detection_in_world.py

"""
Object detection in world space.
"""

import numpy as np


class DetectionInWorld:
    """
    Typically on the ground.
    """

    __create_key = object()

    @classmethod
    def create(
        cls, vertices: np.ndarray, centre: np.ndarray, label: int, confidence: float
    ) -> "tuple[bool, DetectionInWorld | None]":
        """
        vertices is a quadrilateral of 4 points.
        centre is a point.
        A point is an xy coordinate (index 0 and 1 respectively).
        """
        if vertices.shape != (4, 2):
            return False, None

        if centre.shape != (2,):
            return False, None

        if label < 0:
            return False, None

        if confidence < 0.0 or confidence > 1.0:
            return False, None

        return True, DetectionInWorld(cls.__create_key, vertices, centre, label, confidence)

    def __init__(
        self,
        class_private_create_key: object,
        vertices: np.ndarray,
        centre: np.ndarray,
        label: int,
        confidence: float,
    ) -> None:
        """
        Private constructor, use create() method.
        """
        assert class_private_create_key is DetectionInWorld.__create_key, "Use create() method"

        self.vertices = vertices
        self.centre = centre
        self.label = label
        self.confidence = confidence

    def __str__(self) -> str:
        """
        To string.
        """
        return f"{self.__class__}, vertices: {self.vertices.tolist()}, centre: {self.centre}, label: {self.label}, confidence: {self.confidence}"

    def __repr__(self) -> str:
        """
        For collections (e.g. list).
        """
        return str(self)