Implement tunings

index.html

@@ -15,11 +15,10 @@
         <div id="keyboard" class="overflow-auto"></div>
         <label>
           Volume
-          <input type="range" min="0.0" max="2.0" value="1.0" step="0.01" id="range">
+          <input type="range" min="0.0" max="2.0" value="1.0" step="0.01" id="volume">
         </label>
       </article>
       <section id="options">
-        <form>
         <article>
           <h3 id="current-note">-</h3>
           <label>
@@ -32,43 +31,45 @@
             <small>Frequency</small>
             <input type="number" id="current-frequency" step="0.01">
           </label>
+          <label>
+            <small id="adjust-value">- Hz</small>
+            <input type="range" min="0.944" max="1.059" value="1.0" step="0.001" id="adjust">
+          </label>
         </article>
         <article>
           <fieldset>
             <legend><small>Tuning</small></legend>
             <label>
-                <input type="radio" name="tuning">
+              <input type="radio" name="tuning" value="equal">
               Equal temperament
             </label>
             <label>
-                <input type="radio" name="tuning">
+              <input type="radio" name="tuning" value="5th">
               Perfect 5th
             </label>
             <label>
-                <input type="radio" name="tuning">
+              <input type="radio" name="tuning" value="4th">
               Perfect 4th
             </label>
             <label>
-                <input type="radio" name="tuning">
+              <input type="radio" name="tuning" value="maj3rd">
               Perfect major 3rd
             </label>
             <label>
-                <input type="radio" name="tuning">
+              <input type="radio" name="tuning" value="min3rd">
               Perfect minor 3rd
             </label>
-              <div id="tune-from" style="display: none">
             <label>
               From:
-                  <select name="tuning-from">
+              <select id="tuning-from"></select>
-                    <option selected disabled value></option>
-                    <option>C2</option>
-                  </select>
             </label>
-              </div>
+            <button id="tune">Tune</button>
-              <button>Tune</button>
           </fieldset>
         </article>
-        </form>
+        <article>
+          <button class="secondary" id="reset">Reset all</button>
+          <button class="secondary" id="zero">Zero all</button>
+        </article>
       </section>
     </main>
   </body>

index.js

@@ -98,7 +98,19 @@ class Voice {
     }
 }
 
+function radioValue(name) {
+    try {
+        return document.getElementsByName(name).values().filter(e => e.checked).next().value.value;
+    } catch (e) {
+        // TypeError
+    }
+    return undefined;
+}
+
 function playNote(frequency, duration=86400) {
+    if (frequency < kA0Frequency) {
+        return undefined;
+    }
     const voice = new Voice(frequency);
     voice.play(duration);
     return voice;
@@ -116,10 +128,16 @@ function noteFrequency(key) {
 }
 
 function setFrequency(key, frequency) {
-    frequencies[keyIndex(key)] = frequency;
+    const index = keyIndex(key);
+    for (let f = frequency, i = index; i >= 0; f *= 0.5, i -= 12) {
+        frequencies[i] = f;
+    }
+    for (let f = frequency * 2, i = index + 12; i < 88; f *= 2, i += 12) {
+        frequencies[i] = f;
+    }
 }
 
-function tuneEqual() {
+function tuneAllEqual() {
     const startFrequency = kA0Frequency;
     let frequency = startFrequency;
     for (let i = 0; i < kMaxKeys; i++) {
@@ -132,7 +150,8 @@ function updateOptions(key) {
     const noteSpan = document.getElementById("current-note");
     const frequencySpan = document.getElementById("current-frequency");
     noteSpan.innerHTML = key;
-    frequencySpan.value = noteFrequency(key).toFixed(2);
+    const freq = noteFrequency(key);
+    frequencySpan.value = freq.toFixed(2);
     const index = keyIndex(key);
     const hold = document.getElementById("hold");
     if (holds[index] !== undefined) {
@@ -140,6 +159,8 @@ function updateOptions(key) {
     } else {
         hold.checked = false;
     }
+    document.getElementById("adjust").value = 1.0;
+    document.getElementById("adjust-value").innerHTML = freq.toFixed(2) + ' Hz';
 }
 
 function onKeyClick(event) {
@@ -148,6 +169,10 @@ function onKeyClick(event) {
     if (holds[keyIndex(key)] === undefined) {
         playNote(noteFrequency(key), 0.5);
     }
+    const currentKey = document.getElementById("current-note").innerHTML;
+    if (currentKey !== '-') {
+        document.getElementById('tuning-from').value = currentKey;
+    }
     updateOptions(key);
 
     keySpan.classList.add('playing');
@@ -174,6 +199,7 @@ function makeKey(note) {
 
 function setupKeyboard(firstKey=kFirstKey, numKeys=kNumKeys) {
     const keyboard = document.getElementById('keyboard');
+    const tuningFrom = document.getElementById('tuning-from');
     keyboard.innerHTML = '';
 
     let curIndex = kNotes.indexOf(firstKey.charAt(0));
@@ -183,6 +209,9 @@ function setupKeyboard(firstKey=kFirstKey, numKeys=kNumKeys) {
         const note = kNotes[curIndex] + octave;
         const key = makeKey(note)
         keyboard.appendChild(key);
+        const opt = document.createElement('option');
+        opt.innerHTML = note;
+        tuningFrom.appendChild(opt);
 
         curIndex += 1;
         if (curIndex >= kNotes.length) {
@@ -214,14 +243,33 @@ function refreshHolds() {
     }
 }
 
+function tuneFraction(key, fromKey, fraction) {
+    const fromIndex = keyIndex(fromKey);
+    const freq = frequencies[fromIndex] * fraction;
+    setFrequency(key, freq);
+}
+
+function tuneEqual(key, fromKey) {
+    const index = keyIndex(key);
+    const fromIndex = keyIndex(fromKey);
+    const diff = index - fromIndex;
+    const freq = frequencies[fromIndex] * Math.pow(kSemiToneMultiplier, diff);
+    setFrequency(key, freq);
+}
+
 function setupListeners() {
     const freq = document.getElementById("current-frequency");
-    freq.onchange = e => {
+    const adjust = document.getElementById("adjust");
+    freq.oninput = e => {
         const key = document.getElementById("current-note").innerHTML;
-        setFrequency(key, parseFloat(freq.value));
+        const adj = parseFloat(adjust.value);
+        const fre = parseFloat(freq.value);
+        const newFreq = adj * fre;
+        setFrequency(key, newFreq);
         refreshHolds();
+        document.getElementById("adjust-value").innerHTML = newFreq.toFixed(2) + ' Hz';
     };
-    freq.oninput = freq.onchange;
+    adjust.oninput = freq.oninput;
 
     const hold = document.getElementById("hold");
     hold.onchange = e => {
@@ -232,16 +280,50 @@ function setupListeners() {
             removeHold(key);
         }
     }
-    const range = document.getElementById("range");
+    const volume = document.getElementById("volume");
-    range.oninput = e => {
+    volume.oninput = e => {
-        const val = parseFloat(range.value);
+        const val = parseFloat(volume.value);
         globalVolume.gain.value = val;
         refreshHolds();
     }
+    document.getElementById("reset").onclick = () => {
+        tuneAllEqual();
+        refreshHolds();
+        const currentKey = document.getElementById("current-note").innerHTML;
+        if (currentKey !== '-') {
+            updateOptions(currentKey);
+        }
+    }
+    document.getElementById("zero").onclick = () => {
+        frequencies.fill(0.0);
+        refreshHolds();
+        const currentKey = document.getElementById("current-note").innerHTML;
+        if (currentKey !== '-') {
+            updateOptions(currentKey);
+        }
+    }
+    document.getElementById('tune').onclick = () => {
+        const key = document.getElementById("current-note").innerHTML;
+        const fromkey = document.getElementById('tuning-from').value;
+        const method = radioValue('tuning');
+        if (method === 'equal') {
+            tuneEqual(key, fromkey);
+        } else if (method === '5th') {
+            tuneFraction(key, fromkey, 3/2);
+        } else if (method === '4th') {
+            tuneFraction(key, fromkey, 4/3);
+        } else if (method === 'maj3rd') {
+            tuneFraction(key, fromkey, 5/4);
+        } else if (method === 'min3rd') {
+            tuneFraction(key, fromkey, 6/5);
+        }
+        refreshHolds();
+        updateOptions(key);
+    }
 }
 
 window.addEventListener('load', e => {
     setupKeyboard('C2', 49);
-    tuneEqual();
+    tuneAllEqual();
     setupListeners();
 });