feat(audio): implement reverb effect and integrate into underwater system

include/Cubed/audio/audio_effect.hpp

@@ -0,0 +1,19 @@
+#pragma once
+#include <AL/al.h>
+namespace Cubed {
+class AudioEffect {
+public:
+    AudioEffect();
+    AudioEffect(const AudioEffect&) = delete;
+    AudioEffect(AudioEffect&&) = delete;
+    AudioEffect& operator=(const AudioEffect&) = default;
+    AudioEffect& operator=(AudioEffect&&) = delete;
+    ~AudioEffect();
+    void set_reverb(float decay_time, float reverb_gain, float gain_hf,
+                    float density = 1.0f, float diffusion = 1.0f);
+    ALuint effect() const;
+
+private:
+    ALuint m_effect = 0;
+};
+} // namespace Cubed

include/Cubed/audio/audio_effect_slot.hpp

@@ -0,0 +1,18 @@
+#pragma once
+#include "Cubed/audio/audio_effect.hpp"
+namespace Cubed {
+class AudioEffectSlot {
+public:
+    AudioEffectSlot();
+    AudioEffectSlot(const AudioEffectSlot&) = delete;
+    AudioEffectSlot(AudioEffectSlot&&) = delete;
+    AudioEffectSlot& operator=(const AudioEffectSlot&) = delete;
+    AudioEffectSlot& operator=(AudioEffectSlot&&) = delete;
+    ~AudioEffectSlot();
+    void set_effect(const AudioEffect& effect);
+    ALuint slot() const;
+
+private:
+    ALuint m_slot = 0;
+};
+} // namespace Cubed

include/Cubed/audio/audio_engine.hpp

@@ -54,5 +54,7 @@ private:
     float m_music_volume = 1.0f;
     float m_sfx_volume = 1.0f;
     std::unique_ptr<AudioFilter> m_low_pass_filter;
+    std::unique_ptr<AudioEffect> m_underwater_effect;
+    std::unique_ptr<AudioEffectSlot> m_underwater_slot;
 };
 } // namespace Cubed

include/Cubed/audio/audio_source.hpp

@@ -1,5 +1,6 @@
 #pragma once
 #include "Cubed/audio/audio_buffer.hpp"
+#include "Cubed/audio/audio_effect_slot.hpp"
 #include "Cubed/audio/audio_filter.hpp"
 
 #include <AL/al.h>
@@ -37,6 +38,8 @@ public:
 
     void set_filter(const AudioFilter& filter);
     void clear_filter();
+    void set_effect_slot(const AudioEffectSlot& slot);
+    void clear_effect_slot();
 
 private:
     ALuint m_source = 0;

src/CMakeLists.txt

@@ -52,4 +52,6 @@ target_sources(${PROJECT_NAME}
         audio/source_pool.cpp
         audio/audio_fade.cpp
         audio/audio_filter.cpp
+        audio/audio_effect.cpp
+        audio/audio_effect_slot.cpp
 )

src/audio/audio_effect.cpp

@@ -0,0 +1,26 @@
+#include "Cubed/audio/audio_effect.hpp"
+#ifndef AL_ALEXT_PROTOTYPES
+#define AL_ALEXT_PROTOTYPES
+#endif
+#include <AL/efx.h>
+
+namespace Cubed {
+AudioEffect::AudioEffect() { alGenEffects(1, &m_effect); }
+
+AudioEffect::~AudioEffect() {
+    if (m_effect) {
+        alDeleteEffects(1, &m_effect);
+    }
+}
+
+void AudioEffect::set_reverb(float decay_time, float reverb_gain, float gain_hf,
+                             float density, float diffusion) {
+    alEffecti(m_effect, AL_EFFECT_TYPE, AL_EFFECT_REVERB);
+    alEffectf(m_effect, AL_REVERB_DECAY_TIME, decay_time);
+    alEffectf(m_effect, AL_REVERB_GAIN, reverb_gain);
+    alEffectf(m_effect, AL_REVERB_GAINHF, gain_hf);
+    alEffectf(m_effect, AL_REVERB_DENSITY, density);
+    alEffectf(m_effect, AL_REVERB_DIFFUSION, diffusion);
+}
+ALuint AudioEffect::effect() const { return m_effect; }
+} // namespace Cubed

src/audio/audio_effect_slot.cpp

@@ -0,0 +1,19 @@
+#include "Cubed/audio/audio_effect_slot.hpp"
+#ifndef AL_ALEXT_PROTOTYPES
+#define AL_ALEXT_PROTOTYPES
+#endif
+#include <AL/efx.h>
+namespace Cubed {
+AudioEffectSlot::AudioEffectSlot() { alGenAuxiliaryEffectSlots(1, &m_slot); }
+
+AudioEffectSlot::~AudioEffectSlot() {
+    if (m_slot) {
+        alDeleteAuxiliaryEffectSlots(1, &m_slot);
+    }
+}
+
+void AudioEffectSlot::set_effect(const AudioEffect& effect) {
+    alAuxiliaryEffectSloti(m_slot, AL_EFFECTSLOT_EFFECT, effect.effect());
+}
+ALuint AudioEffectSlot::slot() const { return m_slot; }
+} // namespace Cubed

src/audio/audio_engine.cpp

@@ -19,6 +19,10 @@ AudioEngine::~AudioEngine() {
     m_pool.reset();
     m_sounds.clear();
 
+    m_low_pass_filter.reset();
+    m_underwater_effect.reset();
+    m_underwater_slot.reset();
+
     alcMakeContextCurrent(nullptr);
     alcDestroyContext(context);
     alcCloseDevice(device);
@@ -49,6 +53,12 @@ void AudioEngine::init() {
         m_low_pass_filter = std::make_unique<AudioFilter>();
 
         m_low_pass_filter->set_lowpass(1.0f, 0.15f);
+
+        m_underwater_effect = std::make_unique<AudioEffect>();
+        m_underwater_effect->set_reverb(0.8f, 0.3162f, 0.01f);
+        // m_underwater_effect->set_reverb(20.0f, 1.0f, 1.0f);
+        m_underwater_slot = std::make_unique<AudioEffectSlot>();
+        m_underwater_slot->set_effect(*m_underwater_effect);
     }
 
     alDistanceModel(AL_INVERSE_DISTANCE_CLAMPED);
@@ -120,6 +130,7 @@ void AudioEngine::play_3d(const std::string& sound, const glm::vec3& pos,
         auto& buffer = m_sounds.get_buffer(sound);
         if (m_efx_supported && m_underwater) {
             source->set_filter(*m_low_pass_filter);
+            source->set_effect_slot(*m_underwater_slot);
         }
         source->play_3d(buffer, pos);
     } catch (const std::exception& e) {
@@ -145,6 +156,7 @@ void AudioEngine::play_2d(const std::string& sound, bool check) {
         auto& buffer = m_sounds.get_buffer(sound);
         if (m_efx_supported && m_underwater) {
             source->set_filter(*m_low_pass_filter);
+            source->set_effect_slot(*m_underwater_slot);
         }
         source->play_2d(buffer);
     } catch (const std::exception& e) {
@@ -195,9 +207,10 @@ void AudioEngine::underwater_change(bool underwater) {
     for (auto& source : m_pool->sources()) {
         if (m_underwater) {
             source.set_filter(*m_low_pass_filter);
-
+            source.set_effect_slot(*m_underwater_slot);
         } else {
             source.clear_filter();
+            source.clear_effect_slot();
         }
     }
     if (underwater) {

src/audio/audio_source.cpp

@@ -156,6 +156,7 @@ void AudioSource::reset() {
     alSourcef(m_source, AL_SEC_OFFSET, 0.0f);
 
     clear_filter();
+    clear_effect_slot();
 
     m_duration = 0.0f;
     m_target_volume = 1.0f;
@@ -168,4 +169,15 @@ void AudioSource::set_filter(const AudioFilter& filter) {
 void AudioSource::clear_filter() {
     alSourcei(m_source, AL_DIRECT_FILTER, AL_FILTER_NULL);
 }
+
+void AudioSource::set_effect_slot(const AudioEffectSlot& slot) {
+    alSource3i(m_source, AL_AUXILIARY_SEND_FILTER, slot.slot(), 0,
+               AL_FILTER_NULL);
+}
+
+void AudioSource::clear_effect_slot() {
+    alSource3i(m_source, AL_AUXILIARY_SEND_FILTER, AL_EFFECTSLOT_NULL, 0,
+               AL_FILTER_NULL);
+}
+
 } // namespace Cubed