Steps to implementing an enemy drone

Let's start by implementing the main ingredients of the Strategy pattern:

1. Our first element is the Strategy interface; all our concrete strategies will use it:

namespace Chapter.Strategy
{
    public interface IManeuverBehaviour
    {
        void Maneuver(Drone drone);
    }
}

Note that we are passing a parameter of the Drone type to the Maneuver() method. This is an important detail we will review later.

2. Next up is our Drone class; it's going to use our concrete strategies, so in the overall structure of the Strategy pattern, we will consider it to be our Context class:

using UnityEngine;

namespace Chapter.Strategy {
    public class Drone : MonoBehaviour {

        // Ray parameters
        private RaycastHit _hit;
        private Vector3 _rayDirection;
        private float _rayAngle = -45.0f;
        private float _rayDistance = 15.0f;

        // Movement parameters
        public float speed = 1.0f;
        public float maxHeight = 5.0f;
  ...