Java Question!! Please help! I haven\'t been able to make a functioning code for
ID: 3891426 • Letter: J
Question
Java Question!!
Please help! I haven't been able to make a functioning code for this problem. Can someone please help me out with this question?? thank you!!!!!!
A Sierpinski Triangle is a fractal formed by drawing a triangle, and then using the midpoints of each side of triangle to formm another triangle. This inner triangle is then removed. The result is three smaller triangles (one at the top and one in each corner) on which the process is repeated. After iteration N, the image will contain 3N triangles, each of which is similar to the origi- nal triangle. Write a program that implements a recursive algorithm for drawing a Sierpinski Triangle. The user interface for the program should include a JSlider that allows the user to select a value for N. The slider should allow the user to pick a value for N between 0 and the maximum value of N pos sible based on the size of the program window. The maximum slider value should change as appropriate when the window is resizedExplanation / Answer
I have put the maximum value for JSlider as 6 which will change as the screen dimensions change.
Here is the working code:
import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.*;
import java.util.Random;
import java.util.Stack;
import java.awt.event.ComponentListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
public class Sierpinski extends JFrame {
JPanel panel;
Dimension dim;
int levels; // number of refinement levels ak number of recursive calls
Stack<Triangle> triangles; // buffer for saving the final triangles
Triangle parent; // start triangle
Sierpinski(int levels) {
super("Sierpinski fractal");
this.levels = levels;
triangles = new Stack<Triangle>(); //Stack of triangles
JSlider s = new JSlider(0,6,0); //6 is maximum slider value at start
s.addChangeListener(new ChangeListener() {
public void stateChanged(ChangeEvent e) {
JSlider s = (JSlider)e.getSource();
updateLevels(s.getValue());
panel.repaint();
}
});
s.setSnapToTicks(true);
add(s, BorderLayout.SOUTH);
panel = new TriPanel();
//To listen to changes to the size of screen so that jslider max value can be changed
panel.addComponentListener(new ComponentAdapter() {
int prev_size = 600;
/*Screen dimensions*/
Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
int screenHeight = screenSize.height;
int screenWidth = screenSize.width;
@Override
public void componentResized(ComponentEvent e) {
System.out.println("Resized to " + e.getComponent().getSize().width);
int sliderVal = 6;
if(e.getComponent().getSize().width!=prev_size){
int maximum = (int)((e.getComponent().getSize().width-prev_size)/100); //Max value changes according to screen width changes
s.setMaximum(6+maximum);
}
}
});
add(panel, BorderLayout.CENTER);
setDefaultCloseOperation(EXIT_ON_CLOSE);
pack();
setVisible(true);
}
public void updateLevels(int l) {
if (l >= 0)
levels = l;
}
public class TriPanel extends JPanel {
Dimension dim;
public TriPanel() {
dim = new Dimension(600, 600);
setPreferredSize(dim);
// make the initial triangle
parent = new Triangle(
0, dim.width/2, dim.width, // x1, x2, x3,
dim.height, // y1
(int)(dim.width*(1.0 - Math.sin(Math.PI/3))), // y2
dim.height); // y3
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
makeTriangles(parent, 0); // call the recursive method calculating the triangles
Random r = new Random(); // for some random coloring
for (Polygon p: triangles) { // draw triangles
g.setColor(new Color(r.nextInt(256), r.nextInt(256), r.nextInt(256)));
g.fillPolygon(p);
}
triangles.clear();
}
/**
* Recursive method calculating new smaller triangles
* @param t
* @param curLevel
*/
private void makeTriangles(Triangle t, int curLevel) {
if (curLevel == levels) {
// base level reached. Push the triangle on the stack.
triangles.push(t);
} else {
// calculate 3 new triangles based on @param t
// and do a recursive call with each on.
Triangle[] smallerTriangles = t.getSierpinskiTri();
for (Triangle tt: smallerTriangles)
makeTriangles(tt, curLevel+1);
}
}
}
/**
* Class representing a triangle. Based on the java api class Polygon.
*/
public class Triangle extends Polygon {
public Triangle(int x1, int x2, int x3, int y1, int y2, int y3) {
super(new int[]{x1, x2, x3}, new int[]{y1, y2, y3}, 3);
}
public Triangle(Point p1, Point p2, Point p3) {
super(new int[]{p1.x, p2.x, p3.x}, new int[]{p1.y, p2.y, p3.y}, 3);
}
/**
* @param i Point index.
* @return The point at the specified index.
*/
public Point getPoint(int i) {
if (i >= npoints) return null;
return new Point(xpoints[i], ypoints[i]);
}
/**
* Calculates the mean point from two given points.
* @param p1 Point one.
* @param p2 Point two.
* @return The mean point.
*/
private Point mean(Point p1, Point p2) {
return new Point((p1.x + p2.x) / 2, (p1.y + p2.y) / 2);
}
/**
* Generates 3 new triangles inside this triangle.
* @return The calculated triangles.
*/
public Triangle[] getSierpinskiTri() {
Triangle[] t = new Triangle[3];
Point newP1 = mean(getPoint(0), getPoint(1));
Point newP2 = mean(getPoint(1), getPoint(2));
Point newP3 = mean(getPoint(2), getPoint(0));
t[0] = new Triangle(getPoint(0), newP1, newP3);
t[1] = new Triangle(newP1, getPoint(1), newP2);
t[2] = new Triangle(newP3, newP2, getPoint(2));
return t;
}
}
public static void main(String[] args) {
new Sierpinski(0);
}
}
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.