/// Single particle in a particle filter cloud snapshot.
class Particle {
  const Particle({required this.x, required this.y, required this.weight});

  /// Normalised 0..1 coordinates (same space as [Position]).
  final double x;
  final double y;

  /// Unnormalised likelihood weight.
  final double weight;

  factory Particle.fromJson(Map<String, dynamic> json) => Particle(
        x: (json['x'] as num).toDouble(),
        y: (json['y'] as num).toDouble(),
        weight: (json['weight'] as num).toDouble(),
      );
}