refactor: modal-gate helper + data-driven colormap table

Two extensibility easy-wins, both behavior-preserving:

- UiModalOpen() centralizes the "an overlay owns input" check that was
  copy-pasted as `!showFileBrowser && !showAbout` across 6 input gates.
  New overlays now update one place.
- Colormaps become a COLORMAPS[] table (name + function) indexed by enum.
  GetColormapColor and the sidebar both read it, so adding a colormap is
  one enum value + one Cmap* fn + one row — and the sidebar name can no
  longer drift from the enum (deleted the parallel colormapNames[] array).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/render.c

@@ -41,48 +41,79 @@ float MeasureTextScaled(const char* text, float baseSize)
 }
 
 // ===== Colormaps =====
-static Color GetColormapColor(float t, ColormapType type)
+// Each colormap maps t in [0,1] to a Color. To add a colormap: add an enum
-{
+// value in spectrogram_types.h, write a Cmap* function, and add one row to
-    t = Clamp(t, 0.0f, 1.0f);
+// COLORMAPS[] below — the sidebar names and lookups follow automatically.
+typedef Color (*ColormapFn)(float t);
 
-    switch (type) {
+static Color CmapGrays(float t)
-        case COLORMAP_GRAYS: {
+{
     unsigned char v = (unsigned char)(t * 255);
     return (Color){ v, v, v, 255 };
-        }
+}
-        case COLORMAP_INFERNO: {
+
+static Color CmapInferno(float t)
+{
     float r = 0.0f, g = 0.0f, b = 0.0f;
     if (t < 0.25f) { t = t / 0.25f; r = 0.0f + t * 0.5f; g = 0.0f; b = 0.0f + t * 0.3f; }
     else if (t < 0.5f) { t = (t - 0.25f) / 0.25f; r = 0.5f + t * 0.5f; g = 0.0f + t * 0.3f; b = 0.3f + t * 0.4f; }
     else if (t < 0.75f) { t = (t - 0.5f) / 0.25f; r = 1.0f; g = 0.3f + t * 0.5f; b = 0.7f + t * 0.2f; }
     else { t = (t - 0.75f) / 0.25f; r = 1.0f; g = 0.8f + t * 0.2f; b = 0.9f + t * 0.1f; }
     return (Color){ (unsigned char)(r * 255), (unsigned char)(g * 255), (unsigned char)(b * 255), 255 };
-        }
+}
-        case COLORMAP_VIRIDIS: {
+
+static Color CmapViridis(float t)
+{
     float r, g, b;
     if (t < 0.25f) { t = t / 0.25f; r = 0.27f + t * 0.13f; g = 0.00f + t * 0.33f; b = 0.33f + t * 0.27f; }
     else if (t < 0.5f) { t = (t - 0.25f) / 0.25f; r = 0.40f + t * 0.16f; g = 0.33f + t * 0.29f; b = 0.60f - t * 0.20f; }
     else if (t < 0.75f) { t = (t - 0.5f) / 0.25f; r = 0.56f + t * 0.24f; g = 0.62f + t * 0.23f; b = 0.40f - t * 0.20f; }
     else { t = (t - 0.75f) / 0.25f; r = 0.80f + t * 0.17f; g = 0.85f + t * 0.12f; b = 0.20f - t * 0.15f; }
     return (Color){ (unsigned char)(r * 255), (unsigned char)(g * 255), (unsigned char)(b * 255), 255 };
-        }
+}
-        case COLORMAP_PLASMA: {
+
+static Color CmapPlasma(float t)
+{
     float r = 0.05f + t * 0.9f;
     float g = 0.0f + t * 0.6f + (t > 0.5f ? (t - 0.5f) * 0.4f : 0.0f);
     float b = 0.6f - t * 0.5f;
     return (Color){ (unsigned char)(r * 255), (unsigned char)(g * 255), (unsigned char)(b * 255), 255 };
-        }
+}
-        case COLORMAP_HOT: {
+
+static Color CmapHot(float t)
+{
     float r = Clamp(t * 3.0f, 0.0f, 1.0f);
     float g = Clamp((t - 0.33f) * 3.0f, 0.0f, 1.0f);
     float b = Clamp((t - 0.66f) * 3.0f, 0.0f, 1.0f);
     return (Color){ (unsigned char)(r * 255), (unsigned char)(g * 255), (unsigned char)(b * 255), 255 };
-        }
+}
-        case COLORMAP_COOL: {
+
+static Color CmapCool(float t)
+{
     return (Color){ (unsigned char)(t * 255), (unsigned char)((1.0f - t) * 255), 255, 255 };
-        }
+}
-        default: return GRAY;
+
-    }
+typedef struct { const char* name; ColormapFn fn; } ColormapDef;
+
+static const ColormapDef COLORMAPS[COLORMAP_COUNT] = {
+    [COLORMAP_GRAYS]   = { "Grays",   CmapGrays },
+    [COLORMAP_INFERNO] = { "Inferno", CmapInferno },
+    [COLORMAP_VIRIDIS] = { "Viridis", CmapViridis },
+    [COLORMAP_PLASMA]  = { "Plasma",  CmapPlasma },
+    [COLORMAP_HOT]     = { "Hot",     CmapHot },
+    [COLORMAP_COOL]    = { "Cool",    CmapCool },
+};
+
+static Color GetColormapColor(float t, ColormapType type)
+{
+    if (type < 0 || type >= COLORMAP_COUNT) return GRAY;
+    return COLORMAPS[type].fn(Clamp(t, 0.0f, 1.0f));
+}
+
+const char* ColormapName(ColormapType type)
+{
+    if (type < 0 || type >= COLORMAP_COUNT) return "?";
+    return COLORMAPS[type].name;
 }
 
 void GenerateColormapTexture(void)

src/render.h

@@ -11,6 +11,7 @@ float MeasureTextScaled(const char* text, float baseSize);
 
 // --- Colormaps ---
 void GenerateColormapTexture(void);
+const char* ColormapName(ColormapType type);
 
 // --- Spectrogram texture ---
 // GenerateSpectrogramTexture recomputes the synchrosqueezed reassignment (use

src/spectrogram.c

@@ -217,7 +217,7 @@ int main(int argc, char* argv[])
         }
         
         // File browser toggle
-        if (IsKeyPressed(KEY_O) && !app.showFileBrowser && !app.showAbout) {
+        if (IsKeyPressed(KEY_O) && !UiModalOpen()) {
             app.showFileBrowser = true;
             ScanDirectory(GetWorkingDirectory());
         }
@@ -258,7 +258,7 @@ int main(int argc, char* argv[])
         }
 
         // View controls
-        if (app.loaded && !app.showFileBrowser && !app.showAbout) {
+        if (app.loaded && !UiModalOpen()) {
             // Spectrogram area fills remaining window space (scaled)
             float viewScale = GetUIScale();
             float sidebarWidth = 320 * viewScale;
@@ -438,7 +438,7 @@ int main(int argc, char* argv[])
         }
 
         // Keyboard shortcuts (SPACE for play/stop toggle, ESC for clear)
-        if (IsKeyPressed(KEY_SPACE) && !app.showFileBrowser && !app.showAbout) {
+        if (IsKeyPressed(KEY_SPACE) && !UiModalOpen()) {
             if (app.isPlaying && AudioPlaybackSound.frameCount > 0) {
                 // Currently playing - stop it
                 StopSound(AudioPlaybackSound);
@@ -459,7 +459,7 @@ int main(int argc, char* argv[])
         }
 
         // Export PNG
-        if (IsKeyPressed(KEY_E) && !app.showFileBrowser && !app.showAbout && app.stftComputed) {
+        if (IsKeyPressed(KEY_E) && !UiModalOpen() && app.stftComputed) {
             ExportPNG(&app, app.exportDir);
         }
 
@@ -540,7 +540,7 @@ int main(int argc, char* argv[])
         }
 
         // LMB drag = box select (time + frequency) OR drag existing selection
-        if (app.loaded && !app.showFileBrowser && !app.showAbout && CheckCollisionPointRec(mousePos, selBounds)) {
+        if (app.loaded && !UiModalOpen() && CheckCollisionPointRec(mousePos, selBounds)) {
             // Set cursor to resize all when near divider
             if (mouseNearDivider && !app.isDividing) {
                 SetMouseCursor(MOUSE_CURSOR_RESIZE_ALL);
@@ -639,7 +639,7 @@ int main(int argc, char* argv[])
 
         // Handle divider drag. Works whether or not the scope is currently shown
         // (when hidden, the handle sits at the bottom and can be dragged back up).
-        if (app.loaded && !app.showFileBrowser && !app.showAbout) {
+        if (app.loaded && !UiModalOpen()) {
             // Grab the handle. The starting position is the *effective* divider,
             // which is the bottom of the view (1.0) while the scope is hidden.
             if (mouseNearDivider && IsMouseButtonPressed(MOUSE_LEFT_BUTTON)) {

src/spectrogram_types.h

@@ -226,6 +226,13 @@ extern Font mainFont;
 // (defined in spectrogram.c; used by every load path).
 void ResetForNewSignal(void);
 
+// True when a modal overlay owns input; normal spectrogram/keyboard interaction
+// is gated off while this is the case. Add new overlays here in one place.
+static inline bool UiModalOpen(void)
+{
+    return app.showFileBrowser || app.showAbout;
+}
+
 // ============================================================================
 // Small math helpers (header-inline so every module can use them)
 // ============================================================================

src/ui.c

@@ -394,7 +394,6 @@ void DrawSidebar(void)
 
     // Colormap dropdown
     DrawTextScaled("Colormap:", x, y, 14, LIGHTGRAY); y += 20 * scale;
-    const char* colormapNames[] = { "Grays", "Inferno", "Viridis", "Plasma", "Hot", "Cool" };
     Rectangle cmapButton = { x, y, sidebarWidth - 10 * scale, 25 * scale };
     if (CheckCollisionPointRec(GetMousePosition(), cmapButton) && IsMouseButtonPressed(MOUSE_LEFT_BUTTON)) {
         app.colormap = (ColormapType)((app.colormap + 1) % COLORMAP_COUNT);
@@ -403,7 +402,7 @@ void DrawSidebar(void)
     }
     DrawRectangleRec(cmapButton, (Color){ 50, 50, 60, 255 });
     DrawRectangleLinesEx(cmapButton, 1, GRAY);
-    DrawTextScaled(colormapNames[app.colormap], cmapButton.x + 10 * scale, cmapButton.y + 6 * scale, 14, WHITE);
+    DrawTextScaled(ColormapName(app.colormap), cmapButton.x + 10 * scale, cmapButton.y + 6 * scale, 14, WHITE);
     DrawTexturePro(colormapTexture, (Rectangle){ 0, 0, 256, 1 },
                    (Rectangle){ cmapButton.x + cmapButton.width - 60 * scale, cmapButton.y + 5 * scale, 50 * scale, 15 * scale },
                    (Vector2){ 0, 0 }, 0.0f, WHITE);