feat(audio): add day/night-based BGM switching

include/Cubed/audio/audio_engine.hpp

@@ -26,6 +26,7 @@ public:
 
     void init();
     void play_bgm();
+    void change_bgm(const std::string& sound);
     void play_3d(const std::string& sound, const glm::vec3& pos,
                  bool check = false);
     void play_2d(const std::string& sound, bool check = false);

include/Cubed/audio/audio_fade.hpp

@@ -6,6 +6,7 @@ public:
     AudioFade(AudioSource* source, float fade_in = 0.0f, float fade_out = 0.0f);
     ~AudioFade();
     void update();
+    void reset();
 
 private:
     AudioSource* m_source = nullptr;

src/audio/audio_engine.cpp

@@ -71,6 +71,20 @@ void AudioEngine::init() {
 
 void AudioEngine::play_bgm() { m_bgm->play(); }
 
+void AudioEngine::change_bgm(const std::string& sound) {
+    Logger::info("change bgm {}", sound);
+    m_bgm->stop();
+    m_bgm->reset();
+    m_bgm->set_buffer_2d(m_sounds.get_buffer(sound));
+    m_bgm->set_target_volume(m_music_volume);
+    m_bgm->set_volume(m_music_volume);
+    auto it = m_fade_map.find("bgm");
+    if (it != m_fade_map.end()) {
+        it->second.reset();
+    }
+    m_bgm->play();
+};
+
 void AudioEngine::play_3d(const std::string& sound, const glm::vec3& pos,
                           bool check) {
     if (!m_pool) {

src/audio/audio_fade.cpp

@@ -16,6 +16,14 @@ AudioFade::AudioFade(AudioSource* source, float fade_in, float fade_out)
     m_source->set_volume(0.0f);
 }
 AudioFade::~AudioFade() {}
+
+void AudioFade::reset() {
+    m_active = true;
+    m_fade_in = true;
+    m_start_gain = 0.0f;
+    m_source->set_volume(0.0f);
+}
+
 void AudioFade::update() {
     if (!m_active || !m_source) {
         return;

src/audio/audio_source.cpp

@@ -47,6 +47,8 @@ void AudioSource::set_buffer_3d(const AudioBuffer& buffer,
     alSourcef(m_source, AL_REFERENCE_DISTANCE, 4.0f);
     alSourcef(m_source, AL_ROLLOFF_FACTOR, 1.0f);
     alSourcef(m_source, AL_MAX_DISTANCE, 48.0f);
+
+    /*
     ALfloat l[3];
     alGetListenerfv(AL_POSITION, l);
 
@@ -55,6 +57,7 @@ void AudioSource::set_buffer_3d(const AudioBuffer& buffer,
     alGetSourcefv(m_source, AL_POSITION, p);
 
     Logger::info("Source Pos = ({}, {}, {})", p[0], p[1], p[2]);
+    */
 }
 
 void AudioSource::set_loop(bool on) {

src/audio/sound_manager.cpp

@@ -12,6 +12,7 @@ void SoundManager::clear() { m_buffers.clear(); }
 void SoundManager::init() {
     try {
         load("bgm/bgm001.mp3");
+        load("bgm/bgm002.ogg");
         load("ambient/birds.ogg");
     } catch (const std::exception& e) {
     }

src/gameplay/client_world.cpp

@@ -407,6 +407,14 @@ void ClientWorld::init(std::string_view player_name,
         }
     });
 
+    m_timers.try_emplace("bgm change", 350.0f, [this]() {
+        if (m_day_tick >= 17000 || m_day_tick < 5000) {
+            m_audio.change_bgm("bgm/bgm002.ogg");
+        } else {
+            m_audio.change_bgm("bgm/bgm001.mp3");
+        }
+    });
+
     LoginReq req;
     req.set_name(m_player.get_name());
     while (!client->is_connected()) {