AB3: BodyLinkedList working

src/Vector3.java

@@ -4,7 +4,6 @@ import codedraw.CodeDraw;
  * This class represents vectors in a 3D vector space.
  */
 public class Vector3 {
-
     private double x;
     private double y;
     private double z;
@@ -27,33 +26,21 @@ public class Vector3 {
      * Returns the sum of this vector and vector 'v'.
      */
     public Vector3 plus(Vector3 v) {
-        Vector3 result = new Vector3();
-        result.x = x + v.x;
-        result.y = y + v.y;
-        result.z = z + v.z;
-        return result;
+        return new Vector3(x + v.x, y + v.y, z + v.z);
     }
 
     /**
      * Returns the product of this vector and 'd'.
      */
     public Vector3 times(double d) {
-        Vector3 result = new Vector3();
-        result.x = x * d;
-        result.y = y * d;
-        result.z = z * d;
-        return result;
+        return new Vector3(x * d, y * d, z * d);
     }
 
     /**
      * Returns the sum of this vector and -1*v.
      */
     public Vector3 minus(Vector3 v) {
-        Vector3 result = new Vector3();
-        result.x = x - v.x;
-        result.y = y - v.y;
-        result.z = z - v.z;
-        return result;
+        return new Vector3(x - v.x, y - v.y, z - v.z);
     }
 
     /**
@@ -85,15 +72,21 @@ public class Vector3 {
         z /= length;
     }
 
+    public double getScreenX(CodeDraw cd) {
+        return cd.getWidth() * (this.x + Simulation.SECTION_SIZE / 2) / Simulation.SECTION_SIZE;
+    }
+
+    public double getScreenY(CodeDraw cd) {
+        return cd.getWidth() * (this.y + Simulation.SECTION_SIZE / 2) / Simulation.SECTION_SIZE;
+    }
+
     /**
      * Draws a filled circle with a specified radius centered at the (x,y) coordinates of this vector
      * in the canvas associated with 'cd'. The z-coordinate is not used.
      */
     public void drawAsFilledCircle(CodeDraw cd, double radius) {
-        double x = cd.getWidth() * (this.x + Simulation.SECTION_SIZE / 2) / Simulation.SECTION_SIZE;
-        double y = cd.getWidth() * (this.y + Simulation.SECTION_SIZE / 2) / Simulation.SECTION_SIZE;
         radius = cd.getWidth() * radius / Simulation.SECTION_SIZE;
-        cd.fillCircle(x, y, Math.max(radius, 1.5));
+        cd.fillCircle(getScreenX(cd), getScreenY(cd), Math.max(radius, 1.5));
     }
 
     /**