Aufgabenblatt 5

src/Massive.java

@@ -0,0 +1,64 @@
+// Represents a coherent mass with a mass center in 3D space. Has two naming schemes for its
+// methods. Please, do not change this interface definition!
+//
+public interface Massive extends Drawable {
+
+    // Returns the mass.
+    default double mass() {
+
+        return getMass();
+    }
+
+    // Returns the mass center.
+    default Vector3 massCenter() {
+
+        return getMassCenter();
+    }
+
+    // Returns the mass.
+    default double getMass() {
+
+        return mass();
+    }
+
+    // Returns the mass center.
+    default Vector3 getMassCenter() {
+
+        return massCenter();
+    }
+
+    // Returns the approximate radius of 'this', assuming it is a coherent round mass.
+    // (It is assumed that the radius r is related to the mass m by r = m ^ 0.5,
+    // where m and r measured in solar units.)
+    default double getRadius() {
+
+        return radius();
+    }
+
+    // Returns the approximate radius of 'this', assuming it is a coherent round mass.
+    // (It is assumed that the radius r is related to the mass m by r = m ^ 0.5,
+    // where m and r measured in solar units.)
+    default double radius() {
+
+        return SpaceDraw.massToRadius(mass());
+    }
+
+    // Returns a vector representing the gravitational force exerted by 'b' on this mass.
+    // The gravitational Force F is calculated by F = G*(m1*m2)/(r*r), with m1 and m2 being the
+    // masses of the objects interacting, r being the distance between the centers of the masses
+    // and G being the gravitational constant.
+    default Vector3 gravitationalForce(Massive b) {
+
+        Vector3 direction = b.massCenter().minus(this.massCenter());
+        double distance = direction.length();
+        direction.normalize();
+        double force = Simulation.G*this.mass()*b.mass()/(distance * distance);
+        return direction.times(force);
+    }
+
+    // Centers this mass at a new position, according to the specified force vector 'force' exerted
+    // on it, and updates the current velocity vector accordingly.
+    // (Velocity depends on the mass of 'this', its current velocity and the exerted force.)
+    void move(Vector3 force);
+
+}