refactor: split spectrogram.c into per-concern modules

spectrogram.c was ~2950 lines holding everything. Break it into cohesive translation units; spectrogram.c keeps only globals + the main frame loop. New modules: - spectrogram_types.h shared types, constants, extern globals, inline math - fft.c/.h FFT, bit-reverse, twiddle (standalone, no app deps) - stft.c/.h STFT compute, adaptive resolution, FFT-size LRU cache - audio.c/.h WAV/ffmpeg load, FreeSignal, bandpass, playback - render.c/.h UI scaling, colormaps, texture gen, on-screen drawing - ui.c/.h file browser, sidebar, sliders, PNG export Also: - utils.c now includes utils.h instead of re-typedef'ing AudioSignal/ SignalStats (they had to be hand-synced before). - Remove dead code: ApplyHannWindow and ComputeSTFTHighResRange were never called (the live high-res path is ComputeNextHighResChunk). - Delete the unused raylib-template main.c. - rspektrum.make: build the new units. premake5.lua: glob src/**.c so a future regen stays correct. Pure code movement otherwise; no behavior change. Builds clean (-Wshadow). Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-25 01:15:51 -07:00
parent ebe35bcd95
commit 3a8f20b783
16 changed files with 2038 additions and 2043 deletions
@@ -0,0 +1,222 @@
+// spectrogram_types.h - Shared types, constants, globals, and small math helpers.
+// This is the "spine" header included by every module.
+#ifndef SPECTROGRAM_TYPES_H
+#define SPECTROGRAM_TYPES_H
+
+#include "raylib.h"
+#include "utils.h"        // AudioSignal, SignalStats
+#include "primitives.h"   // ScopeView, WaveformData
+
+#include <stdbool.h>
+#include <math.h>
+
+#ifndef M_PI
+    #define M_PI 3.14159265358979323846
+#endif
+
+#ifndef CYAN
+    #define CYAN (Color){ 0, 255, 255, 255 }
+#endif
+
+// ============================================================================
+// Configuration
+// ============================================================================
+
+#define FFT_SIZE_DEFAULT 2048
+#define FFT_SIZE_MAX 2048
+#define FFT_SIZE_MIN 128
+#define HOP_RATIO 4  // FFT_SIZE / HOP_SIZE = 4 means 75% overlap
+#define MAX_SAMPLE_RATE 48000
+#define LOUDNESS_FLOOR_DB -80.0f
+
+// Base resolution for proportional UI scaling (see GetUIScale in render.c)
+#define BASE_WIDTH 1280
+#define BASE_HEIGHT 800
+
+#define FFT_CACHE_SIZE 4
+
+// ============================================================================
+// Data Structures
+// ============================================================================
+
+typedef enum {
+    COLORMAP_GRAYS = 0,
+    COLORMAP_INFERNO,
+    COLORMAP_VIRIDIS,
+    COLORMAP_PLASMA,
+    COLORMAP_HOT,
+    COLORMAP_COOL,
+    COLORMAP_COUNT
+} ColormapType;
+
+typedef struct {
+    float frequency;
+    float amplitude;
+    float phase;
+} FrequencyData;
+
+typedef struct {
+    FrequencyData* spectrum;
+    FrequencyData* derivativeSpectrum;  // STFT with derivative window (for synchrosqueezing)
+    int numBins;
+    int sampleOffset;
+    int sampleCount;
+} StftSegment;
+
+typedef struct {
+    StftSegment* segments;
+    int numSegments;
+    int sampleRate;
+    int totalSamples;
+    bool useHannWindow;
+} StftResult;
+
+typedef struct {
+    int fftSize;
+    StftResult result;
+    int accessOrder;  // lower = more recently accessed
+} FFTCacheEntry;
+
+typedef struct {
+    FFTCacheEntry entries[FFT_CACHE_SIZE];
+    int count;
+    int nextOrder;
+} FFTSizeCache;
+
+typedef struct {
+    AudioSignal signal;
+    StftResult stft;
+    Image spectrogramImage;
+    Texture2D spectrogramTexture;
+    bool loaded;
+    bool stftComputed;
+
+    // Playback state
+    float playheadT;           // 0-1 normalized position in selection
+    float playheadElapsed;     // Elapsed seconds since play started
+
+    // Time selection (0-1 normalized)
+    float timeSelectionStart;
+    float timeSelectionEnd;
+    bool isTimeSelecting;
+
+    // Frequency selection (0-1 normalized)
+    float freqSelectionStart;
+    float freqSelectionEnd;
+    bool isFreqSelecting;
+
+    // Export settings
+    float exportScale;
+    char exportDir[4096];
+    char exportMessage[256];
+
+    Vector2 selectStartPos;  // For minimum drag distance check
+    bool isDraggingSelection;  // Dragging existing selection box
+    Vector2 dragSelectionStartPos;  // Mouse position when started dragging selection
+    float dragSelectionTimeStart;  // Selection start time when dragging
+    float dragSelectionFreqStart;  // Selection freq start when dragging
+
+    // Viewport/zoom controls
+    float viewStart;      // 0-1, start of visible time region
+    float viewEnd;        // 0-1, end of visible time region
+    float freqViewStart;  // 0-1, start of visible frequency region (0 = 0Hz)
+    float freqViewEnd;    // 0-1, end of visible frequency region (1 = Nyquist)
+    bool isPanning;
+    float panStartViewStart;
+    float panStartViewEnd;
+    float panStartFreqViewStart;
+    float panStartFreqViewEnd;
+    Vector2 panStartPos;
+
+    // Cached visible texture
+    Texture2D visibleTexture;
+    int cachedVisibleStart;
+    int cachedVisibleEnd;
+    int cachedVisibleStartY;
+    int cachedVisibleEndY;
+    bool visibleTextureValid;
+
+    // Display settings
+    float amplitudeFloorDb;
+    float amplitudeCeilingDb;
+    ColormapType colormap;
+    bool showGrid;
+    int fftSize;  // Current FFT size (128-2048)
+
+    // File browser state
+    bool showFileBrowser;
+    char browserPath[512];
+    char** browserFiles;
+    bool* browserIsDir;
+    int browserFileCount;
+    int browserScroll;
+    int browserSelected;
+    bool isBrowsing;
+
+    // Playback state
+    bool isPlaying;
+    bool playbackFinished;  // Track if playback completed naturally
+
+    // Loading/processing state
+    int loadingPhase;         // 0 = computing STFT, 1 = generating texture
+    float loadingProgress;    // 0.0 to 1.0 overall progress
+    int currentSTFTSegment;   // Which segment we're on for incremental processing
+
+    // Adaptive resolution: skipFactor=1 means compute all segments, skipFactor=N
+    // means compute every Nth segment (faster initial load, overview-only).
+    // highResFinished tracks whether full-res segments have been computed for
+    // the current view range.
+    int skipFactor;
+    bool highResFinished;
+
+    // Background high-res computation state.
+    // After the overview (skipFactor-strided) loads, missing segments are
+    // filled in at full resolution in the background while the user is idle.
+    int bgHighResSeg;       // next segment index to compute at high-res
+    bool bgFinished;        // true when all segments are computed at high-res
+    int lastInteractedFrame; // frame counter when last user interaction occurred
+    bool isBgProcessing;    // true while background task is actively computing
+
+    // FFT size cache — LRU cache of previously computed STFT results.
+    // When user switches FFT sizes, we check the cache first to avoid
+    // recomputing. When cache is full, we evict the least-recently-used entry.
+    FFTSizeCache fftCache;
+
+    // Waveform scope view (underneath spectrogram viewport)
+    ScopeView scopeView;
+    bool showScope;       // Toggle to show/hide scope view
+
+    // Scope view divider
+    float dividerY;       // Y position of divider between spectrogram and scope (0-1 normalized)
+    bool isDividing;      // True while user is dragging the divider
+    Vector2 dividerStartPos;  // Mouse position when started dividing
+    float dividerStartY;      // Spectro height when started dividing
+} SpectrogramApp;
+
+// ============================================================================
+// Global State (defined in spectrogram.c)
+// ============================================================================
+
+extern SpectrogramApp app;
+extern Sound AudioPlaybackSound;
+extern Texture2D colormapTexture;
+extern Font mainFont;
+
+// ============================================================================
+// Small math helpers (header-inline so every module can use them)
+// ============================================================================
+
+static inline float AmplitudeToDecibels(float amplitude)
+{
+    if (amplitude < 0.0001f) amplitude = 0.0001f;
+    return 20.0f * log10f(amplitude);
+}
+
+static inline float Clamp(float value, float min, float max)
+{
+    if (value < min) return min;
+    if (value > max) return max;
+    return value;
+}
+
+#endif // SPECTROGRAM_TYPES_H