src/music/allegro_m.cpp

   1 /*
   2  * This file is part of OpenTTD.
   3  * 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.
   4  * 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.
   5  * 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/>.
   6  */
   7
   8 /** @file allegro_m.cpp Playing music via allegro. */
   9
  10 #ifdef WITH_ALLEGRO
  11
  12 #include "../stdafx.h"
  13 #include "../debug.h"
  14 #include "allegro_m.h"
  15 #include "midifile.hpp"
  16 #include <allegro.h>
  17
  18 #include "../safeguards.h"
  19
  20 static FMusicDriver_Allegro iFMusicDriver_Allegro;
  21 static MIDI *_midi = nullptr;
  22
  23 /**
  24  * There are multiple modules that might be using Allegro and
  25  * Allegro can only be initiated once.
  26  */
  27 extern int _allegro_instance_count;
  28
  29 std::optional<std::string_view> MusicDriver_Allegro::Start(const StringList &)
  30 {
  31         if (_allegro_instance_count == 0 && install_allegro(SYSTEM_AUTODETECT, &errno, nullptr)) {
  32                 Debug(driver, 0, "allegro: install_allegro failed '{}'", allegro_error);
  33                 return "Failed to set up Allegro";
  34         }
  35         _allegro_instance_count++;
  36
  37         /* Initialise the sound */
  38         if (install_sound(DIGI_AUTODETECT, MIDI_AUTODETECT, nullptr) != 0) {
  39                 Debug(driver, 0, "allegro: install_sound failed '{}'", allegro_error);
  40                 return "Failed to set up Allegro sound";
  41         }
  42
  43         /* Okay, there's no soundcard */
  44         if (midi_card == MIDI_NONE) {
  45                 Debug(driver, 0, "allegro: no midi card found");
  46                 return "No sound card found";
  47         }
  48
  49         return std::nullopt;
  50 }
  51
  52 void MusicDriver_Allegro::Stop()
  53 {
  54         if (_midi != nullptr) destroy_midi(_midi);
  55         _midi = nullptr;
  56
  57         if (--_allegro_instance_count == 0) allegro_exit();
  58 }
  59
  60 void MusicDriver_Allegro::PlaySong(const MusicSongInfo &song)
  61 {
  62         std::string filename = MidiFile::GetSMFFile(song);
  63
  64         if (_midi != nullptr) destroy_midi(_midi);
  65         if (!filename.empty()) {
  66                 _midi = load_midi(filename.c_str());
  67                 play_midi(_midi, false);
  68         } else {
  69                 _midi = nullptr;
  70         }
  71 }
  72
  73 void MusicDriver_Allegro::StopSong()
  74 {
  75         stop_midi();
  76 }
  77
  78 bool MusicDriver_Allegro::IsSongPlaying()
  79 {
  80         return midi_pos >= 0;
  81 }
  82
  83 void MusicDriver_Allegro::SetVolume(uint8_t vol)
  84 {
  85         set_volume(-1, vol);
  86 }
  87
  88 #endif /* WITH_ALLEGRO */