refactor: rewriting of Moon

core/src/sagittarius/model/Moon.java

@@ -2,40 +2,38 @@ package sagittarius.model;
 
 import com.badlogic.gdx.graphics.Color;
 import com.badlogic.gdx.math.MathUtils;
+import com.badlogic.gdx.math.Vector2;
 
 public class Moon extends Planet {
 
-    private Planet planet;
+    private Planet sun;
     private float altitude;
 
 // ---------- CONSTRUCTORs ----------
 
-    public Moon(Planet planet, float mass, float radius, float altitude) {
+    public Moon(Planet sun, float mass, float radius, float altitude, Color color) {
-        super(planet.position, mass, radius);
+        super(new Vector2(), mass, radius, color);
-        this.planet = planet;
+        this.sun = sun;
         this.altitude = altitude;
     }
 
-    Moon(Planet planet, float mass, float radius, float altitude, Color color) {
-        super(planet.position, mass, radius, color);
-    }
-
 // ---------- METHODs ----------
 
-    void update(double deltaTime) {
+    @Override
+    public void act(float deltaTime) {
 
-        this.angle += 10.0f / altitude;
+        this.rotateBy(10.0f / this.altitude);
 
-        this.position.x = planet.position.x + altitude*MathUtils.cosDeg(angle);
+        this.setX(sun.getX() + this.altitude*MathUtils.cosDeg(this.getRotation()));
-        this.position.y = planet.position.y + altitude*MathUtils.sinDeg(angle);
+        this.setY(sun.getY() + this.altitude*MathUtils.sinDeg(this.getRotation()));
 
     }
 
     /**
      * @return the Planet which the Moon orbits.
      */
-    Planet getPlanet() {
+    Planet getSun() {
-        return this.planet;
+        return this.sun;
     }
 
 }