I'm trying to make a game with a youtube tutorial and I am currently attempting to create and fill a rectangle the size of the window. Instead of going black, it stays grey (my default colour).
Any ideas? Thanks in advance!
Code:
import javax.swing.*;
import java.awt.image.BufferStrategy;
import java.awt.*;
public class Game extends Canvas implements Runnable {
private static final long serialVersionUID = 1L;
public static int width = 300;
public static int height = width / 16 * 9;
public static int scale = 3;
private Thread thread;
private JFrame frame; // Creates a window
private boolean running = false; // Checks to see if the game is running
public Game() {
Dimension size = new Dimension(width * scale, height * scale); // The window size
setPreferredSize(size); // Choosing the size I want
frame = new JFrame(); // Calling the frame
}
public synchronized void start() {
running = true;
thread = new Thread(new Game(), "Display"); // Calling the class
thread.start(); // Starting the class
}
public synchronized void stop() { // Ending the game
running = false;
try {
thread.join();
} catch(InterruptedException e) {
e.printStackTrace();
}
}
public void run() {
while(running) {
update();
render();
}
}
public void update() {
}
public void render() {
BufferStrategy bs = getBufferStrategy();
if(bs == null) {
createBufferStrategy(3); // Triple buffering strategy (speeds up process)
return;
}
Graphics g = bs.getDrawGraphics(); // Create a link between buffer and drawing on screen
g.setColor(Color.BLACK);
g.fillRect(0, 0, getWidth(), getHeight());
g.dispose();
bs.show();
}
public static void main(String[] args) {
Game game = new Game(); // Calling the class to be able to change things in it
game.frame.setResizable(true); // Stopping window changing in size (causes graphical errors)
game.frame.setTitle("Game Window");
game.frame.add(game); // Fills the window with the class (can be done because of 'Canvas')
game.frame.pack(); // Sets the size of the window based on what is in the component above.
game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
game.frame.setLocationRelativeTo(null); // Centres the window in the screen
game.frame.setVisible(true);
game.start(); // Starts the game
}
}
Change thread = new Thread(new Game(), "Display"); to use this instead of new Game().
I am making Pac-Man and I'm having trouble with drawing graphics on a frame, when i draw my point image it looks like a game of snake, i tried putting my drawing methods for background and char both in the render method, but than my point image flickers
What it currently looks like, feel free to ignore the random face it was an inside joke.
Also this is my very first game so any tips on structure, pointers on what I am doing right (if anything) and what I'm doing wrong, and general tips would be extremely helpful!
Also I am aware that i have a couple unused methods
Code:
package game;
import graphics.map;
import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
public class main extends Canvas implements Runnable{
private static final long serialVersionUID = 1L; //not sure why it wanted me to do this, maybe ask bender, or just google it later
public static boolean running = false;
public static int HEIGHT = 800;
public static int WIDTH = 600;
public static int posX = 50;
public static int posY = 50;
public static final String name = "Pac Man Alpha 1.4";
private static final double speed = 1.2;
public input input;
static BufferedImage background = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);;
static BufferedImage pacman = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);;
static BufferedImage settingsBackground = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);;
static BufferedImage level1 = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);;
static BufferedImage level2 = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);;
static BufferedImage points = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);;
static BufferedImage point = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);;
static JFrame frame;
private input keypress = new input();
private map map;
private static boolean charLoaded = false;
public static boolean MAIN_MENU = true;
public static boolean GAME = false;
public static boolean level1test = true;
public static boolean level2test = false;
public static boolean level3test = false;
public static boolean level4test = false;
static boolean drawn = false;
public static boolean key_down;
public static boolean key_up;
public static boolean key_right;
public static boolean key_left;
//private Screen screen;
JButton startButton = new JButton("Start"); //Start
JButton settingsButton = new JButton("Settings"); //Settings
JButton exitButton = new JButton("Exit"); //Exit
public main()
{
setMinimumSize(new Dimension(WIDTH , HEIGHT ));
setMaximumSize(new Dimension(WIDTH , HEIGHT )); // keeps the canvas same size
setPreferredSize(new Dimension(WIDTH, HEIGHT));
frame = new JFrame(name);
if(MAIN_MENU == true && GAME == false){
buttons(frame.getContentPane());
}
frame.setLayout(new BorderLayout());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // ends program on
// close
frame.addKeyListener(new input() );
frame.add(this, BorderLayout.CENTER);
frame.pack(); // keeps size correct
frame.setResizable(false);
frame.setVisible(true);
this.addKeyListener(keypress);
}
public static void main(String[] args)
{
try {
background = ImageIO.read(new File("res\\Background.png"));
pacman = ImageIO.read(new File("res\\pacmansprites.png"));
settingsBackground = ImageIO.read(new File("res\\Background.png"));
level1 = ImageIO.read(new File("res\\level1.png"));
//level2 = ImageIO.read(new File("res\\level2.png"));
point = ImageIO.read(new File("res\\Points for pacman.png"));
} catch (IOException e) {
}
running = true;
new main().start();
}
public void run()
{
long lastTime = System.nanoTime();
double nsPerTick = 1000000000 / 60D;
long lastTimer = System.currentTimeMillis();
double delta = 0;
int frames = 0;
int ticks = 0;
while (running == true) {
long now = System.nanoTime();
delta += (now - lastTime) / nsPerTick;
lastTime = now;
boolean render = false;
while (delta >= 1) {
ticks++;
tick();
delta -= 1;
render = true;
}
try {
Thread.sleep(3); //keep the Frames from going to high
} catch (InterruptedException e) {
e.printStackTrace();
}
if(render == true){
frames++;
render();
}
if (System.currentTimeMillis() - lastTimer >= 1000) {
lastTimer +=1000;
//System.out.println("Frames: " + frames + " Ticks: " + ticks);
frames = 0;
ticks = 0;
}
}
}
public synchronized void start()
{
new Thread(this).start();
run();
}
public synchronized void stop()
{
running = false;
}
public void tick()
{
if (key_up) posY -= speed / 2;
if (key_down) posY += speed;
if (key_left) posX -= speed / 2;
if (key_right) posX += speed;
}
public void render()
{
drawn = false;
if(MAIN_MENU == false && GAME == true)
{
drawMap();
drawChar();
}
else if(MAIN_MENU == false && GAME == false) {
Graphics g = getGraphics();
{
g.drawImage(settingsBackground,0,0,getWidth(),getHeight(),null);
g.dispose();
}
} else {
Graphics g = getGraphics();{
g.drawImage(background,0,0,getWidth(), getHeight(),null);
g.dispose(); //kill it
}
}
}
public void drawMap(){
if(level1test == true){
Graphics g = getGraphics();
{
g.drawImage(level1,0,0,getWidth(),getHeight(),null);
g.dispose();
}
}
if(level2test == true && drawn == false){
Graphics g = getGraphics();
{
g.drawImage(level2,0,0,getWidth(),getHeight(),null);
}
g.dispose();
}
drawn = true;
}
public void drawChar(){
//drawMap();
Graphics g = getGraphics();{
g.drawImage(point,posX,posY,20, 20,null);
g.dispose();
revalidate();
}
}
public void begin() {
if (key_up) System.out.println("up");
if (key_down) System.out.println("down");
if (key_left) System.out.println("left");
if (key_right) System.out.println("right");
}
public void loadMap(){
if(!drawn && level1test){
}else if(!drawn && level2test){
//draw 2nd map here
}else if(!drawn && level3test){
//draw 3rd map here
}
}
public void buttons(Container pane)
{
pane.setLayout(null);
startButton.addActionListener( new ActionListener() {
public void actionPerformed(ActionEvent ae) {
MAIN_MENU = false;
GAME = true;
frame.remove(startButton);
frame.remove(settingsButton);
frame.remove(exitButton);
frame.revalidate();
drawMap();
System.out.println("Start Button Clicked");
}
} );
settingsButton.addActionListener( new ActionListener() {
public void actionPerformed(ActionEvent ae) {
MAIN_MENU = false;
GAME = false;
frame.remove(startButton);
frame.remove(settingsButton);
frame.remove(exitButton);
frame.revalidate();
frame.repaint();
System.out.println("Settings Button Clicked");
}
} );
exitButton.addActionListener( new ActionListener() {
public void actionPerformed(ActionEvent ae) {
System.out.println("Exit Button Clicked");
System.exit(0);
}
} );
pane.add(startButton);
pane.add(settingsButton);
pane.add(exitButton);
Insets insets = pane.getInsets();
Dimension size = startButton.getPreferredSize();
startButton.setBackground(new Color(0, 0, 0));
startButton.setForeground(Color.CYAN);
startButton.setFocusPainted(false);
startButton.setFont(new Font("Calabri", Font.BOLD, 16));
settingsButton.setBackground(new Color(0, 0, 0));
settingsButton.setForeground(Color.RED);
settingsButton.setFocusPainted(false);
settingsButton.setFont(new Font("Calabri", Font.BOLD, 16));
exitButton.setBackground(new Color(0, 0, 0));
exitButton.setForeground(Color.YELLOW);
exitButton.setFocusPainted(false);
exitButton.setFont(new Font("Calabri", Font.BOLD, 16));
startButton.setBounds((WIDTH - 125) + insets.left, 10 + insets.top,
size.width + 50, size.height + 10);
settingsButton.setBounds((WIDTH - 125) + insets.left, 55 + insets.top,
size.width + 50, size.height + 10);
exitButton.setBounds((WIDTH - 125) + insets.left, 100 + insets.top,
size.width + 50, size.height + 10);
}
}
getGraphics is not how custom painting is done. You should, in your case, override the paint method, and make sure you call super.paint before doing any custom painting.
getGraphics returns the Graphics context last used to paint the component, which could be discarded on the next paint cycle, be null or no longer used by the component
Remember, painting uses the "painters canvas" approach, that is, just like painting in a physical canvas, when you paint into it, you paint over what was previously there, but not erasing it.
Now, if you override paint, you will find that you will have a flickering problem. This is because Canvas
is not double buffered
To solve this, you should consider user a BufferStrategy, which allows you to not only generate multiple buffers to paint to, but also to take control of the paint process itself
Just don't forget to clear each buffer before you paint to it...
Double buffering is the trick that allows you to have flicker-free animation. Basically you have two representations of your canvas, one that's currently being displayed and one that you can draw on. If you're finished with drawing, you copy the draw-canvas over the display-canvas. Depending on system and hardware there are more elegant ways where you can just tell the hardware to switch canvases (page flipping).
Without double buffering or a similar techniques, it is almost impossible to have flicker-free animation.
With double buffering you can afford to draw the background and then the foreground sprites. It is possibly more efficient to draw only those parts of the background that have been destroyed by the foreground sprites (there are various techniques for that as well, including of taking a snapshot image of the affected areas before you paint the sprites).
You can find a simple example for Java double buffering here. Java's BufferStrategy is a more complex solution that can use hardware features for page flipping.
I think the problem is that you only draw onto the image background, never erasing the old drawing from your image. You will need to clear the area and then start drawing in order to get your desired results.
I have never attempted to make a game but when I do simple animations I usually will do them on a JFrame or JPanel. With a JFrame you can Override the paint() method and with a JPanel, the paintComponent() method. It helps to keep everything that I'm drawing centralized, which makes it much easier for me to modify my code. When you call the respective super method in your overridden method, it will start you off with a clean slate, meaning you will have to paint the (image) background and your characters all over again. Calling the super method is also necessary to paint that component's children if you decide to add anything onto the JFrame/JPanel.
If you chose to use one of the above then I would recommend a JPanel due to it offering double buffering, which will help make your animations look smooth/fluid. Also, do not forget to call repaint();.
Here is a quick example, which can be used to duplicate your issue if you comment out super.paintComponent(g);.
*Note that I am extending and using a JPanel for this example.
Code:
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Trial extends JPanel{
public static void main(String[] args)
{
new Trial();
}
int x = 5; // will represent the x axis position for our crude animation.
javax.swing.Timer timer = new javax.swing.Timer( 500, new ActionListener(){
// Timer used to control the animation and
// the listener is used to update x position and tell it to paint every .5 seconds.
#Override
public void actionPerformed(ActionEvent e) {
x += 5;
if ( x > 250)
timer.stop();
repaint(); // will call the paintComponent method.
}
});
Trial()
{
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.add(this);
frame.setSize(300, 200);
frame.setVisible(true);
timer.start();
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g); // calling the super paintComponent method to paint children. can comment it
// out to duplicate your error, which happens when the frame isn't "refreshed".
Graphics2D g2d = (Graphics2D) g.create(); // creating a copy of the graphics object. // I do this to not alter the original
// Good practice and also Graphics2D
// offers a bit more to work with.
g2d.drawString("Graphics", x, 60); // painting a string.
g2d.drawRect(x, 80, 10, 10); // painting a rectangle.
}
}
Edit:
If you have a bunch of stuff to do and don't want to add it all into your paintComponent(); method you could create a method for various things and call them from inside your Overriden paint method, you could also pass them your graphics object. It will help you keep things relatively simple.
I'm following a Java game programming series on youtube, and all have been going well until we add some code to the program. The code for the program is:
package com.fagyapong.rain;
import javax.swing.*;
import java.awt.*;
import java.awt.image.*;
public class Game extends Canvas implements Runnable{
private static final long serialVersionUID = -247215114548172830L;
public static int width = 300;
public static int height = width / 16 * 9;
public static int scale = 3;
private JFrame frame;
public Thread thread;
private boolean running = false;
public Game() {
// Setup Game window
Dimension size = new Dimension(width * scale, height * scale);
setPreferredSize(size);
frame = new JFrame();
}
public synchronized void start() {
running = true;
thread = new Thread(this, "Display");
thread.start();
}
public synchronized void stop() {
running = false;
try {
thread.join();
}
catch (InterruptedException e) {
e.printStackTrace();
}
}
public void run() {
while (running) {
update();
render();
}
}
public void update() {
}
public void render() {
// Get the canvas' BufferStragy object
BufferStrategy bs = getBufferStrategy();
if (bs == null) {
createBufferStrategy(3);
return;
}
Graphics g = bs.getDrawGraphics();
g.setColor(Color.GRAY);
g.fillRect(0, 0, getWidth(), getHeight());
g.dispose();
bs.show();
}
public static void main(String[] args) {
Game game = new Game();
game.frame.setResizable(false);
game.frame.setTitle("Rain");
game.frame.add(game);
game.frame.pack();
game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
game.frame.setLocationRelativeTo(null);
game.frame.setVisible(true);
game.start();
}
}
Below is code that causes the system freeze(it has been commented out in the above code)
Graphics g = bs.getDrawGraphics();
g.setColor(Color.GRAY);
g.fillRect(0, 0, getWidth(), getHeight());
g.dispose();
bs.show();
Okay, I figured out the problem a bit. I was having the same issue. The issue for me was the triple buffering. Instead, set the code to:
createBufferStrategy(2);
That way it's only double buffering. I don't have a fantastic computer, so I had to set it to 1 instead of 2. At that point, my guess is that it's not buffering at all. This is how I got it to work though.
I have this code here for creating and drawing an array of pixels into an image:
import javax.swing.JFrame;
import java.awt.Canvas;
import java.awt.Graphics;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;
public class test extends Canvas implements Runnable {
private static final long serialVersionUID = 1L;
public static int WIDTH = 800;
public static int HEIGHT = 600;
public boolean running = true;
public int[] pixels;
public BufferedImage img;
public static JFrame frame;
private Thread thread;
public static void main(String[] arg) {
test wind = new test();
frame = new JFrame("WINDOW");
frame.add(wind);
frame.setVisible(true);
frame.setSize(WIDTH, HEIGHT);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
wind.init();
}
public void init() {
thread = new Thread(this);
thread.start();
img = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
pixels = ((DataBufferInt) img.getRaster().getDataBuffer()).getData();
}
public void run() {
while (running) {
render();
try {
thread.sleep(55);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
public void render() {
BufferStrategy bs = this.getBufferStrategy();
if (bs == null) {
createBufferStrategy(4);
return;
}
drawRect(0, 0, 150, 150);
Graphics g = bs.getDrawGraphics();
g.drawImage(img, 0, 0, WIDTH, HEIGHT, null);
g.dispose();
bs.show();
}
private void drawRect(int x, int y, int w, int h) {
for (int i = x; i < w; i++) {
for (int j = x; j < h; j++) {
pixels[i + j * WIDTH] = 346346;
}
}
}
}
Why do I get "Component must be a valid peer" error when I remove the line:
frame.add(wind);
Why do I want to remove it? Because I want to create a frame using a class object (from another file) and use the code Window myWindow = new Window() to do exactly the same thing.
As #nIcE cOw comments, you appear to be Mixing Heavyweight and Lightweight Components. Substituting Frame still leaves the underlying problem: createBufferStrategy() throws the exception because the Canvas is not displayable until added to the Frame, which relies on the features of the heavyweight peer component provided by the host platform. In effect you are trying to choose a BufferStrategy without specifying which buffer should use the strategy.
Instead, use an existing engine, or rely on the default buffer strategy provided by JComponent, for example.
Exception in thread "Thread-2" java.lang.IllegalStateException: Component must have a valid peer
at java.awt.Component$FlipBufferStrategy.createBuffers(Component.java:3843)
at java.awt.Component$FlipBufferStrategy.(Component.java:3817)
at java.awt.Component$FlipSubRegionBufferStrategy.(Component.java:4358)
at java.awt.Component.createBufferStrategy(Component.java:3699)
at java.awt.Canvas.createBufferStrategy(Canvas.java:166)
at java.awt.Component.createBufferStrategy(Component.java:3623)
at java.awt.Canvas.createBufferStrategy(Canvas.java:141)
at test.render(test.java:52)
at test.run(test.java:40)
at java.lang.Thread.run(Thread.java:680)
Next semester we have a module in making Java applications in a team. The requirement of the module is to make a game. Over the Christmas holidays I've been doing a little practice, but I can't figure out the best way to draw graphics.
I'm using the Java Graphics2D object to paint shapes on screen, and calling repaint() 30 times a second, but this flickers terribly. Is there a better way to paint high performance 2D graphics in Java?
What you want to do is to create a canvas component with a BufferStrategy and render to that, the code below should show you how that works, I've extracted the code from my self written Engine over here.
Performance solely depends on the stuff you want to draw, my games mostly use images. With around 1500 of them I'm still above 200 FPS at 480x480. And with just 100 images I'm hitting 6k FPS when disabling the frame limiting.
A small game (this one has around 120 images at once at the screen) I've created can be found here (yes the approach below also works fine as an applet.)
import java.awt.Canvas;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsEnvironment;
import java.awt.Toolkit;
import java.awt.Transparency;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import javax.swing.WindowConstants;
public class Test extends Thread {
private boolean isRunning = true;
private Canvas canvas;
private BufferStrategy strategy;
private BufferedImage background;
private Graphics2D backgroundGraphics;
private Graphics2D graphics;
private JFrame frame;
private int width = 320;
private int height = 240;
private int scale = 1;
private GraphicsConfiguration config =
GraphicsEnvironment.getLocalGraphicsEnvironment()
.getDefaultScreenDevice()
.getDefaultConfiguration();
// create a hardware accelerated image
public final BufferedImage create(final int width, final int height,
final boolean alpha) {
return config.createCompatibleImage(width, height, alpha
? Transparency.TRANSLUCENT : Transparency.OPAQUE);
}
// Setup
public Test() {
// JFrame
frame = new JFrame();
frame.addWindowListener(new FrameClose());
frame.setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
frame.setSize(width * scale, height * scale);
frame.setVisible(true);
// Canvas
canvas = new Canvas(config);
canvas.setSize(width * scale, height * scale);
frame.add(canvas, 0);
// Background & Buffer
background = create(width, height, false);
canvas.createBufferStrategy(2);
do {
strategy = canvas.getBufferStrategy();
} while (strategy == null);
start();
}
private class FrameClose extends WindowAdapter {
#Override
public void windowClosing(final WindowEvent e) {
isRunning = false;
}
}
// Screen and buffer stuff
private Graphics2D getBuffer() {
if (graphics == null) {
try {
graphics = (Graphics2D) strategy.getDrawGraphics();
} catch (IllegalStateException e) {
return null;
}
}
return graphics;
}
private boolean updateScreen() {
graphics.dispose();
graphics = null;
try {
strategy.show();
Toolkit.getDefaultToolkit().sync();
return (!strategy.contentsLost());
} catch (NullPointerException e) {
return true;
} catch (IllegalStateException e) {
return true;
}
}
public void run() {
backgroundGraphics = (Graphics2D) background.getGraphics();
long fpsWait = (long) (1.0 / 30 * 1000);
main: while (isRunning) {
long renderStart = System.nanoTime();
updateGame();
// Update Graphics
do {
Graphics2D bg = getBuffer();
if (!isRunning) {
break main;
}
renderGame(backgroundGraphics); // this calls your draw method
// thingy
if (scale != 1) {
bg.drawImage(background, 0, 0, width * scale, height
* scale, 0, 0, width, height, null);
} else {
bg.drawImage(background, 0, 0, null);
}
bg.dispose();
} while (!updateScreen());
// Better do some FPS limiting here
long renderTime = (System.nanoTime() - renderStart) / 1000000;
try {
Thread.sleep(Math.max(0, fpsWait - renderTime));
} catch (InterruptedException e) {
Thread.interrupted();
break;
}
renderTime = (System.nanoTime() - renderStart) / 1000000;
}
frame.dispose();
}
public void updateGame() {
// update game logic here
}
public void renderGame(Graphics2D g) {
g.setColor(Color.BLACK);
g.fillRect(0, 0, width, height);
}
public static void main(final String args[]) {
new Test();
}
}
The flickering is due to you writing direct to the screen. Use a buffer to draw on and then write the entire screen in 1 go. This is Double Buffering which you may have heard of before. Here is the simplest form possible.
public void paint(Graphics g)
{
Image image = createImage(size + 1, size + 1);
Graphics offG = image.getGraphics();
offG.setColor(Color.BLACK);
offG.fillRect(0, 0, getWidth(), getHeight());
// etc
See the use of the off screen graphics offG. It is expensive to create the off screen image so I would suggest creating it only on first call.
There's other areas you can improve this further eg creating a compatible image, using clipping etc. For more fine tuned control of animation you should look into active rendering.
There's a decent page I have bookmarked discussing game tutorials here.
Good luck!
Java OpenGL (JOGL) is one way.
I think you made an override from paint(Graphics g)? This is not the good way. Use the same code but in paintComponent(Graphics g) instead of paint(Graphics g).
A label you can search is doublebuffer. That is what will be done automatically by overriding paintComponent.
There is a simple way to optimize your program. Get rid of any complex code and just use JComponent instead Canvas and paint your objects on it. Thats all. Enjoy it...