Double buffering on large pane
I have a large JPanel which I'm drawing onto which is about 5000 x 5000. To eliminate screen flicker when dragging objects I'm trying to use double buffering. The problem is the image is too big and I get an out of memory error message.
I've tried using clipped rectangles to display just the size of image needed but they give erratic results or the scrolling doesn't work. I need it to display the rest of the image when scrolling. Does anyone have any suggestions on how to solve this?
I've thought about creating the image to be just the size of the screen and to just have the objects that are meant to be at that part but I think this would involve going from device space from user space but I don't know how to do this. Thanks.
Alan
ok, if you want it to be interactive with scrolling, then you have to keep the image large, but unless your video card has 71.5MB free space for that image, you're not going to get good results, not to mention CPU will be hurting if you need to do any processing of the image (transforms, loads, saves, etc.)
options:
1. forget interaction and just get the viewable image area and paint that portion of the image
2. Get a graphics supercomputer!
3. try to fake the interaction somehow
what else? dunno, did that help
Similar Messages
-
Double Buffering a large image - is it a good idea to do so ?
I'm developing a small maze like game. I'm using double buffering. So I double buffer the enter screen area (1024x768) and copy them all back to the on screen buffer...
I need my code to run atleast at 18 - 24 fps.
Is there a better/efficient way to do this...
Note : I'm manually double buffer. I don't use any Buffer manager.
like this
public void update(Graphics g)
Image i = createImage(...) ;
paint(i.getGraphics() );
g.drawImage(i..)
}Hi chaos,
I am developing a game too and I achieve very high frame rate (up to 60 fps) using the hardware accelerated pipelines and the double buffering/page flipping strategy.
here is the method I call to update my the entire screen of my game:
private void screenUpdate()
try
Graphics gScr = bufferStrategy.getDrawGraphics();
gameRender(gScr); //this is where I paint the game screen
gScr.dispose();
if (!bufferStrategy.contentsLost())
bufferStrategy.show();
} catch (Exception e)
e.printStackTrace();
running = false;
}Here is how I create the buffer strategy in the main JFrame:
try
EventQueue.invokeAndWait(new Runnable()
public void run()
createBufferStrategy(NUM_BUFFERS);
} catch (Exception e)
System.out.println("Error while creating buffer strategy");
System.exit(0);
bufferStrategy = getBufferStrategy();In my gameRender method, I use only draming method that works without breaking the hardware acceleration (by default enabled with java 6.0). I just make sure to use BufferedImage without rotation or manually written filters and the game runs at 60 fps without any issue.
The CPU is even still sleeping more than 70% of the time which gives a lot room for all other processing such as path finders, A.I., ...
Cheers.
Vince. -
Panel refreshing and double buffering
Hi all swing experts
Could any one solve the problem.I have an application,which is having a JSplit pane.
On the left of the JSplit pane , there is a tree. When u click a node from the tree
that will be selected and you can place that node into the right side panel.
And the same way you can click an another node (redirection or sink) and drop into the
panel.you can draw a line by clicking the source and the sink / or redirection.
The line is getting drawn dynamically by getting the x,y coordinates of the node.
once the line is drawn am storing the line into vector, since this is getting drawn
dynamically once if i minimize and maxmize it will disappear.
For avoiding this am trying to redraw the old line from the vector when the window
is getting activated, here the problem starts it draws the line but the line
is getting disappeared immly.
HOW DO I SOLVE THIS?
is it possible to solve this problem with double buffering tech? if so how?
PL HELP.
Software - Visual Tool
Last Modified -7/23/01
sami
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.util.*;
import javax.swing.*;
import javax.swing.border.TitledBorder;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.plaf.FontUIResource;
import javax.swing.tree.*;
import java.lang.System;
import java.net.*;
import java.awt.image.*;
import javax.swing.event.*;
public class CompTree extends JFrame implements TreeSelectionListener,WindowListener{
// Swing components declarations
public JSplitPane jSplitPane1,jSplitPaneTop;
public JScrollPane treeScrollPane,splitScrollPane;
public JTree mainTree,jtree ;
public static DefaultMutableTreeNode topchildnode1, topchildnode2, topchildnode3,toptreenode;
DrawPanel dp = new DrawPanel();
public int i=0;
public int j=0;
public int flag = 1 ;
public String var,S,R,D;
Frame fr = new Frame("GUI TOOL");
public CompTree()
File nFile = null ;
mainTree = DrawTree(nFile,"N") ;
mainTree.updateUI();
mainTree.setBackground(new Color(105,205,159));
// Tree is getting added into scroll pane
treeScrollPane = new JScrollPane(mainTree);
treeScrollPane.setVerticalScrollBarPolicy(javax.swing.JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
treeScrollPane.setHorizontalScrollBarPolicy(javax.swing.JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
splitScrollPane = new JScrollPane();
splitScrollPane.setViewportView(dp.panel1);
splitScrollPane.setVerticalScrollBarPolicy(javax.swing.JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
splitScrollPane.setHorizontalScrollBarPolicy(javax.swing.JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
jSplitPane1 = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,treeScrollPane,splitScrollPane);
jSplitPane1.setOneTouchExpandable(true);
jSplitPane1.setContinuousLayout(true);
jSplitPane1.addComponentListener(new ComponentAdapter(){
public void componentResized(ComponentEvent e) {
System.out.println("Componenet resized");
flag = 1;
paint(dp.panel1.getGraphics());
//Provide minimum sizes for the two components in the split pane
Dimension minimumSize = new Dimension(150,75);
splitScrollPane.setMinimumSize(minimumSize);
//Provide a preferred size for the split pane
jSplitPane1.setPreferredSize(new Dimension(700, 500));
//setContentPane(jSplitPane1);
fr.add(jSplitPane1);
fr.setSize(700,500);
fr.setVisible(true);
fr.addWindowListener(this);
public void windowActivated(WindowEvent we){
System.out.println("activated");
dp.draw();
public void windowClosed(WindowEvent we){System.out.println("closed");}
public void windowIconified(WindowEvent we){System.out.println("iconified");}
public void windowDeiconified(WindowEvent we){
dp.draw();
System.out.println("deiconified");
public void windowDeactivated(WindowEvent we){System.out.println("deactivated");}
public void windowOpened(WindowEvent we){
dp.repaint();
System.out.println("opened");
public void windowClosing(WindowEvent we){
System.exit(0);
System.out.println("closing");
public void valueChanged(TreeSelectionEvent e) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode)
mainTree.getLastSelectedPathComponent();
String strRootNode = "" ;
try{
Object rootNode = node.getRoot();
strRootNode = rootNode.toString() ;
catch(Exception eRoot)
System.out.println("Error in geting Root Node");
if (node == null) return;
Object nodeInfo = node.getUserObject();
TreeNode ParentNode = node.getParent();
final String strParentName = node.toString() ;
if (strParentName.equals("Source"))
System.out.println("Before source");
var = "S";
System.out.println("This is source");
else if (strParentName.equals("Redirection"))
var ="R";
else if (strParentName.equals("Sink") )
var ="D";
else
if ( strRootNode != strParentName){
public JTree DrawTree( File file, String strIsValid)
jtree = new JTree();
toptreenode = new DefaultMutableTreeNode("Start");
topchildnode1 = new DefaultMutableTreeNode("Source");
topchildnode2 = new DefaultMutableTreeNode("Sink");
topchildnode3 = new DefaultMutableTreeNode("Redirection");
toptreenode.add(topchildnode1);
toptreenode.add(topchildnode2);
toptreenode.add(topchildnode3);
jtree.putClientProperty("JTree.lineStyle", "Angled");
DefaultTreeModel defaulttreemodel = new DefaultTreeModel(toptreenode);
jtree.setModel(defaulttreemodel);
DefaultTreeSelectionModel defaulttreeselectionmodel = new DefaultTreeSelectionModel();
defaulttreeselectionmodel.setSelectionMode(1);
jtree.setSelectionModel(defaulttreeselectionmodel);
jtree.addTreeSelectionListener(this);
jtree.setEditable(true);
return jtree;
public static void main(String args[]){
CompTree ct = new CompTree();
* This class contains all the component related to panel 1
* this can be used for .....
public class DrawPanel extends JPanel implements ActionListener,
ComponentListener,MouseListener,KeyListener{
public JRadioButton uniRadio,multiRadio,show;
public JButton sBut,rBut,dBut;
public int flag = 1 ;
public int Radio = 1;
public boolean sIndicator = true;
public boolean rIndicator = true;
public boolean isDestSelected = false;
public boolean isDestFirstTime = true;
public int x1 = 0 ;
public int y1 = 0 ;
public int x2 = 0 ;
public int y2 = 0;
public int x3 = 0;
public int y3 = 0;
public int k=0;
public int l = 40;
public int b = 40;
public String connection1,connection2,connection3,destination1,destination2;
public int locX;
public int locY;
public JPanel panel1 = new JPanel ();
public JPanel panel2 = new JPanel ();
Vector lines = new Vector();
Vector colors = new Vector();
Vector obj = new Vector();
Vector source = new Vector();
Vector loc = new Vector();
BasicStroke stroke = new BasicStroke(2.0f);
Icon compImage = new ImageIcon("network1.gif"); //new
Icon workImage = new ImageIcon("tconnect02.gif");
Icon lapImage = new ImageIcon("server02.gif");
public DrawPanel(){
am adding radio button for checking the mode unicast and broad cast mode -- new
uniRadio = new JRadioButton("Unicast Mode");
uniRadio.setMnemonic(KeyEvent.VK_B);
uniRadio.setSelected(true);
multiRadio = new JRadioButton("Broadcast Mode");
multiRadio.setMnemonic(KeyEvent.VK_C);
show = new JRadioButton("show Panel");
show.setMnemonic(KeyEvent.VK_C);
ButtonGroup group = new ButtonGroup();
group.add(uniRadio);
group.add(multiRadio);
group.add(show);
/* Border border = ButtonGroup.getBorder();
Border margin = new EmptyBorder(10,10,10,10);
ButtonGroup.setBorder(new CompoundBorder(border,margin)); */
uniRadio.addActionListener(this);
multiRadio.addActionListener(this);
show.addActionListener(this);
panel1.add(uniRadio);
panel1.add(multiRadio);
panel1.add(show);
uniRadio.setBounds(150,15,100,40);
multiRadio.setBounds(260,15,120,40);
show.setBounds(390,15,100,40);
uniRadio.setBackground(new Color(105,200,205));
multiRadio.setBackground(new Color(105,200,205));
show.setBackground(new Color(105,200,205));
/*****************PANEL 1*********************/
panel1.setLayout(null);
panel1.setBounds(new Rectangle(0,0,400,400));
panel1.setBackground(new Color(105,100,205));
panel1.addComponentListener(this);
panel1.addMouseListener(this);
public void sourceObject(String name)
sBut = new JButton(compImage);
panel1.add(sBut);
sBut.setMnemonic(KeyEvent.VK_F);
sBut.setBounds(new Rectangle(locX,locY,l,b));
sBut.addActionListener(this);
sBut.addMouseListener(this);
sBut.addKeyListener(this);
System.out.println("am inside the source object") ;
sBut.setBackground(new Color(105,100,205));
System.out.println("key number" +sBut.getMnemonic());
System.out.println("MY LOCATION : SBUT : "+ sBut.getLocation());
public void redirectionObject(String name)
rBut = new JButton(workImage);
panel1.add(rBut);
rBut.setBounds(new Rectangle(locX,locY,l,b));
rBut.addActionListener(this);
rBut.addMouseListener(this);
rBut.addKeyListener(this);
rBut.setBackground(new Color(105,100,205));
System.out.println("am inside the redirection :" + j) ;
System.out.println("MY LOCATION : RBUT : "+ rBut.getLocation());
public void destinationObject(String name){
dBut = new JButton(lapImage);
panel1.add(dBut);
dBut.setBackground(new Color(105,100,205));
System.out.println("am inside the destination object") ;
dBut.setBounds(new Rectangle(locX,locY,l,b));
System.out.println("am inside the destination:" + j) ;
dBut.addActionListener(this);
dBut.addMouseListener(this);
dBut.addKeyListener(this);
System.out.println("MY LOCATION : DBUT : "+ dBut.getLocation());
public void paintComponent(Graphics g){
super.paintComponent(g);
System.out.println("inside paint");
Graphics2D g2 = (Graphics2D) g;
g2.setStroke(stroke);
if(flag == 1){
/* this is for drawing current line, this will be drawn when component event happens */
g.setColor(getForeground());
System.out.println("inside flag");
int np = lines.size();
System.out.println("Total number of lines present the buffer to draw :" + np);
for (int I=0; I < np; I++) {
Rectangle p = (Rectangle)lines.elementAt(I);
g2.setColor((Color)colors.elementAt(I));
System.out.println("width" + p.width);
g2.setColor(Color.red);
// g2.setPaint(p.x,p.y,p.width,p.height);
g2.drawLine(p.x,p.y,p.width,p.height);
System.out.println("$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$");
System.out.println(obj.elementAt(I));
System.out.println("$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$");
System.out.println(p.x +"," +","+ p.y + ","+ ","+ p.width+ "," + ","+ p.height);
flag = -1;
}else if(flag == -1){
if(x1 != 0 && y1 != 0 && x2 != 0 && y2 != 0 ){
connection1 = "source to redirection";
g2.setColor(Color.red);
g2.drawLine(x1,y1,x2,y2);
lines.addElement(new Rectangle(x1,y1,x2,y2));
colors.addElement(getForeground());
obj.addElement(connection1);
x1 = 0 ;y1 = 0 ;
x2 = 0 ;y2 = 0 ;
else if (x2 != 0 && y2 != 0 && x3 != 0 && y3 != 0 )
connection2 = "Redirection to Destination";
g2.setColor(Color.green);
g2.drawLine(x2,y2,x3,y3);
colors.addElement(getForeground());
lines.addElement(new Rectangle(x2,y2,x3,y3));
obj.addElement(connection2);
x2 = 0; y2 = 0 ;
x3 = 0 ; y3 = 0 ;
else if (x1 != 0 && y1 != 0 && x3 != 0 && y3 != 0)
connection3 = "Source to Destination";
g2.setColor(Color.red);
g2.drawLine(x1,y1,x3,y3);
colors.addElement(getForeground());
lines.addElement(new Rectangle(x1,y1,x3,y3));
obj.addElement(connection3);
x1 = 0; y1 = 0 ;
x3 = 0 ; y3 = 0 ;
/* Image offscreen = panel1.createImage(400,400);
Graphics og = offscreen.getGraphics();
og.drawLine(200,200,500,500);
g.drawImage(offscreen,0,0,null); */
// Component Listener's method
public void componentHidden(ComponentEvent e) {
if(e.getSource().equals(panel1)){System.out.println("Componenet Hidden");}
System.out.println("Componenet Hidden");
public void componentMoved(ComponentEvent e) {
System.out.println("Componenet moved");
draw();
public void componentResized(ComponentEvent e) {
System.out.println("Componenet resized");
flag = 1;
paintComponent(panel1.getGraphics());
public void componentShown(ComponentEvent e) {
System.out.println("Componenet Shown");
// Mouse Listerner's Method
public void mouseClicked(MouseEvent me){
if (me.getSource().equals(panel1))
System.out.println("inside mouse clicked");
if(var == "S"){
the boolean sIndicator will allow the usage of source object only once
This is the case for both unicast and multi cast.It has been restricted
to single use.
if (sIndicator){
System.out.println("inside mouse clicked");
System.out.println("locX" + locX);
locX = me.getX();
locY = me.getY();
sourceObject("Source");
sIndicator = false;
}else{}
}else if (var == "R")
if(rIndicator){
if(!isDestSelected){
System.out.println("redirection" + locX);
locX = me.getX();
locY = me.getY();
redirectionObject("Redirection");
rIndicator = false;
}else{}
} else{}
}else if(var == "D"){
if(Radio == 1 && isDestSelected == false){
System.out.println("Destination -- uni cast mode" + locX);
locX = me.getX();
locY = me.getY();
destinationObject("Sink");
isDestSelected = true;
} else if (Radio == 2)
System.out.println("Destination -- Multicast mode" + locX);
locX = me.getX();
locY = me.getY();
destinationObject("Sink");
isDestSelected = true;
public void mousePressed(MouseEvent me){System.out.println("am inside mouse pressed"); }
public void mouseReleased(MouseEvent me){
System.out.println("am inside mouse released");
paintComponent(panel1.getGraphics());
public void mouseEntered(MouseEvent me){}
public void mouseExited(MouseEvent me){}
// key Listener
public void keyReleased(KeyEvent e) {
Component compo =(JButton)e.getSource();
if (e.getKeyChar() == e.VK_DELETE){
remove(compo);
public void keyTyped(KeyEvent e) {}
public void keyPressed(KeyEvent e){}
public void remove(Component comp){
System.out.println("inside delete key" );
panel1.remove(comp);
panel1.repaint();
public void draw(){
super.paint(panel1.getGraphics());
System.out.println("inside draw");
flag = 1;
paintComponent(panel1.getGraphics());
public void actionPerformed(ActionEvent e)
if(e.getSource().equals(sBut)){
System.out.println("am s button");
x1 = sBut.getX() + l;
y1 = sBut.getY() + (b/2);
else if(e.getSource().equals(rBut)){
System.out.println("am r button");
x2 = rBut.getX() ;
y2 = rBut.getY()+ b/2;
System.out.println("x2 : " + x2 + "y2 :" +y2 );
else if(e.getSource().equals(dBut)){
System.out.println("am d button");
x3 = dBut.getX();
y3 = dBut.getY()+ b/2;
else if (e.getSource().equals(uniRadio)){
System.out.println("uni radio");
Radio = 1 ;
} else if (e.getSource().equals(multiRadio)){
System.out.println("multi radio");
Radio = 2;
} else if (e.getSource().equals(show)){
System.out.println("inside show");
*********************************************ok
i don't take a long time tracing your code, but i think u have to overwrite the repaint methode so it 's call the methode which will paint the line each time.
hope this will help! -
Need double buffering enabled if I print a JTable
Hi @ all
I have printed a very large JTable. The Problem is if I disable double
buffering the horizontal lines move after some pages.
If I enable double buffering the printout looks very bad(as all know).
But the horizontal lines are OK!
You can produce this failure with the print tutorial(and a large table).
Has someone an idea how I can fix my bug ?
many thanks for helpingmay be you have to disable double buffering generaly to all the element envolved in the printing component, try this:
private void setDoubleBuffering(Component c, boolean isEnabled) {
RepaintManager manager = RepaintManager.currentManager(c);
manager.setDoubleBufferingEnabled(isEnabled);
} -
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 sideI 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();
// 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);
}My paint is right under neath and heres how it looks
This snipet of code works but when I change the method to
public paintComponent(Graphics g){
super.paintComponent(g)...
everythign stops working and get a compilation error and says that it can't find paintComponent in javax.swing.JFrame.
public void paint(Graphics g)
super.paint(g);
//if game starting display menue
if (show_menue)
//to restart lives if player dies
lives = 3;
menue.draw_menue(g);
menue_ufo1.draw_shape(g);
menue_ufo2.shape_color = Color.DARK_GRAY;
menue_ufo2.draw_shape(g);
menue_ufo3.shape_color = Color.BLUE;
menue_ufo3.draw_shape(g);
menue_ufo4.shape_color = new Color(82, 157, 22);
menue_ufo4.draw_shape(g);
menue_ufo5.draw_shape(g);
menue_ufo6.shape_color = new Color(130, 3, 3); ;
menue_ufo6.draw_shape(g);
menue_turret.draw_ship(g);
menue_ammo.draw_ammo(g);
else
//otherwise redraw game objects
gunner.draw_ship(g);
y_ammo.draw_ammo(g);
grass.draw_bar(g);
o_ufo.draw_shape(g);
b_ufo.draw_shape(g);
m_ufo.draw_shape(g);
s_ufo.draw_shape(g);
z_ufo.draw_shape(g);
xx_ufo.draw_shape(g);
info.draw_bar(g);
live_painter.draw_lives(g, lives);
score_painter.draw_score(g, score);
level_display.draw_level(g, level);
explosion.draw_boom(g);
}I just want to get rid of the flickering for now so any help will be greatly appreciated. Depending which will be simpler I can either try to double buffer this program or port it all to swing but I'm not sure which elements are effected by AWT and which by Swing. Also I read some of the Java documentation but couldn't really understand how to implement it to fix my program.
Thanks in advance
SebastianThis is a simple animation example quickly thrown together. I have two classes, an animation panel which is a JPanel subclass that overrides paintComponent and draws the animation, and a JApplet subclass that simply holds the animation panel in the applet's contentpane:
SimpleAnimationPanel.java
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.JPanel;
import javax.swing.Timer;
class SimpleAnimationPanel extends JPanel
private static final int DELAY = 20;
public static final int X_TRANSLATION = 2;
public static final int Y_TRANSLATION = 2;
private Point point = new Point(5, 32);
private BufferedImage duke = null;
private Timer timer = new Timer(DELAY, new TimerAction());
public SimpleAnimationPanel()
try
// borrow an image from sun.com
duke = ImageIO.read(new URL(
"http://java.sun.com/products/plugin/images/duke.wave.med.gif"));
catch (MalformedURLException e)
e.printStackTrace();
catch (IOException e)
e.printStackTrace();
setPreferredSize(new Dimension(600, 400));
timer.start();
// do our drawing here in the paintComponent override
@Override
protected void paintComponent(Graphics g)
super.paintComponent(g);
if (duke != null)
g.drawImage(duke, point.x, point.y, this);
private class TimerAction implements ActionListener
@Override
public void actionPerformed(ActionEvent e)
int x = point.x;
int y = point.y;
Dimension size = SimpleAnimationPanel.this.getSize();
if (x > size.width)
x = 0;
else
x += X_TRANSLATION;
if (y > size.height)
y = 0;
else
y += Y_TRANSLATION;
point.setLocation(new Point(x, y)); // update the point
SimpleAnimationPanel.this.repaint();
}AnimationApplet.java
import java.lang.reflect.InvocationTargetException;
import javax.swing.JApplet;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class AnimationApplet extends JApplet
public void init()
try
SwingUtilities.invokeAndWait(new Runnable()
public void run()
// construct the panel
JPanel simpleAnimation = new SimpleAnimationPanel();
// put it in the contentPane of the JApplet
getContentPane().add(simpleAnimation);
setSize(simpleAnimation.getPreferredSize());
catch (InterruptedException e)
e.printStackTrace();
catch (InvocationTargetException e)
e.printStackTrace();
}Here's a 3rd bonus class that shows how to put the JPanel into a stand-alone program, a JFrame. It's very similar to doing it in the JApplet:
AnimationFrame.java
import javax.swing.JFrame;
public class AnimationFrame
private static void createAndShowUI()
JFrame frame = new JFrame("SimpleAnimationPanel");
frame.getContentPane().add(new SimpleAnimationPanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
public static void main(String[] args)
java.awt.EventQueue.invokeLater(new Runnable()
public void run()
createAndShowUI();
}Edited by: Encephalopathic on Mar 15, 2008 11:01 PM -
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));
} -
Using 6533 DIO32HS, is it possible to use double buffered output with varying pauses?
I'm using Level-Ack handshaking to transmit data. Currently, I'm hooked up to a loop-back on the DIO32HS card.
If I don't use double-buffering, I end up with pauses in data transmission, so I need to use double buffering. Unfortunately, I can't seem to set up a delay in the middle of a double buffered scheme.
What I need to do is this:
Transmit 64 packets of data (16 bits each) on group 2 / Receive 64 packets of data (16 bits each) on group 1
Delay for .2 ms
Transmit the same packets again / receive
The delay in the middle will need to be varied, from .2 to 20 ms.
I'm programming in Visual C++ 6.0 under Windows 2000, with (as suggested above) group1 c
onfigured as input (DIOA and DIOB) and group2 set up as output (DIOC and DIOD). Due to the speed of transmission (256kHz) and the small size of the data set, the program I wrote, no matter how tight I try to make it, cannot insert the proper delay and start the next send on time.
Does anyone have any idea if such a pause is possible? Anyone know how to do it, or any suggestions on what to try?
Thanks!.2 ms is a very small time delay to use in software. Windows usually isn't more accurate than about 10 or 20 ms. If you need to have small, precise delays you could either use a real time OS, like pharlap and LabVIEW RT, or use extra hardware to generate the delays correctly.
I would recommend using a separate MIO or counter/timer board (like a 660x) to generate timing pulses for the DIO32HS. This gives you precise timing control at high speed. If the 32HS is in Level ACK Mode, it will respond to external ACK and REQ signals. This is covered in more detail on page 5-10 of the PCI-DIO32HS User Manual. -
I was searching through posts to find an answer to my problem of getting double buffering working without flickering when I came across this response:
Upgrade your SDK, early 1.4 implementations had this problem on Windows2k (It's a bug). Pretty much the second buffer will point to an empty portion of video memory always, the solution to this without updating is to fill the entire backbuffer completely, flip it, fill it again, and then flip it again. You should then be able to use it normaly.
-Jason Thomas.
Since I am on dialup I can't really download the SDK, so could someone give me some code to do what Jason has suggested?
Jonathan O'BrienNo I am not recreating the bufferstrategy every frame. Overriding update didn't work either. Here is my code for main:
GraphicsEnvironment env = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice device = env.getDefaultScreenDevice();
GraphicsConfiguration gc = device.getDefaultConfiguration();
Frame myFrame = new Frame(gc);
BufferCapabilities bufferCaps = gc.getBufferCapabilities();
boolean multiBuffer = bufferCaps.isMultiBufferAvailable();
boolean fullScreen = device.isFullScreenSupported();
System.out.println("Full screen supported = " + fullScreen);
System.out.println("Multi buffer available = " + multiBuffer);
System.out.println("Page flipping = " + bufferCaps.isPageFlipping());
myFrame.setUndecorated(true);
myFrame.setIgnoreRepaint(true);
if ((fullScreen) && (multiBuffer))
device.setFullScreenWindow(myFrame);
device.setDisplayMode(new DisplayMode(800, 600, 16, 0));
rectBounds = myFrame.getBounds();
myFrame.createBufferStrategy(2);
bufferStrategy = myFrame.getBufferStrategy();
bufferReady = true;
Game thisGame = new Game(args[0]);
myFrame.add(thisGame);
// myFrame.getContentPane().add(thisGame);
myFrame.show();
And here is the relevant code for my run method:
if (bufferReady)
Graphics g = bufferStrategy.getDrawGraphics();
if (!bufferStrategy.contentsLost()) {
g.fillRect(0,0,getWidth(),getHeight());
g.dispose();
bufferStrategy.show(); -
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 -
Hi there,
I have a frame F that contains two panels P1 and P2.
P1 uses double buffering for drawing circles and lines.
P2 has buttons and a JList.
When i click on a JList to have popup menu
or when i move the frame F on the screen
the panel P2 lost some of JList drawing.
Actually i iconify the frame in order to oblige
JVM to do repaint.
How can i resolve this problem please.Do not ever mix heavyweight and lightweight, or else
you won't be able to set up the correct zorder.But when i iconfiy and desiconify my frame Java
repaint correctly.
I need a nice tip article of how to simulate
desiconify repainting process.
Thabk u -
HELP!!! lol i'm trying to figure out how to get the whole double buffering thing to work with a picture like a gif image i drew in paint. i can't quite understand anything aobut how to do it. lol i've read some things and looked at some code samples but they all do it with a polygon. i just can't seem to get it right. i learn best from code snipets if that helps. don't give me a whole program i just want some lines that will help me learn it like what i have to import. and other things. i know a little about using images but not a whole lot. if anyone can help it will be appreciated.
andyPsst... Tell you teacher that one can read an image with ImageIO, often in one line:
BufferedImage image = ImageIO.read(file_or_url_or_inputstream);(No need for a MediaTracker!) And the resulting BufferedImage (a subclass of Image)
is easier to work with than Image and has more useful features.
Welcome to Java 2D. -
Hi there......
Ive created a game that uses double buffering...basically the user hits the ball that is moving around the screen... after 5 goes the program needs to display a graph....
I have got the two components working seperatly... but when i combine that classes into one (the graph + the game) when theg graph is displayed the screen flickers..... and u cant see the graph properly....
How do you stop the screen from trying to keep refreshing and display the final image? (which is no longer animated)
Many thanks....search this site or google
there are hundreds of posts about double buffering -
I understand that DAQmx is supposed to do double buffering automatically. When I run the example below in continuous mode, It will run continuously without error. when I hit stop, it will give me a "Not enough memory to complete this operation." error. This error occurs only when i've acquired greater than about 70M samples. If I don't hit stop it will run to about 300M samples, give the above error and also an unspecified Labview error. The rate does not appear to affect this. Am I actually double buffering?
Does it only do double buffering with the "Continuous Samples" mode? I've been using the example below with both continuous and finite samples and in both cases it seems to acquire more samples the 64MB.
Does this have anything to do with what i'm seeing?
http://digital.ni.com/public.nsf/allkb/7DF86CA91D739AD386256DF900785211
Equipment:
Labview 8.2
NI-8350 Controller
MXI-4
PXI-6534You are creating the second buffer in your application. DAQmx is not at fault here. You are wiring the output from the DAQmx Read VI to an auto-index tunnel on the While Loop. As your program runs this auto-index tunnel builds an array of every value that was sent to it in every iteration of the loop. So as time goes on, this array gets bigger and bigger. Eventually you will run out of available memory.
You should look into other ways of streaming data out of a loop, such as using Queues. You could then have a background loop to handle any data analysis or display.
Jarrod S.
National Instruments -
Double buffering circle not round anymore
I am making an applet where some circles are painted to the screen. When not using the double buffering scenario, the shapes appear correctly.
The problem is when i use the double-buffering technique, the circles are still there, but they look like very ugly. I would call that some "squarcles".
What is the bug here and how to get some decent double buffering with thoses circles?Ok, i had some problem with the running thread when closing the applet viewer, but now this situation is corrected by setting the animation thread to null before calling stop().
Maybe explanation of the problem is not clear, so i made two versions of the same applet with only 2 lines of code different so that there is one applet that is not double buffered.
You can check these by yourself at this place:
Double buffered circles: http://www.geocities.com/xeneve/cooltrail/ demo_cooltrail.htm
No double buffer:
http://www.geocities.com/xeneve/cooltrail/demo_cooltrail_ndb.htm
This is just annoying to get this result. I realise that maybe not many peoples are coding applets so i guess there is few people that may have a workaround for this.
Maybe you are looking for
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