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This commit is contained in:
Lorenz Stechauner
2022-03-28 10:31:17 +02:00
parent dca869995a
commit fcacaa8657
9 changed files with 152 additions and 88 deletions

2
src/Aufgabe1Test.java

@ -1,9 +1,7 @@
import java.awt.*;
public class Aufgabe1Test {
public static void main(String[] args) {
//test classes Body and Vector3
// create two bodies

69
src/Body.java

@ -1,6 +1,8 @@
import codedraw.CodeDraw;
// This class represents celestial bodies like stars, planets, asteroids, etc..
/**
* This class represents celestial bodies like stars, planets, asteroids, etc...
*/
public class Body {
private double mass;
private Vector3 massCenter; // position of the mass center.
@ -12,16 +14,20 @@ public class Body {
this.currentMovement = currentMovement;
}
// Returns the distance between the mass centers of this body and the specified body 'b'.
/**
* Returns the distance between the mass centers of this body and the specified body 'b'.
*/
public double distanceTo(Body b) {
return massCenter.distanceTo(b.massCenter);
}
// Returns a vector representing the gravitational force exerted by 'b' on this body.
// 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.
// Hint: see simulation loop in Simulation.java to find out how this is done.
/**
* Returns a vector representing the gravitational force exerted by 'b' on this body.
* 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.
* Hint: see simulation loop in Simulation.java to find out how this is done.
*/
public Vector3 gravitationalForce(Body b) {
Vector3 direction = b.massCenter.minus(massCenter);
double distance = direction.length();
@ -30,10 +36,12 @@ public class Body {
return direction.times(force);
}
// Moves this body to a new position, according to the specified force vector 'force' exerted
// on it, and updates the current movement accordingly.
// (Movement depends on the mass of this body, its current movement and the exerted force.)
// Hint: see simulation loop in Simulation.java to find out how this is done.
/**
* Moves this body to a new position, according to the specified force vector 'force' exerted
* on it, and updates the current movement accordingly.
* (Movement depends on the mass of this body, its current movement and the exerted force.)
* Hint: see simulation loop in Simulation.java to find out how this is done.
*/
public void move(Vector3 force) {
// F = m*a -> a = F/m
Vector3 newPosition = massCenter.plus(force.times(1.0 / mass)).plus(currentMovement);
@ -46,19 +54,26 @@ public class Body {
currentMovement = newMovement;
}
// Returns the approximate radius of this body.
// (It is assumed that the radius r is related to the mass m of the body by r = m ^ 0.5,
// where m and r measured in solar units.)
/**
* Returns the approximate radius of this body.
* (It is assumed that the radius r is related to the mass m of the body by r = m ^ 0.5,
* where m and r measured in solar units.)
*/
public double radius() {
return SpaceDraw.massToRadius(mass);
}
/**
* Return the mass of the Body.
*/
public double mass() {
return mass;
}
// Returns a new body that is formed by the collision of this body and 'b'. The impulse
// of the returned body is the sum of the impulses of 'this' and 'b'.
/**
* Returns a new body that is formed by the collision of this body and 'b'. The impulse
* of the returned body is the sum of the impulses of 'this' and 'b'.
*/
public Body merge(Body b) {
double mass = this.mass + b.mass;
return new Body(
@ -68,25 +83,27 @@ public class Body {
);
}
// Draws the body to the specified canvas as a filled circle.
// The radius of the circle corresponds to the radius of the body
// (use a conversion of the real scale to the scale of the canvas as
// in 'Simulation.java').
// Hint: call the method 'drawAsFilledCircle' implemented in 'Vector3'.
/**
* Draws the body to the specified canvas as a filled circle.
* The radius of the circle corresponds to the radius of the body
* (use a conversion of the real scale to the scale of the canvas as
* in 'Simulation.java').
* Hint: call the method 'drawAsFilledCircle' implemented in 'Vector3'.
*/
public void draw(CodeDraw cd) {
cd.setColor(SpaceDraw.massToColor(mass));
massCenter.drawAsFilledCircle(cd, SpaceDraw.massToRadius(mass));
}
// Returns a string with the information about this body including
// mass, position (mass center) and current movement. Example:
// "5.972E24 kg, position: [1.48E11,0.0,0.0] m, movement: [0.0,29290.0,0.0] m/s."
/**
* Returns a string with the information about this body including
* mass, position (mass center) and current movement. Example:
* "5.972E24 kg, position: [1.48E11,0.0,0.0] m, movement: [0.0,29290.0,0.0] m/s."
*/
public String toString() {
return String.format(
"%f kg, position: %s m, movement: %s m/s.",
mass, massCenter.toString(), currentMovement.toString()
);
}
}

33
src/BodyForceMap.java

@ -1,8 +1,8 @@
// A map that associates a body with a force exerted on it. The number of
// key-value pairs is not limited.
//
/**
* A map that associates a body with a force exerted on it. The number of
* key-value pairs is not limited.
*/
public class BodyForceMap {
private int size = 0;
private int capacity;
private Body[] keys;
@ -12,17 +12,21 @@ public class BodyForceMap {
this(4);
}
// Initializes this map with an initial capacity.
// Precondition: initialCapacity > 0.
/**
* Initializes this map with an initial capacity.
* Precondition: initialCapacity > 0.
*/
public BodyForceMap(int initialCapacity) {
this.capacity = initialCapacity;
this.keys = new Body[this.capacity];
this.values = new Vector3[this.capacity];
}
// Adds a new key-value association to this map. If the key already exists in this map,
// the value is replaced and the old value is returned. Otherwise 'null' is returned.
// Precondition: key != null.
/**
* Adds a new key-value association to this map. If the key already exists in this map,
* the value is replaced and the old value is returned. Otherwise 'null' is returned.
* Precondition: key != null.
*/
public Vector3 put(Body key, Vector3 force) {
if (size == capacity) {
doubleCapacity();
@ -55,9 +59,11 @@ public class BodyForceMap {
return null;
}
// Returns the value associated with the specified key, i.e. the returns the force vector
// associated with the specified body. Returns 'null' if the key is not contained in this map.
// Precondition: key != null.
/**
* Returns the value associated with the specified key, i.e. the returns the force vector
* associated with the specified body. Returns 'null' if the key is not contained in this map.
* Precondition: key != null.
*/
public Vector3 get(Body key) {
int left = 0;
int right = size - 1;
@ -94,6 +100,9 @@ public class BodyForceMap {
return null;
}
/**
* Doubles the capacity of the map.
*/
private void doubleCapacity() {
capacity *= 2;
Body[] tmpKeys = new Body[capacity];

45
src/BodyQueue.java

@ -1,10 +1,10 @@
// A queue of bodies. A collection designed for holding bodies prior to processing.
// The bodies of the queue can be accessed in a FIFO (first-in-first-out) manner,
// i.e., the body that was first inserted by 'add' is retrieved first by 'poll'.
// The number of elements of the queue is not limited.
//
/**
* A queue of bodies. A collection designed for holding bodies prior to processing.
* The bodies of the queue can be accessed in a FIFO (first-in-first-out) manner,
* i.e., the body that was first inserted by 'add' is retrieved first by 'poll'.
* The number of elements of the queue is not limited.
*/
public class BodyQueue {
private int capacity;
private int head = 0;
private int tail = 0;
@ -14,17 +14,21 @@ public class BodyQueue {
this(4);
}
// Initializes this queue with an initial capacity.
// Precondition: initialCapacity > 0.
/**
* Initializes this queue with an initial capacity.
* Precondition: initialCapacity > 0.
*/
public BodyQueue(int initialCapacity) {
this.capacity = initialCapacity;
this.queue = new Body[this.capacity];
}
// Initializes this queue as an independent copy of the specified queue.
// Calling methods of this queue will not affect the specified queue
// and vice versa.
// Precondition: q != null.
/**
* Initializes this queue as an independent copy of the specified queue.
* Calling methods of this queue will not affect the specified queue
* and vice versa.
* Precondition: q != null.
*/
public BodyQueue(BodyQueue q) {
this.capacity = q.capacity;
this.head = q.size();
@ -35,7 +39,9 @@ public class BodyQueue {
}
}
// Adds the specified body 'b' to this queue.
/**
* Adds the specified body 'b' to this queue.
*/
public void add(Body b) {
queue[head] = b;
head = (head + 1) % capacity;
@ -45,8 +51,10 @@ public class BodyQueue {
}
}
// Retrieves and removes the head of this queue, or returns 'null'
// if this queue is empty.
/**
* Retrieves and removes the head of this queue, or returns 'null'
* if this queue is empty.
*/
public Body poll() {
if (tail == head) {
return null;
@ -57,11 +65,16 @@ public class BodyQueue {
return b;
}
// Returns the number of bodies in this queue.
/**
* Returns the number of bodies in this queue.
*/
public int size() {
return (head - tail + capacity) % capacity;
}
/**
* Double the capacity of the queue.
*/
private void doubleCapacity() {
Body[] tmp = new Body[capacity * 2];
for (int i = head, j = 0; i < tail + capacity; i++, j++) {

9
src/Simulation.java

@ -12,7 +12,9 @@ import java.util.Random;
// 3. Beim Methodenaufruf steht links vom `.` entweder das Objekt, oder die Klasse. In Java beginnen Variablennamen
// üblicherweise mit Kleinbuchstaben und Klassennamen üblicherweise mit einem Großbuchstaben.
// Simulates the formation of a massive solar system.
/**
* Simulates the formation of a massive solar system.
*/
public class Simulation {
// gravitational constant
@ -37,7 +39,9 @@ public class Simulation {
// all quantities are based on units of kilogram respectively second and meter.
// The main simulation method using instances of other classes.
/**
* The main simulation method using instances of other classes.
*/
public static void main(String[] args) {
// simulation
CodeDraw cd = new CodeDraw();
@ -127,6 +131,5 @@ public class Simulation {
bodies = newBodies;
}
}
}

24
src/SpaceDraw.java

@ -2,17 +2,21 @@ import java.awt.*;
public class SpaceDraw {
// Returns the approximate radius of a celestial body with the specified mass.
// (It is assumed that the radius r is related to the mass m of the body by r = m ^ 0.5,
// where m and r measured in solar units.)
/**
* Returns the approximate radius of a celestial body with the specified mass.
* (It is assumed that the radius r is related to the mass m of the body by r = m ^ 0.5,
* where m and r measured in solar units.)
*/
public static double massToRadius(double mass) {
return Simulation.SUN_RADIUS * (Math.pow(mass / Simulation.SUN_MASS, 0.5));
}
// Returns the approximate color of a celestial body with the specified mass. The color of
// the body corresponds to the temperature of the body, assuming the relation of mass and
// temperature of a main sequence star.
/**
* Returns the approximate color of a celestial body with the specified mass. The color of
* the body corresponds to the temperature of the body, assuming the relation of mass and
* temperature of a main sequence star.
*/
public static Color massToColor(double mass) {
Color color;
if (mass < Simulation.SUN_MASS / 10) {
@ -26,7 +30,9 @@ public class SpaceDraw {
return color;
}
// Returns the approximate color of temperature 'kelvin'.
/**
* Returns the approximate color of temperature 'kelvin'.
*/
private static Color kelvinToColor(int kelvin) {
double k = kelvin / 100D;
@ -41,7 +47,9 @@ public class SpaceDraw {
);
}
// A transformation used in the method 'kelvinToColor'.
/**
* A transformation used in the method 'kelvinToColor'.
*/
private static int limitAndDarken(double color, int kelvin) {
int kelvinNorm = kelvin - 373;

46
src/Vector3.java

@ -1,6 +1,8 @@
import codedraw.CodeDraw;
// This class represents vectors in a 3D vector space.
/**
* This class represents vectors in a 3D vector space.
*/
public class Vector3 {
private double x;
@ -21,7 +23,9 @@ public class Vector3 {
this.z = z;
}
// Returns the sum of this vector and vector 'v'.
/**
* Returns the sum of this vector and vector 'v'.
*/
public Vector3 plus(Vector3 v) {
Vector3 result = new Vector3();
result.x = x + v.x;
@ -30,7 +34,9 @@ public class Vector3 {
return result;
}
// Returns the product of this vector and 'd'.
/**
* Returns the product of this vector and 'd'.
*/
public Vector3 times(double d) {
Vector3 result = new Vector3();
result.x = x * d;
@ -39,7 +45,9 @@ public class Vector3 {
return result;
}
// Returns the sum of this vector and -1*v.
/**
* Returns the sum of this vector and -1*v.
*/
public Vector3 minus(Vector3 v) {
Vector3 result = new Vector3();
result.x = x - v.x;
@ -48,8 +56,10 @@ public class Vector3 {
return result;
}
// Returns the Euclidean distance of this vector
// to the specified vector 'v'.
/**
* Returns the Euclidean distance of this vector
* to the specified vector 'v'.
*/
public double distanceTo(Vector3 v) {
double dX = x - v.x;
double dY = y - v.y;
@ -57,13 +67,17 @@ public class Vector3 {
return Math.sqrt(dX * dX + dY * dY + dZ * dZ);
}
// Returns the length (norm) of this vector.
/**
* Returns the length (norm) of this vector.
*/
public double length() {
return distanceTo(new Vector3());
}
// Normalizes this vector: changes the length of this vector such that it becomes 1.
// The direction and orientation of the vector is not affected.
/**
* Normalizes this vector: changes the length of this vector such that it becomes 1.
* The direction and orientation of the vector is not affected.
*/
public void normalize() {
double length = length();
x /= length;
@ -71,8 +85,10 @@ public class Vector3 {
z /= length;
}
// 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.
/**
* 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;
@ -80,11 +96,11 @@ public class Vector3 {
cd.fillCircle(x, y, Math.max(radius, 1.5));
}
// Returns the coordinates of this vector in brackets as a string
// in the form "[x,y,z]", e.g., "[1.48E11,0.0,0.0]".
/**
* Returns the coordinates of this vector in brackets as a string
* in the form "[x,y,z]", e.g., "[1.48E11,0.0,0.0]".
*/
public String toString() {
return String.format("[%f,%f,%f]", x, y, z);
}
}