How to keep the image onto the screen? - java

import java.applet.Applet;
import java.awt.*;
import java.awt.image.*;
import java.io.*;
import java.net.URL;
import javax.imageio.*;
import java.awt.Component;
public class ImageExample3 extends Applet
{
private BufferedImage img;
int counter = 0;
private BufferedImage next2;
Point lll;
public void init ()
{
resize (500, 500);
try
{
URL url = new URL (getCodeBase (), "Pacman.png");
img = ImageIO.read (url);
}
catch (IOException e)
{
}
repaint ();
}
public void paint (Graphics g)
{
if (counter == 0)
{
g.drawImage (img, 0, 0, null);
Dimension appletSize = this.getSize ();
lll = getLocationOnScreen ();
try
{
next2 = new Robot ().createScreenCapture (new Rectangle (lll.x, lll.y, 500, 500));
}
catch (java.awt.AWTException e)
{
}
g.drawImage (next2, 0, 0, null);
System.out.println (lll);
counter++;
}
}
}
What I am trying to do is to load a picture and then paint it, and then in the paint method, I used a point to tell me the location of the applet window on the screen and take a screenshot of it and then draw it on the applet. However, I want this to happen only once so I add a counter but whenever I run it, it draws the image and then gets replaced by a white box. What can I do to fix it?

The screen constantly needs to refresh. To show graphics, it paints an image every time the screen refreshes by calling the update method. The update method clears the screen by painting it white. Then, the update method calls the paint method (or repaint depending on context).
Because you only paint graphics once, your graphics are painted over by a blank screen and not refreshed. You need to paint your graphics every time that the screen refreshes, or they will be erased.
Always paint, but only take the screenshot once. Here's an example of the paint method:
public void paint (Graphics g)
{
g.drawImage (img, 0, 0, null);
Dimension appletSize = this.getSize ();
lll = getLocationOnScreen ();
if (counter == 0) //try taking the screenshot when counter is 0
{
try
{
next2 = new Robot ().createScreenCapture (new Rectangle (lll.x, lll.y, 500, 500));
}
catch (java.awt.AWTException e) {}
}
if (next2 != null) //if you took the screenshot and saved it to next2, draw it
g.drawImage (next2, 0, 0, null);
System.out.println (lll);
counter++;
}

Related

How to overwrite a BufferedImage drawn to JPanel outside PaintComponent() with getGraphics()

I am working on a simple 2D game. Each tick, I want to check an effects queue that will start a thread for a certain effect(fading transitions, audio fade in and out, etc). For example, pressing "Play" on the menu screen will add a "FadeOut" message to this queue, which will be processed and start a thread to draw a black rectangle with an increasing alpha value over my GamePanel.
I'm overriding paintComponent() and sending my Graphics object to my GameStateManager, which passes along the Graphics object to the current states' draw(). I currently don't have an effects state (which maybe I should) to route the paintComponent() graphics object to, but I do pass my gamepanel to my effects thread, where I can use getGraphics() to draw on it. Drawing a rectangle to the GamePanel directly just causes flickering, as the gameloop is still rendering the game.
I found I can draw a black rectangle with increasing alpha to a BufferedImage, set the composite to AlphaComposite.Src (which causes the new draw to replace the old) then draw the BufferedImage over the game panel. The problem is the BufferedImages drawn to the game panel don't get overridden each draw, so the fade out happens really quickly because these black BufferedImages of various alphas just stack on each other.
I wrote this short program to test composite settings and see what is getting overridden. All drawing is done in the draw(), which would be my run() in the effects thread.
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class ScratchPad extends JPanel implements Runnable
{
private JFrame oFrame = null;
private Thread oGameThread = null;
private Graphics2D oPanelGraphics = null;
private Graphics2D oImageGraphics = null;
private BufferedImage oImage = null;
public static void main(String args[]) throws Exception
{
new ScratchPad();
}
public ScratchPad()
{
createFrame();
initPanel();
addAndShowComponents();
oGameThread = new Thread(this, "Game_Loop");
oGameThread.start();
}
private void addAndShowComponents()
{
oFrame.add(this);
oFrame.setVisible(true);
}
private void initPanel()
{
this.setOpaque(true);
this.setBackground(Color.cyan);
}
private void createFrame()
{
oFrame = new JFrame("Fade");
oFrame.setSize(700, 300);
oFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
oFrame.setLocationRelativeTo(null);
}
public void run()
{
oImage = new BufferedImage(200, 200, BufferedImage.TYPE_INT_ARGB);
while(true)
{
try
{
draw();
Thread.sleep(100);
}
catch(InterruptedException e)
{
}
}
}
private void draw()
{
oPanelGraphics = (Graphics2D)this.getGraphics();
oImageGraphics = oImage.createGraphics();
oImageGraphics.setComposite(AlphaComposite.Src);
oImageGraphics.setColor(new Color(0,0,0,90));
oImageGraphics.fillRect(0, 0, oImage.getWidth(), oImage.getHeight());
oPanelGraphics.drawImage(oImage, 10, 10, null);
oImageGraphics.setColor(new Color(0,0,0,60));
oImageGraphics.fillRect(0, 0, oImage.getWidth(), oImage.getHeight());
oPanelGraphics.drawImage(oImage, 220, 10, null);
oImageGraphics.setColor(new Color(0,0,0,30));
oImageGraphics.fillRect(0, 0, oImage.getWidth(), oImage.getHeight());
oPanelGraphics.drawImage(oImage, 430, 10, null);
// Drawing this image over location of first image, should overwrite first
// after setting composite to 'Src'
oPanelGraphics.setComposite(AlphaComposite.Src);
oImageGraphics.setColor(new Color(0,0,0,10));
oImageGraphics.fillRect(0, 0, oImage.getWidth(), oImage.getHeight());
oPanelGraphics.drawImage(oImage, 10, 10, null);
oImageGraphics.dispose();
oPanelGraphics.dispose();
}
} // end class
What's interesting is setting the composite on 'oPanelGraphics' causes any alpha to the BufferedImage to go away, resulting in a fully opaque black image being drawn over the image that was previously there. Even setting the color to something other than black doesn't have an effect.
What's also interesting is setting the composite for the BufferedImage to:
oImageGraphics.setComposite(AlphaComposite.SrcIn);
causes nothing to be shown. The Oracle documentation on compositing graphics in Java2D states this for 'SrcIn':
"If pixels in the source and the destination overlap, only the source pixels in the overlapping area are rendered."
So, I would expect this to have the same behavior I get with AlphaComposite.Src.
Maybe someone out there can shed some light on whats going on with these composites, and how I could achieve my desired effect.
There are a number issues with what you "seem" to be trying to do
Don't call getGraphics on a component. This can return null and only returns a snapshot of what was last painted during a Swing paint cycle. Anything you paint to it will be erased on the next paint cycle
You should also never dispose of Graphics context you did not create, doing so could effect other components that are painted by Swing
Painting is compounding, this means that painting to the same Graphics context (or BufferedImage) over and over again, will continue to apply those changes over the top of what was previously painted
You also don't seem to have a concept of how animation should work. Instead of trying to paint your fade effect in a single pass, where the results can't be applied to the screen, you need to apply a phase on each cycle and allow that to be updated to the screen before the next pass runs.
The following is a really basic example of what I'm talking about. It takes a "base" image (this could be the "base" state of the game, but I've used a static image) and the paints effects over the top.
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private Engine engine;
private Image frame;
public TestPane() {
engine = new Engine();
engine.setEngineListener(new EngineListener() {
#Override
public void updateDidOccur(Image img) {
frame = img;
repaint();
}
});
engine.start();
addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
engine.addEffect(new FadeOutEffect(Color.BLACK));
}
});
}
#Override
public Dimension getPreferredSize() {
return engine.getSize();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (frame != null) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawImage(frame, 0, 0, null);
g2d.dispose();
}
}
}
public interface EngineListener {
public void updateDidOccur(Image img);
}
public class Engine {
// This is the "base" image, without effects
private BufferedImage base;
private Timer timer;
private EngineListener listener;
private List<Effect> effects = new ArrayList<Effect>(25);
public Engine() {
try {
base = ImageIO.read(new File("/Volumes/Big Fat Extension/Dropbox/MegaTokyo/megatokyo_omnibus_1_3_cover_by_fredrin-d4oupef 50%.jpg"));
} catch (IOException ex) {
ex.printStackTrace();
}
timer = new Timer(10, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
int width = base.getWidth();
int height = base.getHeight();
BufferedImage frame = new BufferedImage(width, height, base.getType());
Graphics2D g2d = frame.createGraphics();
g2d.drawImage(base, 0, 0, null);
Iterator<Effect> it = effects.iterator();
while (it.hasNext()) {
Effect effect = it.next();
if (!effect.applyEffect(g2d, width, height)) {
it.remove();
}
}
g2d.dispose();
if (listener != null) {
listener.updateDidOccur(frame);
}
}
});
}
public void start() {
timer.start();
}
public void stop() {
timer.stop();
}
public void addEffect(Effect effect) {
effects.add(effect);
}
public void setEngineListener(EngineListener listener) {
this.listener = listener;
}
public Dimension getSize() {
return base == null ? new Dimension(200, 200) : new Dimension(base.getWidth(), base.getHeight());
}
}
public interface Effect {
public boolean applyEffect(Graphics2D context, int width, int height);
}
public class FadeOutEffect implements Effect {
private int tick = 0;
private Color fadeToColor;
public FadeOutEffect(Color fadeToColor) {
this.fadeToColor = fadeToColor;
}
#Override
public boolean applyEffect(Graphics2D context, int width, int height) {
tick++;
float alpha = (float) tick / 100.0f;
if (alpha > 1.0) {
return false;
}
Graphics2D g2d = (Graphics2D) context.create();
g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha));
g2d.setColor(fadeToColor);
g2d.fillRect(0, 0, width, height);
g2d.dispose();
return true;
}
}
}
Remember, every effect or change should be applied within the same "main loop", this means you shouldn't have multiple threads, in fact, since Swing is not thread safe, you should avoid having any additional threads if possible. This example make use of a Swing Timer to act as the "main loop" because the ActionListers actionPerformed method is called within the context of the EDT, making it safe to update the UI from. It also provides a simple synchronisation method, as the UI can't be painted while the actionPerformed method is been called

Java, redraw scrolling background image at the same point the last image ends

My problem is that i have an image which is X in length, and i want to make it so that the image continually scrolls in the background of my game.
In order to do this, and it no be obvious to the player the next background image has to be redrawn at the point at which the previous image ends, this is what i cannot figure out.
Currently i can have continuous redrawing of the image, but just as the old image ends the new image is drawn back at (0,0) so it is obvious that the background is being redrawn.
I know what the problem is, but the solution is avoiding me. The problem is that when i redrawn the image, i reset location to 0. I can't figure out another way to do this currently so maybe someone could help me in someway.
Just a side note the JPanel is 1000 in width.
Here is the code so far:
package cje.chris.edwards.game;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import javax.swing.*;
public class Board extends JPanel implements ActionListener{
Player player;
Image background;
Timer timer;
private int scrollSpeed, location;
public Board(){
player = new Player();
this.addKeyListener(new Listener());
setFocusable(true);
ImageIcon img_ic = new ImageIcon("map.png");
background= img_ic.getImage();
location = 0;
//5 milliseconds
scrollSpeed = -2;
timer = new Timer(5, this);
timer.start();
}
#Override
public void actionPerformed(ActionEvent e) {
//called using timer.start() and its delay
repaint();
}
public void paint(Graphics g){
super.paint(g);
Graphics2D graphics_2d = (Graphics2D) g;
//This is the section where my problem lies.
if(location != 0 && Math.abs(location) % (background.getWidth(null) - 1000) == 0){
graphics_2d.drawImage(background, 1000, 0, null);
location = 0;
}
graphics_2d.drawImage(background, location += scrollSpeed, 0, null);
graphics_2d.drawImage(player.getImage(), 50, 100, null);
System.out.println(location);
}
private class Listener extends KeyAdapter{
public void keyPressed(KeyEvent e){
scrollSpeed = -1;
player.move(e);
}
}
}
Is there a way i can reset location to the end of the last image? so it looks completely seamless. Thanks again!
This is the image i am using, just in case anybody wants to try my code:
https://warosu.org/data/ic/img/0015/95/1385339455019.png
try this
public void paint(Graphics g){
super.paint(g);
Graphics2D graphics_2d = (Graphics2D) g;
// define bounds by width of image
while (location > background.getWidth(null)){
location -= background.getWidth(null);
}
while (location < -background.getWidth(null)){
location += background.getWidth(null);
}
// draw image twice to handle any overlap
graphics_2d.drawImage(background, location += scrollSpeed, 0, null);
graphics_2d.drawImage(background, location + background.getWidth(null), 0, null);
System.out.println(location);
}

How to force calling paintComponent?

I have a JLabel with the paintComponent() overriden.I want it to be forcefully called since the code that updates my Label UI is this event.How can I force its calling and updating of UI? (by the way,repaint does not work!)
here is my code :
BufferedImage background;
String Uri;
public CustomClockLabel(String Uri){
init(Uri);
this.Uri = Uri;
}
public void init(String Uri){
try {
URL inp = CustomClockLabel.class.getResource(Uri);
background = ImageIO.read(inp);
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
protected void paintComponent(Graphics g){
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
if(background != null){
g2.drawImage(background, 0, 0,getWidth(),getHeight(), this);
}
g2.dispose();
super.paintComponent(g);
}
here is the code that updates labels and it is called recursively :
lblHour1 = new CustomClockLabel("/icons/noa_en/"+Hour.charAt(0)+".png");
lblHour1.repaint();
lblHour2 = new CustomClockLabel("/icons/noa_en/"+Hour.charAt(1)+".png");
lblHour2.repaint();
lblMin1 = new CustomClockLabel("/icons/noa_en/"+Minute.charAt(0)+".png");
lblMin1.repaint();
lblMin2 = new CustomClockLabel("/icons/noa_en/"+Minute.charAt(1)+".png");
lblMin1.repaint();
You may be under the false impression that creating new labels will update what's on the screen, doing this...
lblHour1 = new CustomClockLabel("/icons/noa_en/"+Hour.charAt(0)+".png");
lblHour2 = new CustomClockLabel("/icons/noa_en/"+Hour.charAt(1)+".png");
lblMin1 = new CustomClockLabel("/icons/noa_en/"+Minute.charAt(0)+".png");
lblMin2 = new CustomClockLabel("/icons/noa_en/"+Minute.charAt(1)+".png");
Will change the reference of the variables, so they will no longer be the same variables as those you added to the screen.
Assuming that the above variables have being added to the screen already, you could simply update them by using something like...
lblHour1.init(new ImageIcon("/icons/noa_en/"+Hour.charAt(0)+".png"));
lblHour2.init(new ImageIcon("/icons/noa_en/"+Hour.charAt(1)+".png"));
lblMin1.init(new ImageIcon("/icons/noa_en/"+Minute.charAt(0)+".png"));
lblMin2.init(new ImageIcon("/icons/noa_en/"+Minute.charAt(1)+".png"));
revalidate();
repaint();
If that fails, you should try setting one the labels border's properties so you can see if it's actually been added to the screen.
Updated
After some experimentation with what little you code you have made available, here are some more recommendations...
As has already being mentioned, make sure you are calling super.paintComponent first, as one of the jobs of this method is to clear the graphics ready for painting...
Make sure you provide a suitable sizing hint to the component, so the layout managers have some kind of idea of how big you might like the component to be. This ensures that the component is not sized to 0x0
The following example is very simple, but takes (what little) code you supplied and builds a runnable example from it...
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class PaintComponentTest {
public static void main(String[] args) {
new PaintComponentTest();
}
private int time = 0;
public PaintComponentTest() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
final CustomClockLabel counter = new CustomClockLabel("/icons/0.png");
Timer timer = new Timer(1000, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
time++;
if (time > 9) {
time = 0;
}
counter.init("/icons/" + Integer.toString(time) + ".png");
counter.repaint();
}
});
timer.start();
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(counter);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class CustomClockLabel extends JPanel {
BufferedImage background;
String Uri;
public CustomClockLabel(String Uri) {
init(Uri);
this.Uri = Uri;
}
public void init(String Uri) {
try {
URL inp = getClass().getResource(Uri);
background = ImageIO.read(inp);
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(100, 100);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
if (background != null) {
g2.drawImage(background, 0, 0, getWidth(), getHeight(), this);
}
g2.dispose();
}
}
}
Calling repaint() on the component in question will force it to paint again.
The problem you have does not appear to repainting, as you are actually changing the labels on the panel. Make sure you remove the old labels and add the new ones instead and call revalidate(). (The code you posted looks like you are just updating the label references and not actually changing them out on the panel.)
Overall, the design could be improved dramatically by making your CustomClockLabel class take in a parameter that changes the image and therefore allows you to just call repaint().
lblHour1 = new CustomClockLabel("/icons/noa_en/"+Hour.charAt(0)+".png");
The above code doesn't do anything. All is does is create a new component. But that component is not added to the GUI so it obviously doesn't repaint.
There is nothing in your class that would cause it to need repainting, so your question doesn't make sense. You have a design problem. I don't see any reason to create a custom label.
If you want to change the image, then just use a standard JLabel with an Icon. Then to change the image you just use the setIcon(...) method and the label will repaint itself automatically.
(by the way,repaint does not work!)
If it isn't, then the only thing i can suspect, the fault is in your painting order: where you are calling super.paintComponent(g); after you are drawing the image. If your label is non-opaque and has background color, then you will not see the image, as the later painting super.paintComponent(g) will be drawn above the previous painting.
Try changing the order:
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
if(background != null){
g2.drawImage(background, 0, 0,getWidth(),getHeight(), this);
}
g2.dispose();

Swing double Buffering and Animation

I am trying to prevent redrawing an animation by the EDT. The first thing i have done is excluding the actual drawing tasks into a different thread, writing into a VolatileImage, which gets redrawn by EDT within paintComponent method of my corresponding JPanel.
If i exclude the repaint into another thread, this works properly. Nevertheless, i do have positioned a couple of other panels above my animation.
In result, having called the repaint method of my painter (animation) panel, has caused the others to also get redrawn without flickering.
Therefore to redraw the other panels, calling repaint on painter, results in flickering. Repaint of a single panel results in an opaque redraw with rarely flickering.
Does somebody know, how to synchronize an own repaint of a jpanel, for instance into my already available bufferimage. Id say the repaint triggered to EDT results in flickering, since its not synchronized.
My repaint call to animation
#Override
public void KeyframeChanged(Keyframe frame) {
if (painter.isVisible()) {
map.getMainMap().doPaintComponent(painter.getBuffer().getGraphics());
painter.renderAnimation();
painter.updateScreen();
}
}
painter methods:
public void updateScreen() {
Graphics g = this.getGraphics();
if (g != null) // component already visible?
{
// is there a backBuffer to draw?
if (backBuffer != null) {
g.drawImage(backBuffer, 0, 0, null);
} else {
// if not, create one and render on it
createBackBuffer();
renderAnimation();
}
}
}
public void renderAnimation() {
// Do drawing stuff here
}
#Override
protected void paintComponent(Graphics g) {
// super.paintComponent(g);
}// end of paint
Thanks
Thanks for answers and links. I still need to read a few of them. Nevertheless in order to illustrate the current behavior, this small SSCCE shall help.
package repaintexample;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.VolatileImage;
import javax.swing.JFrame;
import javax.swing.JLayeredPane;
import javax.swing.JPanel;
class Painter extends JPanel {
private VolatileImage backBuffer;
private Graphics2D g2d;
public Painter() {
setDoubleBuffered(false);
setOpaque(false);
}
#Override
public boolean isOptimizedDrawingEnabled() {
return false;
}
private void createBackBuffer() {
backBuffer = this.getGraphicsConfiguration().createCompatibleVolatileImage(1920, 1200);
}
public void adjustBackBufferSize() {
if (backBuffer != null) {
if (getWidth() > backBuffer.getWidth() || getHeight() > backBuffer.getHeight()) {
createBackBuffer();
}
}
}
public void updateScreen(Graphics g) {
if (g != null) // component already visible?
{
// is there a backBuffer to draw?
if (backBuffer != null) {
g.drawImage(backBuffer, 0, 0, null);
} else {
// if not, create one and render on it
createBackBuffer();
}
}
}
public void renderAnimation(int i, int j) {
if (backBuffer == null) {
createBackBuffer();
}
do {
if (backBuffer.validate(getGraphicsConfiguration()) == VolatileImage.IMAGE_INCOMPATIBLE) {
createBackBuffer();
}
g2d = (Graphics2D) backBuffer.getGraphics();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(Color.white);
g2d.fillRect(0, 0, getWidth(), getHeight());
g2d.setColor(Color.red);
g2d.fillOval(i, j, 50, 50);
} while (backBuffer.contentsLost());
}
#Override
protected void paintComponent(Graphics g) {
// super.paintComponent(g);
updateScreen(g);
}// end of paint
public VolatileImage getBuffer() {
return backBuffer;
}
}
class ContainerFrame extends JFrame {
private Painter mapPainter;
private JPanel informationPanel; // covers a lot of metainformation - Actually own JTable instance updating the same objects for repainting in each circle
private JPanel controller; // Maptools
private JPanel tabbedPabe; // Change redraw content
public ContainerFrame() {
this.setSize(1600, 1024);
this.setVisible(true);
initComponents();
initPositions();
Thread animation = new Thread(new Runnable() {
#Override
public void run() {
// My application is a mapping application, in which i first draw the tiles, before goin on with the "real" animated stuff
// clearing backbuffer content with g.fillRect(0, 0, getWidth(), getHeight());
while (true) {
for (int i = 0; i < mapPainter.getWidth(); i += 100) {
for (int j = 0; j < mapPainter.getHeight(); j += 5) {
mapPainter.renderAnimation(i, j);
int repaintCase = 2;
switch (repaintCase) {
case 0:
// Default case redrawing via EDT, triggering the others in proper order
mapPainter.repaint();
break;
case 1:
// case repainting by current Thread - necessity of repainting above positioned panels
// results in flickering, since not synchronized
mapPainter.updateScreen(mapPainter.getGraphics());
informationPanel.repaint();
controller.repaint();
tabbedPabe.repaint();
break;
case 2:
// painting components on buffer
// Results in rarely flickering and opague repaint
// is there any common way, to manually repaint onto anything - like image
informationPanel.paintAll(mapPainter.getBuffer().getGraphics());
controller.paintAll(mapPainter.getBuffer().getGraphics());
tabbedPabe.paintAll(mapPainter.getBuffer().getGraphics());
mapPainter.updateScreen(mapPainter.getGraphics());
break;
}
}
}
try {
Thread.sleep(30);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
});
animation.start();
}
private void initComponents() {
mapPainter = new Painter();
mapPainter.setSize(this.getSize());
informationPanel = new JPanel();
informationPanel.setSize(new Dimension(360, 800));
controller = new JPanel();
controller.setSize(new Dimension(500, 250));
tabbedPabe = new JPanel();
tabbedPabe.setSize(new Dimension(300, 300));
this.getLayeredPane().add(mapPainter, JLayeredPane.DEFAULT_LAYER);
this.getLayeredPane().add(controller, JLayeredPane.MODAL_LAYER);
this.getLayeredPane().add(tabbedPabe, JLayeredPane.MODAL_LAYER);
this.getLayeredPane().add(informationPanel, JLayeredPane.MODAL_LAYER);
}
private void initPositions() {
controller.setLocation(mapPainter.getWidth() - controller.getWidth(), mapPainter.getHeight() - controller.getHeight());
tabbedPabe.setLocation(this.getWidth() - tabbedPabe.getWidth(), mapPainter.getHeight() - controller.getHeight() - tabbedPabe.getHeight() - 400);
informationPanel.setLocation(10, mapPainter.getHeight() - informationPanel.getHeight() - 200);
}
}
public class RepaintExample {
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
// TODO code application logic here
ContainerFrame f = new ContainerFrame();
}
}
I do use case 0 at the moment and do see having either great or pretty bad fps - either 30 or around 6. I am not certain, how that may be possible and i may be able to find sth. in the already posted links. I thought making sure to relieve the EDT at best, could become a proper solution.
Additionally the content of the 3 panels, i illustrated do not need a repaint in the same frequency as the animation does. Unfortunately i haven't found a proper way to prevent the repaint. The only way i have used for quite a while was a paintimmediately in an invokelater call for those areas, which are known as "animated". A common repaint(Rectangle rec) has not been working, since single calls have been summarized to a big one, covering more pixels, than i have passed in.
public void drawCachedSprite(Graphics2D g, CachedSprites sprites, int zoom, double cog, double x, double y, double w, double h) {
try{
pos_x = x;
pos_y = y;
RenderingUtil.getRenderQuality();
transform.setToIdentity();
// Compute the corner, the drawing needs to start with
transform.translate(x - (w / 2.0), y - (h / 2.0));
g.drawImage(sprites.getSprite(DefaultResources.getType(), spriteColor, zoom, cog), transform, null);
} catch (IllegalArgumentException e) {
e.printStackTrace();
System.out.println("width or height not set properly");
}
}

How to get rid of the flicker that appears during my animation?

I'm learning Java by making a small game in a JApplet.
I got a little problem with my sprite's animation.
Here is the code :
this.sprite.setBounds(0,0,20,17);
this.sprite.setIcon(this.rangerDown);
for(int i = 0; i< 16;i++)
{
this.sprite.setBounds(this.sprite.getX(), this.sprite.getY()+1, 20, 17);
this.sprite.update(this.sprite.getGraphics());
try{
Thread.currentThread().sleep(100);
}catch(InterruptedException e){
}
}
It left some flicker during the animation. Once the animation end, the flicker disappears, but it's kind of ugly... I guess there is some step I missed.
I use this method because it gives the better result for now, but I would like to stay without AWT if possible, using Swing instead.
Any ideas how to get rid of the flicker?
Thanks for reading.
Screenshoot (Can't post images, sorry).
This is not a shadow. Its the border of your sprite. It just happens to be black and appears as a shadow. If you change the amount you shift your sprite (lets say by 50 pixels, not just 1) you will see what i mean.
To fix it what you need to do is to draw the background as well each time you update the location of your sprite. Although this will probably produce flickering.
The correct way to do it is to change the way you draw your objects. You need to override the paintComponent method of your panel and then simply call repaint each time you have updated the locations of your sprites.
EDIT:
See this code sample for basic usage. NOTE: This is NOT how you should write animation using Threads. I wrote that to show you what goes in the paintComponent method and wrote the animation Thread to show you that the "shadow" you mentioned is gone. NEVER have a non ending run loop in a thread :)
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Test {
public static void main(String[] args) {
JFrame f = new JFrame("Test");
MyPanel c = new MyPanel();
f.getContentPane().add(c);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(350, 100);
f.setVisible(true);
}
}
class MyPanel extends JPanel {
int x = 0;
boolean toTheRight = true;
public MyPanel() {
new Thread(new Runnable() {
#Override
public void run() {
while (true) {
x = (toTheRight)?x+5:x-5;
if (x>300)
toTheRight = false;
if (x<0)
toTheRight = true;
repaint();
try {
Thread.sleep(50);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}).start();
}
#Override
protected void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D)g.create();
g2.setPaint(Color.white);
g2.fillRect(0, 0, getWidth(), getHeight());
g2.setPaint(Color.red);
g2.fillOval(x-2, 50, 4, 4);
}
}
The problem is double buffering.
In Applets:
Double buffering is done almost automatically. Call repaint() instead of paint in your method.
In Swing, there are many ways to do it. I usually go for the BufferStrategy route. When you're initializing your frame, do this:
JFrame frame;
... code to init frame here
frame.createBufferStrategy(2);
Then in your draw methods:
Graphics g = getBufferStrategy().getDrawGraphics();
..code to do drawing here...
g.dispose();
getBufferStrategy().show();

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