added zoom for #5

ParticleSimulation/ParticleSimulationScene.cs

@@ -7,17 +7,34 @@ public class ParticleSimulationScene : Node2D
 {
     private Node2D _particleNodes;
 
+    private Camera2D _camera;
+    private Tween _cameraTween;
+
+    private Vector2 _cameraZoomTarget;
+    private Vector2 _cameraPosTarget;
+
+    private float _maxZoom;
+    private Vector2 _spaceSize;
+    
+    private const float CameraZoomSpeed = 0.5f;
+
     private ParticleSimulation _particleSimulation;
     public float PhysicsInterpolationFraction;
 
     public void Initialize(int seed, int nParticles, float zoom)
     {
+        _maxZoom = zoom;
+        _camera = GetNode<Camera2D>("Camera2D");
+        _cameraTween = GetNode<Tween>("CameraTween");
         _particleNodes = GetNode<Node2D>("ParticleNodes");
+        _cameraZoomTarget = _camera.Zoom;
+        _cameraPosTarget = _camera.Position;
         GD.Seed((ulong)seed);
         GD.Print("Last Seed: " + seed);
         var viewSize = GetViewportRect().Size;
-        GetNode<Camera2D>("Camera2D").Zoom = new Vector2(zoom, zoom);
+        _camera.Zoom = new Vector2(zoom, zoom);
         var spaceSize = viewSize * zoom;
+        _spaceSize = spaceSize;
         _particleSimulation = new ParticleSimulation
         {
             SpaceSize = spaceSize
@@ -28,10 +45,92 @@ public class ParticleSimulationScene : Node2D
 
     public override void _Process(float delta)
     {
+        // Game state inputs
         if (Input.IsActionJustPressed("quit")) 
             GetParent<Main>().ExitToMenu();
         if (Input.IsActionJustPressed("reset")) 
             GetParent<Main>().RestartSimulation();
+
+        var shouldTweenStop = false;
+        
+        if (Input.IsActionJustReleased("zoom_in"))
+        {
+            shouldTweenStop = true;
+
+            // Zoom
+            _cameraZoomTarget -= new Vector2(0.1f, 0.1f);
+
+            // Movement
+            var mousePos = GetGlobalMousePosition();
+            var posDelta = _cameraPosTarget - mousePos;
+            posDelta = posDelta.Clamped(500f);
+            _cameraPosTarget -= posDelta * 0.2f;
+        }
+        if (Input.IsActionJustReleased("zoom_out"))
+        {
+            shouldTweenStop = true;
+
+            // Zoom
+            _cameraZoomTarget += new Vector2(0.1f, 0.1f);
+
+            // Movement
+            var mousePos = GetGlobalMousePosition();
+            var posDelta = _cameraPosTarget - mousePos;
+            posDelta = posDelta.Clamped(500f);
+            _cameraPosTarget += posDelta * 0.2f;
+        }
+        
+        var cameraDir = new Vector2();
+
+        if (Input.IsActionPressed("up"))
+            cameraDir += new Vector2(0, -1);
+        if (Input.IsActionPressed("down"))
+            cameraDir += new Vector2(0, 1);
+        if (Input.IsActionPressed("left"))
+            cameraDir += new Vector2(-1, 0);
+        if (Input.IsActionPressed("right"))
+            cameraDir += new Vector2(1, 0);
+
+        if (cameraDir.LengthSquared() != 0)
+        {
+            shouldTweenStop = true;
+            cameraDir = cameraDir.Normalized();
+            _cameraPosTarget += cameraDir * 1000f * delta;
+        }
+
+        if (Input.IsActionPressed("key_zoom_in"))
+        {
+            shouldTweenStop = true;
+            _cameraZoomTarget -= new Vector2(0.01f, 0.01f);
+        }
+
+        if (Input.IsActionPressed("key_zoom_out"))
+        {
+            shouldTweenStop = true;
+            _cameraZoomTarget += new Vector2(0.01f, 0.01f);
+        }
+
+        if (shouldTweenStop)
+        {
+            _cameraTween.StopAll();
+            
+            _cameraZoomTarget.x = Mathf.Clamp(_cameraZoomTarget.x, 0.01f, _maxZoom);
+            _cameraZoomTarget.y = Mathf.Clamp(_cameraZoomTarget.y, 0.01f, _maxZoom);
+
+            _cameraPosTarget.x = Mathf.Clamp(_cameraPosTarget.x,
+                0f - (_maxZoom - _cameraZoomTarget.x) * (_spaceSize.x / (Mathf.Sqrt2 * 2)),
+                0f + (_maxZoom - _cameraZoomTarget.x) * (_spaceSize.x / (Mathf.Sqrt2 * 2)));
+            _cameraPosTarget.y = Mathf.Clamp(_cameraPosTarget.y,
+                0f - (_maxZoom - _cameraZoomTarget.y) * (_spaceSize.y / (Mathf.Sqrt2 * 2)),
+                0f + (_maxZoom - _cameraZoomTarget.y) * (_spaceSize.y / (Mathf.Sqrt2 * 2)));
+            
+            _cameraTween.InterpolateProperty(_camera, "zoom", _camera.Zoom, _cameraZoomTarget, CameraZoomSpeed,
+                Tween.TransitionType.Quint, Tween.EaseType.Out);
+            _cameraTween.InterpolateProperty(_camera, "position", _camera.Position, _cameraPosTarget, CameraZoomSpeed,
+                Tween.TransitionType.Quint, Tween.EaseType.Out);
+            _cameraTween.Start();
+        }
+        
         PhysicsInterpolationFraction = Engine.GetPhysicsInterpolationFraction();
     }
 
@@ -51,7 +150,7 @@ public class ParticleSimulationScene : Node2D
         {
             var simulationParticle = _particleSimulation.GetParticle(particleNode.SimulationId);
             particleNode.LastSimulationPosition = particleNode.Position;
-            particleNode.CurrentSimulationPosition = simulationParticle.Position;
+            particleNode.CurrentSimulationPosition = simulationParticle.Position - (_spaceSize / 2.0f);
             particleNode.SetColor(simulationParticle.Type.Hue, simulationParticle.Health,
                 Mathf.Clamp(simulationParticle.AverageSpeed / 1.5f, 1f, 1f));
             particleNode.WasTeleportedLast = simulationParticle.WasTeleportedLast;

ParticleSimulation/ParticleSimulationScene.tscn

@@ -8,6 +8,8 @@ script = ExtResource( 1 )
 [node name="ParticleNodes" type="Node2D" parent="."]
 
 [node name="Camera2D" type="Camera2D" parent="."]
-anchor_mode = 0
 current = true
 zoom = Vector2( 1.35, 1.35 )
+smoothing_speed = 100.0
+
+[node name="CameraTween" type="Tween" parent="."]

project.godot

@@ -29,6 +29,50 @@ quit={
 "events": [ Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":16777217,"physical_scancode":0,"unicode":0,"echo":false,"script":null)
  ]
 }
+up={
+"deadzone": 0.5,
+"events": [ Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":87,"physical_scancode":0,"unicode":0,"echo":false,"script":null)
+, Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":16777232,"physical_scancode":0,"unicode":0,"echo":false,"script":null)
+ ]
+}
+down={
+"deadzone": 0.5,
+"events": [ Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":16777234,"physical_scancode":0,"unicode":0,"echo":false,"script":null)
+, Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":83,"physical_scancode":0,"unicode":0,"echo":false,"script":null)
+ ]
+}
+left={
+"deadzone": 0.5,
+"events": [ Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":65,"physical_scancode":0,"unicode":0,"echo":false,"script":null)
+, Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":16777231,"physical_scancode":0,"unicode":0,"echo":false,"script":null)
+ ]
+}
+right={
+"deadzone": 0.5,
+"events": [ Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":16777233,"physical_scancode":0,"unicode":0,"echo":false,"script":null)
+, Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":68,"physical_scancode":0,"unicode":0,"echo":false,"script":null)
+ ]
+}
+zoom_in={
+"deadzone": 0.5,
+"events": [ Object(InputEventMouseButton,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"button_mask":0,"position":Vector2( 0, 0 ),"global_position":Vector2( 0, 0 ),"factor":1.0,"button_index":4,"pressed":false,"doubleclick":false,"script":null)
+ ]
+}
+zoom_out={
+"deadzone": 0.5,
+"events": [ Object(InputEventMouseButton,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"button_mask":0,"position":Vector2( 0, 0 ),"global_position":Vector2( 0, 0 ),"factor":1.0,"button_index":5,"pressed":false,"doubleclick":false,"script":null)
+ ]
+}
+key_zoom_in={
+"deadzone": 0.5,
+"events": [ Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":69,"physical_scancode":0,"unicode":0,"echo":false,"script":null)
+ ]
+}
+key_zoom_out={
+"deadzone": 0.5,
+"events": [ Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":81,"physical_scancode":0,"unicode":0,"echo":false,"script":null)
+ ]
+}
 
 [mono]