Files
playdate-kit/Sources/PlaydateKit/Sound/Synth/Classes/Sequence.swift
T

135 lines
5.4 KiB
Swift

internal import CPlaydate
extension Sound {
/// A collection of tracks with tempo and loop control, playable from a
/// MIDI file. Wraps `SoundSequence`.
public final class Sequence {
private static var api: UnsafePointer<playdate_sound_sequence> { Playdate.sequenceAPI.unsafelyUnwrapped }
let pointer: OpaquePointer
private var retainedTracks: [SequenceTrack] = []
var finishCallback: ((Sequence) -> Void)?
public init() {
pointer = Sequence.api.pointee.newSequence.unsafelyUnwrapped().unsafelyUnwrapped
}
/// Creates a sequence and loads the MIDI file at `path`.
public convenience init(path: String) throws(PlaydateError) {
self.init()
try loadMIDIFile(path: path)
}
deinit {
Sequence.api.pointee.freeSequence.unsafelyUnwrapped(pointer)
}
public func loadMIDIFile(path: String) throws(PlaydateError) {
let loaded = path.withPlaydateCString {
Sequence.api.pointee.loadMIDIFile.unsafelyUnwrapped(pointer, $0) != 0
}
if !loaded {
throw PlaydateError(message: "unable to load MIDI file: \(path)")
}
}
/// Starts playback. `completion` is called when the sequence finishes.
public func play(completion: ((Sequence) -> Void)? = nil) {
finishCallback = completion
if completion != nil {
Sequence.api.pointee.play.unsafelyUnwrapped(pointer, { _, userdata in
guard let userdata else { return }
let sequence = Unmanaged<Sequence>.fromOpaque(userdata).takeUnretainedValue()
sequence.finishCallback?(sequence)
}, Unmanaged.passUnretained(self).toOpaque())
} else {
Sequence.api.pointee.play.unsafelyUnwrapped(pointer, nil, nil)
}
}
/// Stops playback.
public func stop() {
Sequence.api.pointee.stop.unsafelyUnwrapped(pointer)
}
/// Whether the sequence is playing.
public var isPlaying: Bool {
Sequence.api.pointee.isPlaying.unsafelyUnwrapped(pointer) != 0
}
/// The playback position, in samples.
public var time: UInt32 {
get { Sequence.api.pointee.getTime.unsafelyUnwrapped(pointer) }
set { Sequence.api.pointee.setTime.unsafelyUnwrapped(pointer, newValue) }
}
/// The tempo, in steps per second.
public var tempo: Float {
get { Sequence.api.pointee.getTempo.unsafelyUnwrapped(pointer) }
set { Sequence.api.pointee.setTempo.unsafelyUnwrapped(pointer, newValue) }
}
/// The sequence's length in steps, including the tail of the last note.
public var length: UInt32 {
Sequence.api.pointee.getLength.unsafelyUnwrapped(pointer)
}
/// Loops the range `loopStart..<loopEnd` (steps) `loops` times while
/// playing; 0 loops endlessly.
public func setLoops(start: Int, end: Int, count: Int = 0) {
Sequence.api.pointee.setLoops.unsafelyUnwrapped(pointer, Int32(start), Int32(end), Int32(count))
}
/// The current step, and the time offset (in samples) into that step.
public var currentStep: (step: Int, timeOffset: Int) {
var timeOffset: Int32 = 0
let step = Sequence.api.pointee.getCurrentStep.unsafelyUnwrapped(pointer, &timeOffset)
return (Int(step), Int(timeOffset))
}
/// Moves playback to the given step. If `playNotes` is `true`, notes
/// at the position (that started before it) are played.
public func setCurrentStep(_ step: Int, timeOffset: Int = 0, playNotes: Bool = false) {
Sequence.api.pointee.setCurrentStep.unsafelyUnwrapped(pointer, Int32(step),
Int32(timeOffset), playNotes ? 1 : 0)
}
// MARK: Tracks
public var trackCount: Int {
Int(Sequence.api.pointee.getTrackCount.unsafelyUnwrapped(pointer))
}
/// Adds a new track to the sequence. The track is owned by the
/// sequence.
@discardableResult
public func addTrack() -> SequenceTrack {
let track = SequenceTrack(
pointer: Sequence.api.pointee.addTrack.unsafelyUnwrapped(pointer).unsafelyUnwrapped,
isOwned: false)
retainedTracks.append(track)
return track
}
/// The track at `index`. Owned by the sequence.
public func track(at index: Int) -> SequenceTrack? {
guard let track = Sequence.api.pointee.getTrackAtIndex.unsafelyUnwrapped(
pointer, UInt32(index)) else { return nil }
return SequenceTrack(pointer: track, isOwned: false)
}
/// Installs `track` at `index`.
public func setTrack(_ track: SequenceTrack, at index: Int) {
if !retainedTracks.contains(where: { $0 === track }) {
retainedTracks.append(track)
}
Sequence.api.pointee.setTrackAtIndex.unsafelyUnwrapped(pointer, track.pointer, UInt32(index))
}
/// Releases every playing note in the sequence.
public func allNotesOff() {
Sequence.api.pointee.allNotesOff.unsafelyUnwrapped(pointer)
}
}
}