vision_worker.py

vision_worker.py

This is the computational engine of the squid's perception. It runs as a background thread (QThread) to ensure that geometric calculations do not "freeze" the main game animations.

Core Responsibilities:

• Asynchronous Calculation: Performs vision cone and proximity checks at a fixed frequency (20Hz) independently of the main game loop.
• Vision Cone Logic: Determines if objects (food, rocks, plants) are within the squid's 80-degree field of view by calculating the angular difference between the squid's gaze and the object's position.
• Proximity Sensing: Calculates "tactile" proximity to plants. Unlike the vision cone, this uses bounding-box edge distances to detect if the squid is touching or near a plant (0–100 range).
• Change Detection: It monitors the environment and only "alerts" the squid via signals when something meaningful changes (e.g., food just appeared in view).

Key Functions:

• _calculate_visibility() - The math core; checks every scene object against the vision cone and calculates distances.
• update_squid_state() - Receives the squid's current X/Y and gaze angle from the main thread.
• update_scene_objects() - Receives a lightweight list of all items currently in the tank.
• _check_and_emit_changes() - Fires signals like food_visibility_changed or plant_proximity_changed only when state shifts.

Key internal objects

• SquidVisionState: A data class containing a snapshot of the squid's position, size, and gaze angle.
• SceneObject: A lightweight representation of a world object (food, plant, rock) used for visibility checks.
• VisionResult: A container for the output of a vision cycle, listing visible items and proximity values.
• VisionWorker: The QThread subclass that constantly calculates what is inside the vision cone.

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"Producer-Consumer" model:

1. Input: Squid.py periodically sends its position to the VisionWorker.
2. Processing: VisionWorker (in the background) identifies what is visible and sends a VisionResult back to the Squid.
3. Behaviour: The Squid uses that result to decide if it should chase food or feel calm near a plant.
4. Display: If the VisionWindow is open, it reads those same results to display the "Visible Objects" list to the user.

• Note: The VisionWorker includes a "Circuit Breaker" logic to prevent the squid from chasing "ghost food" that was just eaten but hasn't been cleared from the background thread's cache yet.