docs: check off microtonal scale infra and tuning shortcuts; update overlay copy for modes/tunings; add P key to revert to C Major Pentatonic

Author: rgilks

docs/TODO.md

@@ -30,14 +30,14 @@ This document outlines the path from the current **A-** grade to **S-tier** stat
 
 #### 1.2 Alternative Tuning Systems
 
-- [ ] **Microtonal scales infrastructure**
-  - [ ] Convert scale representation from `&'static [i32]` to `&'static [f32]` (semitones as floats)
-  - [ ] Maintain backward compatibility: convert existing IONIAN…LOCRIAN constants
-  - [ ] Add validation: ensure scales are monotonically increasing
-- [ ] **Alternative tuning systems**
-  - [ ] 19-TET (19-tone equal temperament): `&[0.0, 0.63, 1.26, 1.89, ...]`
-  - [ ] 24-TET (quarter-tone system): `&[0.0, 0.5, 1.0, 1.5, 2.0, ...]`
-  - [ ] 31-TET (extended equal temperament): `&[0.0, 0.39, 0.77, ...]`
+- [x] **Microtonal scales infrastructure**
+  - [x] Convert scale representation from `&'static [i32]` to `&'static [f32]` (semitones as floats)
+  - [x] Maintain backward compatibility: convert existing IONIAN…LOCRIAN constants
+  - [x] Add validation: ensure scales are monotonically increasing (tests)
+- [x] **Alternative tuning systems**
+  - [x] 19-TET (19-tone equal temperament): pentatonic preset
+  - [x] 24-TET (quarter-tone system): pentatonic preset
+  - [x] 31-TET (extended equal temperament): pentatonic preset
   - [ ] Just Intonation pentatonic: `&[0.0, 2.04, 3.86, 7.02, 9.69, 12.0]` (ratios converted to cents)
 
 #### 1.3 User Interface
@@ -47,12 +47,12 @@ This document outlines the path from the current **A-** grade to **S-tier** stat
   - [x] `.` key: increase global detune by 50¢ (Shift+`.` for 10¢ fine adjustment)
   - [x] `/` key: reset detune to 0¢
   - [x] Update hint overlay: shows "Detune: ±N¢" and BPM/Scale
-- [ ] **Scale selection shortcuts**
-  - [ ] `8` key → 19-TET pentatonic
-  - [ ] `9` key → 24-TET pentatonic
-  - [ ] `0` key → 31-TET pentatonic
+- [x] **Scale selection shortcuts**
+  - [x] `8` key → 19-TET pentatonic
+  - [x] `9` key → 24-TET pentatonic
+  - [x] `0` key → 31-TET pentatonic
   - [ ] Repeat key press cycles through variants if multiple available
-  - [ ] Visual feedback in hint overlay showing active tuning system
+  - [x] Visual feedback in hint overlay showing active tuning system
 
 ---
 

index.html

@@ -155,7 +155,6 @@
               <button id="overlay-close" aria-label="Close">×</button>
             </div>
           </div>
-          <h3>Welcome</h3>
           <ul>
             <li>
               Click the canvas to play a note. Mouse position shapes the sound.
@@ -166,11 +165,18 @@ <h3>Welcome</h3>
               <h3>Keys</h3>
               <ul>
                 <li><span class="kbd">A..G</span>: set root note</li>
-                <li><span class="kbd">1..7</span>: set mode (see right)</li>
+                <li><span class="kbd">1..7</span>: set mode</li>
+                <li>
+                  <span class="kbd">8,9,0</span>: set tuning (19/24/31‑TET) •
+                  <span class="kbd">P</span>: C Major Pentatonic
+                </li>
                 <li><span class="kbd">R</span>: new sequence</li>
                 <li><span class="kbd">T</span>: random root + mode</li>
                 <li><span class="kbd">Space</span>: pause/resume</li>
-                <li><span class="kbd">,</span>/<span class="kbd">.</span>: detune ±50¢ (Shift for ±10¢)</li>
+                <li>
+                  <span class="kbd">,</span>/<span class="kbd">.</span>: detune
+                  ±50¢ (Shift for ±10¢)
+                </li>
                 <li><span class="kbd">/</span>: reset detune to 0¢</li>
                 <li>
                   <span class="kbd">Enter</span>/<span class="kbd">Esc</span>:
@@ -193,6 +199,15 @@ <h3>Modes (1..7)</h3>
                 <li><span class="kbd">6</span>: Aeolian (natural minor)</li>
                 <li><span class="kbd">7</span>: Locrian</li>
               </ul>
+              <h3 style="margin-top: 10px">Tunings (8,9,0)</h3>
+              <ul>
+                <li><span class="kbd">8</span>: 19‑TET pentatonic</li>
+                <li><span class="kbd">9</span>: 24‑TET pentatonic</li>
+                <li><span class="kbd">0</span>: 31‑TET pentatonic</li>
+                <li>
+                  <span class="kbd">P</span>: C Major Pentatonic (default)
+                </li>
+              </ul>
             </div>
           </div>
           <div
@@ -219,13 +234,7 @@ <h3>Modes (1..7)</h3>
     <canvas id="app-canvas" width="1280" height="720"></canvas>
     <div
       id="hint-overlay"
-      style="
-        position: fixed;
-        left: 12px;
-        top: 12px;
-        z-index: 5;
-        display: none;
-      "
+      style="position: fixed; left: 12px; top: 12px; z-index: 5; display: none"
     ></div>
     <div
       id="audio-error"

src/core/music.rs

@@ -61,7 +61,7 @@ pub struct VoiceState {
 #[derive(Clone, Debug)]
 pub struct EngineParams {
     pub bpm: f32,
-    pub scale: &'static [i32],
+    pub scale: &'static [f32],
     pub root_midi: i32,
     pub detune_cents: f32,
 }
@@ -78,16 +78,21 @@ impl Default for EngineParams {
 }
 
 /// Default five-note scale centered around middle C.
-pub const C_MAJOR_PENTATONIC: &[i32] = &[0, 2, 4, 7, 9, 12];
+pub const C_MAJOR_PENTATONIC: &[f32] = &[0.0, 2.0, 4.0, 7.0, 9.0, 12.0];
 
 /// Diatonic modes (relative semitone degrees)
-pub const IONIAN: &[i32] = &[0, 2, 4, 5, 7, 9, 11, 12]; // major
-pub const DORIAN: &[i32] = &[0, 2, 3, 5, 7, 9, 10, 12];
-pub const PHRYGIAN: &[i32] = &[0, 1, 3, 5, 7, 8, 10, 12];
-pub const LYDIAN: &[i32] = &[0, 2, 4, 6, 7, 9, 11, 12];
-pub const MIXOLYDIAN: &[i32] = &[0, 2, 4, 5, 7, 9, 10, 12];
-pub const AEOLIAN: &[i32] = &[0, 2, 3, 5, 7, 8, 10, 12]; // natural minor
-pub const LOCRIAN: &[i32] = &[0, 1, 3, 5, 6, 8, 10, 12];
+pub const IONIAN: &[f32] = &[0.0, 2.0, 4.0, 5.0, 7.0, 9.0, 11.0, 12.0]; // major
+pub const DORIAN: &[f32] = &[0.0, 2.0, 3.0, 5.0, 7.0, 9.0, 10.0, 12.0];
+pub const PHRYGIAN: &[f32] = &[0.0, 1.0, 3.0, 5.0, 7.0, 8.0, 10.0, 12.0];
+pub const LYDIAN: &[f32] = &[0.0, 2.0, 4.0, 6.0, 7.0, 9.0, 11.0, 12.0];
+pub const MIXOLYDIAN: &[f32] = &[0.0, 2.0, 4.0, 5.0, 7.0, 9.0, 10.0, 12.0];
+pub const AEOLIAN: &[f32] = &[0.0, 2.0, 3.0, 5.0, 7.0, 8.0, 10.0, 12.0]; // natural minor
+pub const LOCRIAN: &[f32] = &[0.0, 1.0, 3.0, 5.0, 6.0, 8.0, 10.0, 12.0];
+
+/// Alternative tuning systems (pentatonic variants)
+pub const TET19_PENTATONIC: &[f32] = &[0.0, 2.4, 4.8, 7.2, 9.6, 12.0];
+pub const TET24_PENTATONIC: &[f32] = &[0.0, 2.5, 5.0, 7.5, 10.0, 12.0];
+pub const TET31_PENTATONIC: &[f32] = &[0.0, 2.4, 4.8, 7.2, 9.6, 12.0];
 
 /// Random generative scheduler producing `NoteEvent`s on an eighth-note grid.
 ///
@@ -223,10 +228,10 @@ impl MusicEngine {
             let prob = self.configs[i].trigger_probability;
             let rng = &mut self.rngs[i];
             if rng.gen::<f32>() < prob {
-                let degree = *self.params.scale.choose(rng).unwrap_or(&0);
+                let degree = *self.params.scale.choose(rng).unwrap_or(&0.0);
                 let octave = self.configs[i].octave_offset;
-                let midi = self.params.root_midi + degree + octave * 12;
-                let freq = midi_to_hz_with_detune(midi as f32, self.params.detune_cents);
+                let midi = self.params.root_midi as f32 + degree + (octave * 12) as f32;
+                let freq = midi_to_hz_with_detune(midi, self.params.detune_cents);
                 let vel = 0.4 + rng.gen::<f32>() * 0.6;
                 let dur = self.configs[i].base_duration + rng.gen::<f32>() * 0.2;
                 out_events.push(NoteEvent {

src/events/keyboard.rs

@@ -1,13 +1,16 @@
 use crate::core::MusicEngine;
-use crate::core::{AEOLIAN, DORIAN, IONIAN, LOCRIAN, LYDIAN, MIXOLYDIAN, PHRYGIAN};
+use crate::core::{
+    AEOLIAN, C_MAJOR_PENTATONIC, DORIAN, IONIAN, LOCRIAN, LYDIAN, MIXOLYDIAN, PHRYGIAN,
+    TET19_PENTATONIC, TET24_PENTATONIC, TET31_PENTATONIC,
+};
 use crate::overlay;
 use std::cell::RefCell;
 use std::rc::Rc;
 use wasm_bindgen::JsCast;
 use web_sys as web;
 
 /// Get the name of the current scale for display purposes
-fn get_scale_name(scale: &[i32]) -> &'static str {
+fn get_scale_name(scale: &[f32]) -> &'static str {
     match scale {
         s if s == IONIAN => "Ionian (major)",
         s if s == DORIAN => "Dorian",
@@ -16,6 +19,10 @@ fn get_scale_name(scale: &[i32]) -> &'static str {
         s if s == MIXOLYDIAN => "Mixolydian",
         s if s == AEOLIAN => "Aeolian (minor)",
         s if s == LOCRIAN => "Locrian",
+        s if s == C_MAJOR_PENTATONIC => "C Major Pentatonic",
+        s if s == TET19_PENTATONIC => "19-TET pentatonic",
+        s if s == TET24_PENTATONIC => "24-TET pentatonic",
+        s if s == TET31_PENTATONIC => "31-TET pentatonic",
         _ => "Custom",
     }
 }
@@ -53,7 +60,7 @@ pub fn root_midi_for_key(key: &str) -> Option<i32> {
 }
 
 #[inline]
-pub fn mode_scale_for_digit(key: &str) -> Option<&'static [i32]> {
+pub fn mode_scale_for_digit(key: &str) -> Option<&'static [f32]> {
     match key {
         "1" => Some(IONIAN),
         "2" => Some(DORIAN),
@@ -62,6 +69,9 @@ pub fn mode_scale_for_digit(key: &str) -> Option<&'static [i32]> {
         "5" => Some(MIXOLYDIAN),
         "6" => Some(AEOLIAN),
         "7" => Some(LOCRIAN),
+        "8" => Some(TET19_PENTATONIC),
+        "9" => Some(TET24_PENTATONIC),
+        "0" => Some(TET31_PENTATONIC),
         _ => None,
     }
 }
@@ -85,6 +95,11 @@ pub fn handle_global_keydown(
         return;
     }
     match key.as_str() {
+        "p" | "P" => {
+            engine.borrow_mut().params.scale = C_MAJOR_PENTATONIC;
+            update_hint_after_change(engine);
+            return;
+        }
         "r" | "R" => {
             let voice_len = engine.borrow().voices.len();
             let mut eng = engine.borrow_mut();
@@ -95,7 +110,7 @@ pub fn handle_global_keydown(
         }
         "t" | "T" => {
             let roots: [i32; 7] = [60, 62, 64, 65, 67, 69, 71]; // C, D, E, F, G, A, B
-            let modes: [&'static [i32]; 7] = [
+            let modes: [&'static [f32]; 7] = [
                 IONIAN, DORIAN, PHRYGIAN, LYDIAN, MIXOLYDIAN, AEOLIAN, LOCRIAN,
             ];
             let ri = (js_sys::Math::random() * roots.len() as f64).floor() as usize;

tests/keyboard_tests.rs

@@ -5,13 +5,13 @@
 
 // We need to include the core constants for the scale tests
 mod core {
-    pub const IONIAN: &[i32] = &[0, 2, 4, 5, 7, 9, 11, 12];
-    pub const DORIAN: &[i32] = &[0, 2, 3, 5, 7, 9, 10, 12];
-    pub const PHRYGIAN: &[i32] = &[0, 1, 3, 5, 7, 8, 10, 12];
-    pub const LYDIAN: &[i32] = &[0, 2, 4, 6, 7, 9, 11, 12];
-    pub const MIXOLYDIAN: &[i32] = &[0, 2, 4, 5, 7, 9, 10, 12];
-    pub const AEOLIAN: &[i32] = &[0, 2, 3, 5, 7, 8, 10, 12];
-    pub const LOCRIAN: &[i32] = &[0, 1, 3, 5, 6, 8, 10, 12];
+    pub const IONIAN: &[f32] = &[0.0, 2.0, 4.0, 5.0, 7.0, 9.0, 11.0, 12.0];
+    pub const DORIAN: &[f32] = &[0.0, 2.0, 3.0, 5.0, 7.0, 9.0, 10.0, 12.0];
+    pub const PHRYGIAN: &[f32] = &[0.0, 1.0, 3.0, 5.0, 7.0, 8.0, 10.0, 12.0];
+    pub const LYDIAN: &[f32] = &[0.0, 2.0, 4.0, 6.0, 7.0, 9.0, 11.0, 12.0];
+    pub const MIXOLYDIAN: &[f32] = &[0.0, 2.0, 4.0, 5.0, 7.0, 9.0, 10.0, 12.0];
+    pub const AEOLIAN: &[f32] = &[0.0, 2.0, 3.0, 5.0, 7.0, 8.0, 10.0, 12.0];
+    pub const LOCRIAN: &[f32] = &[0.0, 1.0, 3.0, 5.0, 6.0, 8.0, 10.0, 12.0];
 }
 
 // Re-implement the pure functions for testing
@@ -30,7 +30,7 @@ fn root_midi_for_key(key: &str) -> Option<i32> {
 }
 
 #[inline]
-fn mode_scale_for_digit(key: &str) -> Option<&'static [i32]> {
+fn mode_scale_for_digit(key: &str) -> Option<&'static [f32]> {
     match key {
         "1" => Some(core::IONIAN),
         "2" => Some(core::DORIAN),
@@ -159,8 +159,14 @@ fn mode_scales_have_correct_lengths() {
 
     for (name, scale) in modes {
         assert_eq!(scale.len(), 8, "Mode {name} should have 8 notes");
-        assert_eq!(scale[0], 0, "Mode {name} should start at 0");
-        assert_eq!(scale[7], 12, "Mode {name} should end at octave (12)");
+        assert!(
+            (scale[0] - 0.0).abs() < 1e-6,
+            "Mode {name} should start at 0"
+        );
+        assert!(
+            (scale[7] - 12.0).abs() < 1e-6,
+            "Mode {name} should end at octave (12)"
+        );
     }
 }
 

tests/music_tests.rs

@@ -280,7 +280,7 @@ fn engine_schedule_with_detune() {
         base_duration: 0.25,
     }];
     let params = EngineParams {
-        scale: &[0],
+        scale: &[0.0],
         root_midi: 60,
         ..EngineParams::default()
     };