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);
}
}

Disegno di un cerchio

import java.awt.event.*;
import java .awt.*;
import javax.swing.*;
public class TestaCerchio {
public static void main(String Args[]){
Cerchio c1=new Cerchio();
JFrame f1=new JFrame("Cerchio");
f1.setSize(500,500);
f1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f1.add(BorderLayout.CENTER,c1);
f1.setVisible(true);
}
}

import java.awt.event.*;
import java .awt.*;
import javax.swing.*;
public class Cerchio extends JPanel implements MouseListener {
private int x1;
private int y1;
private int x2;
private int y2;
private double raggio=0;
private int raggioCast=0;
private int conta=0;
public Cerchio(){
addMouseListener(this);
}
@Override public void mouseClicked(MouseEvent e){

}
@Override public void mouseEntered(MouseEvent e){

}
@Override public void mouseExited(MouseEvent e){

}
@Override public void mousePressed(MouseEvent e){
int x=e.getX();
int y=e.getY();
conta++;
if(conta==1){
x1=x;
y1=y;
}
if(conta==2){
x2=x;
y2=y;
double differenza1=x1-x2;
double differenza2=y1-y2;
raggio=Math.sqrt(Math.pow(differenza1,2)+(differenza2));
System.out.println(raggio);
raggioCast=(int)raggio;
System.out.println(raggioCast);
conta=0;
repaint();
}
}
@Override public void mouseReleased(MouseEvent e){

}
@Override public void paintComponent(Graphics g){
g.setColor(Color.BLUE);
g.drawOval(x1, y1, raggioCast, raggioCast);
}
}

Poligono cliccando sui vertici

import java.awt.event.*;
import java .awt.*;
import javax.swing.*;
public class Retta extends JPanel implements MouseListener {
private int x1;
private int y1;
private int x2;
private int y2;
private int conta=0;
private int i=0;
private int[] ascisse=new int[50];
private int[] ordinate=new int[50];
private int numero=5;
public Retta(){
addMouseListener(this);
}
@Override public void mouseClicked(MouseEvent e){

}
@Override public void mouseEntered(MouseEvent e){

}
@Override public void mouseExited(MouseEvent e){

}
@Override public void mousePressed(MouseEvent e){
ascisse[i]=e.getX();
ordinate[i]=e.getY();
i++;
if(i>numero-1){
i=0;
repaint();
}
}
@Override public void mouseReleased(MouseEvent e){
}
@Override public void paintComponent(Graphics g){
int j=0;
g.setColor(Color.red);
for(j=0;j g.drawLine(ascisse[j], ordinate[j], ascisse[j+1], ordinate[j+1]);
}
g.drawLine(ascisse[0], ordinate[0], ascisse[j], ordinate[j]);
}
}



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