit sound
+tone.MAX_16 // max volume for 16 bit sound
 
 ```javascript
 var tone = require('tonegenerator');
-var A440 = tone(440, 20, 30); // get PCM data for a 440hz A, 20 seconds, volume 30
-var A440_low_sample = tone(440, 20, 30, 22050); // this array has lower sample rate and will only be half as long
+var A440 = tone({ freq: 440, lengthInSeconds: 20, volume: 30 }); // get PCM data for a 440hz A, 20 seconds, volume 30
+var A440_low_sample = tone(440, 20, 30, 22050); // (old interface) this array has lower sample rate and will only be half as long
 ```
@@ -30,5 +55,5 @@
 // An A-major chord
-var tone1 = tone(440, 2, 60)
-var tone2 = tone(554.37, 2, 30)
-var tone3 = tone(659.26, 2, 30)
+var tone1 = tone({ freq: 440, lengthInSecs: 2, volume: 60 })
+var tone2 = tone({ freq: 554.37, lengthInSecs: 2, volume: 30 })
+var tone3 = tone({ freq: 659.26, lengthInSecs: 2, volume: 30 })
 
@@ -63,3 +88,3 @@ // "playing" one tone at the time
 var file = fs.createWriteStream('8bit-example.wav')
-var samples = tone(440, 2, tone.MAX_8)
+var samples = tone({ freq: 440, lengthInSecs: 2, volume: tone.MAX_8 })
 
@@ -96,3 +121,3 @@ file.write(header(samples.length, {
 var file = fs.createWriteStream('16bit-example.wav')
-var samples = tone(440, 2, tone.MAX_16)
+var samples = tone({ freq: 440, lengthInSecs: 2, volume: tone.MAX_16 })
 
@@ -134,5 +159,5 @@ file.write(header(samples.length * 2, {
 // A loud A for channel 1
-var channel1 = tone(440, 2, tone.MAX_16)
+var channel1 = tone({ freq: 440, lengthInSecs: 2, volume: tone.MAX_16 })
 // A not so loud C for channel 2
-var channel2 = tone(554.37, 2, tone.MAX_16 / 4)
+var channel2 = tone({ freq: 554.37, lengthInSecs: 2, volume: tone.MAX_16 / 4 })
 
@@ -139,0 +164,0 @@ // create an array where the 2 channels are interleaved:

test.js

@@ -7,6 +7,8 @@ var assert = require('assert')
 
-var tone1 = tonegenerator(440, 2, 10)
-var tone2 = tonegenerator(440, 2, 30)
-var tonefrequency = tonegenerator(440, 2, 10, 22050)
+var tone1 = tonegenerator({ freq: 440, lengthInSecs: 2, volume: 10 })
+var tone2 = tonegenerator({ freq: 440, lengthInSecs: 2, volume: 30 })
+var tonefrequency = tonegenerator({ freq: 440, lengthInSecs: 2, volume: 10, rate: 22050 })
 
+
+console.log('Testing Sine Waves')
 assert(Array.isArray(tone1), 'Data is an array')
@@ -23,2 +25,64 @@
 
+
+console.log('Testing Triangle Waves')
+var tone4 = tonegenerator({ freq: 440, lengthInSecs: 2, volume: 10, shape: 'triangle' })
+// test that max is correct
+assert.strictEqual(Math.max.apply(Math, tone4), 9)
+// test that min is correct
+assert.strictEqual(Math.min.apply(Math, tone4), -10)
+// test that there are intermediate values
+assert(tone4.includes(0))
+assert(tone4.includes(-1))
+
+
+console.log('Testing Saw Waves')
+var tone5 = tonegenerator({ freq: 440, lengthInSecs: 2, volume: 10, shape: 'saw' })
+// test first val, should be min
+assert.strictEqual(tone5.shift(), -10)
+// test last val, should be max
+assert.strictEqual(tone5.pop(), 9)
+// test that there's intermediate values generated
+assert(tone5.includes(0))
+
+
+console.log('Testing Square Waves')
+var tone6 = tonegenerator({ freq: 440, lengthInSecs: 2, volume: 10, shape: 'square' })
+// test first val
+assert.strictEqual(tone6.pop(), 9)
+// test last val
+assert.strictEqual(tone6.shift(), -10)
+// make sure there's no intermediate values
+assert(!tone6.includes(0))
+
+
+console.log('Testing Custom Waves')
+var tone7 = tonegenerator({
+  freq: 440,
+  lengthInSecs: 2,
+  volume: 11,
+  shape: function (i, cycle, volume) {
+    return volume - 1;
+  }
+})
+// test first val
+assert.strictEqual(tone7.pop(), 10)
+// test last val
+assert.strictEqual(tone7.shift(), 10)
+// make sure there's no intermediate values
+assert(!tone7.includes(0))
+
+
+console.log('Testing old-style interface')
+var tone8 = tonegenerator(440, 2, 10)
+var tone9 = tonegenerator(440, 2, 30)
+var tonefrequency2 = tonegenerator(440, 2, 10, 22050)
+// takes the volume argument - 1 as max
+assert.strictEqual(Math.max.apply(Math, tone8), 9)
+// takes the volume argument as min
+assert.strictEqual(Math.min.apply(Math, tone8), -10)
+// takes the volume argument as max
+assert.strictEqual(Math.max.apply(Math, tone9), 29)
+
+assert.equal(tone8.length/2, tonefrequency2.length, 'when halving audio sampling rate, the array length should be half of default')
+
 console.log('...done')

No alert changes

Improved metrics

Total package byte prevSize

12339

increased by74.11%

Lines of code

146

increased by224.44%

Number of lines in readme file

192

increased by14.97%

No dependency changes