feat: Add debug-only file change detection for rapid iteration

Enables --hot-reload flag to watch config files and notify on changes.
Detects modifications to assets/sequences/music for rebuild workflow.
Completely stripped from release builds (0 bytes overhead).

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/src/main.cc b/src/main.cc
index 59001fb..b4091e7 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -11,6 +11,7 @@
 #include "audio/tracker.h"
 #if !defined(STRIP_ALL)
 #include "audio/backend/wav_dump_backend.h"
+#include "util/file_watcher.h"
 #include <vector>
 #endif
 #include "generated/assets.h" // Include generated asset header
@@ -32,6 +33,7 @@ int main(int argc, char** argv) {
   bool dump_wav = false;
   bool tempo_test_enabled = false;
   const char* wav_output_file = "audio_dump.wav";
+  bool hot_reload_enabled = false;
 
 #if !defined(STRIP_ALL)
   for (int i = 1; i < argc; ++i) {
@@ -57,6 +59,9 @@ int main(int argc, char** argv) {
       }
     } else if (strcmp(argv[i], "--tempo") == 0) {
       tempo_test_enabled = true;
+    } else if (strcmp(argv[i], "--hot-reload") == 0) {
+      hot_reload_enabled = true;
+      printf("Hot-reload enabled (watching config files)\n");
     }
   }
 #else
@@ -167,6 +172,16 @@ int main(int argc, char** argv) {
   g_last_audio_time = audio_get_playback_time(); // Initialize after start
 
 #if !defined(STRIP_ALL)
+  // Hot-reload setup
+  FileWatcher file_watcher;
+  if (hot_reload_enabled) {
+    file_watcher.add_file("assets/final/demo_assets.txt");
+    file_watcher.add_file("assets/demo.seq");
+    file_watcher.add_file("assets/music.track");
+  }
+#endif
+
+#if !defined(STRIP_ALL)
   // In WAV dump mode, run headless simulation and write audio to file
   if (dump_wav) {
     printf("Running WAV dump simulation...\n");
@@ -255,6 +270,15 @@ int main(int argc, char** argv) {
     // context
     fill_audio_buffer(audio_dt, current_physical_time);
 
+#if !defined(STRIP_ALL)
+    // Hot-reload: Check for file changes
+    if (hot_reload_enabled && file_watcher.check_changes()) {
+      printf("\n[Hot-Reload] Config files changed - rebuild required\n");
+      printf("[Hot-Reload] Run: cmake --build build -j4 && ./build/demo64k\n");
+      file_watcher.reset();
+    }
+#endif
+
     // --- Graphics Update ---
     const float aspect_ratio = platform_state.aspect_ratio;