View3D can untrack objects and zoom in different modes

- updateDistance zooms between 0 and infinity
- Camera switches from third person to bird's eye when reaching a set distance
- Only one subject can be tracked at a time

#story[1190]

racevisionGame/src/main/java/visualiser/Controllers/RaceController.java

@@ -225,6 +225,10 @@ public class RaceController extends Controller {
             trackBoat.start();
         }
         view3D.updatePivot(new Translate(250, 0, 210));
+
+        view3D.setOnScroll(e -> {
+            view3D.updateDistance(e.getDeltaY());
+        });
     }
 
 

racevisionGame/src/main/java/visualiser/layout/View3D.java

@@ -1,5 +1,7 @@
 package visualiser.layout;
 
+import javafx.beans.value.ChangeListener;
+import javafx.beans.value.ObservableValue;
 import javafx.collections.ListChangeListener;
 import javafx.collections.ObservableList;
 import javafx.geometry.Point3D;
@@ -31,6 +33,10 @@ public class View3D extends Pane {
      * Map for selecting Subject3D from Shape3D
      */
     private Map<Shape3D, Subject3D> selectionMap;
+    /**
+     * Subject tracked by camera
+     */
+    private Subject3D target;
     /**
      * Rendering container for shapes
      */
@@ -60,12 +66,23 @@ public class View3D extends Pane {
      */
     private Rotate pitch;
 
+    private ChangeListener<? super Number> pivotHeading = (o, prev, curr) -> yaw.setAngle((double)curr);
+
+    private ChangeListener<? super Number> pivotX = (o, prev, curr) -> pivot.setX((double)curr);
+
+    private ChangeListener<? super Number> pivotY = (o, prev, curr) -> pivot.setY((double)curr);
+
+    private ChangeListener<? super Number> pivotZ = (o, prev, curr) -> pivot.setZ((double)curr);
+
+    private double THIRD_PERSON_LIMIT = 100;
+
     /**
      * Default constructor for View3D. Sets up Scene and PerspectiveCamera.
      */
     public View3D() {
         world = new Group();
         selectionMap = new HashMap<>();
+        target = null;
 
         SubScene scene = new SubScene(world, 300, 300);
         scene.widthProperty().bind(this.widthProperty());
@@ -77,14 +94,7 @@ public class View3D extends Pane {
         scene.setOnMousePressed(e -> {
             PickResult result = e.getPickResult();
             if(result != null && result.getIntersectedNode() != null && result.getIntersectedNode() instanceof Shape3D) {
-                Subject3D target = selectionMap.get(result.getIntersectedNode());
+                trackSubject(selectionMap.get(result.getIntersectedNode()));
-                target.getPosition().xProperty().addListener((o, prev, curr) -> pivot.setX((double)curr));
-                target.getPosition().yProperty().addListener((o, prev, curr) -> pivot.setY((double)curr));
-                target.getPosition().zProperty().addListener((o, prev, curr) -> pivot.setZ((double)curr));
-                target.getHeading().angleProperty().addListener((o, prev, curr) -> setYaw((double)curr));
-
-                this.setDistance(100);
-                this.setPitch(30);
             }
         });
 
@@ -132,6 +142,31 @@ public class View3D extends Pane {
         });
     }
 
+    private void untrackSubject() {
+        if(target != null) {
+            target.getPosition().xProperty().removeListener(pivotX);
+            target.getPosition().yProperty().removeListener(pivotY);
+            target.getPosition().zProperty().removeListener(pivotZ);
+            target.getHeading().angleProperty().removeListener(pivotHeading);
+        }
+    }
+
+    private void trackSubject(Subject3D subject) {
+        untrackSubject();
+        target = subject;
+
+        updatePivot(target.getPosition());
+        setYaw(target.getHeading().getAngle());
+
+        target.getPosition().xProperty().addListener(pivotX);
+        target.getPosition().yProperty().addListener(pivotY);
+        target.getPosition().zProperty().addListener(pivotZ);
+        target.getHeading().angleProperty().addListener(pivotHeading);
+
+        this.setDistance(THIRD_PERSON_LIMIT);
+        this.setPitch(20);
+    }
+
     public void setNearClip(double nearClip) {
         this.nearClip = nearClip;
     }
@@ -155,7 +190,18 @@ public class View3D extends Pane {
     }
 
     public void updateDistance(double delta) {
-        this.distance.setZ(this.distance.getZ() - delta);
+        double distance = -this.distance.getZ() + delta;
+
+        if(distance <= 0) {
+            this.setDistance(0);
+        } else if(distance > THIRD_PERSON_LIMIT) {
+            untrackSubject();
+            this.setYaw(0);
+            this.setPitch(60);
+            this.setDistance(distance);
+        } else {
+            this.setDistance(distance);
+        }
     }
 
     /**