3 files changed, 50 insertions, 10 deletions

diff --git a/audio/mixer.cpp b/audio/mixer.cpp
index dc0287e3fb..547d2d5f55 100644
--- a/audio/mixer.cpp
+++ b/audio/mixer.cpp
@@ -168,6 +168,9 @@ MixerImpl::MixerImpl(OSystem *system, uint sampleRate)
 
 	int i;
 
+	for (i = 0; i < ARRAYSIZE(_mute); ++i)
+		_mute[i] = false;
+
 	for (i = 0; i < ARRAYSIZE(_volumeForSoundType); i++)
 		_volumeForSoundType[i] = kMaxMixerVolume;
 
@@ -322,6 +325,21 @@ void MixerImpl::stopHandle(SoundHandle handle) {
 	_channels[index] = 0;
 }
 
+void MixerImpl::setMuteForSoundType(SoundType type, bool mute) {
+	assert(0 <= type && type < ARRAYSIZE(_mute));
+	_mute[type] = mute;
+
+	for (int i = 0; i != NUM_CHANNELS; ++i) {
+		if (_channels[i] && _channels[i]->getType() == type)
+			_channels[i]->notifyGlobalVolChange();
+	}
+}
+
+bool MixerImpl::getMuteForSoundType(SoundType type) const {
+	assert(0 <= type && type < ARRAYSIZE(_mute));
+	return _mute[type];
+}
+
 void MixerImpl::setChannelVolume(SoundHandle handle, byte volume) {
 	Common::StackLock lock(_mutex);
 
@@ -486,17 +504,21 @@ void Channel::updateChannelVolumes() {
 	// volume is in the range 0 - kMaxMixerVolume.
 	// Hence, the vol_l/vol_r values will be in that range, too
 
-	int vol = _mixer->getVolumeForSoundType(_type) * _volume;
-
-	if (_balance == 0) {
-		_volL = vol / Mixer::kMaxChannelVolume;
-		_volR = vol / Mixer::kMaxChannelVolume;
-	} else if (_balance < 0) {
-		_volL = vol / Mixer::kMaxChannelVolume;
-		_volR = ((127 + _balance) * vol) / (Mixer::kMaxChannelVolume * 127);
+	if (!_mixer->getMuteForSoundType(_type)) {
+		int vol = _mixer->getVolumeForSoundType(_type) * _volume;
+
+		if (_balance == 0) {
+			_volL = vol / Mixer::kMaxChannelVolume;
+			_volR = vol / Mixer::kMaxChannelVolume;
+		} else if (_balance < 0) {
+			_volL = vol / Mixer::kMaxChannelVolume;
+			_volR = ((127 + _balance) * vol) / (Mixer::kMaxChannelVolume * 127);
+		} else {
+			_volL = ((127 - _balance) * vol) / (Mixer::kMaxChannelVolume * 127);
+			_volR = vol / Mixer::kMaxChannelVolume;
+		}
 	} else {
-		_volL = ((127 - _balance) * vol) / (Mixer::kMaxChannelVolume * 127);
-		_volR = vol / Mixer::kMaxChannelVolume;
+		_volL = _volR = 0;
 	}
 }
 
diff --git a/audio/mixer.h b/audio/mixer.h
index a048124ca3..fe24b85613 100644
--- a/audio/mixer.h
+++ b/audio/mixer.h
@@ -197,6 +197,20 @@ public:
 	virtual bool isSoundHandleActive(SoundHandle handle) = 0;
 
 
+	/**
+	 * Set the mute state for a given sound type.
+	 *
+	 * @param mute Whether to mute (= true) or not (= false).
+	 * @param type the sound type
+	 */
+	virtual void setMuteForSoundType(SoundType type, bool mute) = 0;
+
+	/**
+	 * Query the mute state for a given sound type.
+	 *
+	 * @param type the sound type
+	 */
+	virtual bool getMuteForSoundType(SoundType type) const = 0;
 
 	/**
 	 * Set the channel volume for the given handle.
diff --git a/audio/mixer_intern.h b/audio/mixer_intern.h
index dd2746e9ea..c42436b9a4 100644
--- a/audio/mixer_intern.h
+++ b/audio/mixer_intern.h
@@ -64,6 +64,7 @@ private:
 	bool _mixerReady;
 	uint32 _handleSeed;
 
+	bool _mute[4];
 	int _volumeForSoundType[4];
 	Channel *_channels[NUM_CHANNELS];
 
@@ -97,6 +98,9 @@ public:
 
 	virtual bool isSoundHandleActive(SoundHandle handle);
 
+	virtual void setMuteForSoundType(SoundType type, bool mute);
+	virtual bool getMuteForSoundType(SoundType type) const;
+
 	virtual void setChannelVolume(SoundHandle handle, byte volume);
 	virtual void setChannelBalance(SoundHandle handle, int8 balance);