Double-buffered html JTextPane

Hi there !
I am using a JtextPane, displaying a html page, refreshed every second by a thread. This html page changes every second (just a few data). The problem is that the display is flikering and so obnoxious. I tried in vain to make it double-buffered.
How could I do to fix that ?
Thx alot.
Julien

I'm assuming that you are using the latest version of CVI and NI-DAQ. Then there is a DAQmx example that ships with NI-DAQ that does a Continuous Acquisition with an External Scan Clock and Digital Start Trigger.
You can find this example in the CVI Folder: ...\CVI70\samples\DAQmx\Analog In\Measure Voltage\Cont Acq-Ext Clk-Dig Start
Kind regards,
Karsten
Applications Engineer
National Instruments

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    import java.applet.*;
    import java.awt.event.*;
    import java.awt.*;
    import java.awt.image.*;
    import java.util.*;
    class Brick
        public int x,y;   
        public Brick(int x,int y) {this.x = x;this.y = y;}
    class Ball
        public int x,y,a,b;
        public Ball(int x, int y) {this.x = x;this.y = y;}
    public class Pong2 extends JApplet implements MouseListener, MouseMotionListener, Runnable, KeyListener
        long tm = System.currentTimeMillis();
        int delay;
        int a1=0,b1=0,c1=0,d1=0;
        int dead;
        int ranB1,ranB2;
        boolean pauseB = false;
        boolean starttext = true;
        int ani = 0;
        String stringWin;
        Graphics offscreen;Image image;
        private final int INIT_ACTIVE = 0;
        private final int INTRO_ACTIVE = 1;
        private final int GAME1_ACTIVE = 2;
        private final int GAME2_ACTIVE = 3;
        private final int GAME3_ACTIVE = 4;
        private int r1,r2,r3,r4,r5,starter=0,win=0,own=0;
        private int gameflag;
        private boolean player = true,moveB = true,thisB = true,timerB = true;
        private boolean drawB = true;
        private int counte=0;
        private int time = -2;
        private int movecheck1; int movecheck2;int movecheck3;int movecheck4;
        private int c;
        private int god = 0;
        private int tempx1, tempy1,tempx2,tempy2;
        private int pause = 2, resume = 0;
        private int ran, ran2,ran3,ran4;
        private int yCheck1,yCheck2,yCheck3,yCheck4,xCheck1,xCheck2,xCheck3,xCheck4;
        private int begin = 0;
        private int counter = 0, colorChange =0;
        private Brick brick[] = new Brick[4];
        private Ball ball[] = new Ball[2];
        private Ball ball2[] = new Ball[8];
        private int cons1 = 0,cons2 = 0,cons3=0,cons4=0;
        private int score1=10, score2=10,score3=10,score4=10;
        private Thread t;
        private Font font;
        private AudioClip match,teleport,headshot, ballbounce, dkill,humiliation,one,two,three,fight,prepare;   
        public Image paddle3,paddle4,rarrow,dbuffer,paddle,paddle2,bricks,blood,title,edge,m_imgOffScr;
        private Graphics dbuffer_gfx,m_gOffScr,dbg;
        private Color Color1 = new Color(255,255,255);
        private Color sColor3 = new Color(139,80,14);
        private Color sColor2 = new Color(0,255,0);
        private Color sColor4 = new Color(255,255,0);
        private Polygon poly1 = new Polygon();Polygon poly2 = new Polygon(); 
        private Polygon poly3 = new Polygon();Polygon poly4 = new Polygon();
        private boolean p1Dead=false, p2Dead=false, p3Dead=false, p4Dead=false;
        private int ranLoc, winner;
        public void initgame()
            poly1.addPoint(0,0);poly1.addPoint(0,125);poly1.addPoint(125,0);
            poly2.addPoint(0,650);poly2.addPoint(125,650);poly2.addPoint(0,525);
            poly3.addPoint(650,0);poly3.addPoint(650,125);poly3.addPoint(525,0);
            poly4.addPoint(650,650);poly4.addPoint(650,525);poly4.addPoint(525,650);
            for (int j = 0; j < ball.length; j++){ball[j] = new Ball(325,325);}
            brick[0] = new Brick(25,285);
            brick[1] = new Brick(615,285);
            brick[2] = new Brick(285,25);
            brick[3] = new Brick(285,615);
            yCheck1 = brick[0].y; yCheck2 = brick[1].y; yCheck3 = brick[2].y; yCheck4 = brick[3].y;
            xCheck1 = brick[0].x; xCheck2 = brick[1].x; xCheck3 = brick[2].x; xCheck4 = brick[3].x;
            if(player)
            for (int n = 0; n<8; n++)
                r1 = (int)(Math.random() * 600)+10;r2 = (int)(Math.random() * 600)+10;
                ball2[n] = new Ball(r1,r2);
                if (n == 0||n==4) {ball2[n].a = 3; ball2[n].b = 3;}if (n == 1||n==5) {ball2[n].a = -3; ball2[n].b = 3;}
                if (n == 2||n==6) {ball2[n].a = 3; ball2[n].b = -3;}if (n == 3||n==7) {ball2[n].a = -3; ball2[n].b = -3;}           
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        public void init()
            gameflag = INIT_ACTIVE;
            setSize(650,725);
            requestFocus();      
            Font font = new Font ("Arial", Font.BOLD,50);
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            paddle2 = getImage(getCodeBase(), "paddle2.jpg");
            paddle3 = getImage(getCodeBase(), "paddle3.jpg");
            paddle4 = getImage(getCodeBase(), "paddle4.jpg");
            bricks = getImage(getCodeBase(), "bricks.jpg");
            blood = getImage(getCodeBase(), "blood.jpg");
            title = getImage(getCodeBase(), "title.jpg"); 
            headshot = getAudioClip(getCodeBase(), "headshot2.wav");
            ballbounce = getAudioClip(getCodeBase(), "ir_begin.wav");
            humiliation = getAudioClip(getCodeBase(), "humiliation.wav");
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            teleport = getAudioClip(getCodeBase(), "teleport.wav");
            match = getAudioClip(getCodeBase(), "matchwin.wav");
            dbuffer=createImage(getSize().width,getSize().height);
            dbuffer_gfx=dbuffer.getGraphics();
            initgame();
            addMouseListener(this);
            addMouseMotionListener(this);
            addKeyListener(this);
        public void start()
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            t.start();
            new Thread(pMovement).start();                       
        public void stop()
            t.yield();
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        public void update (Graphics g)
            paint(dbuffer_gfx);
            g.drawImage(dbuffer,0,0,this);
        public void PaintIntro(Graphics g)
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            g.fillRect(0,0,650,725);
            g.setColor(Color.black);
            for(int wa = 0;wa<8;wa++)
            g.fillOval(ball2[wa].x,ball2[wa].y,10,10);
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            g.setFont(new Font("Arial", Font.BOLD,20));
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            g.setFont(new Font("Arial", Font.BOLD,14));
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            if (colorChange==1)g.setColor(Color.blue);
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            g.setColor(Color.black);
            if (colorChange==2)g.setColor(Color.blue);
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        public void PaintGame1 (Graphics g)
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            g.drawImage(blood,0,0,650,650,this);
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            if(p4Dead==false&& own>0)g.drawImage(paddle4,brick[3].x,brick[3].y,80,10,this);
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            g.setFont(new Font("Comic Sans MS", Font.ITALIC,50));
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                g.setColor(Color.orange);g.drawString(Integer.toString(score2),150,705);
                g.setColor(Color.blue);g.drawString(Integer.toString(score3),440,705);
                g.setColor(sColor3);g.drawString(Integer.toString(score4),540,705);}
            //painting gui
            if (starttext) {g.setColor(Color.black);
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            g.setColor(Color1);
            g.setFont(new Font("Arial", Font.BOLD,30));
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            else if(begin==0)g.drawString("START",270,700);
            else if(begin>=1 && begin<=2 && pause==0){g.drawString("PAUSE",270,700);}    
            //start
            g.setFont(font);g.setColor(Color.black);
            if(win ==1){if(winner==1)g.setColor(Color.green);else if(winner==2)g.setColor(Color.orange);
                else if(winner==3)g.setColor(Color.blue);else if(winner==4)g.setColor(sColor3);           
                g.drawString(stringWin,245,325);}
            g.setColor(Color.black);
            if (time == 1)g.drawString("3",300,325);
            else if (time==2)g.drawString("2",300,325);
            else if (time==3)g.drawString("1",300,325);          
        public void PaintGame2(Graphics g)
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            g.drawImage(blood,0,0,650,650,this);
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            if(p2Dead==false&& own>0)g.drawImage(paddle,brick[1].x,brick[1].y,10,80,this);
            g.fillPolygon(poly1);g.fillPolygon(poly2);g.fillPolygon(poly3);g.fillPolygon(poly4);
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            g.drawPolygon(poly1);g.drawPolygon(poly2);g.drawPolygon(poly3);g.drawPolygon(poly4);
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            if(begin==1 && drawB)
            {g.fillOval(ball[0].x,ball[0].y,10,10);g.fillOval(ball[1].x,ball[1].y,10,10);}
            g.drawImage(bricks,1,650,650,75,this);
            //score
            g.setFont(new Font("Comic Sans MS", Font.ITALIC,50));
            if(own>0){
                g.setColor(sColor2);g.drawString(Integer.toString(score1),50,705);
                g.setColor(Color.orange);g.drawString(Integer.toString(score2),540,705);}
            //painting gui
            if (starttext) {g.setColor(Color.black);
                g.setFont(new Font("Arial", Font.ITALIC,30));g.drawString("Click START to Begin",175,325);}
            g.setColor(Color1);
            g.setFont(new Font("Arial", Font.BOLD,30));
            if(pause ==1 && begin>0)g.drawString("RESUME",270,700);
            else if(begin==0)g.drawString("START",270,700);
            else if(begin>=1 && begin<=2 && pause==0){g.drawString("PAUSE",270,700);}    
            //start
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            if(win ==1){if(winner==1)g.setColor(Color.green);else if(winner==2)g.setColor(Color.orange);}
            g.setColor(Color.black);
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            else if (time==2)g.drawString("2",300,325);
            else if (time==3)g.drawString("1",300,325);     
        //paint graphics
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                g.fillRect(0,0,500,500);
                g.setColor(Color.BLACK);
            if (gameflag == INIT_ACTIVE)
                g.setColor(Color.black);
                g.fillRect(0,0,getSize().width,getSize().height);
                g.setColor(Color.white);
                g.drawString("Loading...",getSize().width/2, getSize().height/2);
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            if (gameflag == GAME1_ACTIVE){PaintGame1(g);} 
            if (gameflag == GAME2_ACTIVE || gameflag == GAME3_ACTIVE){PaintGame2(g);}
        public void paddlephys()
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                //P1
                if(p1Dead==false&&ball[j].x-4<=xCheck1 && ball[j].x<=xCheck2 && begin==1)
                    if (ball[j].y>=yCheck1&&ball[j].y<=yCheck1+12) {ball[j].a=2;ball[j].b=-4;ballbounce.play();}
                    else if (ball[j].y>=yCheck1+13&&ball[j].y<=yCheck1+25) {ball[j].a=3;ball[j].b=-3;ballbounce.play();}
                    else if (ball[j].y>=yCheck1+26&&ball[j].y<=yCheck1+39) {ball[j].a=4;ball[j].b=-2;ballbounce.play();}
                    else if (ball[j].y>=yCheck1+40&&ball[j].y<=yCheck1+53) {ball[j].a=4;ball[j].b=2;ballbounce.play();}
                    else if (ball[j].y>=yCheck1+54&&ball[j].y<=yCheck1+66) {ball[j].a=3;ball[j].b=3;ballbounce.play();}
                    else if (ball[j].y>=yCheck1+67&&ball[j].y<=yCheck1+79) {ball[j].a=2;ball[j].b=4;ballbounce.play();}
                //P2
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                    else if (ball[j].y>=yCheck2+13&&ball[j].y<=yCheck2+25) {ball[j].a=-3;ball[j].b=-3;ballbounce.play();}
                    else if (ball[j].y>=yCheck2+26&&ball[j].y<=yCheck2+39) {ball[j].a=-4;ball[j].b=-2;ballbounce.play();}
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                    else if (ball[j].x>=xCheck3+13&&ball[j].x<=xCheck3+25) {ball[j].a=-3;ball[j].b=3;ballbounce.play();}
                    else if (ball[j].x>=xCheck3+26&&ball[j].x<=xCheck3+39) {ball[j].a=-2;ball[j].b=4;ballbounce.play();}
                    else if (ball[j].x>=xCheck3+40&&ball[j].x<=xCheck3+53) {ball[j].a=2;ball[j].b=4;ballbounce.play();}
                    else if (ball[j].x>=xCheck3+54&&ball[j].x<=xCheck3+66) {ball[j].a=3;ball[j].b=3;ballbounce.play();}
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                     else if (movecheck1==-1){brick[0].y+=1;yCheck1 = brick[0].y;} }
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                     if (brick[2].x<570&&brick[2].x>125){if (movecheck3==1){brick[2].x-=1;xCheck3 = brick[2].x;}
                     else if (movecheck3==-1){brick[2].x+=1;xCheck3 = brick[2].x;}  }
                     if (brick[3].x == 445) brick[3].x-=2; if (brick[3].x == 125) brick[3].x+=2;   
                     if (brick[3].x<570&&brick[3].x>0){if (movecheck4==1){brick[3].x-=1;xCheck4 = brick[3].x;}
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                if(gameflag==3 || gameflag==4){p3Dead=true;p4Dead=true;}
                a1=0;b1=0;c1=0;d1=0;drawB=true;
                starttext = false;
                win=0;
                score1=10;score2=10;score3=10;score4=10;
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                own=1;
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                try{Thread.sleep(5000);}catch(InterruptedException e){}
                time=1;
                try{Thread.sleep(1000);}catch(InterruptedException e){}
                time=2;
                try{Thread.sleep(1000);}catch(InterruptedException e){}
                time=3;
                try{Thread.sleep(1000);}catch(InterruptedException e){}
                if(gameflag==2)
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                    ball[1].a=0;ball[1].b=-2;
                if(gameflag==3 || gameflag==4)
                    ball[0].a=2;ball[0].b=0;
                    ball[1].a=-2;ball[1].b=0;
                ball[0].x = 325; ball[0].y = 325;ball[1].x = 325; ball[1].y = 325;
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                    case INIT_ACTIVE:
                        repaint();
                        gameflag = INTRO_ACTIVE;
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                        catch(InterruptedException ex){break;}
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                        try{Thread.sleep(10);}
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                if(pauseB==true){repaint();try{Thread.sleep(7,500);}catch(InterruptedException e){}}
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                    else headshot.play();               
                    score1--;cons1++;              
                    ball[z].y=325;ball[z].x=325;
                    if(ranB1==0){ball[z].a=1;ball[z].b=1;}else if(ranB1==1){ball[z].a=-1;ball[z].b=1;}
                    else if(ranB1==2){ball[z].a=1;ball[z].b=-1;}else if(ranB1==3){ball[z].a=-1;ball[z].b=-1;}               
                    if(score1 == 0)p1Dead=true;                                                        
                //P2 scores
                else if(p2Dead==false&& ball[z].y<525 && ball[z].y>125 && ball[z].x>648)
                    if(score2==1)humiliation.play();
                    else headshot.play();
                    score2--;cons2++;     
                    ball[z].y = 325;ball[z].x=325;
                    if(ranB1==0){ball[z].a=1;ball[z].b=1;}else if(ranB1==1){ball[z].a=-1;ball[z].b=1;}
                    else if(ranB1==2){ball[z].a=1;ball[z].b=-1;}else if(ranB1==3){ball[z].a=-1;ball[z].b=-1;}
                    if(score2 == 0)p2Dead=true;
                //P3 scores
                else if(p3Dead==false&&ball[z].x<525 && ball[z].x>125 && ball[z].y<2)
                    if(score3==1)humiliation.play();
                    else headshot.play();               
                    score3--;cons3++;          
                    ball[z].y = 325; ball[z].x = 325;
                    if(ranB1==0){ball[z].a=1;ball[z].b=1;}else if(ranB1==1){ball[z].a=-1;ball[z].b=1;}
                    else if(ranB1==2){ball[z].a=1;ball[z].b=-1;}else if(ranB1==3){ball[z].a=-1;ball[z].b=-1;}
                    if(score3 == 0)p3Dead=true;
                //P4 Scores
                else if(p4Dead==false&&ball[z].x<525 && ball[z].x>125 && ball[z].y>648)
                    if(score4==1)humiliation.play();
                    else headshot.play();
                    score4--;cons4++;            
                    ball[z].y = 325; ball[z].x = 325;
                    if(ranB1==0){ball[z].a=1;ball[z].b=1;}else if(ranB1==1){ball[z].a=-1;ball[z].b=1;}
                    else if(ranB1==2){ball[z].a=1;ball[z].b=-1;}else if(ranB1==3){ball[z].a=-1;ball[z].b=-1;}
                    if(score4 == 0)p4Dead=true;
                if((p1Dead==true && ball[z].y<525 && ball[z].y>125 && ball[z].x<2) || (gameflag==3 || gameflag == 4))
                    ballbounce.play();ball[z].a*=-1;
                else if((p2Dead==true && ball[z].y<525 && ball[z].y>125 && ball[z].x>648) || (gameflag==3 || gameflag == 4))
                    ballbounce.play();ball[z].a*=-1;
                else if((p3Dead==true &&ball[z].x<525 && ball[z].x>125 && ball[z].y<2) || (gameflag==3 || gameflag == 4))
                    ballbounce.play();ball[z].b*=-1;
                else if((p4Dead==true &&ball[z].x<525 && ball[z].x>125 && ball[z].y>648) || (gameflag==3 || gameflag == 4))
                    ballbounce.play();ball[z].b*=-1;
                if(poly1.contains(ball[z].x,ball[z].y))
                    ballbounce.play();
                    if(ranB1 == 0){ball[z].a=1;ball[z].b=5;}else if(ranB1 == 1){ball[z].a=2;ball[z].b=4;}
                    else if(ranB1 == 2){ball[z].a=5;ball[z].b=1;}else if(ranB1 == 3){ball[z].a=4;ball[z].b=2;}
                else if(poly2.contains(ball[z].x,ball[z].y))
                    ballbounce.play();
                    if(ranB1 == 0){ball[z].a=1;ball[z].b=-5;}else if(ranB1 == 1){ball[z].a=2;ball[z].b=-4;}
                    else if(ranB1 == 2){ball[z].a=5;ball[z].b=-1;}else if(ranB1 == 3){ball[z].a=4;ball[z].b=-2;}
                else if(poly3.contains(ball[z].x,ball[z].y))
                    ballbounce.play();
                    if(ranB1 == 0){ball[z].a=-1;ball[z].b=5;}else if(ranB1 == 1){ball[z].a=-2;ball[z].b=4;}
                    else if(ranB1 == 2){ball[z].a=-5;ball[z].b=1;}else if(ranB1 == 3){ball[z].a=-4;ball[z].b=2;}
                else if(poly4.contains(ball[z].x,ball[z].y))
                    ballbounce.play();
                    if(ranB1 == 0){ball[z].a=-1;ball[z].b=-5;}else if(ranB1 == 1){ball[z].a=-2;ball[z].b=-4;}
                    else if(ranB1 == 2){ball[z].a=-5;ball[z].b=-1;}else if(ranB1 == 3){ball[z].a=-4;ball[z].b=-2;}
        public void resetter()
            brick[0].x=25;brick[0].y=285;brick[1].x=615;brick[1].y=285;brick[2].x=285;brick[2].y=25;brick[3].x=285;brick[3].y=615;
            if(p4Dead==true && p3Dead==true && p2Dead==true && p1Dead==false){ball[0].x = 325;ball[0].y = 325;ball[1].x = 325;ball[1].y = 325;
                ball[0].a=0;ball[0].b=0;ball[1].a=0;ball[1].b=0;drawB=false;match.play();pause=5;p1Dead=true;begin=0;win=1;winner=1;stringWin="Player 1 Wins";}
            else if(p4Dead==true && p3Dead==true && p2Dead==false && p1Dead==true){ball[0].x = 325;ball[0].y = 325;ball[1].x = 325;ball[1].y = 325;
                ball[0].a=0;ball[0].b=0;ball[1].a=0;ball[1].b=0;drawB=false;match.play();pause=5;p2Dead=true;begin=0;win=1;winner=2;stringWin="Player 2 Wins";}
            else if(p4Dead==true && p3Dead==false && p2Dead==true && p1Dead==true){ball[0].x = 325;ball[0].y = 325;ball[1].x = 325;ball[1].y = 325;
                ball[0].a=0;ball[0].b=0;ball[1].a=0;ball[1].b=0;drawB=false;match.play();pause=5;p3Dead=true;begin=0;win=1;winner=3;stringWin="Player 3 Wins";}
            else if(p4Dead==false && p3Dead==true && p2Dead==true && p1Dead==true){ball[0].x = 325;ball[0].y = 325;ball[1].x = 325;ball[1].y = 325;
                ball[0].a=0;ball[0].b=0;ball[1].a=0;ball[1].b=0;drawB=false;match.play();pause=5;p4Dead=true;begin=0;win=1;winner=4;stringWin="Player 4 Wins";}       
        public boolean countDead()
            if(gameflag==2)
                if(p4Dead==true)a1=1;if(p3Dead==true)b1=1;if(p2Dead==true)c1=1;if(p1Dead==true)d1=1;
                dead = a1 + b1 + c1 + d1;
                if(dead>2)return true;
                else return false;
            if(gameflag==3 || gameflag==4)
                if(p2Dead==true)c1=1;if(p1Dead==true)d1=1;
                dead = c1 + d1;
                if(dead==1) return true;
                else return false;
            return false;
        public void physicsintro()
            for(int aw = 0;aw<8;aw++)
                if(ball2[aw].x >645 || ball2[aw].x < 5)ball2[aw].a *= -1;
                if(ball2[aw].y > 720 || ball2[aw].y <5)ball2[aw].b *= -1;
        public void mouseExited(MouseEvent e){}
        public void mouseEntered(MouseEvent e){}
        public void mouseReleased(MouseEvent e){}
        public void mousePressed(MouseEvent e){}
        public void mouseClicked(MouseEvent e) 
                // resume
                if(pause==1 && e.getX()>=270 && e.getX()<= 360 && e.getY()>=650)
                    pauseB=false;pause=0;
                // pause
                else if(pause==0 && e.getX()>=270 && e.getX()<= 360 && e.getY()>=650)
                   pauseB=true;pause=1;             
                //start
                else if(begin == 0 && e.getX()>=270 && e.getX()<= 360 && e.getY()>=650)
                    starter = 1;              
        public void mouseMoved(MouseEvent e)
            //gui light up
            if(e.getX()>=270 && e.getX()<= 360 && e.getY()>=650){Color1 = new Color(255,255,255);}
            else{Color1 = new Color(0,0,0);}         
            repaint();
        public void mouseDragged(MouseEvent e){}
        public void keyTyped(KeyEvent e){}
        public void keyPressed(KeyEvent e)
            c = e.getKeyCode();
            if(gameflag==2 || gameflag==3)
            switch(c)
                case KeyEvent.VK_1:
                movecheck1 = 1;break;
                case KeyEvent.VK_2:
                movecheck1 = -1;break;           
                case KeyEvent.VK_V:
                movecheck2 = 1;break;
                case KeyEvent.VK_B:
                movecheck2 = -1;break;
                case KeyEvent.VK_K:
                movecheck3 = 1;break;
                case KeyEvent.VK_L:
                movecheck3 = -1;break;
                case KeyEvent.VK_LEFT:
                movecheck4 = 1;break;
                case KeyEvent.VK_DOWN:
                movecheck4 = -1;break;
            if(gameflag==1)
            switch(c)
                case KeyEvent.VK_UP:
                if(colorChange==0)colorChange=2;
                else if(colorChange==1)colorChange=0;
                else if(colorChange==2)colorChange=1;break;
                case KeyEvent.VK_DOWN:
                if(colorChange==0)colorChange=1;
                else if(colorChange==1)colorChange=2;
                else if(colorChange==2)colorChange=0;break;
                case KeyEvent.VK_ENTER:
                if(colorChange==0)gameflag=2;
                if(colorChange==1)gameflag=3;
                if(colorChange==2)gameflag=4;
                 break;
        public void keyReleased(KeyEvent e)
            c = e.getKeyCode();
            if (gameflag==2 || gameflag==3)
            switch(c)
                case KeyEvent.VK_1:
                movecheck1 = 0;break;
                case KeyEvent.VK_2:
                movecheck1 = 0;break;
                case KeyEvent.VK_V:
                movecheck2 = 0;break;
                case KeyEvent.VK_B:
                movecheck2 = 0;break;
                case KeyEvent.VK_K:
                movecheck3 = 0;break;
                case KeyEvent.VK_L:
                movecheck3 = 0;break;
                case KeyEvent.VK_LEFT:
                movecheck4 = 0;break;
                case KeyEvent.VK_DOWN:
                movecheck4 = 0;break;
    {co                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  

    Japplet is Swing. Your double buffering code is unneccessary. And you are painting wrong. You should be using paintComponent and not paint. And throw away the
    buffered image and update while you are at it.

  • Alternative to Double-Buffered Canvas

    I am working on a program in which I use a double-buffered Canvas inside a JScrollPane. The problem is that the Canvas draws over the scrollbars. I have tried extending JComponent, JPanel, JApplet, and Component instead of Canvas, and none of them are double buffered. Here is the code I used to debug this problem:
    import java.awt.*;
    import java.awt.geom.*;
    import java.awt.image.*;
    import javax.swing.*;
    public class Test implements  Runnable
         JFrame f;
         JScrollPane scroller;
         JPanel panel;
         TestCanvas canvas;
         Thread runner;
         BufferStrategy strategy;
         public static void main (String[] args) {
              Test app = new Test();
              app.init();
         public void init() {
              f = new JFrame();
              f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
              panel = new JPanel();
              canvas = new TestCanvas();
              panel.add(canvas);
              scroller = new JScrollPane(panel);
              scroller.setWheelScrollingEnabled(true);
              f.getContentPane().add(scroller);
              f.pack();
              f.setSize(300,300);
              f.setVisible(true);
              canvas.createBufferStrategy(2);
              strategy = canvas.getBufferStrategy();
              runner = new Thread(this);
              runner.run();
         public void run() {
              int x = 0;
              while(x != 65536) {
                   Graphics2D g = (Graphics2D)strategy.getDrawGraphics().create();
                   g.setColor(new Color(x%256,0,0));
                   g.fill(new Ellipse2D.Double(0,0,600,600));
                   strategy.show();
                   x++;
    }Any suggestions?

    The main culprit is that you are mixing AWT components with Swing ones.
    In addition, your are doing so many of useless things and wrong things in your code.
    Swing components are defaulted for using double-buffering.
    See: http://java.sun.com/products/jfc/tsc/articles/painting/index.html
    Try and study this code.
    import java.awt.*;
    import java.awt.event.*;
    import java.awt.geom.*;
    import java.awt.image.*;
    import javax.swing.*;
    public class Fox1229{
      JFrame f;
      JScrollPane scroller;
      TestCanvas canvas;
      int x;
      Timer t;
      public static void main (String[] args) {
        Fox1229 app = new Fox1229();
        app.init();
      public void init() {
        x = 0;
        f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        canvas = new TestCanvas();
        scroller = new JScrollPane(canvas);
        scroller.setWheelScrollingEnabled(true);
        f.getContentPane().add(scroller, BorderLayout.CENTER);
        f.setSize(300, 300);
        f.setVisible(true);
        t = new Timer(50, new ActionListener(){
          public void actionPerformed(ActionEvent e){
            canvas.setOc(new Color(x % 256, 0, 0));
            canvas.repaint();
            if (++x == 1024){
              t.stop();
        t.start();
    class TestCanvas extends JPanel{
      Color oc;
      public TestCanvas (){
        oc = new Color(0, 0, 0);
      public void setOc(Color c){
        oc = c;
      public Dimension getPreferredSize(){
        return new Dimension(600, 600);
      public void paintComponent(Graphics g){
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D)g;
        g2d.setColor(Color.blue);
        g2d.fill(new Rectangle(0, 0, 600, 600));
        g2d.setColor(oc);
        g2d.fill(new Ellipse2D.Double(0, 0, 600, 600));
    }

  • Double buffering still gives flickering graphics.

    I copied code from a tutorail which is supposed to illustrate double buffering.
    After I run it, it still flickers though.
    I use applet viewer, which is part of netbeans to run my applet.
    Link to tutorial: http://www.javacooperation.gmxhome.de/TutorialStartEng.html
    My questions are:
    Is the strategy used for double buffering correct?
    Why does it flicker?
    Why does the program change the priority a couple of times?
    Can you make fast games in JApplets or is there a better way to make games? (I think C++ is too hard)
    Here is the code:
    package ballspel;
    import java.awt.Color;
    import java.awt.Graphics;
    import java.awt.Image;
    import javax.swing.JApplet;
    //import java.applet.*;
    * @author Somelauw
    public class BallApplet extends /*Applet*/ JApplet implements Runnable {
    private Image dbImage;
    private Graphics dbg;
    private int radius = 20;
    private int xPos = 10;
    private int yPos = 100;
    * Initialization method that will be called after the applet is loaded
    * into the browser.
    @Override
    public void init() {
    //System.out.println(this.isDoubleBuffered()); //returns false
    // Isn't there a builtin way to force double buffering?
    // TODO start asynchronous download of heavy resources
    @Override
    public void start() {
    Thread th = new Thread(this);
    th.start();
    public void run() {
    Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
    while (true) {
    xPos++;
    repaint();
    try {
    Thread.sleep(20);
    } catch (InterruptedException ex) {
    ex.printStackTrace();
    Thread.currentThread().setPriority(Thread.MAX_PRIORITY);
    @Override
    public void paint(Graphics g) {
    super.paint(g);
    //g.clear();//, yPos, WIDTH, WIDTH)
    g.setColor(Color.red);
    g.fillOval(xPos - radius, yPos - radius, 2 * radius, 2 * radius);
    @Override
    public void update(Graphics g) {
    super.update(g);
    // initialize buffer
    if (dbImage == null) {
    dbImage = createImage(this.getSize().width, this.getSize().height);
    dbg = dbImage.getGraphics();
    // clear screen in background
    dbg.setColor(getBackground());
    dbg.fillRect(0, 0, this.getSize().width, this.getSize().height);
    // draw elements in background
    dbg.setColor(getForeground());
    paint(dbg);
    // draw image on the screen
    g.drawImage(dbImage, 0, 0, this);
    // TODO overwrite start(), stop() and destroy() methods
    }

    Somelauw wrote:
    I copied code from a tutorail which is supposed to illustrate double buffering.
    After I run it, it still flickers though.
    I use applet viewer, which is part of netbeans.. AppletViewer is part of the JDK, not NetBeans.
    ..to run my applet.
    Link to tutorial: http://www.javacooperation.gmxhome.de/TutorialStartEng.html
    Did you specifically mean the code mentioned on this page?
    [http://www.javacooperation.gmxhome.de/BildschirmflackernEng.html]
    Don't expect people to go hunting around the site, looking for the code you happen to be referring to.
    As an aside, please use the code tags when posting code, code snippets, XML/HTML or input/output. The code tags help retain the formatting and indentation of the sample. To use the code tags, select the sample and click the CODE button.
    Here is the code you posted, as it appears in code tags.
    package ballspel;
    import java.awt.Color;
    import java.awt.Graphics;
    import java.awt.Image;
    import javax.swing.JApplet;
    //import java.applet.*;
    * @author Somelauw
    public class BallApplet extends /*Applet*/ JApplet implements Runnable {
        private Image dbImage;
        private Graphics dbg;
        private int radius = 20;
        private int xPos = 10;
        private int yPos = 100;
         * Initialization method that will be called after the applet is loaded
         * into the browser.
        @Override
        public void init() {
            //System.out.println(this.isDoubleBuffered()); //returns false
            // Isn't there a builtin way to force double buffering?
            // TODO start asynchronous download of heavy resources
        @Override
        public void start() {
            Thread th = new Thread(this);
            th.start();
        public void run() {
            Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
            while (true) {
                xPos++;
                repaint();
                try {
                    Thread.sleep(20);
                } catch (InterruptedException ex) {
                    ex.printStackTrace();
                Thread.currentThread().setPriority(Thread.MAX_PRIORITY);
        @Override
        public void paint(Graphics g) {
            super.paint(g);
            //g.clear();//, yPos, WIDTH, WIDTH)
            g.setColor(Color.red);
            g.fillOval(xPos - radius, yPos - radius, 2 * radius, 2 * radius);
        @Override
        public void update(Graphics g) {
            super.update(g);
            // initialize buffer
            if (dbImage == null) {
                dbImage = createImage(this.getSize().width, this.getSize().height);
                dbg = dbImage.getGraphics();
            // clear screen in background
            dbg.setColor(getBackground());
            dbg.fillRect(0, 0, this.getSize().width, this.getSize().height);
            // draw elements in background
            dbg.setColor(getForeground());
            paint(dbg);
            // draw image on the screen
            g.drawImage(dbImage, 0, 0, this);
        // TODO overwrite start(), stop() and destroy() methods
    }Edit 1:
    - For animation code, it would be typical to use a javax.swing.Timer for triggering updates, rather than implementing Runnable (etc.)
    - Attempting to set the thread priority will throw a SecurityException, though oddly it occurs when attempting to set the Thread priority to maximum, whereas the earlier call to set the Thread priority to minimum passed without comment (exception).
    - The paint() method of that applet is not double buffered.
    - It is generally advisable to override paintComponent(Graphics) in a JPanel that is added to the top-level applet (or JFrame, or JWindow, or JDialog..) rather than the paint(Graphics) method of the top-level container itself.
    Edited by: AndrewThompson64 on Jan 22, 2010 12:47 PM

  • How to draw a point without double buffering?

    Hello all,
    I am drawing points as small red circles, but they are a bit ugly without double buffering. Am I able to draw the points to be nice? I mean not to draw them as just circles, but some special circle with light border that will looks much more nicer?
    Or what radius and position of the circle must be to be a nice small circle containing only 5 pixels? (upper, lower, right, left, middle)
    ps - they are ugly in the way of having a strange dot on the left side

    I use this method:
        private static final float POINT_RADIUS = 2f;
        private static final float POINT_DIAMETER = POINT_RADIUS * 2;
    private void drawPoint(float x, float y, Color c) {
            Ellipse2D point = new Ellipse2D.Float(x - POINT_RADIUS, -y
                    - POINT_RADIUS, POINT_DIAMETER, POINT_DIAMETER);
            graphics.setStroke(new BasicStroke(0.2f));
            graphics.fill(point);
    // and points looks like this:
       ***

  • Problem with Double Buffering and Swing

    Hi
    I made a game and basically it works pretty well, my only problem is it flickers really badly right now. I read up on a whole lot of forums about double buffering and none of those methods seemed to work. Then I noticed that Swing has double buffering built in so I tried that but then I get compilation errors and I'm really not sure why. My original code was a console application and worked perfectly, then I ported it into a JApplet and it still works but it flickers and thats what I'm tryign to fix now.
    The code below is in my main class under the constructor.
    Heres the double buffering code I'm trying to use, I'm sure you all seen it before lol
    public void update(Graphics g)
              // initialize buffer
              if (dbImage == null)
                   dbImage = createImage(this.getSize().width, this.getSize().height);
                   dbg = dbImage.getGraphics();
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