QtFM::FmSound Class

The FmSound type is one sound effect: a patch, and how it plays. More…

List of all members, including inherited members

Public Functions

Reimplemented Public Functions

Signals

Detailed Description

Set source to a patch file (JSON, or an AdLib SBI instrument) or patch to an FmPatchValue, then call play(). Each play() starts another voice; maxInstances caps how many run at once. pitch, gain and pan apply to the voices that play, smoothed, so they can be bound to the game:

property FmSound coin: FmSound {
    patch: FmPatch.generate(FmPatch.Pickup, 3)
    pitchVariance: 1            // +/- semitones per play
    maxInstances: 4
}
property FmSound engineHum: FmSound {
    patch: FmPatch.generate(FmPatch.Engine, 42)
    loop: true
    pitch: game.speed / 10      // bound live, smoothed on the audio thread
}
property FmSound laser: FmSound {
    patch: FmPatch.generate(FmPatch.Laser, 4, FmChip.OPL2)
    chip: FmChip.OPL2           // played on the emulated AdLib
}

Setting chip to FmChip.OPL2 or FmChip.OPL3 plays the sound on the emulated chip; FmChip.None, the default, on the native engine.

Differences from Qt

Member Function Documentation

[explicit] QtFM::FmSound::FmSound(QObject *parent = nullptr)

Constructs a sound with parent.

[override] QtFM::FmSound::~FmSound()

Destroys the sound. Its voices play on.

int QtFM::FmSound::bus() const

Returns the bus: 0 effects (the default), 1 music, 2 interface.

[signal] void QtFM::FmSound::busChanged()

This signal is emitted when bus() changes.

int QtFM::FmSound::chip() const

Returns the chip to play on, an FmChip value; FmChip.None for the native engine. Set it before the engine plays its first sound.

[signal] void QtFM::FmSound::chipChanged()

This signal is emitted when chip() changes.

[override] void QtFM::FmSound::classBegin()

Reimplements QQmlParserStatus::classBegin().

[override] void QtFM::FmSound::componentComplete()

Reimplements QQmlParserStatus::componentComplete().

Patch QtFM::FmSound::currentPatch() const

Returns the patch that play() plays: patch if set, else the one loaded from source, with loop and chip applied.

QString QtFM::FmSound::error() const

Returns why source could not be loaded, or an empty string.

[signal] void QtFM::FmSound::errorChanged()

This signal is emitted when error() changes.

[signal] void QtFM::FmSound::finished()

This signal is emitted when the last voice of the sound ends.

double QtFM::FmSound::gain() const

Returns the gain in decibels; changing it also affects the voices playing.

[signal] void QtFM::FmSound::gainChanged()

This signal is emitted when gain() changes.

bool QtFM::FmSound::isPlaying() const

Returns true if a voice of the sound plays.

bool QtFM::FmSound::loop() const

Returns true if the sound sustains until stop(); the patch's own setting until it is set.

[signal] void QtFM::FmSound::loopChanged()

This signal is emitted when loop() changes.

int QtFM::FmSound::maxInstances() const

Returns the number of voices of this sound that play at once; 0, the default, for no limit. A play() beyond it stops the oldest.

[signal] void QtFM::FmSound::maxInstancesChanged()

This signal is emitted when maxInstances() changes.

double QtFM::FmSound::pan() const

Returns the pan, from -1 to 1; changing it also moves the voices playing.

[signal] void QtFM::FmSound::panChanged()

This signal is emitted when pan() changes.

FmPatchValue * QtFM::FmSound::patch() const

Returns the patch set from FmPatch, which is played instead of source, or nullptr.

[signal] void QtFM::FmSound::patchChanged()

This signal is emitted when patch() changes.

double QtFM::FmSound::pitch() const

Returns the semitones added to the patch's note; changing them also moves the voices playing.

[signal] void QtFM::FmSound::pitchChanged()

This signal is emitted when pitch() changes.

double QtFM::FmSound::pitchVariance() const

Returns the pitch variance: each play() moves the pitch by a random amount of up to this many semitones either way.

[signal] void QtFM::FmSound::pitchVarianceChanged()

This signal is emitted when pitchVariance() changes.

void QtFM::FmSound::play()

Starts a voice of the sound.

[signal] void QtFM::FmSound::playingChanged()

This signal is emitted when isPlaying() changes.

int QtFM::FmSound::priority() const

Returns the priority of the voices: a higher one survives voice stealing.

[signal] void QtFM::FmSound::priorityChanged()

This signal is emitted when priority() changes.

void QtFM::FmSound::setBus(int bus)

Sets the bus property to bus.

See also bus().

void QtFM::FmSound::setChip(int chip)

Sets the chip property to chip.

See also chip().

void QtFM::FmSound::setGain(double dB)

Sets the gain property to dB.

See also gain().

void QtFM::FmSound::setLoop(bool loop)

Sets the loop property to loop.

See also loop().

void QtFM::FmSound::setMaxInstances(int count)

Sets the maxInstances property to count.

See also maxInstances().

void QtFM::FmSound::setPan(double pan)

Sets the pan property to pan.

See also pan().

void QtFM::FmSound::setPatch(FmPatchValue *patch)

Sets the patch property to patch.

See also patch().

void QtFM::FmSound::setPitch(double semitones)

Sets the pitch property to semitones.

See also pitch().

void QtFM::FmSound::setPitchVariance(double semitones)

Sets the pitchVariance property to semitones.

See also pitchVariance().

void QtFM::FmSound::setPriority(int priority)

Sets the priority property to priority.

See also priority().

void QtFM::FmSound::setSource(const QUrl &source)

Sets the source property to source.

See also source().

QUrl QtFM::FmSound::source() const

Returns the url of a patch file: JSON, or an SBI instrument. Relative urls are relative to the document.

[signal] void QtFM::FmSound::sourceChanged()

This signal is emitted when source() changes.

void QtFM::FmSound::stop(bool immediate = false)

Releases every voice of the sound; if immediate is true, they fade out in 2 ms instead.