Struct RuntimeEventBus 

pub struct RuntimeEventBus { /* private fields */ }

Typed per-frame event accumulator for runtime plugin communication.

Stored on super::output::RuntimeOutput and accessible via ctx.output.events from any plugin step. Events accumulate during the frame and are returned to the app in super::output::RuntimeOutput at the end of each super::ViewportRuntime::step call.

Events are cleared each frame because RuntimeOutput is constructed fresh on every step call. Use super::resources::RuntimeResources for state that must persist across frames.

The event type IS the category. Define a distinct struct for each kind of event your plugin emits. Multiple plugins can emit events of the same type; all accumulate and are visible together.

Example

// Emit from a plugin step.
ctx.output.events.emit(TriggerEntered { trigger_id, actor_id });

// Read from a later plugin in the same frame.
for ev in ctx.output.events.read::<TriggerEntered>() { ... }

// Read from the app after step() returns.
for ev in output.events.read::<TriggerEntered>() { ... }

// Drain (take ownership) after step() returns.
for ev in output.events.drain::<TriggerEntered>() { ... }

Implementations

impl RuntimeEventBus

pub fn new() -> Self

Create an empty event bus.

pub fn emit<T: Send + 'static>(&mut self, event: T)

Emit an event. Multiple calls accumulate; all are visible to later readers.

pub fn read<T: Send + 'static>(&self) -> impl Iterator<Item = &T> + '_

Iterate over all events of type T emitted this frame.

pub fn drain<T: Send + 'static>(&mut self) -> Vec<T>

Remove and return all events of type T, leaving the slot empty.

Calling this twice for the same type returns an empty vec on the second call.

pub fn has<T: Send + 'static>(&self) -> bool

Returns true if any events of type T have been emitted this frame.

pub fn count<T: Send + 'static>(&self) -> usize

Number of events of type T emitted this frame.

pub fn is_empty(&self) -> bool

Returns true if no events of any type have been emitted this frame.

Trait Implementations

impl Default for RuntimeEventBus

fn default() -> RuntimeEventBus

Returns the “default value” for a type.