#include <adlib_worx.h>

Inheritance diagram for Darkseed::MidiDriver_Worx_AdLib:

Public Member Functions
	MidiDriver_Worx_AdLib (OPL::Config::OplType oplType, int timerFrequency=OPL::OPL::kDefaultCallbackFrequency)

Public Member Functions inherited from MidiDriver_ADLIB_Multisource
	MidiDriver_ADLIB_Multisource (OPL::Config::OplType oplType, int timerFrequency=OPL::OPL::kDefaultCallbackFrequency)

int	open () override

bool	isOpen () const override

void	close () override

uint32	property (int prop, uint32 param) override

uint32	getBaseTempo () override

MidiChannel *	allocateChannel () override

MidiChannel *	getPercussionChannel () override

void	send (int8 source, uint32 b) override

void	sysEx (const byte *msg, uint16 length) override

void	metaEvent (int8 source, byte type, byte *data, uint16 length) override

void	stopAllNotes (bool stopSustainedNotes=false) override

void	stopAllNotes (uint8 source, uint8 channel) override

void	deinitSource (uint8 source) override

Public Member Functions inherited from MidiDriver_Multisource
void	send (uint32 b) override

uint32	property (int prop, uint32 param) override

void	setSourceType (SourceType type)

void	setSourceType (uint8 source, SourceType type)

void	setSourceVolume (uint16 volume)

void	setSourceVolume (uint8 source, uint16 volume)

void	resetSourceVolume ()

void	resetSourceVolume (uint8 source)

void	setSourceNeutralVolume (uint16 volume)

void	setSourceNeutralVolume (uint8 source, uint16 volume)

void	startFade (uint16 duration, uint16 targetVolume)

void	startFade (uint8 source, uint16 duration, uint16 targetVolume)

void	abortFade (FadeAbortType abortType=FADE_ABORT_TYPE_END_VOLUME)

void	abortFade (uint8 source, FadeAbortType abortType=FADE_ABORT_TYPE_END_VOLUME)

bool	isFading ()

bool	isFading (uint8 source)

void	setControllerDefault (ControllerDefaultType type)

void	setControllerDefault (ControllerDefaultType type, int16 value)

void	setControllerDefaults (ControllerDefaultType type, int16 *values)

void	clearControllerDefault (ControllerDefaultType type)

void	setInstrumentRemapping (const byte *instrumentRemapping)

void	syncSoundSettings ()

void	setTimerCallback (void *timer_param, Common::TimerManager::TimerProc timer_proc) override

Public Member Functions inherited from MidiDriver
void	midiDriverCommonSend (uint32 b)

void	midiDriverCommonSysEx (const byte *msg, uint16 length)

virtual void	setPitchBendRange (byte channel, uint range)

void	sendMT32Reset ()

void	sendGMReset ()

virtual void	setEngineSoundFont (Common::SeekableReadStream *soundFontData)

virtual bool	acceptsSoundFontData ()

Public Member Functions inherited from MidiDriver_BASE
void	send (byte status, byte firstOp, byte secondOp)

void	send (int8 source, byte status, byte firstOp, byte secondOp)

virtual uint16	sysExNoDelay (const byte *msg, uint16 length)

virtual void	metaEvent (byte type, byte *data, uint16 length)

virtual bool	isReady (int8 source=-1)

Protected Member Functions
uint8	allocateOplChannel (uint8 channel, uint8 source, uint8 instrumentId) override

uint16	calculateFrequency (uint8 channel, uint8 source, uint8 note) override

uint8	calculateUnscaledVolume (uint8 channel, uint8 source, uint8 velocity, OplInstrumentDefinition &instrumentDef, uint8 operatorNum) override

Protected Member Functions inherited from MidiDriver_ADLIB_Multisource
void	applySourceVolume (uint8 source) override

virtual void	initOpl ()

virtual void	noteOff (uint8 channel, uint8 note, uint8 velocity, uint8 source)

virtual void	noteOn (uint8 channel, uint8 note, uint8 velocity, uint8 source)

virtual void	polyAftertouch (uint8 channel, uint8 note, uint8 pressure, uint8 source)

virtual void	controlChange (uint8 channel, uint8 controller, uint8 value, uint8 source)

virtual void	programChange (uint8 channel, uint8 program, uint8 source)

virtual void	channelAftertouch (uint8 channel, uint8 pressure, uint8 source)

virtual void	pitchBend (uint8 channel, uint8 pitchBendLsb, uint8 pitchBendMsb, uint8 source)

virtual void	modulation (uint8 channel, uint8 modulation, uint8 source)

virtual void	dataEntry (uint8 channel, uint8 dataMsb, uint8 dataLsb, uint8 source)

virtual void	volume (uint8 channel, uint8 volume, uint8 source)

virtual void	panning (uint8 channel, uint8 panning, uint8 source)

virtual void	expression (uint8 channel, uint8 expression, uint8 source)

virtual void	sustain (uint8 channel, uint8 sustain, uint8 source)

virtual void	registeredParameterNumber (uint8 channel, uint8 rpnMsb, uint8 rpnLsb, uint8 source)

virtual void	allSoundOff (uint8 channel, uint8 source)

virtual void	resetAllControllers (uint8 channel, uint8 source)

virtual void	allNotesOff (uint8 channel, uint8 source)

virtual void	applyControllerDefaults (uint8 source)

virtual void	recalculateFrequencies (uint8 channel, uint8 source)

virtual void	recalculateVolumes (uint8 channel, uint8 source)

virtual InstrumentInfo	determineInstrument (uint8 channel, uint8 source, uint8 note)

void	determineMelodicChannels ()

virtual int32	calculatePitchBend (uint8 channel, uint8 source, uint16 oplFrequency)

virtual uint8	calculateVolume (uint8 channel, uint8 source, uint8 velocity, OplInstrumentDefinition &instrumentDef, uint8 operatorNum)

virtual bool	isVolumeApplicableToOperator (OplInstrumentDefinition &instrumentDef, uint8 operatorNum)

virtual uint8	calculatePanning (uint8 channel, uint8 source)

virtual void	setRhythmMode (bool rhythmMode)

uint16	determineOperatorRegisterOffset (uint8 oplChannel, uint8 operatorNum, OplInstrumentRhythmType rhythmType=RHYTHM_TYPE_UNDEFINED, bool fourOperator=false)

uint16	determineChannelRegisterOffset (uint8 oplChannel, bool fourOperator=false)

void	writeInstrument (uint8 oplChannel, InstrumentInfo instrument)

void	writeKeyOff (uint8 oplChannel, OplInstrumentRhythmType rhythmType=RHYTHM_TYPE_UNDEFINED, bool forceWrite=false)

void	writeRhythm (bool forceWrite=false)

virtual void	writeVolume (uint8 oplChannel, uint8 operatorNum, OplInstrumentRhythmType rhythmType=RHYTHM_TYPE_UNDEFINED)

virtual void	writePanning (uint8 oplChannel, OplInstrumentRhythmType rhythmType=RHYTHM_TYPE_UNDEFINED)

virtual void	writeFrequency (uint8 oplChannel, OplInstrumentRhythmType rhythmType=RHYTHM_TYPE_UNDEFINED)

void	writeRegister (uint16 reg, uint8 value, bool forceWrite=false)

Protected Member Functions inherited from MidiDriver_Multisource
void	updateFading ()

virtual void	onTimer ()

Protected Member Functions inherited from MidiDriver_BASE
void	midiDumpInit ()

int	midiDumpVarLength (const uint32 &delta)

void	midiDumpDelta ()

void	midiDumpDo (uint32 b)

void	midiDumpSysEx (const byte *msg, uint16 length)

void	midiDumpFinish ()

Additional Inherited Members
Public Types inherited from MidiDriver_ADLIB_Multisource
enum	AccuracyMode { ACCURACY_MODE_SB16_WIN95, ACCURACY_MODE_GM }

enum	ChannelAllocationMode { ALLOCATION_MODE_DYNAMIC, ALLOCATION_MODE_STATIC }

enum	InstrumentWriteMode { INSTRUMENT_WRITE_MODE_NOTE_ON, INSTRUMENT_WRITE_MODE_PROGRAM_CHANGE, INSTRUMENT_WRITE_MODE_FIRST_NOTE_ON }

enum	NoteSelectMode { NOTE_SELECT_MODE_0, NOTE_SELECT_MODE_1 }

enum	ModulationDepth { MODULATION_DEPTH_LOW, MODULATION_DEPTH_HIGH }

enum	VibratoDepth { VIBRATO_DEPTH_LOW, VIBRATO_DEPTH_HIGH }

Public Types inherited from MidiDriver_Multisource
enum	SourceType { SOURCE_TYPE_UNDEFINED, SOURCE_TYPE_MUSIC, SOURCE_TYPE_SFX }

enum	FadeAbortType { FADE_ABORT_TYPE_END_VOLUME, FADE_ABORT_TYPE_CURRENT_VOLUME, FADE_ABORT_TYPE_START_VOLUME }

enum	ControllerDefaultType { CONTROLLER_DEFAULT_PROGRAM, CONTROLLER_DEFAULT_INSTRUMENT_BANK, CONTROLLER_DEFAULT_DRUMKIT, CONTROLLER_DEFAULT_CHANNEL_PRESSURE, CONTROLLER_DEFAULT_PITCH_BEND, CONTROLLER_DEFAULT_MODULATION, CONTROLLER_DEFAULT_VOLUME, CONTROLLER_DEFAULT_PANNING, CONTROLLER_DEFAULT_EXPRESSION, CONTROLLER_DEFAULT_SUSTAIN, CONTROLLER_DEFAULT_RPN, CONTROLLER_DEFAULT_PITCH_BEND_SENSITIVITY }

Public Types inherited from MidiDriver
enum	DeviceStringType { kDriverName, kDriverId, kDeviceName, kDeviceId }

enum	{ MERR_CANNOT_CONNECT = 1, MERR_DEVICE_NOT_AVAILABLE = 3, MERR_ALREADY_OPEN = 4 }

enum	{ PROP_OLD_ADLIB = 2, PROP_CHANNEL_MASK = 3, PROP_SCUMM_OPL3 = 4, PROP_USER_VOLUME_SCALING = 5, PROP_MIDI_DATA_REVERSE_PANNING = 6, PROP_OPL_ACCURACY_MODE = 7, PROP_OPL_CHANNEL_ALLOCATION_MODE = 8, PROP_MILES_VERSION = 9, PROP_OPL_RHYTHM_MODE_IGNORE_NOTE_OFF = 10 }

typedef uint32	DeviceHandle

Static Public Member Functions inherited from MidiDriver_ADLIB_Multisource
static bool	detectOplType (OPL::Config::OplType oplType)

Static Public Member Functions inherited from MidiDriver
static Common::String	musicType2GUIO (uint32 musicType)

static MidiDriver *	createMidi (DeviceHandle handle)

static DeviceHandle	detectDevice (int flags)

static DeviceHandle	getDeviceHandle (const Common::String &identifier)

static bool	checkDevice (DeviceHandle handle, int flags, bool quiet)

static MusicType	getMusicType (DeviceHandle handle)

static Common::String	getDeviceString (DeviceHandle handle, DeviceStringType type)

static const char *	getErrorName (int error_code)

Static Public Attributes inherited from MidiDriver_ADLIB_Multisource
static const uint8	OPL2_NUM_CHANNELS = 9

static const uint8	OPL3_NUM_CHANNELS = 18

static const uint8	MELODIC_CHANNELS_OPL2 [9]

static const uint8	MELODIC_CHANNELS_OPL2_RHYTHM [6]

static const uint8	MELODIC_CHANNELS_OPL3 [18]

static const uint8	MELODIC_CHANNELS_OPL3_RHYTHM [15]

static const uint8	OPL_NUM_RHYTHM_INSTRUMENTS = 5

static const uint8	OPL_RHYTHM_INSTRUMENT_CHANNELS [OPL_NUM_RHYTHM_INSTRUMENTS]

static const uint8	OPL_REGISTER_TEST = 0x01

static const uint8	OPL_REGISTER_TIMER1 = 0x02

static const uint8	OPL_REGISTER_TIMER2 = 0x03

static const uint8	OPL_REGISTER_TIMERCONTROL = 0x04

static const uint8	OPL_REGISTER_NOTESELECT_CSM = 0x08

static const uint8	OPL_REGISTER_RHYTHM = 0xBD

static const uint8	OPL_REGISTER_BASE_FREQMULT_MISC = 0x20

static const uint8	OPL_REGISTER_BASE_LEVEL = 0x40

static const uint8	OPL_REGISTER_BASE_DECAY_ATTACK = 0x60

static const uint8	OPL_REGISTER_BASE_RELEASE_SUSTAIN = 0x80

static const uint8	OPL_REGISTER_BASE_WAVEFORMSELECT = 0xE0

static const uint8	OPL_REGISTER_BASE_FNUMLOW = 0xA0

static const uint8	OPL_REGISTER_BASE_FNUMHIGH_BLOCK_KEYON = 0xB0

static const uint8	OPL_REGISTER_BASE_CONNECTION_FEEDBACK_PANNING = 0xC0

static const uint16	OPL3_REGISTER_CONNECTIONSELECT = 0x104

static const uint16	OPL3_REGISTER_NEW = 0x105

static const uint16	OPL_REGISTER_SET_2_OFFSET = 0x100

static const uint8	OPL_REGISTER_RHYTHM_OFFSETS []

static const uint8	OPL_MASK_LEVEL = 0x3F

static const uint8	OPL_MASK_FNUMHIGH_BLOCK = 0x1F

static const uint8	OPL_MASK_KEYON = 0x20

static const uint8	OPL_MASK_PANNING = 0x30

static const uint8	OPL_PANNING_CENTER = 0x30

static const uint8	OPL_PANNING_LEFT = 0x10

static const uint8	OPL_PANNING_RIGHT = 0x20

static OplInstrumentDefinition	OPL_INSTRUMENT_BANK []

static OplInstrumentDefinition	OPL_RHYTHM_BANK []

Static Public Attributes inherited from MidiDriver_Multisource
static const uint8	MAXIMUM_SOURCES = 10

static const uint16	DEFAULT_SOURCE_NEUTRAL_VOLUME = 255

Static Public Attributes inherited from MidiDriver
static const byte	_mt32ToGm [128]

static const byte	_gmToMt32 [128]

Static Public Attributes inherited from MidiDriver_BASE
static const uint8	MIDI_CHANNEL_COUNT = 16

static const uint8	MIDI_RHYTHM_CHANNEL = 9

static const byte	MIDI_COMMAND_NOTE_OFF = 0x80

static const byte	MIDI_COMMAND_NOTE_ON = 0x90

static const byte	MIDI_COMMAND_POLYPHONIC_AFTERTOUCH = 0xA0

static const byte	MIDI_COMMAND_CONTROL_CHANGE = 0xB0

static const byte	MIDI_COMMAND_PROGRAM_CHANGE = 0xC0

static const byte	MIDI_COMMAND_CHANNEL_AFTERTOUCH = 0xD0

static const byte	MIDI_COMMAND_PITCH_BEND = 0xE0

static const byte	MIDI_COMMAND_SYSTEM = 0xF0

static const byte	MIDI_CONTROLLER_BANK_SELECT_MSB = 0x00

static const byte	MIDI_CONTROLLER_MODULATION = 0x01

static const byte	MIDI_CONTROLLER_DATA_ENTRY_MSB = 0x06

static const byte	MIDI_CONTROLLER_VOLUME = 0x07

static const byte	MIDI_CONTROLLER_BALANCE = 0x08

static const byte	MIDI_CONTROLLER_PANNING = 0x0A

static const byte	MIDI_CONTROLLER_EXPRESSION = 0x0B

static const byte	MIDI_CONTROLLER_BANK_SELECT_LSB = 0x20

static const byte	MIDI_CONTROLLER_DATA_ENTRY_LSB = 0x26

static const byte	MIDI_CONTROLLER_SUSTAIN = 0x40

static const byte	MIDI_CONTROLLER_PORTAMENTO = 0x41

static const byte	MIDI_CONTROLLER_SOSTENUTO = 0x42

static const byte	MIDI_CONTROLLER_SOFT = 0x43

static const byte	MIDI_CONTROLLER_REVERB = 0x5B

static const byte	MIDI_CONTROLLER_CHORUS = 0x5D

static const byte	MIDI_CONTROLLER_RPN_LSB = 0x64

static const byte	MIDI_CONTROLLER_RPN_MSB = 0x65

static const byte	MIDI_CONTROLLER_ALL_SOUND_OFF = 0x78

static const byte	MIDI_CONTROLLER_RESET_ALL_CONTROLLERS = 0x79

static const byte	MIDI_CONTROLLER_ALL_NOTES_OFF = 0x7B

static const byte	MIDI_CONTROLLER_OMNI_ON = 0x7C

static const byte	MIDI_CONTROLLER_OMNI_OFF = 0x7D

static const byte	MIDI_CONTROLLER_MONO_ON = 0x7E

static const byte	MIDI_CONTROLLER_POLY_ON = 0x7F

static const uint16	MIDI_RPN_PITCH_BEND_SENSITIVITY = 0x0000

static const uint16	MIDI_RPN_MASTER_TUNING_FINE = 0x0001

static const uint16	MIDI_RPN_MASTER_TUNING_COARSE = 0x0002

static const uint16	MIDI_RPN_NULL = 0x7F7F

static const uint8	MIDI_META_END_OF_TRACK = 0x2F

static const uint8	MIDI_META_SEQUENCER = 0x7F

static const uint16	MIDI_PITCH_BEND_DEFAULT = 0x2000

static const uint8	MIDI_PANNING_DEFAULT = 0x40

static const uint8	MIDI_EXPRESSION_DEFAULT = 0x7F

static const uint16	MIDI_MASTER_TUNING_FINE_DEFAULT = 0x2000

static const uint8	MIDI_MASTER_TUNING_COARSE_DEFAULT = 0x40

static const uint8	MT32_PITCH_BEND_SENSITIVITY_DEFAULT = 0x0C

static const uint8	GM_PITCH_BEND_SENSITIVITY_DEFAULT = 0x02

static const uint8	GS_RHYTHM_FIRST_NOTE = 0x1B

static const uint8	GS_RHYTHM_LAST_NOTE = 0x58

Protected Attributes inherited from MidiDriver_ADLIB_Multisource
OPL::Config::OplType	_oplType

OPL::OPL *	_opl

bool	_isOpen

int	_timerFrequency

AccuracyMode	_accuracyMode

ChannelAllocationMode	_allocationMode

InstrumentWriteMode	_instrumentWriteMode

bool	_rhythmModeIgnoreNoteOffs

bool	_channel10Melodic

uint8	_defaultChannelVolume

NoteSelectMode	_noteSelect

ModulationDepth	_modulationDepth

VibratoDepth	_vibratoDepth

bool	_rhythmMode

OplInstrumentDefinition *	_instrumentBank

OplInstrumentDefinition *	_rhythmBank

uint8	_rhythmBankFirstNote

uint8	_rhythmBankLastNote

MidiChannelControlData	_controlData [MAXIMUM_SOURCES][MIDI_CHANNEL_COUNT]

ActiveNote	_activeNotes [OPL3_NUM_CHANNELS]

ActiveNote	_activeRhythmNotes [5]

uint8	_channelAllocations [MAXIMUM_SOURCES][MIDI_CHANNEL_COUNT]

const uint8 *	_melodicChannels

uint8	_numMelodicChannels

uint32	_noteCounter

float	_oplFrequencyConversionFactor

uint8	_shadowRegisters [0x200]

Common::Mutex	_allocationMutex

Common::Mutex	_activeNotesMutex

Protected Attributes inherited from MidiDriver_Multisource
MidiSource	_sources [MAXIMUM_SOURCES]

ControllerDefaults	_controllerDefaults

const byte *	_instrumentRemapping

bool	_userVolumeScaling

uint16	_userMusicVolume

uint16	_userSfxVolume

bool	_userMute

Common::Mutex	_fadingMutex

uint16	_fadeDelay

uint32	_timerRate

void *	_timer_param

Common::TimerManager::TimerProc	_timer_proc

Protected Attributes inherited from MidiDriver_BASE
bool	_midiDumpEnable

uint32	_prevMillis

Common::Array< byte >	_midiDumpCache

Static Protected Attributes inherited from MidiDriver_ADLIB_Multisource
static const uint8	OPL_LEVEL_DEFAULT = 0x3F

static const uint8	OPL_MIDI_PANNING_LEFT_LIMIT = 0x2F

static const uint8	OPL_MIDI_PANNING_RIGHT_LIMIT = 0x51

static const uint16	OPL_NOTE_FREQUENCIES []

static const uint8	OPL_VOLUME_LOOKUP []

Static Protected Attributes inherited from MidiDriver_Multisource
static const uint16	FADING_DELAY = 25 * 1000

Detailed Description

Implementation of the AdLib code from the Worx Toolkit library, based on version 2.1, as used by Dark Seed (CD version). Implements the OPL channel allocation algorithm and note frequency and volume calculation.

TODO Implementation is incomplete, because Dark Seed does not use some functionality of the library:

OPL rhythm mode
Transpose controllers 0x68 and 0x69 (seems to be buggy)

Member Function Documentation

◆ allocateOplChannel()

uint8 Darkseed::MidiDriver_Worx_AdLib::allocateOplChannel	(	uint8	channel,
		uint8	source,
		uint8	instrumentId
	)

overrideprotectedvirtual

Allocates an OPL channel to play a note on the specified MIDI channel and source with the specified instrument ID. Allocation behavior depends on the active channel allocation mode:

Dynamic: allocates an unused channel, a channel playing a note using the same instrument or the channel playing the oldest note. This will always allocate a channel to play the note. This is the same behavior as the Win95 SB16 driver.
Static: allocates an unused OPL channel and assigns it to the MIDI channel playing the note. All subsequent notes on this MIDI channel will be played using this OPL channel. If there are no free channels, it will fail to allocate a channel. The MIDI data must play one note at a time on each channel and not use more MIDI channels than there are OPL channels for this algorithm to work properly.

Parameters

channel	The MIDI channel on which the note is played.
source	The source playing the note.
instrumentId	The ID of the instrument playing the note. Not used by the static channel allocation mode.

Returns: The number of the allocated OPL channel; 0xFF if allocation failed (not possible using the dynamic channel allocation mode).

Reimplemented from MidiDriver_ADLIB_Multisource.

◆ calculateFrequency()

uint16 Darkseed::MidiDriver_Worx_AdLib::calculateFrequency	(	uint8	channel,
		uint8	source,
		uint8	note
	)

overrideprotectedvirtual

Calculates the OPL frequency (F-num) and octave (block) to play the specified note on the specified MIDI channel and source, taking into account the MIDI controllers pitch bend and (on accuracy mode GM) pitch bend sensitivity and master tuning. The result is returned in the format of the Ax (low byte) and Bx (high byte) OPL registers. Note that the MIDI note range exceeds the frequency range of an OPL chip, so the highest MIDI notes will be shifted down one or two octaves. The SB16 Win95 accuracy mode calculates the same frequencies as the Windows 95 SB16 driver. The GM accuracy mode is more accurate, but the calculations are more CPU intensive. This mode also supports pitch bend sensitivity (which is fixed at 2 semitones in SB16 Win95 mode) and master tuning.

Parameters

channel	The MIDI channel on which the note is played.
source	The source playing the note.
note	The MIDI note which is played.

Returns: The F-num and block to play the note on the OPL chip.

Reimplemented from MidiDriver_ADLIB_Multisource.

◆ calculateUnscaledVolume()

uint8 Darkseed::MidiDriver_Worx_AdLib::calculateUnscaledVolume	(	uint8	channel,
		uint8	source,
		uint8	velocity,
		OplInstrumentDefinition &	instrumentDef,
		uint8	operatorNum
	)

overrideprotectedvirtual

Calculates the unscaled volume for the specified operator of a note on the specified MIDI channel and source, using the specified MIDI velocity and instrument definition. The SB16 Win95 accuracy mode calculates the same values as the Windows 95 SB16 driver. The GM accuracy mode is more accurate to the volume curve in the General MIDI specification and supports the expression controller, but the calculation is more CPU intensive. The volume is returned as an OPL 2x register volume (level) value, i.e. 0 = maximum volume, 3F = minimum volume.

Parameters

channel	The MIDI channel on which the note is played.
source	The source playing the note.
velocity	The MIDI velocity of the note for which volume should be calculated.
instrumentDef	The instrument definition used to play the note.
operatorNum	The number of the operator for which volume should be calculated; 0-1 for 2 operator instruments, 0-3 for 4 operator instruments.

Returns: The calculated unscaled operator volume (level).

Reimplemented from MidiDriver_ADLIB_Multisource.

The documentation for this class was generated from the following file:

engines/darkseed/adlib_worx.h

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ allocateOplChannel()

◆ calculateFrequency()

◆ calculateUnscaledVolume()