// API Reference

This reference covers the core surface shared across all engine bindings. State is kept internal. All calls are thread-safe unless noted.

start(optional_model_path: const char* = nullptr) -> bool

Initializes SDK.

Auto-resolves model and camera if no path is provided.

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stop() -> bool

Stops capture and processing threads.

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get_last_error() -> int

Returns last fatal code from start().

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get_version() -> const char*

SDK version string.

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poll_blink_events()

Drains the queue and invokes your event handlers.
Call exactly once per frame.

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Event Struct (engine-specific name varies)

timestamp_ms : uint64
intensity    : float    # 0.0–1.0
side         : int      # 0=both, 1=left, 2=right

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Engine Plugins

Each engine integration maps these functions into native engine constructs:

• Godot → signals + autoload singleton
• Unity → events + C# wrapper
• Unreal → Blueprint nodes + native C++ module

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Notes

• Inference runs on CPU by default
• Capture and inference run on background threads
• Thread-safe access to blink events
• Avoid calling start()/stop() repeatedly mid-frame

Design guarantees

Feed-only mode

When camera_index == -1, Ollo SDK processes frames from an external source instead of a webcam.

Given:

• Identical configuration
• Identical frame pixel data

Ollo SDK will produce:

• Identical blink events
• Identical signal values

Threading model

All detection and signal updates are handled exclusively on a dedicated internal worker thread.

Event callbacks are invoked directly from the worker thread.

Callbacks must:

• Return quickly
• Never block
• Never call Ollo SDK lifecycle APIs (init, shutdown)

Applications requiring main-thread delivery must enqueue events themselves.