Fix MIDI pause/stop functionality (fluidsynth player only)

Now stop will actually reset to the start, and pause will properly resume on pressing play again.

Looks like fluidsynth can seek now, however it goes by MIDI ticks which might be tricky as we go by milliseconds. If a MIDI has tempo changes we can't really sync the seek bar and the song properly. Might look into it later because it'd be nice to be able to seek when playing MIDIs.

src/Audio/MIDIPlayer.cpp

@@ -114,7 +114,7 @@ class FluidSynthMIDIPlayer : public MIDIPlayer
 	// -------------------------------------------------------------------------
 	// FluidSynthMIDIPlayer class destructor
 	// -------------------------------------------------------------------------
-	virtual ~FluidSynthMIDIPlayer()
+	~FluidSynthMIDIPlayer() override
 	{
 		FluidSynthMIDIPlayer::stop();
 		delete_fluid_audio_driver(fs_adriver_);
@@ -152,7 +152,7 @@ class FluidSynthMIDIPlayer : public MIDIPlayer
 		bool retval = false;
 		for (int a = paths.size() - 1; a >= 0; --a)
 		{
-			auto path = paths[a];
+			const auto& path = paths[a];
 			if (!path.empty())
 			{
 				int fs_id = fluid_synth_sfload(fs_synth_, path.c_str(), 1);
@@ -184,6 +184,7 @@ class FluidSynthMIDIPlayer : public MIDIPlayer
 		if (fs_player_)
 		{
 			fluid_player_add(fs_player_, filename.c_str());
+			elapsed_ms_ = 0;
 			return true;
 		}
 
@@ -210,8 +211,9 @@ class FluidSynthMIDIPlayer : public MIDIPlayer
 
 		if (fs_player_)
 		{
-			// fluid_player_set_loop(fs_player, -1);
+			// fluid_player_set_loop(fs_player_, -1);
 			fluid_player_add_mem(fs_player_, mc.data(), mc.size());
+			elapsed_ms_ = 0;
 			return true;
 		}
 
@@ -229,41 +231,39 @@ class FluidSynthMIDIPlayer : public MIDIPlayer
 	// -------------------------------------------------------------------------
 	bool play() override
 	{
-		stop();
-		timer_.restart();
-
-		if (!fs_initialised_)
+		if (!fs_initialised_ || isPlaying())
 			return false;
 
-		return (fluid_player_play(fs_player_) == FLUID_OK);
+		timer_.restart();
+
+		return fluid_player_play(fs_player_) == FLUID_OK;
 	}
 
 	// -------------------------------------------------------------------------
 	// Pauses playback of the currently loaded MIDI stream
 	// -------------------------------------------------------------------------
 	bool pause() override
 	{
-		if (!isReady())
+		if (!isPlaying())
 			return false;
 
-		return stop();
+		elapsed_ms_ = timer_.getElapsedTime().asMilliseconds();
+
+		return fluid_player_stop(fs_player_) == FLUID_OK;
 	}
 
 	// -------------------------------------------------------------------------
 	// Stops playback of the currently loaded MIDI stream
 	// -------------------------------------------------------------------------
 	bool stop() override
 	{
-		bool stopped = false;
-
-		if (fs_initialised_)
-		{
+		if (isPlaying())
 			fluid_player_stop(fs_player_);
-			// fluid_synth_system_reset(fs_synth_); // Breaks soundfont on play/pause/stop
-			stopped = true;
-		}
 
-		return stopped;
+		fluid_player_seek(fs_player_, 0);
+		elapsed_ms_ = 0;
+
+		return true;
 	}
 
 	// -------------------------------------------------------------------------
@@ -283,15 +283,16 @@ class FluidSynthMIDIPlayer : public MIDIPlayer
 	int position() override
 	{
 		// We cannot query this information from fluidsynth, so we cheat by querying our own timer
-		return timer_.getElapsedTime().asMilliseconds();
+		return elapsed_ms_ + timer_.getElapsedTime().asMilliseconds();
 	}
 
 	// -------------------------------------------------------------------------
 	// Seeks to [pos] in the currently loaded MIDI stream
 	// -------------------------------------------------------------------------
 	bool setPosition(int pos) override
 	{
-		// Cannot currently seek in fluidsynth
+		// While we can seek in fluidsynth, it's only by ticks which makes it
+		// difficult to work with in case of tempo changes etc.
 		return false;
 	}
 
@@ -303,11 +304,7 @@ class FluidSynthMIDIPlayer : public MIDIPlayer
 		if (!isReady())
 			return false;
 
-		// Clamp volume
-		if (volume > 100)
-			volume = 100;
-		if (volume < 0)
-			volume = 0;
+		volume = std::clamp(volume, 0, 100);
 
 		fluid_synth_set_gain(fs_synth_, volume * 0.01f);
 
@@ -322,6 +319,7 @@ class FluidSynthMIDIPlayer : public MIDIPlayer
 
 	bool        fs_initialised_ = false;
 	vector<int> fs_soundfont_ids_;
+	int         elapsed_ms_ = 0; // Time elapsed before last pause
 
 	// -------------------------------------------------------------------------
 	// Initialises fluidsynth
@@ -376,7 +374,7 @@ class TimidityMIDIPlayer : public MIDIPlayer
 	// -------------------------------------------------------------------------
 	// TimidityMIDIPlayer class destructor
 	// -------------------------------------------------------------------------
-	virtual ~TimidityMIDIPlayer() { stop(); }
+	~TimidityMIDIPlayer() override { stop(); }
 
 	// -------------------------------------------------------------------------
 	// Returns true if the MIDIPlayer has a soundfont loaded
@@ -427,7 +425,7 @@ class TimidityMIDIPlayer : public MIDIPlayer
 		wxExecuteEnv env;
 		env.cwd          = string{ strutil::Path::pathOf(snd_timidity_path) };
 		auto commandline = fmt::format(
-			"\"{}\" \"{}\" {}", string(snd_timidity_path), file_, string(snd_timidity_options));
+			R"("{}" "{}" {})", string(snd_timidity_path), file_, string(snd_timidity_options));
 
 		// Execute program
 		pid_ = wxExecute(commandline, wxEXEC_ASYNC | wxEXEC_HIDE_CONSOLE, nullptr, &env);

src/MainEditor/UI/EntryPanel/AudioEntryPanel.cpp

@@ -69,11 +69,11 @@ CVAR(Bool, snd_autoplay, false, CVar::Flag::Save)
 AudioEntryPanel::AudioEntryPanel(wxWindow* parent) :
 	EntryPanel(parent, "audio"),
 	timer_seek_{ new wxTimer(this) },
-	#if (SFML_VERSION_MAJOR > 2)
+#if (SFML_VERSION_MAJOR > 2)
 	sound_{ new sf::Sound(*sound_buffer_) },
-	#else
+#else
 	sound_{ new sf::Sound() },
-	#endif
+#endif
 	music_{ new audio::Music() },
 	mod_{ new audio::ModMusic() },
 	mp3_{ new audio::Mp3Music() }
@@ -725,20 +725,20 @@ void AudioEntryPanel::onTimer(wxTimerEvent& e)
 	// Set slider
 	slider_seek_->SetValue(pos);
 
-	// Stop the timer if playback has reached the end
-	#if (SFML_VERSION_MAJOR > 2)
+// Stop the timer if playback has reached the end
+#if (SFML_VERSION_MAJOR > 2)
 	if (pos >= slider_seek_->GetMax() || (audio_type_ == Sound && sound_->getStatus() == sf::Sound::Status::Stopped)
 		|| (audio_type_ == Music && music_->getStatus() == sf::Sound::Status::Stopped)
 		|| (audio_type_ == Mod && mod_->getStatus() == sf::Sound::Status::Stopped)
 		|| (audio_type_ == Mp3 && mp3_->getStatus() == sf::Sound::Status::Stopped)
 		|| (audio_type_ == MIDI && !audio::midiPlayer().isPlaying()))
-	#else
+#else
 	if (pos >= slider_seek_->GetMax() || (audio_type_ == Sound && sound_->getStatus() == sf::Sound::Stopped)
 		|| (audio_type_ == Music && music_->getStatus() == sf::Sound::Stopped)
 		|| (audio_type_ == Mod && mod_->getStatus() == sf::Sound::Stopped)
 		|| (audio_type_ == Mp3 && mp3_->getStatus() == sf::Sound::Stopped)
 		|| (audio_type_ == MIDI && !audio::midiPlayer().isPlaying()))
-	#endif
+#endif
 	{
 		timer_seek_->Stop();
 		slider_seek_->SetValue(0);