feat: Add --seek command line option for fast-forward debugging

This feature allows developers to jump to a specific time in the demo sequence (e.g., './demo64k --seek 10.5'). It simulates the game logic, audio state (rendering silent buffers), and visual physics (compute shaders) from t=0 up to the target time before starting real-time playback. Audio initialization is refactored to separate device init and start.

1 files changed, 15 insertions, 0 deletions

diff --git a/src/audio/audio.cc b/src/audio/audio.cc
index 6249479..517e376 100644
--- a/src/audio/audio.cc
+++ b/src/audio/audio.cc
@@ -38,7 +38,9 @@ void audio_init() {
     printf("Failed to open playback device.\n");
     return;
   }
+}
 
+void audio_start() {
   if (ma_device_start(&g_device) != MA_SUCCESS) {
     printf("Failed to start playback device.\n");
     ma_device_uninit(&g_device);
@@ -46,6 +48,19 @@ void audio_init() {
   }
 }
 
+void audio_render_silent(float duration_sec) {
+  const int sample_rate = 32000;
+  const int chunk_size = 512;
+  int total_frames = (int)(duration_sec * sample_rate);
+  float buffer[chunk_size * 2]; // Stereo
+
+  while (total_frames > 0) {
+    int frames_to_render = (total_frames > chunk_size) ? chunk_size : total_frames;
+    synth_render(buffer, frames_to_render);
+    total_frames -= frames_to_render;
+  }
+}
+
 void audio_update() {
 }