GameplayEventBus
ClassSource: GameplayEventBus.h
Description
Fixed-capacity FIFO ring buffer for GameplayEvent, single-instance and Engine-owned.
Sized by GAMEPLAY_EVENT_QUEUE_CAPACITY (mirror: pixelroot32::platforms::config::GameplayEventQueueCapacity). Overflow policy is drop-newest: when the buffer is full, publish() discards the incoming event and increments a monotonic drop counter rather than evicting an already-buffered event — this preserves paired TriggerEnter/TriggerExit ordering (see design.md D2).
Non-atomic by design. Unlike AudioCommandQueue (which bridges the game thread and the audio task with std::atomic), this bus is produced and consumed entirely inside the single-threaded Scene::update()/Scene::draw() loop driven from SceneManager::update(). Plain, non-atomic uint16_t head/tail/count indices. Publishing from an ISR or the audio task is explicitly unsupported.
The bus is drained (cleared) by SceneManager on every SceneSwap. It is NOT drained on pushScene()/popScene().
Methods
bool publish(const GameplayEvent& event)
Description:
Publishes an event to the bus.
Parameters:
event: The event to enqueue (copied into the ring).
Returns: true if the event was stored, false if the buffer was full (the event is dropped and the drop counter is incremented).
Never blocks, never allocates.
bool consume(GameplayEvent& outEvent)
Description:
Consumes (pops) the oldest pending event, FIFO order.
Parameters:
outEvent: Reference to receive the dequeued event.
Returns: true if an event was retrieved, false if the buffer was empty.
void clear()
Description:
Clears all pending events without changing the drop counter.
uint32_t getDroppedCount() const
Description:
Returns the number of events dropped due to a full buffer.
uint16_t size() const
Description:
Number of events currently pending.
bool isEmpty() const
Description:
True if no events are pending.
bool isFull() const
Description:
True if the buffer is at capacity.