initial version

2026-03-05 16:51:28 +00:00
commit 5e7954ee24
31 changed files with 4832 additions and 0 deletions
@@ -0,0 +1,154 @@
+import { getPentatonicScale, getFullScale, getChordTones, NOTES } from '../lib/theory'
+
+// Standard tuning: pitch classes of open strings, high-E first (top of diagram)
+const STRINGS = [
+  { label: 'e', root: 4 },   // high E
+  { label: 'B', root: 11 },
+  { label: 'G', root: 7 },
+  { label: 'D', root: 2 },
+  { label: 'A', root: 9 },
+  { label: 'E', root: 4 },   // low E
+]
+
+const NUM_FRETS = 13          // frets 0 (open) through 12
+const FRET_MARKERS = [3, 5, 7, 9]
+const DOUBLE_MARKER = 12
+
+// Layout constants
+const NUT_X = 40             // x of the nut line
+const OPEN_X = 18            // x of open-string dot centres
+const FRET_W = 52            // pixels per fret
+const STRING_H = 28          // pixels between strings
+const PAD_T = 28             // top padding (fret numbers)
+const PAD_B = 18             // bottom padding (fret marker dots)
+const BOARD_W = NUT_X + (NUM_FRETS - 1) * FRET_W + 10
+const BOARD_H = PAD_T + 5 * STRING_H + PAD_B
+const DOT_R = 10
+
+// x centre of a fretted note (fret >= 1)
+const fretX = f => NUT_X + (f - 0.5) * FRET_W
+// y centre of string si (0 = high e, 5 = low E)
+const stringY = si => PAD_T + si * STRING_H
+
+function noteColor(isChordTone, isPenta, isScale) {
+  if (isChordTone) return { fill: '#f59e0b', text: '#000' }   // amber
+  if (isPenta)     return { fill: '#a855f7', text: '#fff' }   // purple
+  if (isScale)     return { fill: '#374151', text: '#d1d5db' } // grey
+  return null
+}
+
+export default function Fretboard({ keyInfo, currentChord, pentatonicOnly = false }) {
+  const { root, mode } = keyInfo ?? {}
+
+  if (!root) return null
+
+  const pentaSet = new Set(getPentatonicScale(root, mode).map(n => NOTES.indexOf(n)))
+  const scaleSet = pentatonicOnly
+    ? pentaSet
+    : new Set(getFullScale(root, mode).map(n => NOTES.indexOf(n)))
+  const chordSet = currentChord
+    ? new Set(getChordTones(currentChord).map(n => NOTES.indexOf(n)))
+    : new Set()
+
+  return (
+    <div className="bg-panel border border-border rounded-2xl p-6">
+      <p className="text-sm text-gray-500 uppercase tracking-widest mb-4">
+        Fretboard — {root} {mode}
+        {currentChord && <span className="text-amber-400 ml-2">/ {currentChord}</span>}
+      </p>
+
+      <div className="overflow-x-auto">
+        <svg
+          width={BOARD_W}
+          height={BOARD_H}
+          style={{ display: 'block', minWidth: BOARD_W }}
+        >
+          {/* Fretboard background */}
+          <rect x={NUT_X} y={PAD_T - 6} width={BOARD_W - NUT_X - 4} height={5 * STRING_H + 12}
+            fill="#1a120b" rx={2} />
+
+          {/* Fret position marker dots (between strings 2–3 and 3–4) */}
+          {FRET_MARKERS.map(f => (
+            <circle key={f}
+              cx={fretX(f)} cy={PAD_T + 2.5 * STRING_H}
+              r={5} fill="#3a2a1a" />
+          ))}
+          {/* Double dot at 12 */}
+          <circle cx={fretX(DOUBLE_MARKER)} cy={PAD_T + 1.5 * STRING_H} r={5} fill="#3a2a1a" />
+          <circle cx={fretX(DOUBLE_MARKER)} cy={PAD_T + 3.5 * STRING_H} r={5} fill="#3a2a1a" />
+
+          {/* Fret lines (1–12) */}
+          {Array.from({ length: NUM_FRETS - 1 }, (_, i) => i + 1).map(f => (
+            <line key={f}
+              x1={NUT_X + f * FRET_W} y1={PAD_T - 6}
+              x2={NUT_X + f * FRET_W} y2={PAD_T + 5 * STRING_H + 6}
+              stroke={f === DOUBLE_MARKER ? '#888' : '#4a3a2a'}
+              strokeWidth={f === DOUBLE_MARKER ? 2 : 1} />
+          ))}
+
+          {/* Nut */}
+          <line x1={NUT_X} y1={PAD_T - 6} x2={NUT_X} y2={PAD_T + 5 * STRING_H + 6}
+            stroke="#c0b090" strokeWidth={4} />
+
+          {/* Strings */}
+          {STRINGS.map((_, si) => (
+            <line key={si}
+              x1={OPEN_X - DOT_R - 2} y1={stringY(si)}
+              x2={BOARD_W - 8} y2={stringY(si)}
+              stroke="#9ca3af"
+              strokeWidth={si < 2 ? 1 : si < 4 ? 1.5 : 2} />
+          ))}
+
+          {/* Fret numbers */}
+          {[3, 5, 7, 9, 12].map(f => (
+            <text key={f}
+              x={fretX(f)} y={PAD_T - 10}
+              textAnchor="middle" fontSize={10} fill="#6b7280"
+            >{f}</text>
+          ))}
+
+          {/* String labels */}
+          {STRINGS.map((s, si) => (
+            <text key={si}
+              x={6} y={stringY(si) + 4}
+              textAnchor="middle" fontSize={10} fill="#6b7280"
+            >{s.label}</text>
+          ))}
+
+          {/* Note dots */}
+          {STRINGS.flatMap((str, si) =>
+            Array.from({ length: NUM_FRETS }, (_, fi) => {
+              const pc = (str.root + fi) % 12
+              const color = noteColor(chordSet.has(pc), pentaSet.has(pc), scaleSet.has(pc))
+              if (!color) return null
+
+              const cx = fi === 0 ? OPEN_X : fretX(fi)
+              const cy = stringY(si)
+
+              return (
+                <g key={`${si}-${fi}`}>
+                  <circle cx={cx} cy={cy} r={DOT_R} fill={color.fill} />
+                  <text
+                    x={cx} y={cy + 4}
+                    textAnchor="middle"
+                    fontSize={9}
+                    fontWeight="600"
+                    fill={color.text}
+                  >
+                    {NOTES[pc]}
+                  </text>
+                </g>
+              )
+            })
+          )}
+        </svg>
+      </div>
+
+      <div className="mt-3 flex gap-5 text-xs text-gray-500">
+        <span><span className="text-amber-400">●</span> Chord tone</span>
+        <span><span className="text-accent">●</span> Pentatonic</span>
+        <span><span className="text-gray-500">●</span> Scale</span>
+      </div>
+    </div>
+  )
+}