XCEngine/engine/src/Audio/WindowsAudioBackend.cpp

#ifdef _WIN32
#define NOMINMAX
#endif

#include <XCEngine/Audio/WindowsAudioBackend.h>
#include <iostream>
#include <algorithm>

namespace XCEngine {
namespace Audio {
namespace WASAPI {

WASAPIBackend::WASAPIBackend()
    : m_audioBuffer1(BufferSize * 2)
    , m_audioBuffer2(BufferSize * 2)
{
}

WASAPIBackend::~WASAPIBackend() {
    Shutdown();
}

bool WASAPIBackend::Initialize(const AudioConfig& config) {
    m_config = config;

    m_waveFormat.wFormatTag = WAVE_FORMAT_PCM;
    m_waveFormat.nChannels = static_cast<WORD>(config.channels);
    m_waveFormat.nSamplesPerSec = config.sampleRate;
    m_waveFormat.nAvgBytesPerSec = config.sampleRate * config.channels * (config.bitsPerSample / 8);
    m_waveFormat.nBlockAlign = static_cast<WORD>(config.channels * (config.bitsPerSample / 8));
    m_waveFormat.wBitsPerSample = config.bitsPerSample;
    m_waveFormat.cbSize = 0;

    MMRESULT result = InitDevice();
    if (result != MMSYSERR_NOERROR) {
        return false;
    }

    result = InitBuffer();
    if (result != MMSYSERR_NOERROR) {
        waveOutClose(m_hWaveOut);
        return false;
    }

    return true;
}

void WASAPIBackend::Shutdown() {
    if (m_isRunning.load()) {
        Stop();
    }

    if (m_hWaveOut != nullptr) {
        waveOutUnprepareHeader(m_hWaveOut, &m_waveHeader1, sizeof(WAVEHDR));
        waveOutUnprepareHeader(m_hWaveOut, &m_waveHeader2, sizeof(WAVEHDR));
        waveOutClose(m_hWaveOut);
        m_hWaveOut = nullptr;
    }
}

std::string WASAPIBackend::GetDeviceName() const {
    return m_deviceName;
}

void WASAPIBackend::GetAvailableDevices(std::vector<std::string>& devices) {
    devices.clear();
    for (const auto& caps : m_waveOutCaps) {
        devices.push_back(caps.szPname);
    }
}

bool WASAPIBackend::SetDevice(const std::string& deviceName) {
    for (UINT i = 0; i < waveOutGetNumDevs(); ++i) {
        WAVEOUTCAPS caps;
        waveOutGetDevCaps(i, &caps, sizeof(WAVEOUTCAPS));
        if (deviceName == caps.szPname) {
            m_deviceName = deviceName;
            return true;
        }
    }
    return false;
}

float WASAPIBackend::GetMasterVolume() const {
    return m_masterVolume.load();
}

void WASAPIBackend::SetMasterVolume(float volume) {
    m_masterVolume.store(std::max(0.0f, std::min(1.0f, volume)));
}

bool WASAPIBackend::IsMuted() const {
    return m_muted.load();
}

void WASAPIBackend::SetMuted(bool muted) {
    m_muted.store(muted);
}

void WASAPIBackend::Start() {
    if (m_isRunning.load()) {
        return;
    }

    m_isRunning = true;
    m_audioThread = std::thread(&WASAPIBackend::AudioThreadProc, this);
}

void WASAPIBackend::Stop() {
    m_isRunning = false;

    if (m_audioThread.joinable()) {
        m_audioThread.join();
    }
}

void WASAPIBackend::Suspend() {
    if (m_hWaveOut != nullptr) {
        waveOutReset(m_hWaveOut);
    }
}

void WASAPIBackend::Resume() {
    if (m_hWaveOut != nullptr) {
        MMRESULT result = waveOutRestart(m_hWaveOut);
        if (result != MMSYSERR_NOERROR) {
            std::cout << "Failed to resume audio playback" << std::endl;
        }
    }
}

void WASAPIBackend::ProcessAudio(float* buffer, uint32 bufferSize,
                                uint32 channels, uint32 sampleRate) {
    if (m_muted.load() || buffer == nullptr) {
        return;
    }

    float volume = m_masterVolume.load();
    if (volume < 0.001f) {
        return;
    }

    uint32 sampleCount = bufferSize / sizeof(float);
    int16_t* backBuffer = m_isBuffer1Front ? m_audioBuffer2.data() : m_audioBuffer1.data();
    uint32 bufferSamples = static_cast<uint32>(m_audioBuffer1.size());

    for (uint32 i = 0; i < sampleCount && i < bufferSamples; ++i) {
        float sample = buffer[i] * volume;
        sample = std::max(-1.0f, std::min(1.0f, sample));
        backBuffer[i] = static_cast<int16_t>(sample * 32767.0f);
    }

    std::lock_guard<std::mutex> lock(m_bufferMutex);
    m_dataReady = true;
    m_dataReadyCond.notify_one();
}

MMRESULT WASAPIBackend::InitDevice() {
    WAVEOUTCAPS waveOutCapsTemp;
    for (UINT i = 0; i < waveOutGetNumDevs(); ++i) {
        waveOutGetDevCaps(i, &waveOutCapsTemp, sizeof(WAVEOUTCAPS));
        m_waveOutCaps.push_back(waveOutCapsTemp);
    }

    MMRESULT result = waveOutOpen(&m_hWaveOut, WAVE_MAPPER, &m_waveFormat,
                                  (DWORD_PTR)&WASAPIBackend::StaticAudioCallback,
                                  reinterpret_cast<DWORD_PTR>(this), CALLBACK_FUNCTION);
    if (result != MMSYSERR_NOERROR) {
        std::cout << "Failed to open audio device" << std::endl;
        return result;
    }

    m_deviceName = "Default Device";
    return MMSYSERR_NOERROR;
}

MMRESULT WASAPIBackend::InitBuffer() {
    m_waveHeader1.lpData = (LPSTR)m_audioBuffer1.data();
    m_waveHeader1.dwBufferLength = static_cast<DWORD>(m_audioBuffer1.size() * sizeof(int16_t));
    m_waveHeader1.dwFlags = 0;

    MMRESULT result = waveOutPrepareHeader(m_hWaveOut, &m_waveHeader1, sizeof(WAVEHDR));
    if (result != MMSYSERR_NOERROR) {
        std::cout << "Failed to prepare audio header1" << std::endl;
        return result;
    }

    m_waveHeader2.lpData = (LPSTR)m_audioBuffer2.data();
    m_waveHeader2.dwBufferLength = static_cast<DWORD>(m_audioBuffer2.size() * sizeof(int16_t));
    m_waveHeader2.dwFlags = 0;

    result = waveOutPrepareHeader(m_hWaveOut, &m_waveHeader2, sizeof(WAVEHDR));
    if (result != MMSYSERR_NOERROR) {
        std::cout << "Failed to prepare audio header2" << std::endl;
        waveOutUnprepareHeader(m_hWaveOut, &m_waveHeader1, sizeof(WAVEHDR));
        return result;
    }

    return MMSYSERR_NOERROR;
}

DWORD WINAPI WASAPIBackend::AudioThreadProc(LPVOID lpParameter) {
    WASAPIBackend* backend = static_cast<WASAPIBackend*>(lpParameter);
    if (backend) {
        backend->AudioThread();
    }
    return 0;
}

void WASAPIBackend::AudioThread() {
    PlayFrontData();
    SwapBuffer();
    PlayFrontData();

    while (m_isRunning.load()) {
        std::unique_lock<std::mutex> lock(m_bufferMutex);
        m_dataReadyCond.wait_for(lock, std::chrono::milliseconds(10), [this] { return m_dataReady || !m_isRunning.load(); });

        if (m_dataReady) {
            PrepareBackData();
            SwapBuffer();
            PlayFrontData();
            m_dataReady = false;
        }
    }
}

void WASAPIBackend::OnAudioCallback(HWAVEOUT hwo, UINT uMsg, DWORD_PTR dwInstance,
                                    DWORD_PTR dwParam1, DWORD_PTR dwParam2) {
    if (uMsg == WOM_DONE) {
        PrepareBackData();
        SwapBuffer();
        PlayFrontData();
    }
}

void CALLBACK WASAPIBackend::StaticAudioCallback(HWAVEOUT hwo, UINT uMsg,
                                                DWORD_PTR dwInstance,
                                                DWORD_PTR dwParam1, DWORD_PTR dwParam2) {
    WASAPIBackend* backend = reinterpret_cast<WASAPIBackend*>(dwInstance);
    if (backend != nullptr) {
        backend->OnAudioCallback(hwo, uMsg, dwInstance, dwParam1, dwParam2);
    }
}

MMRESULT WASAPIBackend::PlayFrontData() {
    WAVEHDR* frontHeader = m_isBuffer1Front ? &m_waveHeader1 : &m_waveHeader2;
    MMRESULT result = waveOutWrite(m_hWaveOut, frontHeader, sizeof(WAVEHDR));
    if (result != MMSYSERR_NOERROR) {
        std::cout << "Failed to write audio data" << std::endl;
    }
    return result;
}

void WASAPIBackend::PrepareBackData() {
}

void WASAPIBackend::SwapBuffer() {
    m_isBuffer1Front = !m_isBuffer1Front;
}

} // namespace WASAPI
} // namespace Audio
} // namespace XCEngine