Implement TSR audio

CMakeLists.txt

@@ -46,6 +46,19 @@ set(COMMON_SOURCES
 set(CLIENT_ONLY_SOURCES
     "src/assets/mesh_builder.hpp"
     "src/assets/mesh_builder.cpp"
+    "src/audio/defs.hpp"
+    "src/audio/master.hpp"
+    "src/audio/master.cpp"
+    "src/audio/ogg.hpp"
+    "src/audio/ogg.cpp"
+    "src/audio/player.hpp"
+    "src/audio/player.cpp"
+    "src/audio/sound_source.hpp"
+    "src/audio/sound_source.cpp"
+    "src/audio/sound.hpp"
+    "src/audio/sound.cpp"
+    "src/audio/source.hpp"
+    "src/audio/source.cpp"
     "src/client/app.hpp"
     "src/client/app.cpp"
     "src/client/gl.hpp"
@@ -117,10 +130,14 @@ endif()
 # Include directories
 target_include_directories(${MAIN_NAME} PRIVATE "src")
 
+target_compile_definitions(${MAIN_NAME} PRIVATE CLIENT)
+
+# add glm
 add_subdirectory(external/glm)
 target_link_libraries(${MAIN_NAME} PRIVATE glm)
 target_include_directories(${MAIN_NAME} PRIVATE "external/stb")
 
+# add bullet3
 set(BUILD_EXAMPLES OFF CACHE BOOL "" FORCE)
 set(BUILD_BULLET2_DEMOS OFF CACHE BOOL "" FORCE)
 set(BUILD_UNIT_TESTS OFF CACHE BOOL "" FORCE)
@@ -131,7 +148,12 @@ add_subdirectory(external/bullet3)
 target_link_libraries(${MAIN_NAME} PRIVATE BulletDynamics BulletCollision LinearMath Bullet3Common)
 target_include_directories(${MAIN_NAME} PRIVATE "external/bullet3/src")
 
-target_compile_definitions(${MAIN_NAME} PRIVATE CLIENT)
+# add ogg
+add_subdirectory(external/ogg)
+
+# add vorbis
+add_subdirectory(external/vorbis)
+target_link_libraries(${MAIN_NAME} PRIVATE vorbisfile vorbis)
 
 # Platform-specific SDL2 handling
 if (CMAKE_SYSTEM_NAME STREQUAL Emscripten)
@@ -196,6 +218,11 @@ endif()
     
     target_link_libraries(${MAIN_NAME} PRIVATE easywsclient)
 
+    # add openal
+    set(ALSOFT_EXAMPLES OFF)
+    add_subdirectory(external/openal-soft)
+    target_link_libraries(${MAIN_NAME} PRIVATE OpenAL)
+
     # build server
     set(ASIO_INCLUDE_DIR "external/asio/include")
     include_directories(${ASIO_INCLUDE_DIR})

src/assets/cache.cpp

@@ -6,3 +6,4 @@ assets::MapCache assets::CacheManager::map_cache_;
 assets::VehicleCache assets::CacheManager::vehicle_cache_;
 
 CLIENT_ONLY(assets::TextureCache assets::CacheManager::texture_cache_;)
+CLIENT_ONLY(assets::SoundCache assets::CacheManager::sound_cache_;)

src/assets/cache.hpp

@@ -8,6 +8,7 @@
 #include "utils/defs.hpp"
 
 #ifdef CLIENT
+#include "audio/sound.hpp"
 #include "gfx/texture.hpp"
 #endif
 
@@ -49,6 +50,12 @@ class TextureCache final : public Cache<gfx::Texture>
 protected:
     PtrType Load(const std::string& key) override { return gfx::Texture::LoadFromFile(key); }
 };
+
+class SoundCache final : public Cache<audio::Sound>
+{
+protected:
+    PtrType Load(const std::string& key) override { return audio::Sound::LoadFromFile(key); }
+};
 #endif // CLIENT
 
 class SkeletonCache final : public Cache<Skeleton>
@@ -87,13 +94,21 @@ public:
 
     static std::shared_ptr<const Map> GetMap(const std::string& filename) { return map_cache_.Get(filename); }
 
-    static std::shared_ptr<const VehicleModel> GetVehicleModel(const std::string& filename) { return vehicle_cache_.Get(filename); }
+    static std::shared_ptr<const VehicleModel> GetVehicleModel(const std::string& filename)
+    {
+        return vehicle_cache_.Get(filename);
+    }
 
 #ifdef CLIENT
     static std::shared_ptr<const gfx::Texture> GetTexture(const std::string& filename)
     {
         return texture_cache_.Get(filename);
     }
+
+    static std::shared_ptr<const audio::Sound> GetSound(const std::string& filename)
+    {
+        return sound_cache_.Get(filename);
+    }
 #endif
 
 private:
@@ -102,6 +117,7 @@ private:
     static MapCache map_cache_;
     static VehicleCache vehicle_cache_;
     CLIENT_ONLY(static TextureCache texture_cache_;)
+    CLIENT_ONLY(static SoundCache sound_cache_;)
 };
 
 } // namespace assets

src/audio/defs.hpp

@@ -0,0 +1,3 @@
+#pragma once
+
+#define AUDIO_DBG(...) __VA_ARGS__

src/audio/master.cpp

@@ -0,0 +1,125 @@
+#include "master.hpp"
+
+#include <iostream>
+
+#include <AL/al.h>
+#include <AL/alc.h>
+
+#include "defs.hpp"
+#include "sound_source.hpp"
+#include "source.hpp"
+
+static const size_t MAX_CATEGORIES = 32;
+
+audio::Master::Master()
+{
+    std::cout << "Initializing audio master...\n";
+
+    categories_.reserve(MAX_CATEGORIES);
+
+    device_ = alcOpenDevice(nullptr);
+
+    if (!device_)
+    {
+        throw std::runtime_error("(AL) Failed to open audio device");
+    }
+
+    // get device info
+    const ALchar* info = alcGetString(device_, ALC_DEVICE_SPECIFIER);
+    std::cout << "Opened audio device: " << (info ? info : "Unknown") << std::endl;
+
+    context_ = alcCreateContext(device_, nullptr);
+
+    if (!context_)
+    {
+        alcCloseDevice(device_);
+        device_ = nullptr;
+        throw std::runtime_error("(AL) Failed to create audio context");
+    }
+
+    std::cout << "Created audio context" << std::endl;
+
+    if (!alcMakeContextCurrent(context_))
+    {
+        alcDestroyContext(context_);
+        alcCloseDevice(device_);
+        context_ = nullptr;
+        device_ = nullptr;
+        throw std::runtime_error("(AL) Failed to make audio context current");
+    }
+
+    std::cout << "Audio context is now current" << std::endl;
+}
+
+void audio::Master::SetListenerOrientation(const glm::vec3& position, const glm::vec3& forward, const glm::vec3& up)
+{
+    alListener3f(AL_POSITION, position.x, position.y, position.z);
+    // alListener3f(AL_VELOCITY, 0.0f, 0.0f, 0.0f);
+    ALfloat orientation[] = {forward.x, forward.y, forward.z, up.x, up.y, up.z};
+    alListenerfv(AL_ORIENTATION, orientation);
+}
+
+void audio::Master::SetListenerOrientation(const glm::mat4& world_matrix)
+{
+    glm::vec3 position = glm::vec3(world_matrix[3]);
+    glm::vec3 forward = -glm::normalize(glm::vec3(world_matrix[2]));
+    glm::vec3 up = glm::normalize(glm::vec3(world_matrix[1]));
+    SetListenerOrientation(position, forward, up);
+}
+
+audio::Category* audio::Master::GetCategory(const std::string& name)
+{
+    auto it = category_map_.find(name);
+    if (it != category_map_.end())
+    {
+        return it->second;
+    }
+
+    if (categories_.size() >= MAX_CATEGORIES)
+    {
+        throw std::runtime_error("(AL) Maximum number of audio categories reached");
+    }
+
+    Category* new_category = &categories_.emplace_back(name);
+    category_map_[name] = new_category;
+
+    AUDIO_DBG(std::cout << "Created new audio category: " << name << std::endl;)
+
+    return new_category;
+}
+
+void audio::Master::SetMasterVolume(float volume)
+{
+    master_volume_ = volume;
+    alListenerf(AL_GAIN, master_volume_);
+    AUDIO_DBG(std::cout << "Set master volume to " << master_volume_ << std::endl;)
+}
+
+audio::Master::~Master()
+{
+    std::cout << "Shutting down audio master...\n";
+
+    if (context_)
+    {
+        alcMakeContextCurrent(nullptr);
+        alcDestroyContext(context_);
+        context_ = nullptr;
+    }
+
+    if (device_)
+    {
+        alcCloseDevice(device_);
+        device_ = nullptr;
+    }
+}
+
+audio::Category::Category(const std::string& name) : name_(name) {}
+
+void audio::Category::SetVolume(float volume)
+{
+    volume_ = volume;
+    for (Source* source = first_source_; source; source = source->cat_next_)
+    {
+        source->UpdateVolume();
+    }
+}

src/audio/master.hpp

@@ -0,0 +1,63 @@
+#pragma once
+
+#include <map>
+#include <string>
+#include <vector>
+
+#include "utils/defs.hpp"
+#include <glm/glm.hpp>
+
+class ALCdevice;
+class ALCcontext;
+
+namespace audio
+{
+
+class Source;
+
+class Category
+{
+public:
+    Category(const std::string& name);
+    DELETE_COPY_MOVE(Category)
+
+    const std::string& GetName() const { return name_; }
+
+    void SetVolume(float volume);
+    float GetVolume() const { return volume_; }
+
+private:
+    float volume_ = 1.0f;
+    std::string name_;
+
+    Source* first_source_ = nullptr;
+    friend class Source;
+};
+
+class Master
+{
+public:
+    Master();
+    DELETE_COPY_MOVE(Master)
+
+    void SetListenerOrientation(const glm::vec3& position, const glm::vec3& forward, const glm::vec3& up);
+    void SetListenerOrientation(const glm::mat4& world_matrix);
+
+    Category* GetCategory(const std::string& name);
+
+    void SetMasterVolume(float volume);
+    float GetMasterVolume() const { return master_volume_; }
+
+    ~Master();
+
+private:
+    ALCdevice* device_ = nullptr;
+    ALCcontext* context_ = nullptr;
+
+    std::vector<Category> categories_;
+    std::map<std::string, Category*> category_map_;
+
+    float master_volume_ = 1.0f;
+};
+
+} // namespace audio

src/audio/ogg.cpp

@@ -0,0 +1,85 @@
+#include "ogg.hpp"
+
+#include <stdexcept>
+
+audio::OggFile::OggFile(const char* filename)
+{
+    int result = ov_fopen(filename, &ogg_file_);
+
+    if (result < 0)
+    {
+        throw std::runtime_error("(OGG) Failed to open OGG file: " + std::string(filename));
+    }
+
+    try
+    {
+        LoadInfo();
+    }
+    catch (const std::exception& e)
+    {
+        ov_clear(&ogg_file_);
+        throw std::runtime_error(std::string("(OGG) Error loading OGG file info: ") + e.what());
+    }
+}
+
+size_t audio::OggFile::GetNumChannels() const
+{
+    return vorbis_info_->channels;
+}
+
+size_t audio::OggFile::GetSampleRate() const
+{
+    return vorbis_info_->rate;
+}
+
+size_t audio::OggFile::GetNumSamples()
+{
+    return ov_pcm_total(&ogg_file_, -1);
+}
+
+size_t audio::OggFile::Read(char* buffer, size_t length)
+{
+    long res = ov_read(&ogg_file_, buffer, static_cast<int>(length), 0, 2, 1, NULL);
+
+    if (res < 0)
+    {
+        throw std::runtime_error("Error reading OGG file");
+    }
+
+    return static_cast<size_t>(res);
+}
+
+std::vector<char> audio::OggFile::ReadAll()
+{
+    size_t total_size = ov_pcm_total(&ogg_file_, -1) * vorbis_info_->channels * 2;
+    std::vector<char> buffer(total_size);
+
+    size_t bytes_read = 0;
+    while (bytes_read < total_size)
+    {
+        size_t bytes_to_read = total_size - bytes_read;
+        size_t read = Read(buffer.data() + bytes_read, bytes_to_read);
+
+        if (read == 0)
+        {
+            break; // End of file reached
+        }
+
+        bytes_read += read;
+    }
+
+    return buffer;
+}
+
+audio::OggFile::~OggFile()
+{
+    ov_clear(&ogg_file_); // Clear the OGG file resources
+}
+
+void audio::OggFile::LoadInfo()
+{
+    vorbis_info_ = ov_info(&ogg_file_, -1); // Initialize the OGG file info
+
+    if (vorbis_info_->channels <= 0 || vorbis_info_->channels > 2)
+        throw std::runtime_error("Unsupported number of channels in OGG file");
+}

src/audio/ogg.hpp

@@ -0,0 +1,36 @@
+#pragma once
+
+#include "utils/defs.hpp"
+#include <vector>
+#include <vorbis/vorbisfile.h>
+
+// class OggVorbis_File;
+// class vorbis_info;
+
+namespace audio
+{
+
+class OggFile
+{
+public:
+    OggFile(const char* filename);
+    DELETE_COPY_MOVE(OggFile)
+
+    size_t GetNumChannels() const;
+    size_t GetSampleRate() const;
+    size_t GetNumSamples();
+
+    size_t Read(char* buffer, size_t length);
+    std::vector<char> ReadAll();
+
+    ~OggFile();
+
+private:
+    void LoadInfo();
+
+private:
+    OggVorbis_File ogg_file_;
+    vorbis_info* vorbis_info_ = nullptr;
+};
+
+} // namespace audio

src/audio/player.cpp

@@ -0,0 +1,30 @@
+#include "player.hpp"
+
+audio::Player::Player(Master& master) : master_(master) {}
+
+audio::SoundSource* audio::Player::PlaySound(const std::shared_ptr<const Sound>& sound,
+                                             const glm::vec3* attach_position)
+{
+    SoundSource* source = new SoundSource(this, sound);
+    source->AttachToPosition(attach_position);
+
+    return source;
+}
+
+void audio::Player::Update()
+{
+    Source* current = first_source_.get();
+    while (current)
+    {
+        current->Update();
+
+        Source* next = current->player_next_.get();
+
+        if (current->ShouldBeDeleted())
+        {
+            current->Delete();
+        }
+
+        current = next;
+    }
+}

src/audio/player.hpp

@@ -0,0 +1,32 @@
+#pragma once
+
+#include <memory>
+
+#include "master.hpp"
+#include "sound_source.hpp"
+
+namespace audio
+{
+
+class Player
+{
+public:
+    Player(Master& master);
+    DELETE_COPY_MOVE(Player)
+
+    SoundSource* PlaySound(const std::shared_ptr<const Sound>& sound, const glm::vec3* attach_position);
+
+    void Update();
+
+    Master& GetMaster() const { return master_; }
+
+    ~Player() = default;
+
+private:
+    Master& master_;
+
+    std::unique_ptr<Source> first_source_;
+    friend class Source;
+};
+
+} // namespace audio

src/audio/sound.cpp

@@ -0,0 +1,66 @@
+#include "sound.hpp"
+
+#include <AL/al.h>
+#include <AL/alc.h>
+
+#include "assets/cmdfile.hpp"
+#include "utils/files.hpp"
+
+#include "ogg.hpp"
+
+audio::Sound::Sound()
+{
+    alGenBuffers(1, &buffer_);
+
+    if (!buffer_)
+        throw std::runtime_error("Failed to generate OpenAL buffer");
+}
+
+static void LoadBufferOGG(ALuint buffer, const char* path)
+{
+    audio::OggFile ogg_file(path);
+    std::vector<char> data = ogg_file.ReadAll();
+
+    ALenum format = ogg_file.GetNumChannels() == 1 ? AL_FORMAT_MONO16 : AL_FORMAT_STEREO16;
+    ALsizei sample_rate = ogg_file.GetSampleRate();
+
+    alBufferData(buffer, format, data.data(), static_cast<ALsizei>(data.size()), sample_rate);
+}
+
+std::shared_ptr<const audio::Sound> audio::Sound::LoadFromFile(const std::string& path)
+{
+    auto sound = std::make_shared<Sound>();
+
+    std::string ogg_path;
+
+    assets::LoadCMDFile(path, [&](const std::string& cmd, std::istringstream& iss) {
+        if (cmd == "ogg")
+        {
+            iss >> ogg_path;
+        }
+        else if (cmd == "category")
+        {
+            iss >> sound->category_name_;
+        }
+        else if (cmd == "volume")
+        {
+            iss >> sound->volume_;
+        }
+        else if (cmd == "pitch")
+        {
+            iss >> sound->pitch_;
+        }
+    });
+
+    if (sound->category_name_.empty())
+        sound->category_name_ = "default";
+
+    LoadBufferOGG(sound->GetBufferId(), ogg_path.c_str());
+
+    return sound;
+}
+
+audio::Sound::~Sound()
+{
+    alDeleteBuffers(1, &buffer_);
+}

src/audio/sound.hpp

@@ -0,0 +1,37 @@
+#pragma once
+
+#include "master.hpp"
+
+#include <memory>
+
+namespace audio
+{
+
+class Sound
+{
+private:
+    Sound();
+    friend std::shared_ptr<Sound> std::make_shared<Sound>();
+
+public:
+    static std::shared_ptr<const Sound> LoadFromFile(const std::string& path);
+
+    unsigned int GetBufferId() const { return buffer_; }
+
+    const std::string& GetCategoryName() const { return category_name_; }
+
+    float GetVolume() const { return volume_; }
+    float GetPitch() const { return pitch_; }
+
+    ~Sound();
+
+private:
+    unsigned int buffer_ = 0;
+
+    std::string category_name_;
+
+    float volume_ = 1.0f;
+    float pitch_ = 1.0f;
+};
+
+} // namespace audio

src/audio/sound_source.cpp

@@ -0,0 +1,67 @@
+#include "sound_source.hpp"
+
+#include <AL/al.h>
+#include <AL/alc.h>
+
+audio::SoundSource::SoundSource(Player* player, std::shared_ptr<const Sound> sound)
+    : Super(sound->GetCategoryName(), player), sound_(std::move(sound))
+{
+    SetVolume(1.0f);
+    SetPitch(1.0f);
+
+    alSourcei(source_, AL_BUFFER, sound->GetBufferId());
+}
+
+void audio::SoundSource::SetLooping(bool looping)
+{
+    alSourcei(source_, AL_LOOPING, looping ? AL_TRUE : AL_FALSE);
+    // TsrDebugf(DML_2, "Set source %p looping to %s\n", this, looping ? "true" : "false");
+}
+
+void audio::SoundSource::SetPitch(float pitch)
+{
+    Super::SetSourcePitch(sound_->GetPitch() * pitch);
+}
+
+void audio::SoundSource::SetVolume(float volume)
+{
+    Super::SetSourceVolume(sound_->GetVolume() * volume);
+}
+
+void audio::SoundSource::Update()
+{
+    Super::Update();
+
+    ALint state;
+    alGetSourcei(source_, AL_SOURCE_STATE, &state);
+
+    finished_ = state == AL_STOPPED;
+
+    switch (state)
+    {
+    case AL_PLAYING: {
+        if (!should_play_)
+            alSourcePause(source_);
+
+        break;
+    }
+
+    case AL_INITIAL:
+    case AL_STOPPED:
+    case AL_PAUSED: {
+        if (should_play_)
+            alSourcePlay(source_);
+
+        break;
+    }
+
+    default:
+        break;
+    }
+}
+
+audio::SoundSource::~SoundSource()
+{
+    alSourceStop(source_);
+    alSourcei(source_, AL_BUFFER, 0);
+}

src/audio/sound_source.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include "sound.hpp"
+#include "source.hpp"
+
+namespace audio
+{
+
+class SoundSource : public Source
+{
+
+public:
+    SoundSource(Player* player, std::shared_ptr<const Sound> sound);
+
+    virtual void SetLooping(bool looping) override;
+    virtual void SetPitch(float pitch) override;
+    virtual void SetVolume(float volume) override;
+
+    virtual void Update() override;
+
+    virtual ~SoundSource() override;
+
+private:
+    using Super = Source;
+
+    std::shared_ptr<const Sound> sound_;
+};
+
+} // namespace audio

src/audio/source.cpp

@@ -0,0 +1,122 @@
+#include "source.hpp"
+
+#include <stdexcept>
+
+#include <AL/al.h>
+#include <AL/alc.h>
+
+#include "defs.hpp"
+#include "player.hpp"
+
+audio::Source::Source(const std::string& category_name, Player* player)
+{
+    alGenSources(1, &source_);
+
+    if (!source_)
+        throw std::runtime_error("Failed to create audio source");
+
+    // link to category
+    category_ = player->GetMaster().GetCategory(category_name);
+    cat_next_ = category_->first_source_;
+    category_->first_source_ = this;
+    cat_prev_next_ = &category_->first_source_;
+    if (cat_next_)
+        cat_next_->cat_prev_next_ = &cat_next_;
+
+    // link to player
+    player_ = player;
+    player_next_ = std::move(player->first_source_);
+    player->first_source_.reset(this);
+    player_prev_next_ = &player->first_source_;
+    if (player_next_)
+        player_next_->player_prev_next_ = &player_next_;
+
+    // TsrDebugf(DML_2, "Created audio source %p in category '%s'\n", this, category->GetName().c_str());
+
+    // alSourcef(m_source, AL_ROLLOFF_FACTOR, 0.0f); // disable rolloff
+    // alSourcef(m_source, AL_REFERENCE_DISTANCE, 1.0f); // set reference distance
+}
+
+void audio::Source::SetPosition(const glm::vec3& position)
+{
+    alSource3f(source_, AL_POSITION, position.x, position.y, position.z);
+}
+
+void audio::Source::SetVelocity(const glm::vec3& velocity)
+{
+    alSource3f(source_, AL_VELOCITY, velocity.x, velocity.y, velocity.z);
+}
+
+void audio::Source::AttachToPosition(const glm::vec3* position)
+{
+    attach_position_ = position;
+    if (attach_position_)
+        SetPosition(*attach_position_);
+    // TsrDebugf(DML_2, "Attached source %p to position %p\n", this, position);
+}
+
+void audio::Source::SetRelativeToListener(bool relative)
+{
+    if (relative)
+    {
+        alSourcei(source_, AL_SOURCE_RELATIVE, AL_TRUE);
+        // TsrDebugf(DML_2, "Set source %p to be relative to listener\n", this);
+    }
+    else
+    {
+        alSourcei(source_, AL_SOURCE_RELATIVE, AL_FALSE);
+        // TsrDebugf(DML_2, "Set source %p to be absolute\n", this);
+    }
+}
+
+void audio::Source::Update()
+{
+    if (attach_position_)
+        SetPosition(*attach_position_);
+}
+
+void audio::Source::Delete()
+{
+    // unlink from player (causes destruction)
+    if (player_next_)
+    {
+        player_next_->player_prev_next_ = player_prev_next_;
+    }
+    std::unique_ptr<Source>& player_prev_next = *player_prev_next_;
+    player_prev_next = std::move(player_next_);
+
+    // TsrDebugf(DML_2, "Deleted audio source %p\n", this);
+}
+
+void audio::Source::SetSourceVolume(float volume)
+{
+    volume_ = volume;
+    UpdateVolume();
+}
+
+void audio::Source::SetSourcePitch(float pitch)
+{
+    alSourcef(source_, AL_PITCH, pitch);
+    // TsrDebugf(DML_2, "Set source %p pitch to %.2f\n", this, pitch);
+}
+
+void audio::Source::UpdateVolume()
+{
+    float cat_volume = category_->GetVolume();
+    float result_volume = volume_ * cat_volume;
+    alSourcef(source_, AL_GAIN, result_volume);
+    // TsrDebugf(DML_2, "Set source %p volume to %.2f (this %.2f, category %.2f)\n", this, result_volume, m_volume,
+    // cat_volume);
+}
+
+audio::Source::~Source()
+{
+    alDeleteSources(1, &source_);
+
+    // unlink from category
+    if (cat_next_)
+    {
+        cat_next_->cat_prev_next_ = cat_prev_next_;
+    }
+    *cat_prev_next_ = cat_next_;
+}

src/audio/source.hpp

@@ -0,0 +1,69 @@
+#pragma once
+
+#include "master.hpp"
+#include <memory>
+
+namespace audio
+{
+
+class Player;
+
+class Source
+{
+protected:
+    Source(const std::string& category_name, Player* player);
+
+public:
+    DELETE_COPY_MOVE(Source)
+
+    void SetPlay(bool play) { should_play_ = play; }
+    void Play() { SetPlay(true); }
+    void Stop() { SetPlay(false); }
+
+    void SetDeleteOnFinish(bool destroy) { delete_on_finish_ = destroy; }
+
+    void SetPosition(const glm::vec3& position);
+    void SetVelocity(const glm::vec3& velocity);
+    void AttachToPosition(const glm::vec3* position);
+    void SetRelativeToListener(bool relative);
+
+    virtual void SetLooping(bool looping) = 0;
+    virtual void SetPitch(float pitch) = 0;
+    virtual void SetVolume(float volume) = 0;
+
+    virtual void Update();
+
+    bool ShouldBeDeleted() { return finished_ && delete_on_finish_; }
+
+    void Delete();
+
+    virtual ~Source();
+
+protected:
+    void SetSourceVolume(float volume);
+    void SetSourcePitch(float pitch);
+
+    unsigned int source_ = 0;
+
+    const glm::vec3* attach_position_ = nullptr;
+    bool should_play_ = true; // auto play when created
+    bool finished_ = false;
+    bool delete_on_finish_ = true; // auto delete when finished
+
+private:
+    void UpdateVolume(); // on this or category volume change
+
+    friend class Category;
+    Category* category_ = nullptr;
+    Source** cat_prev_next_ = nullptr;
+    Source* cat_next_ = nullptr;
+
+    friend class Player;
+    Player* player_ = nullptr;
+    std::unique_ptr<Source>* player_prev_next_ = nullptr;
+    std::unique_ptr<Source> player_next_ = nullptr;
+
+    float volume_ = 1.0f; // volume set by source
+};
+
+} // namespace audio