cocoa_m.cpp

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/*
 * 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/>.
 */
 
#ifdef WITH_COCOA
 
#include "../stdafx.h"
#include "../os/macosx/macos.h"
#include "cocoa_m.h"
#include "midifile.hpp"
#include "../debug.h"
#include "../base_media_base.h"
 
#include <CoreServices/CoreServices.h>
#include <AudioUnit/AudioUnit.h>
#include <AudioToolbox/AudioToolbox.h>
 
#include "../safeguards.h"
 
#if !defined(HAVE_OSX_1011_SDK)
#define kMusicSequenceFile_AnyType 0
#endif
 
static FMusicDriver_Cocoa iFMusicDriver_Cocoa;
 
 
static MusicPlayer    _player = nullptr;
static MusicSequence  _sequence = nullptr;
static MusicTimeStamp _seq_length = 0;
static bool           _playing = false;
static uint8_t           _volume = 127;
 
 
static void DoSetVolume()
{
  if (_sequence == nullptr) return;
 
  AUGraph graph;
  MusicSequenceGetAUGraph(_sequence, &graph);
 
  AudioUnit output_unit = nullptr;
 
  /* Get output audio unit */
  UInt32 node_count = 0;
  AUGraphGetNodeCount(graph, &node_count);
  for (UInt32 i = 0; i < node_count; i++) {
    AUNode node;
    AUGraphGetIndNode(graph, i, &node);
 
    AudioUnit unit;
    AudioComponentDescription desc;
    AUGraphNodeInfo(graph, node, &desc, &unit);
 
    if (desc.componentType == kAudioUnitType_Output) {
      output_unit = unit;
      break;
    }
  }
  if (output_unit == nullptr) {
    Debug(driver, 1, "cocoa_m: Failed to get output node to set volume");
    return;
  }
 
  Float32 vol = _volume / 127.0f;  // 0 - +127 -> 0.0 - 1.0
  AudioUnitSetParameter(output_unit, kHALOutputParam_Volume, kAudioUnitScope_Global, 0, vol, 0);
}
 
 
std::optional<std::string_view> MusicDriver_Cocoa::Start(const StringList &)
{
  if (NewMusicPlayer(&_player) != noErr) return "failed to create music player";
 
  return std::nullopt;
}
 
 
bool MusicDriver_Cocoa::IsSongPlaying()
{
  if (!_playing) return false;
 
  MusicTimeStamp time = 0;
  MusicPlayerGetTime(_player, &time);
  return time < _seq_length;
}
 
 
void MusicDriver_Cocoa::Stop()
{
  if (_player != nullptr) DisposeMusicPlayer(_player);
  if (_sequence != nullptr) DisposeMusicSequence(_sequence);
}
 
 
void MusicDriver_Cocoa::PlaySong(const MusicSongInfo &song)
{
  std::string filename = MidiFile::GetSMFFile(song);
 
  Debug(driver, 2, "cocoa_m: trying to play '{}'", filename);
 
  this->StopSong();
  if (_sequence != nullptr) {
    DisposeMusicSequence(_sequence);
    _sequence = nullptr;
  }
 
  if (filename.empty()) return;
 
  if (NewMusicSequence(&_sequence) != noErr) {
    Debug(driver, 0, "cocoa_m: Failed to create music sequence");
    return;
  }
 
  std::string os_file = OTTD2FS(filename);
  CFAutoRelease<CFURLRef> url(CFURLCreateFromFileSystemRepresentation(kCFAllocatorDefault, (const UInt8*)os_file.c_str(), os_file.length(), false));
 
  if (MusicSequenceFileLoad(_sequence, url.get(), kMusicSequenceFile_AnyType, 0) != noErr) {
    Debug(driver, 0, "cocoa_m: Failed to load MIDI file");
    return;
  }
 
  /* Construct audio graph */
  AUGraph graph = nullptr;
 
  MusicSequenceGetAUGraph(_sequence, &graph);
  AUGraphOpen(graph);
  if (AUGraphInitialize(graph) != noErr) {
    Debug(driver, 0, "cocoa_m: Failed to initialize AU graph");
    return;
  }
 
  /* Figure out sequence length */
  UInt32 num_tracks;
  MusicSequenceGetTrackCount(_sequence, &num_tracks);
  _seq_length = 0;
  for (UInt32 i = 0; i < num_tracks; i++) {
    MusicTrack     track = nullptr;
    MusicTimeStamp track_length = 0;
    UInt32         prop_size = sizeof(MusicTimeStamp);
    MusicSequenceGetIndTrack(_sequence, i, &track);
    MusicTrackGetProperty(track, kSequenceTrackProperty_TrackLength, &track_length, &prop_size);
    if (track_length > _seq_length) _seq_length = track_length;
  }
  /* Add 8 beats for reverb/long note release */
  _seq_length += 8;
 
  DoSetVolume();
  MusicPlayerSetSequence(_player, _sequence);
  MusicPlayerPreroll(_player);
  if (MusicPlayerStart(_player) != noErr) return;
  _playing = true;
 
  Debug(driver, 3, "cocoa_m: playing '{}'", filename);
}
 
 
void MusicDriver_Cocoa::StopSong()
{
  MusicPlayerStop(_player);
  MusicPlayerSetSequence(_player, nullptr);
  _playing = false;
}
 
 
void MusicDriver_Cocoa::SetVolume(uint8_t vol)
{
  _volume = vol;
  DoSetVolume();
}
 
#endif /* WITH_COCOA */