Added new Editor for controlling Boid count, new methods for adding.removing Boids

Boids/Assets/Boid.cs

@@ -15,6 +15,7 @@ public class Boid : MonoBehaviour {
     [NonSerialized] private bool _isWrappingY = false;
     [NonSerialized] private Renderer[] _renderers;
     [NonSerialized] private Vector2 _centeringVelocity;
+    [NonSerialized] private int _latestNeighborhoodCount = 0;
     private BoidController _parent;
 
     void Start() {
@@ -27,12 +28,8 @@ public class Boid : MonoBehaviour {
     }
 
 void OnDrawGizmos() {
-        // Handles.color = _isWrappingX || _isWrappingY ? Color.red : Color.white;
-        // Vector3 viewportPosition = _parent.cam.WorldToViewportPoint(transform.position);
-        // Handles.Label(transform.position,
-            // $"{(Vector2) viewportPosition} {(_isWrappingX ? "Y" : "N")} {(_isWrappingY ? "Y" : "N")}");
         var transform_ = transform;
-            Handles.Label(transform_.position, $"{transform_.name}");
+        Handles.Label(transform_.position, $"{transform_.name} {_latestNeighborhoodCount}");
 }
 
     void Update() {
@@ -47,6 +44,7 @@ public class Boid : MonoBehaviour {
         }
         else {
             List<Boid> flock = _parent.localFlocks ? GetFlock(_parent.boids, _parent.boidGroupRange) : _parent.boids;
+            _latestNeighborhoodCount = flock.Count;
 
             // Calculate all offsets and multiple by magnitudes given
             if (flock.Count > 0) {
@@ -70,7 +68,7 @@ public class Boid : MonoBehaviour {
         if (!_parent.Space.Contains(_position)) {
             // Activate Wrap, Move
             Vector2 newPosition = transform.position;
-            Vector3 viewportPosition = _parent.cam.WorldToViewportPoint(newPosition);
+            Vector3 viewportPosition = _parent.Cam.WorldToViewportPoint(newPosition);
 
             if (!_isWrappingX && (viewportPosition.x > 1 || viewportPosition.x < 0)) {
                 newPosition.x = -newPosition.x;
@@ -101,6 +99,7 @@ public class Boid : MonoBehaviour {
         _centeringVelocity = Util.LimitVelocity(_parent.Space.center - _position, _parent.boidVelocityLimit / 2.0f);
     }
     
+    // Returns a velocity (Vector2) at a random angle with a specific overall magnitude
     Vector2 GetRandomVelocity(float magnitude) {
         Vector2 vector = new Vector2(magnitude, magnitude);
         return Util.RotateBy(vector, Random.Range(0, 180));

Boids/Assets/BoidController.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using UnityEngine;
+using Debug = System.Diagnostics.Debug;
 using Random = UnityEngine.Random;
 
 public class BoidController : MonoBehaviour {
@@ -20,43 +21,43 @@ public class BoidController : MonoBehaviour {
     public float cohesionBias = 0.05f;
     public bool localFlocks = true;
 
-    // Boid Object Prefab
+    public Boid focusedBoid; // A focused Boid has special rendering
-    public GameObject boidObject;
+    public GameObject boidObject; // Boid Object Prefab
-
+    [NonSerialized] public List<Boid> boids = new List<Boid>(); // Boid Objects for Updates
-    // Boid Objects for Updates
+    [NonSerialized] public Camera Cam; // Used for wrapping detection
-    [NonSerialized] [HideInInspector] public List<Boid> boids = new List<Boid>();
-
-    // Used for wrapping
-    public Camera cam;
 
     private void OnDrawGizmos() {
         // Draw a Wire Cube for the Rectangle Area
         Gizmos.DrawWireCube(Space.center, Space.size);
 
+        if (Cam == null)
+            return;
+
         // Draw a Wire Cube for the Cam's Viewport Area
-        Vector3 screenBottomLeft = cam.ViewportToWorldPoint(new Vector3(0, 0, transform.position.z));
+        var position = transform.position;
-        Vector3 screenTopRight = cam.ViewportToWorldPoint(new Vector3(1, 1, transform.position.z));
+        Vector3 screenBottomLeft = Cam.ViewportToWorldPoint(new Vector3(0, 0, position.z));
+        Vector3 screenTopRight = Cam.ViewportToWorldPoint(new Vector3(1, 1, position.z));
         var screenWidth = screenTopRight.x - screenBottomLeft.x;
         var screenHeight = screenTopRight.y - screenBottomLeft.y;
-        Gizmos.DrawWireCube(cam.transform.position, new Vector3(screenWidth, screenHeight, 1));
+        Gizmos.DrawWireCube(Cam.transform.position, new Vector3(screenWidth, screenHeight, 1));
     }
 
     private void Start() {
         // Setup Camera
-        cam = Camera.main;
+        Cam = Camera.main;
 
         // Size the Rectangle based on the Camera's Orthographic View
-        float height = 2f * cam.orthographicSize;
+        float height = 2f * Cam.orthographicSize;
-        Vector2 size = new Vector2(height * cam.aspect, height);
+        Vector2 size = new Vector2(height * Cam.aspect, height);
         Space = new Rect((Vector2) transform.position - size / 2, size);
 
-        // Add in Boid Objects / Spawn Boid Prefabs
+        AddBoids(boidCount);
-        for (int i = 0; i < boidCount; i++) {
+    }
-            // Generate a new position within the Rect boundaries (minus a little)
+
-            var position = new Vector2(
+    public void AddBoids(int n) {
-                Random.Range(-Space.size.x, Space.size.x) / 2 * 0.95f,
+        for (int i = 0; i < n; i++) {
-                Random.Range(-Space.size.y, Space.size.y) / 2 * 0.95f);
+            // Instantiate a Boid prefab within the boundaries randomly
-            // Spawn a new Boid prefab
+            Vector2 position = RandomPosition() * 0.95f;
             GameObject boid = Instantiate(boidObject, position, Quaternion.identity);
 
             // Set parent, add Boid component to Boids list
@@ -64,4 +65,32 @@ public class BoidController : MonoBehaviour {
             boids.Add(boid.GetComponent<Boid>());
         }
     }
+
+    public void RemoveBoids(int n) {
+        print($"Removing {n} boids");
+        while (n-- > 0 && boids.Count >= 1) {
+            int index = Random.Range(0, boids.Count - 1);
+
+            // Only remove the focused Boid if it is the last one
+            if (boids[index] == focusedBoid)
+                if (boids.Count == 1)
+                    RemoveBoid(1);
+                else
+                    n++;
+            else
+                RemoveBoid(index);
+        }
+    }
+
+    private void RemoveBoid(int index) {
+        Boid boid = boids[index];
+        boids.RemoveAt(index);
+        Destroy(boid.transform.gameObject);
+    }
+
+    private Vector2 RandomPosition() {
+        return new Vector2(
+            Random.Range(-Space.size.x, Space.size.x) / 2,
+            Random.Range(-Space.size.y, Space.size.y) / 2);
+    }
 }

Boids/Assets/BoidController.prefab

@@ -0,0 +1,57 @@
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+  m_Name: 
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+  boidCount: 1
+  boidGroupRange: 4.57
+  boidStartVelocity: 0.05
+  boidVelocityLimit: 0.5
+  separationRange: 2.5
+  separationBias: 0.05
+  alignmentBias: 0.5
+  cohesionBias: 0.01
+  localFlocks: 1
+  focusedBoid: {fileID: 0}
+  boidObject: {fileID: 1737515784064720040, guid: 23e1eaaf69d4ef342ac3ef9590f6c642,
+    type: 3}

Boids/Assets/BoidController.prefab.meta

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Boids/Assets/BoidControllerEditor.cs

@@ -0,0 +1,23 @@
+using System;
+using UnityEditor;
+using UnityEngine;
+
+[CustomEditor(typeof(BoidController))]
+public class BoidControllerEditor : Editor {
+    public override void OnInspectorGUI() {
+        BoidController controller = (BoidController) target;
+        
+        // Boid Count update
+        EditorGUI.BeginChangeCheck();
+        controller.boidCount = EditorGUILayout.IntSlider("Boid Count", controller.boidCount, 1, 500);
+        if (EditorGUI.EndChangeCheck() && Application.isPlaying) {
+            int diff = controller.boidCount - controller.boids.Count;
+            Debug.Log($"Difference: {diff}");
+            if (diff > 1)
+                controller.AddBoids(diff);
+            else if (diff < 0)
+                controller.RemoveBoids(Mathf.Abs(diff));
+        }
+        
+    }
+}

Boids/Assets/BoidControllerEditor.cs.meta

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