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playdate-kit/Sources/PlaydateKit/SoundSignal.swift
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javier 2e7ee12ec1
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Adjusted the naming of the library in the Package file.
2026-07-25 12:02:55 +02:00

346 lines
14 KiB
Swift

//
// SoundSignal.swift
// Signal wrappers: PDSynthSignalValue, PDSynthSignal, PDSynthLFO,
// PDSynthEnvelope, and ControlSignal.
//
internal import CPlaydate
extension Sound {
/// A value that can modulate a parameter. The base class of `Signal`,
/// `LFO`, `Envelope`, and `ControlSignal`. Wraps `PDSynthSignalValue`.
public class SignalValue {
let pointer: OpaquePointer
let isOwned: Bool
init(pointer: OpaquePointer, isOwned: Bool) {
self.pointer = pointer
self.isOwned = isOwned
}
/// Wraps a signal value pointer returned by the OS (not owned).
static func wrap(_ pointer: OpaquePointer?) -> SignalValue? {
guard let pointer else { return nil }
return SignalValue(pointer: pointer, isOwned: false)
}
}
/// A signal object; also provides custom signals driven by Swift
/// callbacks. Wraps `PDSynthSignal`.
public final class Signal: SignalValue {
private static var api: UnsafePointer<playdate_sound_signal> { Playdate.signalAPI.unsafelyUnwrapped }
/// Custom signal callbacks.
public struct Callbacks {
/// Returns the signal's value at the end of the current cycle.
/// `ioFrames` is the number of frames until the cycle ends and
/// may be lowered to interpolate toward `interpolationValue`.
public var step: (_ ioFrames: UnsafeMutablePointer<Int32>?,
_ interpolationValue: UnsafeMutablePointer<Float>?) -> Float
/// Called on note-on events. `length` is -1 for indefinite notes.
public var noteOn: ((_ note: MIDINote, _ velocity: Float, _ length: Float) -> Void)?
/// Called on note-off events. `stopped` is `false` when the note
/// is released and `true` when it actually stops playing;
/// `offset` is the frame offset within the current cycle.
public var noteOff: ((_ stopped: Bool, _ offset: Int) -> Void)?
public init(step: @escaping (_ ioFrames: UnsafeMutablePointer<Int32>?,
_ interpolationValue: UnsafeMutablePointer<Float>?) -> Float,
noteOn: ((_ note: MIDINote, _ velocity: Float, _ length: Float) -> Void)? = nil,
noteOff: ((_ stopped: Bool, _ offset: Int) -> Void)? = nil) {
self.step = step
self.noteOn = noteOn
self.noteOff = noteOff
}
}
private final class Box {
let callbacks: Callbacks
init(_ callbacks: Callbacks) { self.callbacks = callbacks }
}
/// Creates a signal driven by the given callbacks.
public init(callbacks: Callbacks) {
let box = Unmanaged.passRetained(Box(callbacks))
let pointer = Signal.api.pointee.newSignal.unsafelyUnwrapped(
{ userdata, ioFrames, interpolationValue in
guard let userdata else { return 0 }
let box = Unmanaged<Box>.fromOpaque(userdata).takeUnretainedValue()
return box.callbacks.step(ioFrames, interpolationValue)
},
{ userdata, note, velocity, length in
guard let userdata else { return }
let box = Unmanaged<Box>.fromOpaque(userdata).takeUnretainedValue()
box.callbacks.noteOn?(note, velocity, length)
},
{ userdata, stopped, offset in
guard let userdata else { return }
let box = Unmanaged<Box>.fromOpaque(userdata).takeUnretainedValue()
box.callbacks.noteOff?(stopped != 0, Int(offset))
},
{ userdata in
guard let userdata else { return }
Unmanaged<Box>.fromOpaque(userdata).release()
},
box.toOpaque())
super.init(pointer: pointer.unsafelyUnwrapped, isOwned: true)
}
/// Creates a plain signal object wrapping an existing signal value,
/// so it can be scaled and offset.
public init(value: SignalValue) {
let pointer = Signal.api.pointee.newSignalForValue.unsafelyUnwrapped(value.pointer)
super.init(pointer: pointer.unsafelyUnwrapped, isOwned: true)
}
override init(pointer: OpaquePointer, isOwned: Bool) {
super.init(pointer: pointer, isOwned: isOwned)
}
deinit {
if isOwned {
Signal.api.pointee.freeSignal.unsafelyUnwrapped(pointer)
}
}
/// The signal's current value.
public var value: Float {
Signal.api.pointee.getValue.unsafelyUnwrapped(pointer)
}
/// Scales the signal's output.
public func setValueScale(_ scale: Float) {
Signal.api.pointee.setValueScale.unsafelyUnwrapped(pointer, scale)
}
/// Offsets the signal's output.
public func setValueOffset(_ offset: Float) {
Signal.api.pointee.setValueOffset.unsafelyUnwrapped(pointer, offset)
}
}
// MARK: - LFO
/// A low-frequency oscillator signal. Wraps `PDSynthLFO`.
public final class LFO: SignalValue {
private static var api: UnsafePointer<playdate_sound_lfo> { Playdate.lfoAPI.unsafelyUnwrapped }
/// The oscillator's waveform.
public enum Shape: UInt32, Sendable {
case square = 0
case triangle = 1
case sine = 2
case sampleAndHold = 3
case sawtoothUp = 4
case sawtoothDown = 5
case arpeggiator = 6
case function = 7
var cValue: LFOType { LFOType(LFOType.RawValue(rawValue)) }
}
var function: ((LFO) -> Float)?
public init(shape: Shape = .sine) {
let pointer = LFO.api.pointee.newLFO.unsafelyUnwrapped(shape.cValue)
super.init(pointer: pointer.unsafelyUnwrapped, isOwned: true)
}
deinit {
if isOwned {
LFO.api.pointee.freeLFO.unsafelyUnwrapped(pointer)
}
}
public func setShape(_ shape: Shape) {
LFO.api.pointee.setType.unsafelyUnwrapped(pointer, shape.cValue)
}
/// The LFO rate, in cycles per second.
public func setRate(_ rate: Float) {
LFO.api.pointee.setRate.unsafelyUnwrapped(pointer, rate)
}
/// The current phase, 0...1.
public func setPhase(_ phase: Float) {
LFO.api.pointee.setPhase.unsafelyUnwrapped(pointer, phase)
}
/// The phase the LFO starts at when a note starts, 0...1.
public func setStartPhase(_ phase: Float) {
LFO.api.pointee.setStartPhase.unsafelyUnwrapped(pointer, phase)
}
/// The center value of the LFO output.
public func setCenter(_ center: Float) {
LFO.api.pointee.setCenter.unsafelyUnwrapped(pointer, center)
}
/// The amplitude of the LFO around its center.
public func setDepth(_ depth: Float) {
LFO.api.pointee.setDepth.unsafelyUnwrapped(pointer, depth)
}
/// For `.arpeggiator` LFOs: the sequence of values (in half-steps)
/// to step through.
public func setArpeggiation(_ steps: [Float]) {
var steps = steps
steps.withUnsafeMutableBufferPointer { buffer in
LFO.api.pointee.setArpeggiation.unsafelyUnwrapped(pointer, Int32(buffer.count),
buffer.baseAddress)
}
}
/// For `.function` LFOs: the Swift function providing the value. If
/// `interpolate` is `true`, values are interpolated between calls.
public func setFunction(interpolate: Bool = false, _ function: @escaping (LFO) -> Float) {
self.function = function
LFO.api.pointee.setFunction.unsafelyUnwrapped(pointer, { _, userdata in
guard let userdata else { return 0 }
let lfo = Unmanaged<LFO>.fromOpaque(userdata).takeUnretainedValue()
return lfo.function?(lfo) ?? 0
}, Unmanaged.passUnretained(self).toOpaque(), interpolate ? 1 : 0)
}
/// Waits `holdoff` seconds after a note starts, then ramps the LFO
/// depth up over `rampTime` seconds.
public func setDelay(holdoff: Float, rampTime: Float) {
LFO.api.pointee.setDelay.unsafelyUnwrapped(pointer, holdoff, rampTime)
}
/// Whether the LFO phase restarts on every new note.
public func setRetrigger(_ flag: Bool) {
LFO.api.pointee.setRetrigger.unsafelyUnwrapped(pointer, flag ? 1 : 0)
}
/// When `true`, the LFO runs globally instead of per-note.
public func setGlobal(_ global: Bool) {
LFO.api.pointee.setGlobal.unsafelyUnwrapped(pointer, global ? 1 : 0)
}
/// Seeds the random number generator used by `.sampleAndHold` LFOs.
public func setRandomSeed(_ seed: UInt16) {
LFO.api.pointee.setRandomSeed.unsafelyUnwrapped(pointer, seed)
}
public var value: Float {
LFO.api.pointee.getValue.unsafelyUnwrapped(pointer)
}
}
// MARK: - Envelope
/// An ADSR envelope signal. Wraps `PDSynthEnvelope`.
public final class Envelope: SignalValue {
private static var api: UnsafePointer<playdate_sound_envelope> { Playdate.envelopeAPI.unsafelyUnwrapped }
/// Creates an envelope with the given attack and decay times
/// (seconds), sustain level (0...1), and release time (seconds).
public init(attack: Float = 0, decay: Float = 0, sustain: Float = 1, release: Float = 0) {
let pointer = Envelope.api.pointee.newEnvelope.unsafelyUnwrapped(attack, decay, sustain, release)
super.init(pointer: pointer.unsafelyUnwrapped, isOwned: true)
}
override init(pointer: OpaquePointer, isOwned: Bool) {
super.init(pointer: pointer, isOwned: isOwned)
}
deinit {
if isOwned {
Envelope.api.pointee.freeEnvelope.unsafelyUnwrapped(pointer)
}
}
public func setAttack(_ attack: Float) {
Envelope.api.pointee.setAttack.unsafelyUnwrapped(pointer, attack)
}
public func setDecay(_ decay: Float) {
Envelope.api.pointee.setDecay.unsafelyUnwrapped(pointer, decay)
}
public func setSustain(_ sustain: Float) {
Envelope.api.pointee.setSustain.unsafelyUnwrapped(pointer, sustain)
}
public func setRelease(_ release: Float) {
Envelope.api.pointee.setRelease.unsafelyUnwrapped(pointer, release)
}
/// When `true`, a new note while a note is playing does not restart
/// the envelope.
public func setLegato(_ flag: Bool) {
Envelope.api.pointee.setLegato.unsafelyUnwrapped(pointer, flag ? 1 : 0)
}
/// When `true`, a new note restarts the envelope from zero instead of
/// its current value.
public func setRetrigger(_ flag: Bool) {
Envelope.api.pointee.setRetrigger.unsafelyUnwrapped(pointer, flag ? 1 : 0)
}
/// Bends the envelope's segments: 0 is linear, 1 is maximum curvature.
public func setCurvature(_ amount: Float) {
Envelope.api.pointee.setCurvature.unsafelyUnwrapped(pointer, amount)
}
/// How much note velocity scales the envelope's output.
public func setVelocitySensitivity(_ sensitivity: Float) {
Envelope.api.pointee.setVelocitySensitivity.unsafelyUnwrapped(pointer, sensitivity)
}
/// Scales the envelope's rate by note: notes above `start` play the
/// envelope faster (up to `scaling` at `end` and beyond).
public func setRateScaling(_ scaling: Float, start: MIDINote, end: MIDINote) {
Envelope.api.pointee.setRateScaling.unsafelyUnwrapped(pointer, scaling, start, end)
}
public var value: Float {
Envelope.api.pointee.getValue.unsafelyUnwrapped(pointer)
}
}
// MARK: - ControlSignal
/// A signal whose values are set on a sequence timeline. Wraps
/// `ControlSignal`.
public final class ControlSignal: SignalValue {
private static var api: UnsafePointer<playdate_control_signal> { Playdate.controlSignalAPI.unsafelyUnwrapped }
public init() {
let pointer = ControlSignal.api.pointee.newSignal.unsafelyUnwrapped()
super.init(pointer: pointer.unsafelyUnwrapped, isOwned: true)
}
override init(pointer: OpaquePointer, isOwned: Bool) {
super.init(pointer: pointer, isOwned: isOwned)
}
deinit {
if isOwned {
ControlSignal.api.pointee.freeSignal.unsafelyUnwrapped(pointer)
}
}
public func clearEvents() {
ControlSignal.api.pointee.clearEvents.unsafelyUnwrapped(pointer)
}
/// Adds a value at `step` in the signal's timeline. If `interpolate`
/// is `true`, the value ramps from the previous event.
public func addEvent(step: Int, value: Float, interpolate: Bool = false) {
ControlSignal.api.pointee.addEvent.unsafelyUnwrapped(pointer, Int32(step), value,
interpolate ? 1 : 0)
}
public func removeEvent(step: Int) {
ControlSignal.api.pointee.removeEvent.unsafelyUnwrapped(pointer, Int32(step))
}
/// The MIDI controller number for signals loaded from a MIDI file.
public var midiControllerNumber: Int {
Int(ControlSignal.api.pointee.getMIDIControllerNumber.unsafelyUnwrapped(pointer))
}
}
}