Nested parabolic curves with straight lines

Question

I'm having trouble copying a picture for my assignment. I would appreciate any advice or solutions. I believe that I have a general idea, but it is difficult for me to define mathematics in order to reproduce the image and do everything in one cycle.

My program must meet these criteria:

• Matches Image
• Generate random color for each pair of parabolic curves
• Work with any width or height
• Use one cycle to draw the whole picture.

Here is the image: This is what I have tried so far

public static final int WIDTH = 500; public static final int HEIGHT = 500; public static final int LINE_INCREMENT = 5; public static void main(String[] args) { DrawingPanel panel = new DrawingPanel(WIDTH, HEIGHT); Graphics g = panel.getGraphics(); int d = 0; int iterations = HEIGHT/LINE_INCREMENT; Random rand = new Random(); int red = 0, green = 0, blue = 0; red = rand.nextInt(128) + 128; green = rand.nextInt(128) + 128; blue = rand.nextInt(128) + 128; g.setColor(new Color(red,green,blue)); for(int y = 0; y < iterations; y++) { g.drawLine(0, d, d, HEIGHT); g.drawLine(WIDTH, d, d, 0); d += LINE_INCREMENT; } red = rand.nextInt(128) + 128; green = rand.nextInt(128) + 128; blue = rand.nextInt(128) + 128; g.setColor(new Color(red,green,blue)); d = 0; for (int x = 0; x < iterations/2; x++) { g.drawLine(WIDTH/4, d + HEIGHT/4, d + WIDTH/4, HEIGHT - HEIGHT/4); g.drawLine(d + WIDTH/4, WIDTH/4, WIDTH - WIDTH/4, d + WIDTH/4); d += LINE_INCREMENT; } } 

Output:

Answer 1

The way to implement it is to override paintComponent :

 import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.Graphics; import java.awt.Rectangle; import java.util.Random; import javax.swing.JFrame; import javax.swing.JPanel; public class ParabolicCurves extends JFrame { private static final int SIZE = 600; private static final int LINE_INCREMENT = 5; private static final int NUM_OF_PATTERNS = 4; private Random rand = new Random(); ParabolicCurves() { setDefaultCloseOperation(DISPOSE_ON_CLOSE); JPanel panel = new DrawingPanel(SIZE); add(panel, BorderLayout.CENTER); pack(); setVisible(true); } class DrawingPanel extends JPanel{ public DrawingPanel(int size) { setPreferredSize(new Dimension(size, size)); setBackground(Color.WHITE); } @Override public void paintComponent(Graphics g) { super.paintComponent(g); int red, green, blue, delta , iterations; int height, width ,startX, startY, endX, endY ; Rectangle boundingRrectangle = getBounds(); for(int pattern = 0 ; pattern < NUM_OF_PATTERNS; pattern++) { red = rand.nextInt(128) + 128; green = rand.nextInt(128) + 128; blue = rand.nextInt(128) + 128; g.setColor(new Color(red,green,blue)); height = (int) boundingRrectangle.getHeight(); width = (int) boundingRrectangle.getWidth(); startX = (int) boundingRrectangle.getX(); startY = (int) boundingRrectangle.getY(); endX = startX+width; endY = startY+ height; iterations = Math.min(width, height)/LINE_INCREMENT; delta = 0; for (int x = 0; x < iterations ; x++) { g.drawLine(startX, startY+delta, startX+delta, endY); g.drawLine(endX, startY+delta, startX+delta, startY); delta += LINE_INCREMENT; } //change bounding rectangle boundingRrectangle = new Rectangle(startX+(width/4), startY+(width/4), width/2, height/2); } } } public static void main(String[] args) { new ParabolicCurves(); } } 

Output: