add scale highlighting

2 files changed, 93 insertions, 19 deletions

diff --git a/app/app.js b/app/app.js
index 00b18bb..522cb99 100644
--- a/app/app.js
+++ b/app/app.js
@@ -3,6 +3,9 @@ import { pos, width, height } from './style';
 import * as notes from './notes';
 
 const statbyte = (stat, chan) => (stat << 4) | chan;
+const CHANNEL  = 0b1011;
+const ALL_NOTES_OFF = 0x7B;
+const ALL_SOUND_OFF = 0x78;
 const NOTE_ON  = 0b1001;
 const NOTE_OFF = 0b1000;
 const CCHANGE  = 0b1011;
@@ -24,7 +27,7 @@ const parse = message => ({
   val: message.data[2] / 127,
 });
 
-const Hexagon = ({ x, y, children, state, note, send, major }) => {
+const Hexagon = ({ x, y, children, state, note, send, major, scale }) => {
   if (major == 'row') {
     if (y % 2 == 0)
       x += 0.5;
@@ -35,7 +38,7 @@ const Hexagon = ({ x, y, children, state, note, send, major }) => {
 
   return (
     <div
-      className={'hexagon' + (state ? ' active' : '')}
+      className={`hexagon ${state ? ' active' : ''} ${scale}`}
       style={pos([x, y], major)}
     >
       <div
@@ -76,9 +79,35 @@ const layouts = {
   },
 };
 
+const scales = {
+  major: [2, 2, 1, 2, 2, 2, 1],
+  minor_nat: [2, 1, 2, 2, 1, 2, 2],
+  minor_harm: [2, 1, 2, 2, 1, 3, 1],
+  minor_mel: [2, 1, 2, 2, 2, 2, 1],
+  minor_hung: [2, 1, 3, 1, 1, 3, 1],
+  whole: [2, 2, 2, 2, 2, 2],
+  penta: [2, 2, 3, 2, 3],
+};
 
 const range = i => new Array(i).fill(true);
-const Keyboard = ({ w, h, send, layout: { major, map }, showMidi, state }) => (
+const tallyup = (steps, offset=0) => {
+  const notes = [];
+
+  let sum = 0;
+  for (let i = 0; i < steps.length; i++) {
+    notes[i] = offset + sum;
+    sum += steps[i];
+  }
+
+  if (sum != 12) throw new Error(`scale doesn't tally up: ${steps} / ${notes}`);
+
+  return {
+    notes,
+    modulo: notes.map(n => n % 12),
+  };
+};
+
+const Keyboard = ({ w, h, send, layout: { major, map }, showMidi, state, scale }) => (
   <div
     className={`keyboard ${major}-major`}
     style={{
@@ -89,6 +118,8 @@ const Keyboard = ({ w, h, send, layout: { major, map }, showMidi, state }) => (
     {range(w).map((_, x) => (
       range(h).map((_, y) => {
         const note = map([x, y], [w, h]);
+        const onCore = scale && scale.notes.indexOf(note) >= 0;
+        const onScale = scale && scale.modulo.indexOf(note % 12) >= 0;
         return (
           <Hexagon
             key={x + ',' + y}
@@ -97,6 +128,7 @@ const Keyboard = ({ w, h, send, layout: { major, map }, showMidi, state }) => (
             state={state[note]}
             send={send}
             major={major}
+            scale={onCore ? "core" : (onScale ? "" : "disabled")}
           >
             {showMidi ? note : notes.music[note % 12]}
           </Hexagon>
@@ -133,7 +165,9 @@ const ChordView = ({ chord }) => {
 export default class App extends React.Component {
   state = {
     layout: 'wicki_hayden',
-    notes: {},
+    scale: 'major',
+    offset: 60,
+    state: {},
   };
 
   componentDidMount() {
@@ -147,6 +181,9 @@ export default class App extends React.Component {
   }
 
   componentDidUpdate(prevProps) {
+    this.send(CHANNEL, ALL_SOUND_OFF, 0);
+    this.send(CHANNEL, ALL_NOTES_OFF, 0);
+
     if (prevProps.midiin)
       prevProps.midiin.onmidimessage = null;
 
@@ -159,17 +196,21 @@ export default class App extends React.Component {
     setTimeout(() => this.onmessage({ cmd: NOTE_OFF, note }), 250);
   }
 
-  send = (command, note) => {
+  send = (command, note, vel=127) => {
+    if (command === NOTE_ON && this.state.offset === null)
+      this.setState({ offset: note });
+
     if (!this.props.midiout)
       return;
 
-    const msg = [statbyte(command, 0), note, 127];
+    const msg = [statbyte(command, 0), note, vel];
     this.props.midiout.send(msg);
   }
 
-  onlayout = (e) => {
-    this.setState({ layout: e.target.value });
-  }
+  onlayout = (e) => this.setState({ layout: e.target.value })
+  onscale = (e) => this.setState({ scale: e.target.value })
+
+  onoffset = (e) => this.setState({ offset: null });
 
   onmessage = (e) => {
     const message = parse(e);
@@ -182,11 +223,11 @@ export default class App extends React.Component {
 
     switch (message.cmd) {
       case NOTE_ON:
-        this.setState(({ notes }) => ({ notes: { ...notes, [message.note]: true } }));
+        this.setState(({ state }) => ({ state: { ...state, [message.note]: true } }));
         break;
 
       case NOTE_OFF:
-        this.setState(({ notes }) => ({ notes: { ...notes, [message.note]: false } }));
+        this.setState(({ state }) => ({ state: { ...state, [message.note]: false } }));
         break;
     }
   }
@@ -197,7 +238,11 @@ export default class App extends React.Component {
     const note = notes.key2midi[e.code];
     if (!note) return;
     e.preventDefault();
-    this.setState(({ notes }) => ({ notes: { ...notes, [note]: true } }));
+
+    if (this.state.offset === null)
+      this.setState({ offset: note });
+
+    this.setState(({ state }) => ({ state: { ...state, [note]: true } }));
     this.send(NOTE_ON,  note);
   }
 
@@ -207,36 +252,52 @@ export default class App extends React.Component {
     const note = notes.key2midi[e.code];
     if (!note) return;
     e.preventDefault();
-    this.setState(({ notes }) => ({ notes: { ...notes, [note]: false } }));
+
+    this.setState(({ state }) => ({ state: { ...state, [note]: false } }));
     this.send(NOTE_OFF,  note);
   }
 
   render() {
     const { configure, showMidi } = this.props;
-    const { layout, notes } = this.state;
+    const { scale, offset, layout, state } = this.state;
 
-    const chord = Object.entries(notes).filter(([note, on]) => on).map(([k, _]) => k);
+    const chord = Object.entries(state).filter(([note, on]) => on).map(([k, _]) => k);
     chord.sort();
 
     return (
       <div className="app">
         <button onClick={configure}>settings</button>
-        <label>layout:
+        <label>layout:{' '}
           <select name="layout" onChange={this.onlayout} value={layout}>
             <option value="wicki_hayden">Wicki-Hayden</option>
             <option value="harmonic">Harmonic Table</option>
             <option value="gerhard">Gerhard</option>
           </select>
         </label>
+        <label>scale:{' '}
+          <select name="layout" onChange={this.onscale} value={scale}>
+            <option value="none">None</option>
+            <option value="major">Major</option>
+            <option value="minor_nat">Natural Minor</option>
+            <option value="minor_harm">Harmonic Minor</option>
+            <option value="minor_mel">Melodic Minor</option>
+            <option value="minor_hung">Hungarian Minor</option>
+            <option value="whole">Whole-Tone</option>
+            <option value="penta">Pentatonic</option>
+          </select>
+        </label>
+        <button onClick={this.onoffset}>set offset</button>
 
         <div className="main">
           <Keyboard
             w={12}
             h={4}
             send={this.send}
-            layout={layouts[layout]}
             showMidi={showMidi}
-            state={notes}
+            layout={layouts[layout]}
+            scale={scale !== "none" && offset !== null && tallyup(scales[scale], offset)}
+            offset={offset}
+            state={state}
           />
           <ChordView
             chord={chord}
diff --git a/app/style.js b/app/style.js
index ea59e75..0bd718e 100644
--- a/app/style.js
+++ b/app/style.js
@@ -82,17 +82,30 @@ body {
   font-size: ${rem(longSize * 0.5)};
   text-align: center;
   background: #696969;
+  border: 3px solid #696969;
   color: #eeeeee;
   cursor: pointer;
 
-  transition: background 300ms;
+  transition: background 300ms, border 300ms;
 }
+
+.hexagon.disabled > .inner {
+  background: #363636 !important;
+  border-color: #363636;
+  color: #848484;
+}
+.hexagon.core> .inner {
+  border-color: #eeeeee;
+}
+
 .hexagon > .inner:hover {
   background: #848484;
+  border-color: #848484;
 }
 .hexagon > .inner:active,
 .hexagon.active > .inner {
   background: #eeeeee;
+  border-color: #eeeeee;
   color: #696969;
 }