question java awt

i have this code:

Code:

package subdivizare;

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.util.*;

public class Subdivizare extends Frame{

	private static final long serialVersionUID = 1L;
        
     double bx[], by[];
     double ax[][];
     double ay[][];
     
     int n;
     int i, j;
     double t;
     
     Canvas2d c2d;
	
	Subdivizare(){
            /*
		super("Subdivizare");
		
		c2d = new Canvas2d();
		
		add(c2d);
		
		WHandler wh = new WHandler();
		addWindowListener(wh);
                * */
	}
   public void graphic(){
       c2d = new Canvas2d();
       add(c2d);
       
       WHandler wh = new WHandler();
       addWindowListener(wh);
    
   }
    public void read_input(){
           
                System.out.println("Dati n:");
                Scanner sc = new Scanner(System.in);
                n = sc.nextInt();
                
                System.out.println("Dati t: ");
                t = sc.nextDouble();
                
                bx = new double[n + 2];
                by = new double[n + 2];
                
                for(i = 0; i <= n; i++){
                    System.out.println("Dati prima coordonata: ");
                    bx[i] = sc.nextDouble();
                    System.out.println("Dati a doua coordonata: ");
                    by[i] = sc.nextDouble();
                }   
                ax = new double[n + 1][n + 1];
                ay = new double[n + 1][n + 1]; 
    }
    public void make_(){
        
                for(i = 0; i <=n; i++){
                    ax[0][i] = bx[i];
                    ay[0][i] = by[i];
                }
                //Casteljau
                for(i = 1; i <= n; i++)
                    for(j = 0; j <= n - i; j++){
                        ax[i][j] = (1 - t) * ax[i - 1][j] + t * ax[i - 1][j + 1];
                        ay[i][j] = (1 - t) * ay[i - 1][j] + t * ay[i - 1][j + 1];
                    }
    }
    public void print_on_screen_results(){
        
                //afisare puncte de casteljau
                for(i = 0 ;i <= n; i++)
                    for(j = 0; j <= n; j++){
                        System.out.print(ax[i][j] + " ");
                        System.out.print(ay[i][j] + " ");
                        System.out.println();
                    }
                System.out.print("Prima restrictie: ");
                for(i = 0; i <= n; i++){
                  
                   System.out.println(ax[i][0] + " " + ay[i][0]);
                  }
                 int k = 0;
                 System.out.print("A doua restrictie: ");
                 
                 for(j = n; j >= 0; j--)
                 {
                   System.out.println(ax[j][k] + " " + ay[j][k]);
                   k++;
                  }
    }
	class WHandler extends WindowAdapter{
		public void windowClosing(WindowEvent e){
			System.exit(0);
		}      
        }

	public static void main(String[] args) {
            
	  Subdivizare t = new Subdivizare();
          t.read_input();
          t.make_();
          t.print_on_screen_results();  
          t.graphic();
	  t.setSize(600, 600);
	  t.setLocation(200, 200);
	  t.setVisible(true);
	
	}
}

class Canvas2d extends Canvas{

	private static final long serialVersionUID = 1L;

	public void paint(Graphics g){
		
		Graphics2D g2 = (Graphics2D) g;
	        g2.setPaint(Color.red);
                
                Subdivizare ob = new Subdivizare();
              
		int x1, y1, x2, y2;

		x1 = 0;
		y1 = 300;
		x2 = 600;
		y2 = 300;
		
		Line2D l1 = new Line2D.Double(x1, y1, x2, y2); 
		g2.draw(l1);
		
		x1 = 300;
		y1 = 0;
		x2 = 300;
		y2 = 600;
		
		Line2D l2 = new Line2D.Double(x1, y1, x2, y2); 
		g2.draw(l2);
                
                
                 int p = 1, i;
                 double aux1, aux2, aux3, aux4;
                 for(i = 1; i <= ob.n; i++){
                    aux1 = ob.ax[i][0];     
                    aux2 = ob.ay[i][0];
                    aux3 = ob.ax[p][0];
                    aux4 = ob.ay[p][0];  
                    Line2D l3 = new Line2D.Double(aux1 + 300, aux2 + 300, aux3 + 300, aux4 + 300); 
		    g2.draw(l3);
                }
                
                
                
              }
}

everything it works fine, but: starting with the line 149 i want to draw me a line with that elements, and it doesn't.. why? i don't know so much awt.. someone here who does?

 

well I couldn't get it to draw as it isn't my area of expertise I did clean the code up a bit I hope this helps. I may take another crack at it once i get some sleep and do some research.

Code:

import java.awt.Canvas;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.geom.Line2D;
import java.util.Scanner;
import javax.swing.JFrame;

public class Subdivizare extends JFrame
{
	private static final long serialVersionUID = 1L;
        
    double bx[], by[];
    double ax[][], ay[][];
    int i, j, n;
    double t;
    Canvas2d c2d;
    
	
	public Subdivizare()
	{	
		
	}
   
	public void graphic()
   {
       Canvas2d c2d = new Canvas2d();
       add(c2d);
       
       WHandler wh = new WHandler();
       addWindowListener(wh);
   }
    
	public void read_input()
	{
		System.out.println("Dati n:");
        Scanner sc = new Scanner(System.in);
        n = sc.nextInt();
                
        System.out.println("Dati t: ");
        t = sc.nextDouble();
                
        bx = new double[n + 2];
        by = new double[n + 2];
        
        System.out.println("Da prima pozitie de coordonate x");
    	bx[0] = sc.nextDouble();
    	
    	System.out.println("Da prima pozitie de coordonate y");
    	bx[1] = sc.nextDouble();
    	
    	System.out.println("Da doua pozitie de coordonate x");
    	by[0] = sc.nextDouble();
    	
    	System.out.println("Da doua pozitie de coordonate y");
    	by[1] = sc.nextDouble();

        ax = new double[n + 1][n + 1];
        ay = new double[n + 1][n + 1]; 
    }
	
    public void make()
    {     
    	ax[0][0] = bx[0];
    	ax[0][1] = bx[1];
    	ay[0][0] = by[0];
    	ay[0][1] = by[1];
        //Casteljau
                
        for(i = 1; i <= n; i++)
        {
        	for(j = 0; j <= n - i; j++)
            {
        		ax[i][j] = (1 - t) * ax[i - 1][j] + t * ax[i - 1][j + 1];
                ay[i][j] = (1 - t) * ay[i - 1][j] + t * ay[i - 1][j + 1];
            }
        }    
    }
    public void print_on_screen_results()
    {      
    	//afisare puncte de casteljau
    	for(i = 0 ;i <= n; i++)
    	{
    		for(j = 0; j <= n; j++)
            {
            System.out.print(ax[i][j] + " ");
            System.out.print(ay[i][j] + " ");
            System.out.println();
            }
        }    
                
        System.out.print("Prima restrictie: ");
                
        for(i = 0; i <= n; i++)
        { 
        	System.out.println(ax[i][0] + " " + ay[i][0]);
        }
                 
        int k = 0;
                 
        System.out.print("A doua restrictie: ");
                 
        for(j = n; j >= 0; j--)
        {
        	System.out.println(ax[j][k] + " " + ay[j][k]);
            k++;
        }
    }
    
	class WHandler extends WindowAdapter
	{
		public void windowClosing(WindowEvent e)
		{
			System.exit(0);
		}      
    }

	public static void main(String[] args) 
    {       
	  Subdivizare window = new Subdivizare();
      window.read_input();
      window.make();
      window.print_on_screen_results();  
      window.graphic();
	  window.setSize(600, 600);
	  window.setLocation(200, 200);
	  window.setVisible(true);
	}
}

class Canvas2d extends Canvas
{

	private static final long serialVersionUID = 1L;

	
	public void paint (Graphics g) 
	{
	    Graphics2D g2 = (Graphics2D) g;
		g2.setPaint(Color.red);
                
        Subdivizare ob = new Subdivizare();
              
		int x1, y1, x2, y2;

		x1 = 0;
		y1 = 300;
		x2 = 600;
		y2 = 300;
		
		Line2D l1 = new Line2D.Double(x1, y1, x2, y2); 
		g2.draw(l1);
		
		x1 = 300;
		y1 = 0;
		x2 = 300;
		y2 = 600;
		
		Line2D l2 = new Line2D.Double(x1, y1, x2, y2); 
		g2.draw(l2);
                
                
        int p = 1, i;
        double aux1, aux2, aux3, aux4;
          
        for(i = 1; i <= ob.n; i++)
        {
        	aux1 = ob.ax[i][0];     
        	aux2 = ob.ay[i][0];
        	aux3 = ob.ax[p][0];
        	aux4 = ob.ay[p][0];  
        	Line2D l3 = new Line2D.Double(aux1 + 300, aux2 + 300, aux3 + 300, aux4 + 300); 
        	g2.draw(l3);
        }    
	}
}