scummvm/audio/mixer.h

286 lines
7.6 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program 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; either version 2
* of the License, or (at your option) any later version.
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#ifndef SOUND_MIXER_H
#define SOUND_MIXER_H
#include "common/types.h"
#include "common/noncopyable.h"
namespace Audio {
class AudioStream;
class Channel;
class Timestamp;
/**
* A SoundHandle instances corresponds to a specific sound
* being played via the mixer. It can be used to control that
* sound (pause it, stop it, etc.).
* @see The Mixer class
*/
class SoundHandle {
friend class Channel;
friend class MixerImpl;
uint32 _val;
public:
inline SoundHandle() : _val(0xFFFFFFFF) {}
};
/**
* The main audio mixer handles mixing of an arbitrary number of
* audio streams (in the form of AudioStream instances).
*/
class Mixer : Common::NonCopyable {
public:
enum SoundType {
kPlainSoundType = 0,
kMusicSoundType = 1,
kSFXSoundType = 2,
kSpeechSoundType = 3
};
enum {
kMaxChannelVolume = 255,
kMaxMixerVolume = 256
};
public:
Mixer() {}
virtual ~Mixer() {}
/**
* Is the mixer ready and setup? This may not be the case on systems which
* don't support digital sound output. In that case, the mixer proc may
* never be called. That in turn can cause breakage in games which try to
* sync with an audio stream. In particular, the AdLib MIDI emulation...
*
* @return whether the mixer is ready and setup
*
* @todo get rid of this?
*/
virtual bool isReady() const = 0;
/**
* Start playing the given audio stream.
*
* Note that the sound id assigned below is unique. At most one stream
* with a given id can play at any given time. Trying to play a sound
* with an id that is already in use causes the new sound to be not played.
*
* @param type the type (voice/sfx/music) of the stream
* @param handle a SoundHandle which can be used to reference and control
* the stream via suitable mixer methods
* @param stream the actual AudioStream to be played
* @param id a unique id assigned to this stream
* @param volume the volume with which to play the sound, ranging from 0 to 255
* @param balance the balance with which to play the sound, ranging from -128 to 127
* @param autofreeStream a flag indicating whether the stream should be
* freed after playback finished
* @param permanent a flag indicating whether a plain stopAll call should
* not stop this particular stream
* @param reverseStereo a flag indicating whether left and right channels shall be swapped
*/
virtual void playStream(
SoundType type,
SoundHandle *handle,
AudioStream *stream,
int id = -1,
byte volume = kMaxChannelVolume,
int8 balance = 0,
DisposeAfterUse::Flag autofreeStream = DisposeAfterUse::YES,
bool permanent = false,
bool reverseStereo = false) = 0;
/**
* Stop all currently playing sounds.
*/
virtual void stopAll() = 0;
/**
* Stop playing the sound with given ID.
*
* @param id the ID of the sound to affect
*/
virtual void stopID(int id) = 0;
/**
* Stop playing the sound corresponding to the given handle.
*
* @param handle the sound to affect
*/
virtual void stopHandle(SoundHandle handle) = 0;
/**
* Pause/unpause all sounds, including all regular and permanent
* channels
*
* @param paused true to pause everything, false to unpause
*/
virtual void pauseAll(bool paused) = 0;
/**
* Pause/unpause the sound with the given ID.
*
* @param id the ID of the sound to affect
* @param paused true to pause the sound, false to unpause it
*/
virtual void pauseID(int id, bool paused) = 0;
/**
* Pause/unpause the sound corresponding to the given handle.
*
* @param handle the sound to affect
* @param paused true to pause the sound, false to unpause it
*/
virtual void pauseHandle(SoundHandle handle, bool paused) = 0;
/**
* Check if a sound with the given ID is active.
*
* @param id the ID of the sound to query
* @return true if the sound is active
*/
virtual bool isSoundIDActive(int id) = 0;
/**
* Get the sound ID of handle sound
*
* @param handle sound to query
* @return sound ID if active
*/
virtual int getSoundID(SoundHandle handle) = 0;
/**
* Check if a sound with the given handle is active.
*
* @param handle sound to query
* @return true if the sound is active
*/
virtual bool isSoundHandleActive(SoundHandle handle) = 0;
/**
* Set the mute state for a given sound type.
*
* @param type the sound type
* @param mute Whether to mute (= true) or not (= false).
*/
virtual void muteSoundType(SoundType type, bool mute) = 0;
/**
* Query the mute state for a given sound type.
*
* @param type the sound type
*/
virtual bool isSoundTypeMuted(SoundType type) const = 0;
/**
* Set the channel volume for the given handle.
*
* @param handle the sound to affect
* @param volume the new channel volume (0 - kMaxChannelVolume)
*/
virtual void setChannelVolume(SoundHandle handle, byte volume) = 0;
/**
* Get the channel volume for the given handle.
*
* @param handle the sound to affect
* @return channel volume
*/
virtual byte getChannelVolume(SoundHandle handle) = 0;
/**
* Set the channel balance for the given handle.
*
* @param handle the sound to affect
* @param balance the new channel balance:
* (-127 ... 0 ... 127) corresponds to (left ... center ... right)
*/
virtual void setChannelBalance(SoundHandle handle, int8 balance) = 0;
/**
* Get the channel balance for the given handle.
*
* @param handle the sound to affect
* @return channel balance
*/
virtual int8 getChannelBalance(SoundHandle handle) = 0;
/**
* Get approximation of for how long the channel has been playing.
*/
virtual uint32 getSoundElapsedTime(SoundHandle handle) = 0;
/**
* Get approximation of for how long the channel has been playing.
*/
virtual Timestamp getElapsedTime(SoundHandle handle) = 0;
/**
* Check whether any channel of the given sound type is active.
* For example, this can be used to check whether any SFX sound
* is currently playing, by checking for type kSFXSoundType.
*
* @param type the sound type to look for
* @return true if any channels of the specified type are active.
*/
virtual bool hasActiveChannelOfType(SoundType type) = 0;
/**
* Set the volume for the given sound type.
*
* @param type the sound type
* @param volume the new global volume, 0 - kMaxMixerVolume
*/
virtual void setVolumeForSoundType(SoundType type, int volume) = 0;
/**
* Query the global volume.
*
* @param type the sound type
* @return the global music volume, 0 - kMaxMixerVolume
*/
virtual int getVolumeForSoundType(SoundType type) const = 0;
/**
* Query the system's audio output sample rate.
*
* @return the output sample rate in Hz
*/
virtual uint getOutputRate() const = 0;
};
} // End of namespace Audio
#endif