Struct PatternPlayer 

pub struct PatternPlayer { /* private fields */ }

Everything one sequencer track needs on the audio thread.

The bank lives here rather than on the UI side because a pattern switch has to be decided on the audio thread: the quantization point is a tick, the tick arrives in the middle of a callback, and asking the UI what to play next at that moment would make the answer depend on when the UI thread happened to be scheduled. With all eight slots resident, a switch is an index change and a chain is a lookup.

Around 19 kB per sequencer track, allocated once, when the track’s first pattern arrives — the same shape as an instrument allocating its voice array in Plugin::init. Nothing after that reaches the allocator.

Implementations

impl PatternPlayer

pub fn new() -> Self

pub fn apply(&mut self, slot: u8, block: PatternBlock)

Take a pattern for one slot, and with it the UI’s current word on the track-level settings.

pub fn slot(&self, index: usize) -> &PatternBlock

pub fn live_slot(&self) -> u8

pub fn queued_slot(&self) -> Option<u8>

pub fn current_step(&self) -> u8

The step the playhead was over on the last callback. What the UI draws its marker at.

pub fn is_playing(&self) -> bool

pub fn held_notes(&self) -> usize

pub fn silence(&mut self)

Forget every held note without sounding an off. For a panic, where the instruments are reset underneath us.

pub fn countdown(&self, now: i64) -> Option<(u8, i64)>

Where the switch queued on this track will happen, and how many steps away that is from now. None when nothing is queued.

Pure, and the UI computes the same answer from its own mirror: the countdown on screen is arithmetic, not a message from the audio thread that may or may not have arrived yet.

pub fn render( &mut self, window: &PlaybackWindow, transport_playing: bool, out: &mut impl EventSink, )

Produce this callback’s events.

transport_playing is the DAW transport; the pattern also has to be running on its own account. Everything else — which step, which slot, where the switch lands — comes out of the window’s ticks.

Trait Implementations

impl Clone for PatternPlayer

fn clone(&self) -> PatternPlayer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for PatternPlayer

impl Debug for PatternPlayer

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for PatternPlayer

fn default() -> Self

Returns the “default value” for a type.