I am working on a java project which asks me to draw four fractals. Koch Curve, Tree, Sierpinski Triangle, and Sierpinski Carpet.

I have three java files, one is the Fractal.java which I have to work on. The second file turtle.java is a helper class to assist me drawing fractals. The third file is a FractalGUI.java.

Here is the Fractal.java:

package fractal;

import fractal.Turtle;

import java.awt.*;

import java.awt.geom.*;

/**

* A class that implements some basic fractal drawing methods using recursion.

* These methods include the Koch curve, tree, Sierpinski triangle and carpet.

*/

public class Fractal {

private Graphics2D g2d = null; // a Graphics2D object as canvas for drawing

private int width=0, height=0; // image width and height

private int max_recursion_level = 0; // maximum recursion level

private String fractal_type = "Koch Curve"; // type of fractal

private Color color = Color.green; // draw color

public void setGraphics(Graphics g, int w, int h) {

g2d = (Graphics2D)g; width = w; height = h;

}

public void setFractalType(String t) { fractal_type = t; }

public void setColor(Color c) { color = c; }

public void setMaxRecursion(int n) { max_recursion_level = n; }

// Recursive method for drawing the Koch curve given two points and the recursion level

private void drawKochCurve(Point2D p1, Point2D p2, int level) {

if(level==0) { // base case

drawLine(p1, p2);

return;

}

// TODO

// Koch subdivision rule: ___ -> _/\_

}

// Recursive method for drawing a fractal Tree given two points and the recursion level

private void drawTree(Point2D p1, Point2D p2, int level) {

if(level==0) { // base case

drawLine(p1, p2);

return;

}

// TODO

}

// Recursive method for drawing the Sierpinski Triangle given the three points

// that define the triangle and the recursion level

private void drawSierpinskiTriangle(Point2D p1, Point2D p2, Point2D p3, int level) {

if(level==0) { // base case

drawTriangle(p1, p2, p3);

return;

}

// TODO

}

// Recursive method for drawing the Sierpinski Carpet given the lower-left corner

// of the square (p), the side length (a) of the square, and the recursion level

private void drawSierpinskiCarpet(Point2D p, double a, int level) {

if(level==0) { // base case

drawRectangle(p, a, a);

return;

}

// TODO

}

// This method is left for you to experiment with creative fractals

// designed by yourself. You will NOT be graded on this method

void drawMyFractal(/* other parameters that you may need */ int level) {

if(level==0) { // base case

return;

}

/* Your creative fractal shape */

}

/** The code below provides utility methods.

* You should NOT need to modify any code below.

*/

public void draw() {

if(g2d==null || width==0 || height==0) return;

g2d.setBackground(Color.black);

g2d.clearRect(0, 0, width, height);

g2d.setColor(color);

if(fractal_type.equalsIgnoreCase("Koch Curve")) {

drawKochCurve(new Point2D.Double(0.0, 0.4), new Point2D.Double(1.0, 0.4), max_recursion_level);

} else if(fractal_type.equalsIgnoreCase("Snowflake")) {

double r = 0.5;

Point2D p1 = new Point2D.Double(r*Math.cos(Math.toRadians(150))+0.5,

r*Math.sin(Math.toRadians(150))+0.5);

Point2D p2 = new Point2D.Double(r*Math.cos(Math.toRadians(30))+0.5,

r*Math.sin(Math.toRadians(30))+0.5);

Point2D p3 = new Point2D.Double(r*Math.cos(Math.toRadians(-90))+0.5,

r*Math.sin(Math.toRadians(-90))+0.5);

// Snowflake is made of three Koch curves segments

// p1____p2

// \ /

// \/

// p3

drawKochCurve(p1, p2, max_recursion_level);

drawKochCurve(p2, p3, max_recursion_level);

drawKochCurve(p3, p1, max_recursion_level);

} else if(fractal_type.equalsIgnoreCase("Tree")) {

// double the maximum recursion level because tree subdivides very slowly

drawTree(new Point2D.Double(0.6, 0.1), new Point2D.Double(0.6, 0.9),

max_recursion_level*2);

} else if(fractal_type.equalsIgnoreCase("Sp Triangle")) {

double r = 0.5;

Point2D p1 = new Point2D.Double(r*Math.cos(Math.toRadians(90))+0.5,

r*Math.sin(Math.toRadians(90))+0.5);

Point2D p2 = new Point2D.Double(r*Math.cos(Math.toRadians(-150))+0.5,

r*Math.sin(Math.toRadians(-150))+0.5);

Point2D p3 = new Point2D.Double(r*Math.cos(Math.toRadians(-30))+0.5,

r*Math.sin(Math.toRadians(-30))+0.5);

drawSierpinskiTriangle(p1, p2, p3, max_recursion_level);

} else if(fractal_type.equalsIgnoreCase("Sp Carpet")) {

drawSierpinskiCarpet(new Point2D.Double(0, 0), 1, max_recursion_level);

} else {

drawMyFractal(/* other parameters that you may need */ max_recursion_level);

}

}

/** Draw a straight line between two points P1 and P2.

* The given x and y values of p1 and p2 are assumed to be within [0, 1] (i.e. normalized).

* This allows our fractals to be resolution-independent. The method below converts the normalized

* coordinates to integer coordinates based on the actual image resolution.

*/

private void drawLine(Point2D p1, Point2D p2) {

int x1 = (int)(p1.getX()*width);

int x2 = (int)(p2.getX()*width);

// flip the Y coordinate

// because screen Y axis is flipped from mathematical Y axis

int y1 = (int)((1.0-p1.getY())*height);

int y2 = (int)((1.0-p2.getY())*height);

g2d.drawLine(x1, y1, x2, y2);

}

// Draw a solid rectangle given its lower left corner and its size

private void drawRectangle(Point2D p, double w, double h) {

int x0 = (int)(p.getX()*width);

int y0 = (int)((1.0-p.getY())*height);

int x1 = (int)((p.getX()+w)*width);;

int y1 = (int)((1.0-(p.getY()+h))*height);

int xpoints[] = {x0, x0, x1, x1};

int ypoints[] = {y0, y1, y1, y0};

g2d.fillPolygon(xpoints, ypoints, 4);

}

// Draw a solid triangle given its three vertices

private void drawTriangle(Point2D p1, Point2D p2, Point2D p3) {

int xpoints[] = {(int)(p1.getX()*width),

(int)(p2.getX()*width),

(int)(p3.getX()*width)};

int ypoints[] = {(int)((1.0-p1.getY())*height),

(int)((1.0-p2.getY())*height),

(int)((1.0-p3.getY())*height)};

g2d.fillPolygon(xpoints, ypoints, 3);

}

}

Here is the Turtle.java:

package fractal;

import java.awt.geom.Point2D;

/** This is a helper class to assist you in drawing fractals

* YOU DO NOT NEED TO MODIFY ANYTHING HERE

*/

public class Turtle {

private Point2D pos; // current position

private Point2D dir; // direction the turtle is heading to

/** Constructor: the arguments are the initial position of the turtle

* and the target position it's heading to.

*/

public Turtle(Point2D start, Point2D target) {

pos = new Point2D.Double(start.getX(), start.getY()); // clone the position

double dx = target.getX()-pos.getX();

double dy = target.getY()-pos.getY();

double length = start.distance(target);

dir = new Point2D.Double(dx/length, dy/length); // normalize the direction vector

}

// return the current position

public Point2D getPosition() { return pos; }

// move by a given distance, for example 0.1

// this distance can also be negative, in which case if will move backward

public void move(double distance) {

pos = new Point2D.Double(pos.getX(), pos.getY()); // clone to a new point

pos.setLocation(pos.getX()+distance*dir.getX(),

pos.getY()+distance*dir.getY());

}

// set the direction of the turtle to turn left by a certain number of degrees, e.g. 60

// you can also use a negative number, in which case it turns right

public void turnLeft(double degrees) {

double radians = Math.toRadians(degrees);

double new_dx = Math.cos(radians)*dir.getX() - Math.sin(radians)*dir.getY();

double new_dy = Math.sin(radians)*dir.getX() + Math.cos(radians)*dir.getY();

dir.setLocation(new_dx, new_dy);

}

// set the direction of the turtle to turn left by a certain number of degrees, e.g. 60

public void turnRight(double degrees) {

turnLeft(-degrees);

}

}

Here is the FractalGUI.java:

package fractal;

import java.awt.*;

import java.awt.image.*;

import java.io.File;

import javax.imageio.ImageIO;

import javax.swing.*;

@SuppressWarnings("serial")

class FractalGUI extends JFrame {

// Window size. Reduce if it doesn't fit your screen

private static final int winw = 650, winh = 650;

private JButton jButton1;

private JButton jButton2;

private JButton jButton3;

private JButton jButton4;

private JButton jButton5;

private JButton jButton6;

private JSlider jSlider1;

private BufferedImage image = new BufferedImage(winw, winh, BufferedImage.TYPE_INT_RGB);

private JPanel jPanel1;

private Fractal fractal;

public FractalGUI() {

jButton1 = new JButton();

jButton2 = new JButton();

jButton3 = new JButton();

jButton4 = new JButton();

jButton5 = new JButton();

jButton6 = new JButton();

jSlider1 = new JSlider();

JLabel jLabel1 = new JLabel();

jPanel1 = new JPanel();

jButton1.setText("Koch Curve");

jButton1.addActionListener(new java.awt.event.ActionListener() {

public void actionPerformed(java.awt.event.ActionEvent evt) {

jButtonActionPerformed(evt);

}

});

jButton2.setText("Snowflake");

jButton2.addActionListener(new java.awt.event.ActionListener() {

public void actionPerformed(java.awt.event.ActionEvent evt) {

jButtonActionPerformed(evt);

}

});

jButton3.setText("Tree");

jButton3.addActionListener(new java.awt.event.ActionListener() {

public void actionPerformed(java.awt.event.ActionEvent evt) {

jButtonActionPerformed(evt);

}

});

jButton4.setText("Sp Triangle");

jButton4.addActionListener(new java.awt.event.ActionListener() {

public void actionPerformed(java.awt.event.ActionEvent evt) {

jButtonActionPerformed(evt);

}

});

jButton5.setText("Sp Carpet");

jButton5.addActionListener(new java.awt.event.ActionListener() {

public void actionPerformed(java.awt.event.ActionEvent evt) {

jButtonActionPerformed(evt);

}

});

jButton6.setText("My Fractal");

jButton6.addActionListener(new java.awt.event.ActionListener() {

public void actionPerformed(java.awt.event.ActionEvent evt) {

jButtonActionPerformed(evt);

}

});

jSlider1.setMajorTickSpacing(1);

jSlider1.setMaximum(6);

jSlider1.setMinimum(0);

jSlider1.setMinorTickSpacing(1);

jSlider1.setPaintTicks(true);

jSlider1.setSnapToTicks(true);

jSlider1.createStandardLabels(1);

jSlider1.setPaintLabels(true);

jSlider1.setValue(0);

jSlider1.addChangeListener(new javax.swing.event.ChangeListener() {

public void stateChanged(javax.swing.event.ChangeEvent evt) {

jSlider1StateChanged(evt);

}

});

jLabel1.setText("Recursion Level");

jPanel1.setBackground(Color.black);

jPanel1.setPreferredSize(new java.awt.Dimension(winw, winh));

javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);

jPanel1.setLayout(jPanel1Layout);

jPanel1Layout.setHorizontalGroup(

jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

.addGap(0, winw, Short.MAX_VALUE)

);

jPanel1Layout.setVerticalGroup(

jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

.addGap(0, winh, Short.MAX_VALUE)

);

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());

getContentPane().setLayout(layout);

layout.setHorizontalGroup(

layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

.addGroup(layout.createSequentialGroup()

.addContainerGap()

.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)

.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)

.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()

.addComponent(jLabel1)

.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)

.addComponent(jSlider1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))

.addGroup(javax.swing.GroupLayout.Alignment.LEADING, layout.createSequentialGroup()

.addComponent(jButton1)

.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)

.addComponent(jButton2)

.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)

.addComponent(jButton3)

.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)

.addComponent(jButton4)

.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)

.addComponent(jButton5)

.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)

.addComponent(jButton6))))

.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))

);

layout.setVerticalGroup(

layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

.addGroup(layout.createSequentialGroup()

.addContainerGap()

.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)

.addComponent(jButton1)

.addComponent(jButton2)

.addComponent(jButton3)

.addComponent(jButton4)

.addComponent(jButton5)

.addComponent(jButton6))

.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)

.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

.addComponent(jLabel1)

.addComponent(jSlider1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))

.addGap(18, 18, 18)

.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)

.addContainerGap())

);

pack();

fractal = new Fractal();

fractal.setGraphics(image.getGraphics(), winw, winh);

}

public void initdraw() {

jButton1.doClick();

}

public void redraw() {

fractal.draw();

jPanel1.getGraphics().drawImage(image, 0, 0, null);

// enable the section below to save the image to a PNG file

/*try {

File file = new File("output.png");

ImageIO.write(image, "png", file);

} catch(Exception e) {}*/

}

private void jButtonActionPerformed(java.awt.event.ActionEvent evt) {

fractal.setFractalType(evt.getActionCommand());

redraw();

}

private void jSlider1StateChanged(javax.swing.event.ChangeEvent evt) {

fractal.setMaxRecursion(jSlider1.getValue());

redraw();

}

public static void main(String[] args) {

// initialization code to set up Jframe

FractalGUI gui = new FractalGUI();

gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

gui.setTitle("Fun with Fractals");

gui.setLocationRelativeTo(null);

gui.setVisible(true);

gui.initdraw();

}

}

Please help me on this one and I will rate.