implement all basic flock rules

Assets/Boid.cs

@@ -1,10 +1,19 @@
-using System.Collections;
-using System.Collections.Generic;
+using System.Collections.Generic;
 using UnityEngine;
+
 public class Boid {
     private Vector2 _position;
     private Vector2 _velocity;
 
+    Boid(Vector2 position, Vector2 velocity) {
+        _position = position;
+        _velocity = velocity;
+    }
+
+    public void SetPosition(Vector2 position) {
+        _position = position;
+    }
+    
     // Renders the Boid. If focused, the 
     void Render(bool focused = false) {
         
@@ -12,18 +21,50 @@ public class Boid {
 
     // Returns the next position the Boid will be moving to
     Vector2 NextPosition(List<Boid> boids, float[] magnitudes) {
+        // Find the local flock
+        List<Boid> flock = GetFlock(boids, 5);
         
+        // Calculate all offsets and multiple by magnitudes given
+        Vector2 r1 = Rule1(flock) * magnitudes[0];
+        Vector2 r2 = Rule2(flock) * magnitudes[1];
+        Vector2 r3 = Rule3(flock) * magnitudes[2];
+
+        return _position + r1 + r2 + r3;
     }
 
     // Cohesion: Steer towards center of mass of flock
     Vector2 Rule1(List<Boid> flock) {
-        
+        Vector2 center = Vector2.zero;
+        foreach (Boid boid in flock)
+            center += boid._position;
+        center /= flock.Count;
+        return (center - _position) / 100;
+    }
+
+    // Separation: Steer to avoid other Boids within flock
+    Vector2 Rule2(List<Boid> flock) {
+        Vector2 c = Vector2.zero;
+        foreach (Boid boid in flock) {
+            Vector2 diff = boid._position - _position;
+            if (diff.magnitude < 5)
+                c -= diff;
+        }
+        return c;
+    }
+
+    // Alignment: Steer to align with the average heading of the flock
+    Vector3 Rule3(List<Boid> flock) {
+        Vector2 perceived = Vector2.zero;
+        foreach (Boid boid in flock)
+            perceived += boid._velocity;
+        perceived /= flock.Count;
+        return (perceived - _velocity) / 8;
     }
 
     List<Boid> GetFlock(List<Boid> boids, float radius) {
         List<Boid> flock = new List<Boid>();
         foreach(Boid boid in boids)
-            if(Vector2.Distance(this._position, boid._position) <= radius)
+            if(boid != this && Vector2.Distance(_position, boid._position) <= radius)
                 flock.Add(boid);
         return flock;
     }