Aufgabenblatt 4

src/CosmicSystem.java

@@ -0,0 +1,41 @@
+// A representation of a system of bodies with associated forces. Provides methods
+// for computing current mutual forces, updating the positions of bodies and drawing
+// the bodies in a CodeDraw object.
+//
+public interface CosmicSystem extends Drawable {
+
+    // Returns a readable representation of this system.
+    String toString();
+
+    // Returns the mass center of this system.
+    Vector3 getMassCenter();
+
+    // Returns the overall mass of this system.
+    double getMass();
+
+    // Returns the overall number of bodies contained in this system.
+    int numberOfBodies();
+
+    // Returns the distance between the mass centers of 'this' and the specified system.
+    //Precondition: cs != null
+    double distanceTo(CosmicSystem cs);
+
+    // Adds the force that the specified body exerts on each of this systems bodies to each of this
+    // systems bodies.
+    // Precondition: b != null
+    void addForceFrom(Body b);
+
+    // Adds the force that this system exerts on each of the bodies of 'cs' to the bodies in 'cs'.
+    // For exact computations this means that for each body of 'this' its force on each body of
+    // 'cs' is added to this body of 'cs'.
+    // Precondition: cs != null
+    void addForceTo(CosmicSystem cs);
+
+    // Returns a list with all the bodies of 'this'. The order is not defined.
+    BodyLinkedList getBodies();
+
+    // Moves each of the bodies of 'this' according to the previously accumulated forces and
+    // resets all forces to zero.
+    void update();
+
+}