Update .gitignore to exclude new build and tool files

Added FodyWeavers.xsd, .dotnet-home/.dotnet, .dotnet-home/.dotnet/TelemetryStorageService, and .nuget to .gitignore to prevent tracking of generated and tool-related files.

.gitignore

@@ -360,4 +360,7 @@ MigrationBackup/
 .ionide/
 
 # Fody - auto-generated XML schema
-FodyWeavers.xsd
+FodyWeavers.xsd
+/.dotnet-home/.dotnet/TelemetryStorageService
+/.dotnet-home/.dotnet
+/.nuget

FractalVisualizer/Audio/AudioAnalyzer.cs

@@ -50,6 +50,8 @@ public sealed class AudioAnalyzer : IDisposable
     private int _stableNoteIndex = -1;
     private float _stableNoteStrength;
     private float _lastNoteChangeTimeSeconds;
+    private bool _noteIsActive;
+    private int _activeNoteIndex = -1;
 
     private Snapshot _latestSnapshot;
     private bool _disposed;
@@ -295,7 +297,7 @@ public sealed class AudioAnalyzer : IDisposable
         int noteIndex = GetNoteIndexFromFrequency(dominantFrequency);
         float whistleBoost = GetWhistleBoost(dominantFrequency);
         float dominantStrength = Clamp01(dominantMagnitude * profile.NoteStrengthGain * (1f + whistleBoost * 0.65f));
-        DetectChord(_chroma, out int chordRoot, out int chordType, out float chordConfidence);
+        DetectChord(_chroma, _smoothedLevel, profile, out int chordRoot, out int chordType, out float chordConfidence);
         ApplyDetectionStability(
             now,
             profile,
@@ -309,6 +311,7 @@ public sealed class AudioAnalyzer : IDisposable
             out int stableChordRoot,
             out int stableChordType,
             out float stableChordConfidence);
+        bool noteOnset = DetectNoteOnset(stableNoteIndex, stableNoteStrength, profile);
 
         AudioFeatures features = new()
         {
@@ -321,6 +324,7 @@ public sealed class AudioAnalyzer : IDisposable
             DominantFrequencyHz = dominantFrequency,
             DetectedNoteIndex = stableNoteIndex,
             DetectedNoteStrength = stableNoteStrength,
+            NoteOnset = noteOnset,
             DetectedChordRootIndex = stableChordRoot,
             DetectedChordType = stableChordType,
             DetectedChordConfidence = stableChordConfidence,
@@ -404,8 +408,16 @@ public sealed class AudioAnalyzer : IDisposable
         return note;
     }
 
-    private void DetectChord(float[] chroma, out int root, out int type, out float confidence)
+    private void DetectChord(float[] chroma, float level, SensitivityProfile profile, out int root, out int type, out float confidence)
     {
+        if (level < profile.ChordLevelThreshold)
+        {
+            root = -1;
+            type = -1;
+            confidence = 0f;
+            return;
+        }
+
         float total = 0f;
         for (int i = 0; i < chroma.Length; i++)
         {
@@ -463,8 +475,6 @@ public sealed class AudioAnalyzer : IDisposable
             }
         }
 
-        _lastChordRoot = bestRoot;
-        _lastChordType = bestType;
         root = bestRoot;
         type = bestType;
         confidence = conf;
@@ -599,6 +609,41 @@ public sealed class AudioAnalyzer : IDisposable
             stableChordType = _lastChordType;
             stableChordConfidence = chordConfidence;
         }
+        else if (_lastChordRoot >= 0 && (_smoothedLevel <= profile.ChordLevelThreshold || stableNoteStrength <= profile.NoteReleaseThreshold))
+        {
+            // Clear stale chord label when audio falls back to near-silence.
+            if ((now - _lastChordChangeTimeSeconds) >= profile.SwitchHoldSeconds)
+            {
+                _lastChordRoot = -1;
+                _lastChordType = -1;
+                stableChordRoot = -1;
+                stableChordType = -1;
+                stableChordConfidence = 0f;
+            }
+        }
+    }
+
+    private bool DetectNoteOnset(int stableNoteIndex, float stableNoteStrength, SensitivityProfile profile)
+    {
+        if (stableNoteIndex >= 0 && stableNoteStrength >= profile.NoteOnsetThreshold)
+        {
+            if (!_noteIsActive || _activeNoteIndex != stableNoteIndex)
+            {
+                _noteIsActive = true;
+                _activeNoteIndex = stableNoteIndex;
+                return true;
+            }
+
+            return false;
+        }
+
+        if (_noteIsActive && stableNoteStrength <= profile.NoteReleaseThreshold)
+        {
+            _noteIsActive = false;
+            _activeNoteIndex = -1;
+        }
+
+        return false;
     }
 
     private readonly struct SensitivityProfile(
@@ -613,7 +658,10 @@ public sealed class AudioAnalyzer : IDisposable
         float referenceDecay,
         float switchHoldSeconds,
         float noteConfidenceThreshold,
-        float chordConfidenceThreshold)
+        float chordConfidenceThreshold,
+        float noteOnsetThreshold,
+        float noteReleaseThreshold,
+        float chordLevelThreshold)
     {
         public float LevelGain { get; } = levelGain;
         public float BassGain { get; } = bassGain;
@@ -627,6 +675,9 @@ public sealed class AudioAnalyzer : IDisposable
         public float SwitchHoldSeconds { get; } = switchHoldSeconds;
         public float NoteConfidenceThreshold { get; } = noteConfidenceThreshold;
         public float ChordConfidenceThreshold { get; } = chordConfidenceThreshold;
+        public float NoteOnsetThreshold { get; } = noteOnsetThreshold;
+        public float NoteReleaseThreshold { get; } = noteReleaseThreshold;
+        public float ChordLevelThreshold { get; } = chordLevelThreshold;
 
         public static SensitivityProfile Microphone { get; } = new(
             levelGain: 1.20f,
@@ -640,7 +691,10 @@ public sealed class AudioAnalyzer : IDisposable
             referenceDecay: 0.010f,
             switchHoldSeconds: 0.18f,
             noteConfidenceThreshold: 0.11f,
-            chordConfidenceThreshold: 0.18f);
+            chordConfidenceThreshold: 0.18f,
+            noteOnsetThreshold: 0.20f,
+            noteReleaseThreshold: 0.08f,
+            chordLevelThreshold: 0.10f);
 
         public static SensitivityProfile SystemOutput { get; } = new(
             levelGain: 1.00f,
@@ -654,7 +708,10 @@ public sealed class AudioAnalyzer : IDisposable
             referenceDecay: 0.012f,
             switchHoldSeconds: 0.18f,
             noteConfidenceThreshold: 0.12f,
-            chordConfidenceThreshold: 0.14f);
+            chordConfidenceThreshold: 0.14f,
+            noteOnsetThreshold: 0.18f,
+            noteReleaseThreshold: 0.07f,
+            chordLevelThreshold: 0.08f);
     }
 
     private void ThrowIfDisposed()

FractalVisualizer/Game1.cs

@@ -145,7 +145,7 @@ public class Game1 : Game
 
         if (IsPressed(keyboard, Keys.Right))
         {
-            _fractalPresetIndex = Math.Min(21, _fractalPresetIndex + 1);
+            _fractalPresetIndex = Math.Min(23, _fractalPresetIndex + 1);
         }
 
         if (IsPressed(keyboard, Keys.M))
@@ -195,7 +195,7 @@ public class Game1 : Game
             _hudFont.DrawText(_spriteBatch, _pixel, "BEAT  " + _latestFeatures.Beat.ToString("0.000"), 12, 130, 2, Color.White);
             _hudFont.DrawText(_spriteBatch, _pixel, "BPM   " + _latestFeatures.Bpm.ToString("0.0"), 12, 150, 2, Color.White);
             _hudFont.DrawText(_spriteBatch, _pixel, "NOTE  " + GetDetectedNoteName(_latestFeatures.DetectedNoteIndex), 12, 170, 2, Color.White);
-            _hudFont.DrawText(_spriteBatch, _pixel, "CHORD " + GetDetectedChordName(_latestFeatures.DetectedChordRootIndex, _latestFeatures.DetectedChordType), 12, 190, 2, Color.White);
+            _hudFont.DrawText(_spriteBatch, _pixel, "CHORD " + GetDetectedChordName(_latestFeatures.DetectedChordRootIndex, _latestFeatures.DetectedChordType, _latestFeatures.DetectedChordConfidence), 12, 190, 2, Color.White);
             _hudFont.DrawText(_spriteBatch, _pixel, "PAUSED " + (_isPaused ? "YES" : "NO"), 12, 210, 2, Color.White);
             _hudFont.DrawText(_spriteBatch, _pixel, "FPS   " + _fps, 12, 230, 2, Color.White);
             _hudFont.DrawText(_spriteBatch, _pixel, "QUALITY " + _renderQuality + "  1 2 3", 12, 250, 2, Color.White);
@@ -251,6 +251,8 @@ public class Game1 : Game
             19 => "GRAINBARS",
             20 => "NOTEDROP",
             21 => "CHORDS",
+            22 => "NOTESBOOK",
+            23 => "NOTESCROLL",
             _ => "JULIA"
         };
     }
@@ -275,8 +277,13 @@ public class Game1 : Game
         };
     }
 
-    private static string GetDetectedChordName(int rootIndex, int chordType)
+    private static string GetDetectedChordName(int rootIndex, int chordType, float confidence)
     {
+        if (confidence < 0.16f)
+        {
+            return "-";
+        }
+
         string root = GetDetectedNoteName(rootIndex);
         if (root == "-")
         {

FractalVisualizer/Models/AudioFeatures.cs

@@ -11,6 +11,7 @@ public struct AudioFeatures
     public float DominantFrequencyHz;
     public int DetectedNoteIndex;
     public float DetectedNoteStrength;
+    public bool NoteOnset;
     public int DetectedChordRootIndex;
     public int DetectedChordType;
     public float DetectedChordConfidence;

FractalVisualizer/Rendering/FractalRenderer.cs

@@ -19,6 +19,8 @@ public sealed class FractalRenderer : IDisposable
     private Color[] _previousFrame;
     private readonly List<NoteParticle> _notes = [];
     private readonly List<DetectedNoteParticle> _detectedNotes = [];
+    private readonly List<StaffNoteParticle> _staffNotes = [];
+    private readonly List<ScrollingStaffNoteParticle> _scrollStaffNotes = [];
     private readonly List<FireworkRocket> _fireworkRockets = [];
     private readonly List<FireworkSpark> _fireworkSparks = [];
     private readonly Random _rng = new();
@@ -45,8 +47,9 @@ public sealed class FractalRenderer : IDisposable
     };
 
     private float _noteSpawnAccumulator;
-    private float _detectedNoteAccumulator;
     private float _fireworkSpawnAccumulator;
+    private float _sheetOffsetX;
+    private float _lastRenderTimeSeconds = -1f;
     private int _lastChordCode = -1;
     private float _chordFlash;
     private float _runtimePerformanceScale = 1f;
@@ -140,11 +143,14 @@ public sealed class FractalRenderer : IDisposable
         _previousFrame = new Color[_internalWidth * _internalHeight];
         _notes.Clear();
         _detectedNotes.Clear();
+        _staffNotes.Clear();
+        _scrollStaffNotes.Clear();
         _fireworkRockets.Clear();
         _fireworkSparks.Clear();
         _noteSpawnAccumulator = 0f;
-        _detectedNoteAccumulator = 0f;
         _fireworkSpawnAccumulator = 0f;
+        _sheetOffsetX = 0f;
+        _lastRenderTimeSeconds = -1f;
     }
 
     private int ScaleCount(int baseCount, int minCount = 1)
@@ -234,6 +240,12 @@ public sealed class FractalRenderer : IDisposable
             case 21:
                 RenderChordCenter(features, timeSeconds);
                 break;
+            case 22:
+                RenderMusicStaffNotes(features, timeSeconds);
+                break;
+            case 23:
+                RenderScrollingMusicStaff(features, timeSeconds);
+                break;
             default:
                 RenderJulia(features, timeSeconds);
                 break;
@@ -1204,13 +1216,9 @@ public sealed class FractalRenderer : IDisposable
             }
         }
 
-        float whistleBoost = GetWhistleSpawnBoost(features.DominantFrequencyHz);
+        if (features.NoteOnset)
-        float spawnRate = features.DetectedNoteStrength * (0.9f + whistleBoost * 1.7f + Clamp01(features.Beat) * 0.35f);
-        _detectedNoteAccumulator += spawnRate * _runtimePerformanceScale;
-        while (_detectedNoteAccumulator >= 1f)
         {
             SpawnDetectedNote(features);
-            _detectedNoteAccumulator -= 1f;
         }
 
         for (int i = _detectedNotes.Count - 1; i >= 0; i--)
@@ -1232,17 +1240,6 @@ public sealed class FractalRenderer : IDisposable
         }
     }
 
-    private static float GetWhistleSpawnBoost(float frequencyHz)
-    {
-        if (frequencyHz < 800f || frequencyHz > 5000f)
-        {
-            return 0f;
-        }
-
-        float norm = (frequencyHz - 800f) / (5000f - 800f);
-        return Clamp01(norm);
-    }
-
     private void RenderChordCenter(AudioFeatures features, float timeSeconds)
     {
         for (int y = 0; y < _internalHeight; y++)
@@ -1284,6 +1281,248 @@ public sealed class FractalRenderer : IDisposable
         DrawTextPixels(chordText, x0, y0, scale, textColor, 0.95f);
     }
 
+    private void RenderMusicStaffNotes(AudioFeatures features, float timeSeconds)
+    {
+        for (int y = 0; y < _internalHeight; y++)
+        {
+            float t = y / (float)(_internalHeight - 1);
+            Color bg = new(0.98f - t * 0.05f, 0.97f - t * 0.05f, 0.93f - t * 0.04f, 1f);
+            int row = y * _internalWidth;
+            for (int x = 0; x < _internalWidth; x++)
+            {
+                _pixelBuffer[row + x] = bg;
+            }
+        }
+
+        int left = (int)(_internalWidth * 0.08f);
+        int right = (int)(_internalWidth * 0.92f);
+        int top = (int)(_internalHeight * 0.32f);
+        int spacing = Math.Max(5, _internalHeight / 24);
+
+        for (int i = 0; i < 5; i++)
+        {
+            int y = top + i * spacing;
+            DrawRect(left, y, right - left, 1, new Vector3(0.15f, 0.15f, 0.18f), 0.85f);
+        }
+
+        if (features.NoteOnset)
+        {
+            SpawnStaffNote(features, left, right, top, spacing);
+        }
+
+        for (int i = _staffNotes.Count - 1; i >= 0; i--)
+        {
+            StaffNoteParticle n = _staffNotes[i];
+            n.Life -= 0.0065f;
+            n.X += n.Vx;
+            if (n.Life <= 0f || n.X > right + 20)
+            {
+                _staffNotes.RemoveAt(i);
+                continue;
+            }
+
+            _staffNotes[i] = n;
+            DrawStaffNote(n, top, spacing);
+        }
+    }
+
+    private void RenderScrollingMusicStaff(AudioFeatures features, float timeSeconds)
+    {
+        float dt;
+        if (_lastRenderTimeSeconds < 0f)
+        {
+            dt = 1f / 120f;
+        }
+        else
+        {
+            dt = Math.Clamp(timeSeconds - _lastRenderTimeSeconds, 1f / 240f, 1f / 20f);
+        }
+
+        _lastRenderTimeSeconds = timeSeconds;
+
+        for (int y = 0; y < _internalHeight; y++)
+        {
+            float t = y / (float)(_internalHeight - 1);
+            Color bg = new(0.985f - t * 0.04f, 0.98f - t * 0.04f, 0.95f - t * 0.03f, 1f);
+            int row = y * _internalWidth;
+            for (int x = 0; x < _internalWidth; x++)
+            {
+                _pixelBuffer[row + x] = bg;
+            }
+        }
+
+        int left = (int)(_internalWidth * 0.06f);
+        int right = (int)(_internalWidth * 0.94f);
+        int top = (int)(_internalHeight * 0.34f);
+        int spacing = Math.Max(5, _internalHeight / 24);
+
+        float bpm = features.Bpm > 0f ? features.Bpm : 90f;
+        float pxPerSecond = 14f + bpm * 0.24f;
+        float speed = pxPerSecond * dt;
+        _sheetOffsetX += speed;
+        int measureSpacing = Math.Max(30, _internalWidth / 6);
+        if (_sheetOffsetX >= measureSpacing)
+        {
+            _sheetOffsetX -= measureSpacing;
+        }
+
+        for (int i = 0; i < 5; i++)
+        {
+            int y = top + i * spacing;
+            DrawRect(left, y, right - left, 1, new Vector3(0.14f, 0.14f, 0.16f), 0.85f);
+        }
+
+        for (int x = right - (int)_sheetOffsetX; x > left; x -= measureSpacing)
+        {
+            DrawRect(x, top - spacing / 2, 1, spacing * 5, new Vector3(0.2f, 0.2f, 0.24f), 0.55f);
+        }
+
+        if (features.NoteOnset)
+        {
+            SpawnScrollingStaffNote(features, right, top, spacing);
+        }
+
+        for (int i = _scrollStaffNotes.Count - 1; i >= 0; i--)
+        {
+            ScrollingStaffNoteParticle n = _scrollStaffNotes[i];
+            n.X -= speed * (0.95f + n.SpeedJitter);
+            n.Life -= 0.0045f;
+            if (n.Life <= 0f || n.X < left - 30)
+            {
+                _scrollStaffNotes.RemoveAt(i);
+                continue;
+            }
+
+            _scrollStaffNotes[i] = n;
+            DrawScrollingStaffNote(n, top, spacing);
+        }
+    }
+
+    private void SpawnScrollingStaffNote(AudioFeatures features, int right, int top, int spacing)
+    {
+        if (features.DetectedNoteIndex < 0 || _scrollStaffNotes.Count >= ScaleCount(180, 30))
+        {
+            return;
+        }
+
+        int staffStep = NoteToStaffStep(features.DetectedNoteIndex);
+        int staffCenterY = top + spacing * 4;
+        int y = staffCenterY - (staffStep * (spacing / 2));
+        int x = right - 8 + _rng.Next(0, 8);
+
+        _scrollStaffNotes.Add(new ScrollingStaffNoteParticle
+        {
+            X = x,
+            Y = y,
+            Life = 1f,
+            UpStem = _rng.NextDouble() > 0.5,
+            Filled = features.DetectedNoteStrength > 0.20f,
+            SpeedJitter = (float)_rng.NextDouble() * 0.35f
+        });
+    }
+
+    private void DrawScrollingStaffNote(ScrollingStaffNoteParticle n, int top, int spacing)
+    {
+        int x = (int)n.X;
+        int y = n.Y;
+        float a = Clamp01(n.Life);
+        Vector3 ink = new(0.07f, 0.07f, 0.1f);
+
+        int rx = Math.Max(2, spacing / 3);
+        int ry = Math.Max(2, spacing / 4 + 1);
+        DrawEllipse(x, y, rx, ry, ink, a, n.Filled);
+
+        int stemH = spacing * 3;
+        if (n.UpStem)
+        {
+            DrawRect(x + rx, y - stemH, 1, stemH, ink, a);
+        }
+        else
+        {
+            DrawRect(x - rx, y, 1, stemH, ink, a);
+        }
+
+        int staffTop = top;
+        int staffBottom = top + spacing * 4;
+        if (y < staffTop - spacing / 2 || y > staffBottom + spacing / 2)
+        {
+            DrawRect(x - spacing / 2, y, spacing, 1, ink, a * 0.9f);
+        }
+    }
+
+    private void SpawnStaffNote(AudioFeatures features, int left, int right, int top, int spacing)
+    {
+        if (features.DetectedNoteIndex < 0 || _staffNotes.Count >= ScaleCount(120, 20))
+        {
+            return;
+        }
+
+        int noteIndex = features.DetectedNoteIndex;
+        int staffStep = NoteToStaffStep(noteIndex);
+        int staffCenterY = top + spacing * 4;
+        int y = staffCenterY - (staffStep * (spacing / 2));
+        int x = left + _rng.Next(0, Math.Max(10, right - left - 20));
+
+        _staffNotes.Add(new StaffNoteParticle
+        {
+            X = x,
+            Y = y,
+            Vx = 0.20f + (float)_rng.NextDouble() * 0.35f,
+            Life = 1f,
+            UpStem = _rng.NextDouble() > 0.5,
+            Filled = features.DetectedNoteStrength > 0.22f
+        });
+    }
+
+    private static int NoteToStaffStep(int noteIndex)
+    {
+        return noteIndex switch
+        {
+            0 => -1,
+            1 => -1,
+            2 => 0,
+            3 => 0,
+            4 => 1,
+            5 => 2,
+            6 => 2,
+            7 => 3,
+            8 => 3,
+            9 => 4,
+            10 => 4,
+            11 => 5,
+            _ => 0
+        };
+    }
+
+    private void DrawStaffNote(StaffNoteParticle n, int top, int spacing)
+    {
+        int x = (int)n.X;
+        int y = n.Y;
+        float a = Clamp01(n.Life);
+        Vector3 ink = new(0.08f, 0.08f, 0.1f);
+
+        int rx = Math.Max(2, spacing / 3);
+        int ry = Math.Max(2, spacing / 4 + 1);
+        DrawEllipse(x, y, rx, ry, ink, a, n.Filled);
+
+        int stemH = spacing * 3;
+        if (n.UpStem)
+        {
+            DrawRect(x + rx, y - stemH, 1, stemH, ink, a);
+        }
+        else
+        {
+            DrawRect(x - rx, y, 1, stemH, ink, a);
+        }
+
+        int staffTop = top;
+        int staffBottom = top + spacing * 4;
+        if (y < staffTop - spacing / 2 || y > staffBottom + spacing / 2)
+        {
+            DrawRect(x - spacing / 2, y, spacing, 1, ink, a * 0.9f);
+        }
+    }
+
     private void SpawnDetectedNote(AudioFeatures features)
     {
         if (features.DetectedNoteIndex < 0 || features.DetectedNoteIndex > 11)
@@ -1577,6 +1816,49 @@ public sealed class FractalRenderer : IDisposable
         }
     }
 
+    private void DrawEllipse(int cx, int cy, int rx, int ry, Vector3 color, float alpha, bool filled)
+    {
+        int minX = cx - rx - 1;
+        int maxX = cx + rx + 1;
+        int minY = cy - ry - 1;
+        int maxY = cy + ry + 1;
+        float irx = 1f / (rx * rx + 1e-6f);
+        float iry = 1f / (ry * ry + 1e-6f);
+        for (int y = minY; y <= maxY; y++)
+        {
+            if (y < 0 || y >= _internalHeight)
+            {
+                continue;
+            }
+
+            for (int x = minX; x <= maxX; x++)
+            {
+                if (x < 0 || x >= _internalWidth)
+                {
+                    continue;
+                }
+
+                float dx = x - cx;
+                float dy = y - cy;
+                float d = dx * dx * irx + dy * dy * iry;
+                if (filled)
+                {
+                    if (d <= 1f)
+                    {
+                        BlendPixel(x, y, color, alpha);
+                    }
+                }
+                else
+                {
+                    if (d >= 0.7f && d <= 1.2f)
+                    {
+                        BlendPixel(x, y, color, alpha);
+                    }
+                }
+            }
+        }
+    }
+
     private void BlendPixel(int x, int y, Vector3 color, float alpha)
     {
         int idx = y * _internalWidth + x;
@@ -1705,6 +1987,26 @@ public sealed class FractalRenderer : IDisposable
         public Vector3 Color;
     }
 
+    private struct StaffNoteParticle
+    {
+        public float X;
+        public int Y;
+        public float Vx;
+        public float Life;
+        public bool UpStem;
+        public bool Filled;
+    }
+
+    private struct ScrollingStaffNoteParticle
+    {
+        public float X;
+        public int Y;
+        public float Life;
+        public bool UpStem;
+        public bool Filled;
+        public float SpeedJitter;
+    }
+
     private struct FireworkRocket
     {
         public float X;