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Use a dedicated struct for the process context

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This commit is contained in:
Robbert van der Helm 2022-02-04 22:55:10 +01:00
parent 209c19b74f
commit ce3da8ea44
1 changed files with 41 additions and 28 deletions
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69
src/wrapper/vst3.rs
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@ -146,6 +146,32 @@ struct WrapperInner<P: Plugin> {
pub(crate) struct Wrapper<P: Plugin> {
inner: Arc<WrapperInner<P>>,
}
/// A [ProcessContext] implementation for the wrapper. This is a separate object so it can hold on
/// to lock guards for event queues. Otherwise reading these events would require constant
/// unnecessary atomic operations to lock the uncontested RwLocks.
struct WrapperProcessContext<'a, P: Plugin> {
inner: &'a WrapperInner<P>,
}
impl<P: Plugin> ProcessContext for WrapperProcessContext<'_, P> {
fn set_latency_samples(&self, samples: u32) {
// Only trigger a restart if it's actually needed
let old_latency = self.inner.current_latency.swap(samples, Ordering::SeqCst);
if old_latency != samples {
let task_posted = unsafe { self.inner.event_loop.read().assume_init_ref() }
.do_maybe_async(Task::TriggerRestart(
vst3_sys::vst::RestartFlags::kLatencyChanged as i32,
));
nih_debug_assert!(task_posted, "The task queue is full, dropping task...");
}
}
fn next_midi_event(&self) -> Option<NoteEvent> {
// TODO: Instead of having to lock this queue, move the lock guard into
// `WrapperProcessContext`. That's the whole reason this was split up.
self.inner.input_events.write().pop_front()
}
}
/// Tasks that can be sent from the plugin to be executed on the main thread in a non-blocking
@ -266,6 +292,10 @@ impl<P: Plugin> WrapperInner<P> {
wrapper
}
pub fn make_process_context(&self) -> WrapperProcessContext<'_, P> {
WrapperProcessContext { inner: self }
}
/// Convenience function for setting a value for a parameter as triggered by a VST3 parameter
/// update. The same rate is for updating parameter smoothing.
unsafe fn set_normalized_value_by_hash(
@ -321,23 +351,6 @@ impl<P: Plugin> MainThreadExecutor<Task> for WrapperInner<P> {
}
}
impl<P: Plugin> ProcessContext for WrapperInner<P> {
fn set_latency_samples(&self, samples: u32) {
// Only trigger a restart if it's actually needed
let old_latency = self.current_latency.swap(samples, Ordering::SeqCst);
if old_latency != samples {
let task_posted = unsafe { self.event_loop.read().assume_init_ref() }.do_maybe_async(
Task::TriggerRestart(vst3_sys::vst::RestartFlags::kLatencyChanged as i32),
);
nih_debug_assert!(task_posted, "The task queue is full, dropping task...");
}
}
fn next_midi_event(&self) -> Option<NoteEvent> {
self.input_events.write().pop_front()
}
}
impl<P: Plugin> IPluginBase for Wrapper<P> {
unsafe fn initialize(&self, _context: *mut c_void) -> tresult {
// We currently don't need or allow any initialization logic
@ -591,10 +604,11 @@ impl<P: Plugin> IComponent for Wrapper<P> {
// Reinitialize the plugin after loading state so it can respond to the new parmaeters
let bus_config = self.inner.current_bus_config.load();
if let Some(buffer_config) = self.inner.current_buffer_config.load() {
self.inner
.plugin
.write()
.initialize(&bus_config, &buffer_config, self.inner.as_ref());
self.inner.plugin.write().initialize(
&bus_config,
&buffer_config,
&self.inner.make_process_context(),
);
}
kResultOk
@ -977,12 +991,11 @@ impl<P: Plugin> IAudioProcessor for Wrapper<P> {
param.update_smoother(buffer_config.sample_rate, true);
}
if self
.inner
.plugin
.write()
.initialize(&bus_config, &buffer_config, self.inner.as_ref())
{
if self.inner.plugin.write().initialize(
&bus_config,
&buffer_config,
&self.inner.make_process_context(),
) {
// Preallocate enough room in the output slices vector so we can convert a `*mut *mut
// f32` to a `&mut [&mut f32]` in the process call
self.inner
@ -1160,7 +1173,7 @@ impl<P: Plugin> IAudioProcessor for Wrapper<P> {
.plugin
.write()
// SAFETY: Same here
.process(&mut output_buffer, self.inner.as_ref())
.process(&mut output_buffer, &self.inner.make_process_context())
{
ProcessStatus::Error(err) => {
nih_debug_assert_failure!("Process error: {}", err);