scummvm/sound/mixer.h

337 lines
8.5 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.
*
* $URL$
* $Id$
*
*/
#ifndef SOUND_MIXER_H
#define SOUND_MIXER_H
#include "common/scummsys.h"
#include "common/mutex.h"
class OSystem;
namespace Audio {
class AudioStream;
class Channel;
class Mixer;
/**
* 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 Mixer;
uint32 _val;
public:
inline SoundHandle() : _val(0xFFFFFFFF) {}
};
/**
* The main audio mixer handles mixing of an arbitrary number of
* input audio streams (in the form of AudioStream instances).
*/
class Mixer {
public:
/**
* Various flags which can be bit-ORed and then passed to
* Mixer::playRaw resp. makeLinearInputStream to control their
* behavior.
*
* Engine authors are advised not to rely on a certain value or
* order of these flags (in particular, do not store them verbatim
* in savestates).
*/
enum RawFlags {
/** unsigned samples (default: signed) */
FLAG_UNSIGNED = 1 << 0,
/** sound is 16 bits wide (default: 8bit) */
FLAG_16BITS = 1 << 1,
/** samples are little endian (default: big endian) */
FLAG_LITTLE_ENDIAN = 1 << 2,
/** sound is in stereo (default: mono) */
FLAG_STEREO = 1 << 3,
/** reverse the left and right stereo channel */
FLAG_REVERSE_STEREO = 1 << 4,
/** sound buffer is freed automagically at the end of playing */
FLAG_AUTOFREE = 1 << 5,
/** loop the audio */
FLAG_LOOP = 1 << 6
};
enum SoundType {
kPlainSoundType = 0,
kMusicSoundType = 1,
kSFXSoundType = 2,
kSpeechSoundType = 3
};
enum {
kMaxChannelVolume = 255,
kMaxMixerVolume = 256
};
private:
enum {
NUM_CHANNELS = 16
};
OSystem *_syst;
Common::Mutex _mutex;
int _volumeForSoundType[4];
uint32 _handleSeed;
Channel *_channels[NUM_CHANNELS];
bool _mixerReady;
public:
Mixer();
~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
*/
bool isReady() const { return _mixerReady; }
/**
* Start playing the given raw sound data.
* Internally, this simply creates an audio input stream wrapping the data
* (using the makeLinearInputStream factory function), which is then
* passed on to playInputStream.
*/
void playRaw(
SoundType type,
SoundHandle *handle,
void *sound, uint32 size, uint rate, byte flags,
int id = -1, byte volume = 255, int8 balance = 0,
uint32 loopStart = 0, uint32 loopEnd = 0);
/**
* Start playing the given audio input stream.
*
* Note that the sound id assigned below is unique. At most one stream
* with a given idea 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 input 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
*/
void playInputStream(
SoundType type,
SoundHandle *handle,
AudioStream *input,
int id = -1, byte volume = 255, int8 balance = 0,
bool autofreeStream = true,
bool permanent = false,
bool reverseStereo = false);
/**
* Stop all currently playing sounds.
*/
void stopAll();
/**
* Stop playing the sound with given ID.
*
* @param id the ID of the sound to affect
*/
void stopID(int id);
/**
* Stop playing the sound corresponding to the given handle.
*
* @param handle the sound to affect
*/
void stopHandle(SoundHandle handle);
/**
* Pause/unpause all sounds, including all regular and permanent
* channels
*
* @param paused true to pause everything, false to unpause
*/
void pauseAll(bool paused);
/**
* 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
*/
void pauseID(int id, bool paused);
/**
* 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
*/
void pauseHandle(SoundHandle handle, bool paused);
/**
* 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
*/
bool isSoundIDActive(int id);
/**
* Get the sound ID of handle sound
*
* @param handle sound to query
* @return sound ID if active
*/
int getSoundID(SoundHandle handle);
/**
* Check if a sound with the given handle is active.
*
* @param handle sound to query
* @return true if the sound is active
*/
bool isSoundHandleActive(SoundHandle handle);
/**
* Set the channel volume for the given handle.
*
* @param handle the sound to affect
* @param volume the new channel volume (0 - 255)
*/
void setChannelVolume(SoundHandle handle, byte volume);
/**
* 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)
*/
void setChannelBalance(SoundHandle handle, int8 balance);
/**
* Get approximation of for how long the channel has been playing.
*/
uint32 getSoundElapsedTime(SoundHandle handle);
/**
* 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.
*/
bool hasActiveChannelOfType(SoundType type);
/**
* Set the volume for the given sound type.
*
* @param type the sound type
* @param volume the new global volume, 0-kMaxMixerVolume
*/
void setVolumeForSoundType(SoundType type, int volume);
/**
* Query the global volume.
*
* @param type the sound type
* @return the global music volume, 0-kMaxMixerVolume
*/
int getVolumeForSoundType(SoundType type) const;
/**
* Query the system's audio output sample rate. This returns
* the same value as OSystem::getOutputSampleRate().
*
* @return the output sample rate in Hz
*/
uint getOutputRate() const;
protected:
void insertChannel(SoundHandle *handle, Channel *chan);
/**
* Internal main method -- all the actual mixing work is done from here.
*/
void mix(int16 * buf, uint len);
// FIXME: temporary "public" to allow access to mixCallback
// from within OSystem::makeMixer()
public:
/**
* The mixer callback function, passed on to OSystem::setSoundCallback().
* This simply calls the mix() method.
*/
static void mixCallback(void *s, byte *samples, int len);
void setReady(bool ready) { _mixerReady = ready; }
};
} // End of namespace Audio
#endif