Rappresentazione degli assi cartesiani-esercizio svolto in classe

public class Retta4 extends JPanel {
int x1=0;
int y1=32;
int x2=10;
int y2= 50;
int x0=50;
int y0=100;
public void paintComponent(Graphics g){
x2=this.getWidth();
y2=(int) 1.8*x2+32;
y0=getHeight()-50;
g.setColor(Color.RED);
g.drawLine(x1,y1,x2,y2);
g.setColor(Color.BLUE);
g.drawLine(x0,y0,this.getWidth()-10,y0);
g.drawLine(x0, y0, x0, 50);
g.setColor(Color.GREEN);
g.drawLine(x0,32+y0,x2+x0,+y0-y2);
}
}


import java.awt.*;
import javax.swing.*;
public class TestaRetta {
public static void main(String[]args){
JFrame f1=new JFrame("testa retta 4");
f1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Retta4 r1=new Retta4();
f1.add(r1,BorderLayout.CENTER);
f1.setSize(500,500);
f1.setVisible(true);
}
}