win32_s.cpp

Go to the documentation of this file.

/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */
 
#include "../stdafx.h"
#include "../openttd.h"
#include "../driver.h"
#include "../mixer.h"
#include "../core/bitmath_func.hpp"
#include "../core/math_func.hpp"
#include "win32_s.h"
#include <windows.h>
#include <mmsystem.h>
#include <versionhelpers.h>
#include "../os/windows/win32.h"
#include "../thread.h"
 
#include "../safeguards.h"
 
static FSoundDriver_Win32 iFSoundDriver_Win32;
 
using HeaderDataPair = std::pair<WAVEHDR, std::unique_ptr<CHAR[]>>;
 
static HWAVEOUT _waveout;
static HeaderDataPair _wave_hdr[2];
static int _bufsize;
static HANDLE _thread;
static DWORD _threadId;
static HANDLE _event;
 
static void PrepareHeader(HeaderDataPair &hdr)
{
  hdr.second = std::make_unique<CHAR[]>(_bufsize * 4);
  hdr.first.dwBufferLength = _bufsize * 4;
  hdr.first.dwFlags = 0;
  hdr.first.lpData = hdr.second.get();
  if (waveOutPrepareHeader(_waveout, &hdr.first, sizeof(WAVEHDR)) != MMSYSERR_NOERROR) throw "waveOutPrepareHeader failed";
}
 
static DWORD WINAPI SoundThread(LPVOID)
{
  SetCurrentThreadName("ottd:win-sound");
 
  do {
    for (auto &hdr : _wave_hdr) {
      if ((hdr.first.dwFlags & WHDR_INQUEUE) != 0) continue;
      MxMixSamples(hdr.first.lpData, hdr.first.dwBufferLength / 4);
      if (waveOutWrite(_waveout, &hdr.first, sizeof(WAVEHDR)) != MMSYSERR_NOERROR) {
        MessageBox(nullptr, L"Sounds are disabled until restart.", L"waveOutWrite failed", MB_ICONINFORMATION);
        return 0;
      }
    }
    WaitForSingleObject(_event, INFINITE);
  } while (_waveout != nullptr);
 
  return 0;
}
 
std::optional<std::string_view> SoundDriver_Win32::Start(const StringList &parm)
{
  WAVEFORMATEX wfex;
  wfex.wFormatTag = WAVE_FORMAT_PCM;
  wfex.nChannels = 2;
  wfex.wBitsPerSample = 16;
  wfex.nSamplesPerSec = GetDriverParamInt(parm, "hz", 44100);
  wfex.nBlockAlign = (wfex.nChannels * wfex.wBitsPerSample) / 8;
  wfex.nAvgBytesPerSec = wfex.nSamplesPerSec * wfex.nBlockAlign;
 
  /* Limit buffer size to prevent overflows. */
  _bufsize = GetDriverParamInt(parm, "samples", 1024);
  _bufsize = std::min<int>(_bufsize, UINT16_MAX);
 
  try {
    if (nullptr == (_event = CreateEvent(nullptr, FALSE, FALSE, nullptr))) throw "Failed to create event";
 
    if (waveOutOpen(&_waveout, WAVE_MAPPER, &wfex, (DWORD_PTR)_event, 0, CALLBACK_EVENT) != MMSYSERR_NOERROR) throw "waveOutOpen failed";
 
    MxInitialize(wfex.nSamplesPerSec);
 
    for (auto &hdr : _wave_hdr) PrepareHeader(hdr);
 
    if (nullptr == (_thread = CreateThread(nullptr, 8192, SoundThread, 0, 0, &_threadId))) throw "Failed to create thread";
  } catch (const char *error) {
    this->Stop();
    return error;
  }
 
  return std::nullopt;
}
 
void SoundDriver_Win32::Stop()
{
  HWAVEOUT waveout = _waveout;
 
  /* Stop the sound thread. */
  _waveout = nullptr;
  SignalObjectAndWait(_event, _thread, INFINITE, FALSE);
 
  /* Close the sound device. */
  waveOutReset(waveout);
  for (auto &hdr : _wave_hdr) {
    waveOutUnprepareHeader(waveout, &hdr.first, sizeof(WAVEHDR));
    hdr.second.reset();
  }
  waveOutClose(waveout);
 
  CloseHandle(_thread);
  CloseHandle(_event);
}