tweaks

Main.cs

@@ -10,12 +10,17 @@ public class Main : Node2D
     private readonly List<ParticleType> _particleTypes = new List<ParticleType>();
     private List<Particle> _particles;
 
+    private const int MaxParticles = 700;
+
+    private const float HealthDelta = 0.002f;
+    private const float PositiveHealthMultiplier = 2f;
+
     public override void _Ready()
     {
         GD.Randomize();
-        InitializeParticleTypes(10);
+        InitializeParticleTypes(12);
-        InitializeParticles(700);
+        InitializeParticles(MaxParticles);
-        _particles = GetNode<Node2D>("Particles").GetChildren().Cast<Particle>().ToList();
+        
     }
 
     public override void _Process(float delta)
@@ -42,7 +47,9 @@ public class Main : Node2D
 
         foreach (var type1 in _particleTypes)
             foreach (var type2 in _particleTypes)
-            type1.AddRelationship(type2, 20, (float) GD.RandRange(25, 60), (float) GD.RandRange(-0.33 * 2f, 0.35 * 2f));
+                type1.AddRelationship(type2, 
+                    new ParticleRelationshipProps(20, (float) GD.RandRange(25, 60), 
+                        (float) GD.RandRange(-0.33 * 2f, 0.35 * 2f)));
     }
 
     private void InitializeParticles(int nParticles)
@@ -55,6 +62,7 @@ public class Main : Node2D
             GetNode<Node2D>("Particles").AddChild(particle);
             particle.Position = GetRandomParticlePosition();
             particle.Type = _particleTypes[typeCount];
+            particle.Health = 1f;
 
             if (typeCount < _particleTypes.Count - 1)
                 typeCount++;
@@ -63,6 +71,23 @@ public class Main : Node2D
         }
     }
 
+    private void CreateParticle(ParticleType type)
+    {
+        var particleScene = GD.Load<PackedScene>("res://Particle.tscn");
+        var particle = particleScene.Instance<Particle>();
+        GetNode<Node2D>("Particles").AddChild(particle);
+        particle.Position = GetRandomParticlePosition();
+        particle.Type = type;
+        particle.Health = 1f;
+    }
+
+    private void CreateRandomParticle()
+    {
+        var randomIndex = (int)(GD.Randi() % _particleTypes.Count);
+        var type = _particleTypes[randomIndex];
+        CreateParticle(type);
+    }
+    
     private Vector2 GetRandomParticlePosition()
     {
         var viewportRect = GetViewportRect();
@@ -74,27 +99,60 @@ public class Main : Node2D
 
     private void UpdateParticles()
     {
+        _particles = GetNode<Node2D>("Particles").GetChildren().Cast<Particle>().ToList();
         var tasks = new Task[_particles.Count];
         var viewportRect = GetViewportRect();
         for (var i = 0; i < _particles.Count; i++) tasks[i] = Task.Factory.StartNew(UpdateParticle, _particles[i]);
 
         Task.WaitAll(tasks);
 
+        var deletedParticle = false;
+
         foreach (var p in _particles)
         {
+            if (deletedParticle == false && p.Health == 0f)
+            {
+                if (GD.Randf() < 0.2f)
+                {
+                    p.Free();
+                    deletedParticle = true;
+                    continue;
+                }
+            }
             var position = p.Position;
-            p.Velocity = p.Velocity.Clamped(3f * 2f);
+            p.Velocity = p.Velocity.Clamped(3f * 4f);
             position += p.Velocity;
-            p.Velocity *= 0.85f;
+            p.Velocity *= 0.875f;    // friction
             position.x = Mathf.Clamp(position.x, ParticleScreenPadding, viewportRect.Size.x - ParticleScreenPadding);
             position.y = Mathf.Clamp(position.y, ParticleScreenPadding, viewportRect.Size.y - ParticleScreenPadding);
+            p.AddAverageSpeedValue(p.Position.DistanceTo(position));
+            
+            if (p.AverageSpeed < 0.3f)
+                p.Health -= HealthDelta * 1.5f;
+            else
+                p.Health += HealthDelta;
+            
+            if (deletedParticle == false && p.Health == 0f)
+            {
+                if (GD.Randf() < 0.2f)
+                {
+                    p.Free();
+                    deletedParticle = true;
+                    continue;
+                }
+            }
             p.Position = position;
         }
+
+        if (_particles.Count < MaxParticles)
+            if (GD.Randf() < 0.3f)
+                CreateRandomParticle();
     }
 
     private void UpdateParticle(object particle)
     {
         var p1 = (Particle) particle;
+        var closeCount = 0;
         foreach (var p2 in _particles)
         {
             var viewportRect = GetViewportRect();
@@ -105,6 +163,12 @@ public class Main : Node2D
                 continue;
             var direction = p1.Position.DirectionTo(p2.Position);
 
+
+            if (distance < 70)
+            {
+                closeCount++;
+            }
+            
             // collision force
             if (distance < 20)
             {
@@ -121,5 +185,11 @@ public class Main : Node2D
                                 props.Force;
             p1.Velocity += direction * particleForce;
         }
+        
+        if (closeCount < 3 || closeCount > 35)
+            p1.Health -= HealthDelta * 1.5f;
+        else
+            p1.Health += HealthDelta;
+        
     }
 }

Particle.cs

@@ -3,9 +3,23 @@ using Godot;
 public class Particle : Node2D
 {
     private Sprite _spriteNode;
-    private ParticleType _type;
+    private Label _labelNode;
     
+    private ParticleType _type;
+    private float _health = 0f;
+    private float _averageSpeed = 1f;
     public Vector2 Velocity { get; set; }
+    public float AverageSpeed { get => _averageSpeed; }
+
+    public float Health
+    {
+        get => _health;
+        set
+        {
+            _health = Mathf.Clamp(value, 0f, 1f);
+            _spriteNode.Modulate = Color.FromHsv(_type.Hue, Health, 1);
+        }
+    }
 
     public ParticleType Type
     {
@@ -13,12 +27,23 @@ public class Particle : Node2D
         set
         {
             _type = value;
-            _spriteNode.Modulate = Color.FromHsv(_type.Hue, 1, 1);
+            _spriteNode.Modulate = Color.FromHsv(_type.Hue, Health, 1);
         }
     }
 
     public override void _Ready()
     {
         _spriteNode = GetNode<Sprite>("Sprite");
+        _labelNode = GetNode<Label>("Label");
+    }
+
+    public void AddAverageSpeedValue(float speed)
+    {
+        _averageSpeed = (0.99f * _averageSpeed) + (0.01f * speed);
+    }
+
+    public void SetLabelText(string text)
+    {
+        _labelNode.Text = text;
     }
 }

Particle.tscn

@@ -9,3 +9,14 @@ script = ExtResource( 2 )
 [node name="Sprite" type="Sprite" parent="."]
 scale = Vector2( 0.25, 0.25 )
 texture = ExtResource( 1 )
+
+[node name="Label" type="Label" parent="."]
+visible = false
+margin_left = -18.0
+margin_top = -23.0
+margin_right = 18.0
+margin_bottom = -9.0
+text = "0.05"
+__meta__ = {
+"_edit_use_anchors_": false
+}

ParticleType.cs

@@ -28,11 +28,10 @@ public class ParticleType
         set => _hue = Mathf.Clamp(value, 0, 1);
     }
 
-    public void AddRelationship(ParticleType type, float minRadius, float maxRadius, float force)
+    public void AddRelationship(ParticleType type, ParticleRelationshipProps props)
     {
         if (_particleRelationships.ContainsKey(type))
             return;
-        var props = new ParticleRelationshipProps(minRadius, maxRadius, force);
         _particleRelationships[type] = props;
     }