Made snow, now it works wierd. Help needed.

Question

Ok, here's the code:
import java.awt.*;
import javax.swing.*;
public class Blarg
     public static void main(String[] args) throws Exception
          JFrame frame = new JFrame("Blargity");
          APanel panel = new APanel();
          frame.add(panel);
          frame.setSize(250,250);
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          frame.setResizable(false);
          frame.setVisible(true);
          while(true)
               panel.repaint();
               Thread.sleep(100);
import java.awt.*;
import javax.swing.*;
import java.util.Random;
public class APanel extends JPanel
     private Random rand;
     private Font myfont;
     private Color ground,thesky,black,white,blue,star;
     private int[] snow = new int[40];
     private int[] snow2 = new int[40];
     private int[] starsx = new int[10];
     private int[] starsy = new int[10];
     private int num,num2,num3,ycoord,num4,yco2,sub3;
     public APanel()
          rand = new Random();
          myfont = new Font("arial",Font.BOLD|Font.ITALIC,20);
          ground = new Color(0,0,0);
          thesky = new Color(0,0,0);
          black = new Color(0,0,0);
          white = new Color(250,250,250);
          blue = new Color(0,0,255);
          star = new Color(239,252,1);
          //num = 5;
          num2 = 0;
          num3 = 254;
          ycoord = 125;
          num4 = 254;
          yco2 = 124;
          //sub3 = rand.nextInt(250);
          for(int i = 0;i < snow.length;i++)
               snow[i] = rand.nextInt(250);
          for(int i = 0;i < snow2.length;i++)
               snow2[i] = rand.nextInt(250);
          for(int i = 0;i < starsx.length;i++)
               starsx[i] = rand.nextInt(250);
          for(int i = 0;i < starsy.length;i++)
               starsy[i] = rand.nextInt(40);
     public void paint(Graphics g)
          //**-- VARIABLES --**//
          int x = 0;
          int y = 0;
          //**-- SKY --**//
          do
               thesky = new Color(0,0,num3);
               g.setColor(thesky);
               g.drawLine(0,ycoord,250,ycoord);
               ycoord--;
               if(num3 > 0)
                    num3-=2;
          }while(ycoord >= 0);
          //**-- STARS --**//
          g.setColor(star);
          do
               g.drawString("*",starsx[y],starsy[y]);
               y++;
          }while(y < 10);
          //**-- GROUND --**//
          do
               ground = new Color(num4,num4,num4);
               g.setColor(ground);
               g.drawLine(0,yco2,250,yco2);
               yco2++;
               if(num4 > 0)
                    num4-=2;
          }while(yco2 <= 250);
          //**-- SNOWFLAKES --**//
          g.setColor(white);
          do
               if ((snow[x] + num2 > 280) || (snow2[x] + num2 > 280))
                    num2 = 0;
               g.drawOval(snow[x] + num2,snow2[x] + num2,1,1);
               x++;
          }while(x < 40);
          num2+=3;
}Before I made the ground and sky that changed colors, the snow worked, but now it just makes streaks. Why is this so, and how do I fix it?

Answer 1

Clear the graphics context and repaint when you change any color or the position of anything on the screen.
You're seeing the effects of a thread doing automatic repaint commands.