I'm trying to create a square that can move by pressing keys. When I Compiled & Ran the code it wouldn't move. So I began debugging (as well as I'm capable of). The problem seems to be that the run() function isn't being called. Why is this ? My understanding was that when using the interface Runnable, the run method is called automatically. I posted all the code in action.
Why isn't run() being called automatically and how can I change my program so it will call ?
Game.java
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Game extends JPanel implements Runnable{
private static final int WIDTH = 800, HEIGHT = WIDTH / 12 * 9; //Widescreen
private Thread game_thread;
private boolean running = false;
public int x_speed = 0, y_speed = 0;
public Square square;
public Game(){
game_thread = new Thread("GameThread");
square = new Square(this);
addKeyListener(new KeyListener(){
#Override
public void keyPressed(KeyEvent e) {
if(e.getKeyCode() == e.VK_A){
x_speed = -1;
}
if(e.getKeyCode() == e.VK_D){
x_speed = 1;
}
if(e.getKeyCode() == e.VK_S){
y_speed = -1;
}
if(e.getKeyCode() == e.VK_W){
y_speed = 1;
}
}
#Override
public void keyReleased(KeyEvent e) {
}
#Override
public void keyTyped(KeyEvent e) {
}
});
}
public void start(){
System.out.println("Started");
game_thread.start();
running = true;
System.out.println(running);
}
public void stop(){
try{
running = false;
game_thread.join();
}catch(InterruptedException e){
e.printStackTrace();
}
}
public void paint(Graphics g){
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setColor(Color.BLACK);
g2d.fillRect(0, 0, WIDTH, HEIGHT);
square.render(g2d);
}
public void update(){
square.move();
System.out.println(x_speed + ", " + y_speed);
}
public void run(){
System.out.println("run method started");
while(running){
System.out.println("Running");
//Update screen info
update();
//Re-render
repaint();
try{
game_thread.sleep(10);
}catch(InterruptedException e){
e.printStackTrace();
}
}
}
public static void main(String args[]){
JFrame frame = new JFrame("Moving Thangs");
Game game = new Game();
frame.setSize(game.WIDTH, game.HEIGHT);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
frame.setResizable(false);
frame.add(game);
frame.setVisible(true);
game.start();
}
}
Square.java
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
public class Square {
public static final int s_WIDTH = 80, s_HEIGHT = s_WIDTH;
public int x, y;
private Game game;
public Square(Game game){
x = 50;
y = 50;
this.game = game;
}
public void move(){
if(x >= 0 && x <= game.getWidth() - s_WIDTH){
x += game.x_speed;
}
if(y >= 0 && y <= game.getHeight() - s_HEIGHT){
y += game.y_speed;
}
}
public void render(Graphics2D g2d){
g2d.setColor(Color.ORANGE);
g2d.fillRect(x, y, s_WIDTH, s_HEIGHT);
}
}
When you create the thread using new Thread("GameThread") you don't pass this as a runnable to the thread. You need to pass it as the first argument in the constructor like new Thread(this, "GameThread") and then everything should work.
Related
I am trying to create a mini tennis game. I am still a Java beginner and to make the program more organized I tried to create a package of each java file. Once I added the package extension and try to run the program the console displays error: class, interface, or enum expected on both the ball and racquet packages. How do I solve this problem?
/*This is Package minitennis*/
package minitennis;
package ball;
package racquet;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class Game extends JPanel {
Ball ball = new Ball(this);
Racquet racquet = new Racquet(this);
public Game() {
addKeyListener(new KeyListener() {
#Override
public void keyTyped(KeyEvent e) {
}
#Override
public void keyReleased(KeyEvent e) {
racquet.keyReleased(e);
}
#Override
public void keyPressed(KeyEvent e) {
racquet.keyPressed(e);
}
});
setFocusable(true);
}
private void move() {
ball.move();
racquet.move();
}
#Override
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
ball.paint(g2d);
racquet.paint(g2d);
}
public void gameOver() {
JOptionPane.showMessageDialog(this, "Game Over", "Game Over", JOptionPane.YES_NO_OPTION);
System.exit(ABORT);
}
public static void main(String[] args) throws InterruptedException {
JFrame frame = new JFrame("Mini Tennis");
Game game = new Game();
frame.add(game);
frame.setSize(300, 400);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
while (true) {
game.move();
game.repaint();
Thread.sleep(10);
}
}
/*This is Package ball*/
package ball;
package minitennis;
package racquet;
import java.awt.Graphics2D;
import java.awt.Rectangle;
public class Ball {
private static final int DIAMETER = 30;
int x = 0;
int y = 0;
int xa = 1;
int ya = 1;
private Game game;
public Ball(Game game) {
this.game= game;
}
void move() {
if (x + xa < 0)
xa = 1;
if (x + xa > game.getWidth() - DIAMETER)
xa = -1;
if (y + ya < 0)
ya = 1;
if (y + ya > game.getHeight() - DIAMETER)
game.gameOver();
if (collision()){
ya = -1;
y = game.racquet.getTopY() - DIAMETER;
}
x = x + xa;
y = y + ya;
}
private boolean collision() {
return game.racquet.getBounds().intersects(getBounds());
}
public void paint(Graphics2D g) {
g.fillOval(x, y, DIAMETER, DIAMETER);
}
public Rectangle getBounds() {
return new Rectangle(x, y, DIAMETER, DIAMETER);
}
}
/*This is package racquet*/
package racquet;
package minitennis;
package ball;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.KeyEvent;
public class Racquet {
private static final int Y = 330;
private static final int WIDTH = 60;
private static final int HEIGHT = 10;
int x = 0;
int xa = 0;
private Game game;
public Racquet(Game game) {
this.game = game;
}
public void move() {
if (x + xa > 0 && x + xa < game.getWidth() - WIDTH)
x = x + xa;
}
public void paint(Graphics2D g) {
g.fillRect(x, Y, WIDTH, HEIGHT);
}
public void keyReleased(KeyEvent e) {
xa = 0;
}
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_LEFT)
xa = -1;
if (e.getKeyCode() == KeyEvent.VK_RIGHT)
xa = 1;
}
public Rectangle getBounds() {
return new Rectangle(x, Y, WIDTH, HEIGHT);
}
public int getTopY() {
return Y;
}
}
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class Game extends JPanel {
Ball ball = new Ball(this);
Number123 num123 = new Number123(this);
public Game(){
addKeyListener(new KeyListener() {
#Override
public void keyTyped(KeyEvent e) {
}
#Override
public void keyReleased(KeyEvent e) {
ball.keyReleased(e);
}
#Override
public void keyPressed(KeyEvent e) {
ball.keyPressed(e);
}
});
setFocusable(true);
}
private void move() {
ball.move();
}
#Override
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
ball.paint(g2d);
num123.paintComponent(g2d);
}
public static void main(String[] args) throws InterruptedException {
JFrame frame = new JFrame("Two sprites");
Game game = new Game();
frame.add(game);
frame.setSize(600, 800);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
while (true) {
game.move();
game.repaint();
Thread.sleep(10);
}
}
}
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class Ball implements ActionListener, KeyListener{
int x = 0;
int y = 0;
int xa = 0;
int ya = 0;
private Game game;
public Ball(Game game){
this.game= game;
}
void move(){
if (x + xa > 0 && x + xa < game.getWidth()-60)
x = x + xa;
if (y + ya > 0 && y + ya < game.getHeight()-60)
y = y + ya;
}
public void paint(Graphics2D g){
g.fillOval(x, y, 30, 30);
}
public void keyReleased(KeyEvent e) {
if (xa == 1){
xa = 1;}
if (xa == -1){
xa = -1;
}
if (ya == 1){
ya = 1;}
if (ya == -1){
ya = -1;
}
}
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_LEFT)
xa = -1;
if (e.getKeyCode() == KeyEvent.VK_RIGHT)
xa = 1;
if (e.getKeyCode() == KeyEvent.VK_UP)
ya = -1;
if (e.getKeyCode() == KeyEvent.VK_DOWN)
ya = 1;
}
#Override
public void keyTyped(KeyEvent e) {
// TODO Auto-generated method stub
}
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
}
}
new to java so sorry if its a simple answer.
when i run program my circle object moves in angles not vertically and horizontal.
You need to set xa to 0 when you want to move vertically, and ya to 0 when you want to move horizontally. They get initialized that way, but never get reset.
Pong.Java
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
public class Pong {
private static final int WIDTH = 900, HEIGHT = 700;
JFrame win = new JFrame();
Paddle paddleOne = new Paddle(1);
Paddle paddleTwo = new Paddle(2);
Graphics g;
Pong(){
init();
}
void init(){
win.setTitle("PONG");
win.setSize(WIDTH, HEIGHT);
win.addKeyListener(keyListener);
win.setLocationRelativeTo(null);
win.getContentPane().setBackground(Color.black);
win.setVisible(true);
win.getContentPane().validate();
win.repaint();
}
public void paintComponent(Graphics g){
g.setColor(Color.white);
g.fillRect(paddleOne.getX(), paddleOne.getY(), paddleOne.getHEIGHT(), paddleOne.getWIDTH());
System.out.println("drawn");
}
KeyListener keyListener = new KeyListener() {
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
switch(key){
case 87:
System.out.println("Player 1 Up");
break;
case 83:
System.out.println("Player 1 Down");
break;
case 38:
System.out.println("Player 2 Up");
break;
case 40:
System.out.println("Player 2 Down");
break;
}
win.getContentPane().validate();
win.repaint();
}
public void keyReleased(KeyEvent arg0) {
// TODO Auto-generated method stub
}
public void keyTyped(KeyEvent arg0) {
// TODO Auto-generated method stub
}
};
public static void main(String[] args) {
Pong p = new Pong();
}
}
Paddle.Java
public class Paddle{
private int WIDTH = 50, HEIGHT = 150, X, Y;
int playerNum;
Paddle(int playerNum){
if(playerNum == 1){
X = 10;
Y = 10;
}else if (playerNum == 2){
X = 500;
Y = 10;
}
}
public void setX(int x){
X = x;
}
public void setY(int y){
Y = y;
}
public int getWIDTH() {
return WIDTH;
}
public int getHEIGHT() {
return HEIGHT;
}
public int getX() {
return X;
}
public int getY() {
return Y;
}
}
I'm relatively new to Java programming, or more specifically Awt & Swing, what my question is, why isn't my rectangle drawing? Any help is appreciated. Thank you so much!
In order for something to be painted within in Swing, it first must extend from something Swing know's how to paint, this commonly means a JComponent (or more typically a JPanel).
Then you can override one of the paint methods, which is called by the painting subsystem, in this case, it's generally preferred to override paintComponent, but don't forget to call super.paintComponent before you do any custom painting, or you're setting yourself up for some weird and generally unpredictable painting issues.
Take a look at Painting in AWT and Swing and Performing Custom Painting for more details.
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Pongo {
public static void main(String[] args) {
new Pongo();
}
public Pongo() {
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 PongPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class PongPane extends JPanel {
private static final int WIDTH = 900, HEIGHT = 700;
Paddle paddleOne = new Paddle(1);
Paddle paddleTwo = new Paddle(2);
public PongPane() {
setBackground(Color.BLACK);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.white);
g.fillRect(paddleOne.getX(), paddleOne.getY(), paddleOne.getHEIGHT(), paddleOne.getWIDTH());
//System.out.println("drawn"); //Should not put something here which may overhead.
}
}
public class Paddle {
private int WIDTH = 50, HEIGHT = 150, X, Y;
int playerNum;
Paddle(int playerNum) {
if (playerNum == 1) {
X = 10;
Y = 10;
} else if (playerNum == 2) {
X = 500;
Y = 10;
}
}
public void setX(int x) {
X = x;
}
public void setY(int y) {
Y = y;
}
public int getWIDTH() {
return WIDTH;
}
public int getHEIGHT() {
return HEIGHT;
}
public int getX() {
return X;
}
public int getY() {
return Y;
}
}
}
I would also discourage the use of KeyListener within this context and inside advice the use of the key bindings API, it doesn't suffer from the same focus related issues that KeyListener does. See How to Use Key Bindings for more details
You need to overriding paintComponents to draw.
Here is your Pong.java
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
public class Pong {
private static final int WIDTH = 900, HEIGHT = 700;
JFrame win = new JFrame();
Paddle paddleOne = new Paddle(1);
Paddle paddleTwo = new Paddle(2);
Graphics g;
Pong() {
init();
}
void init() {
win.setTitle("PONG");
win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
win.setSize(WIDTH, HEIGHT);
win.addKeyListener(keyListener);
win.setLocationRelativeTo(null);
win.add(new Panel(paddleOne));
win.getContentPane().setBackground(Color.black);
win.setVisible(true);
win.getContentPane().validate();
win.repaint();
}
KeyListener keyListener = new KeyListener() {
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
switch (key) {
case 87:
System.out.println("Player 1 Up");
break;
case 83:
System.out.println("Player 1 Down");
break;
case 38:
System.out.println("Player 2 Up");
break;
case 40:
System.out.println("Player 2 Down");
break;
}
win.getContentPane().validate();
win.repaint();
}
public void keyReleased(KeyEvent arg0) {
// TODO Auto-generated method stub
}
public void keyTyped(KeyEvent arg0) {
// TODO Auto-generated method stub
}
};
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Pong();
}
});
}
}
Here Panel.java in where paintComponent overridden.
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;
public class Panel extends JPanel{
private Paddle paddleOne;
public Panel(Paddle pdl) {
paddleOne = pdl;
}
#Override
public void paintComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.white);
g.fillRect(paddleOne.getX(), paddleOne.getY(), paddleOne.getHEIGHT(), paddleOne.getWIDTH());
//System.out.println("drawn"); //Should not put something here which may overhead.
}
}
I have the following code to show you:
public class Test extends JPanel implements ActionListener, KeyListener
{
Timer tm = new Timer(5, this);
int x = 0, y = 0, velX = 0, velY = 0;
public Test()
{
tm.start(); //starts the timer
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
}
public void paint(Graphics g)
{
super.paint(g);
ImageIcon s = new ImageIcon("C:\\Users\\Owner\\Pictures\\Stick.jpg");
s.paintIcon(this,g,x,y);
}
public void actionPerformed(ActionEvent e)
{
if (x < 0)
{
velX = 0;
x = 0;
}
if (x > 630)
{
velX = 0;
x = 630;
}
if(y < 0)
{
velY = 0;
y = 0;
}
if(y > 430)
{
velY = 0;
y = 430;
}
x = x + velX;
y = y + velY;
repaint();
}
public void keyPressed(KeyEvent e)
{
int c = e.getKeyCode();
if (c == KeyEvent.VK_LEFT)
{
velX = -1;
velY = 0;
}
if(c == KeyEvent.VK_UP)
{
velX = 0;
velY = -1;
}
if(c == KeyEvent.VK_RIGHT)
{
velX = 1;
velY = 0;
}
if(c == KeyEvent.VK_DOWN)
{
velX = 0;
velY = 1;
}
}
public void keyTyped(KeyEvent e){}
public void keyReleased(KeyEvent e)
{
velX = 0;
velY = 0;
}
public static void main(String[] args)
{
Test t = new Test();
JFrame jf = new JFrame();
jf.setTitle("Tutorial");
jf.setSize(700, 600);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jf.add(t);
jf.setVisible(true);
}
My problem is I whenever the user holds the right arrow on the keyboard it changes an image, when the user lets go it goes back the the default image. Please tell me how to do that. I think it is a series of if statements in the Graphics class then calling them to the key input but I'm not quite sure. I am also using Eclipse. Thank You.
Override paintComponent instead of paint. See Performing Custom Painting and Painting in AWT and Swing for more details
Use the key bindings API instead of KeyListener, it will cause you less issues. See How to Use Key Bindings for more details
Essentially, you could just have a Image as a class instance field, which was painted by the paintComponent method. When the key was pressed, you would change the image to the "move image" and when it was released, change it back to the "default image"
Updated with example
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
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 interface Mover {
public enum Direction {
LEFT, RIGHT, NONE;
}
public void setDirection(Direction direction);
public Direction getDirection();
}
public class TestPane extends JPanel implements Mover {
private BufferedImage left;
private BufferedImage right;
private BufferedImage stand;
private BufferedImage current;
private Direction direction = Direction.NONE;
private int xPos;
private int yPos;
public TestPane() {
try {
left = ImageIO.read(getClass().getResource("/Left.png"));
right = ImageIO.read(getClass().getResource("/Right.png"));
stand = ImageIO.read(getClass().getResource("/Stand.png"));
current = stand;
xPos = 100 - (current.getWidth() / 2);
yPos = 100 - (current.getHeight() / 2);
} catch (IOException exp) {
exp.printStackTrace();
}
bindKeyStrokeTo(WHEN_IN_FOCUSED_WINDOW, "move.left", KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0, false), new MoveAction(this, Direction.LEFT));
bindKeyStrokeTo(WHEN_IN_FOCUSED_WINDOW, "stop.left", KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0, true), new MoveAction(this, Direction.NONE));
bindKeyStrokeTo(WHEN_IN_FOCUSED_WINDOW, "move.right", KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0, false), new MoveAction(this, Direction.RIGHT));
bindKeyStrokeTo(WHEN_IN_FOCUSED_WINDOW, "stop.right", KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0, true), new MoveAction(this, Direction.NONE));
Timer timer = new Timer(40, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
updatePosition();
repaint();
}
});
timer.start();
}
protected void bindKeyStrokeTo(int condition, String name, KeyStroke keyStroke, Action action) {
InputMap im = getInputMap(condition);
ActionMap am = getActionMap();
im.put(keyStroke, name);
am.put(name, action);
}
#Override
public Direction getDirection() {
return direction;
}
#Override
public void setDirection(Direction direction) {
this.direction = direction;
}
protected void updatePosition() {
switch (getDirection()) {
case LEFT:
current = left;
xPos -= 1;
break;
case RIGHT:
current = right;
xPos += 1;
break;
case NONE:
current = stand;
break;
}
if (xPos < 0) {
xPos = 0;
current = stand;
} else if (xPos + current.getWidth() > getWidth()) {
current = stand;
xPos = getWidth() - current.getWidth();
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawImage(current, xPos, yPos, this);
g2d.dispose();
}
}
public class MoveAction extends AbstractAction {
private Mover mover;
private Mover.Direction direction;
public MoveAction(Mover mover, Mover.Direction direction) {
this.mover = mover;
this.direction = direction;
}
#Override
public void actionPerformed(ActionEvent e) {
mover.setDirection(direction);
}
}
}
I would like to make my app draw moving image a little smoother than how it is currently drawing them. I am not sure what to do to do that.
This is what my main game Thread looks like:
#Override
public void run(){
int delay = 500; //milliseconds
ActionListener taskPerformer = new ActionListener(){
#Override
public void actionPerformed(ActionEvent evt){
Car car = new Car();
int speed = (int)(3 + Math.floor(Math.random() * (6 - 3)));
car.setSpeed(speed);
MainLoop.this.gameObjects.vehicles.add(car.create("/Media/Graphics/blueCar.png", width - 20, 78));
car.driveTo(0, 78);
}
};
new Timer(delay, taskPerformer).start();
try{
while(true){
this.repaint();
for(GameObject go : this.gameObjects.vehicles){
// loops through objects to move them
Vehicle vh = (Vehicle) go;
this.moveVehicle(vh);
if(vh.getX() <= vh.getDestX()){
vh.markForDeletion(true);
}
}
this.gameObjects.destroyVehicles();
Thread.sleep(1);
}
}catch(Exception e){
e.printStackTrace();
}
}
This is a method that calculates the items next x/y position
protected void moveVehicle(Vehicle vh){
int cx = vh.getX();
int dx = vh.getDestX();
int cy = vh.getY();
int dy = vh.getDestY();
// move along x axis
// getMaxSpeed() = Number between 3 and 6
if(cx > dx && vh.movingX() == -1){
vh.setX(cx - vh.getMaxSpeed());
}else if(cx < dx && vh.movingX() == 1){
vh.setX(cx + vh.getMaxSpeed());
}else{
vh.setX(dx);
}
// move along y axis
// getMaxSpeed() = Number between 3 and 6
if(cy > dy && vh.movingY() == -1){
vh.setY(cy - vh.getMaxSpeed());
}else if(cy < dy && vh.movingY() == 1){
vh.setY(cy + vh.getMaxSpeed());
}else{
vh.setY(dy);
}
}
This is my paint method:
#Override
public void paintComponent(Graphics graphics){
super.paintComponent(graphics);
Graphics2D g = (Graphics2D) graphics;
for(GameObject go : gameObjects.vehicles){
g.drawImage(go.getSprite(), go.getX(), go.getY(), this);
}
}
This is possibly more info than needed, but I would like to know, what should I do to make items move from left -> right top -> bottom as smoothly as possible, without much of a performance loss?
Edit: Requested sscce:
package sscce;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Sscce extends JPanel implements Runnable{
ArrayList<Square> squares = new ArrayList<>();
public Sscce(){
JFrame frame = new JFrame();
frame.setSize(500, 500);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.add(this);
Thread t = new Thread(this);
t.start();
}
public static void main(String[] args){
new Sscce();
}
#Override
public void run(){
int delay = 500; //milliseconds
ActionListener taskPerformer = new ActionListener(){
#Override
public void actionPerformed(ActionEvent evt){
Square squ = new Square();
Sscce.this.squares.add(squ);
squ.moveTo(0);
}
};
new Timer(delay, taskPerformer).start();
while(true){
try{
for(Square s : this.squares){
int objX = s.getX();
int desX = s.getDestX();
if(objX <= desX){
System.out.println("removing");
this.squares.remove(s);
}else{
s.setX(s.getX() - 10);
}
}
this.repaint();
Thread.sleep(30);
}catch(Exception e){
}
}
}
#Override
public void paintComponent(Graphics g){
super.paintComponent(g);
for(Square s : squares){
g.setColor(Color.blue);
g.fillRect(s.getX(), s.getY(), 50, 50);
}
}
}
class Square{
public int x = 0, y = 0, destX = 0;
public Square(){
this.x = 400;
this.y = 100;
}
public void moveTo(int destX){
this.destX = destX;
}
public int getX(){
return this.x;
}
public int getDestX(){
return this.destX;
}
public void setX(int x){
this.x = x;
}
public int getY(){
return this.y;
}
}
First note, for some reason, I had issues with the JPanel implementing Runnable when running it under MacOS - I have no idea why, but that's why I moved it out.
It is possible for your squares to be update while it is been used to paint which will cause an exception (also, removing elements from a list while you're iterating it isn't a good idea either ;))
Instead, I have two lists. I have a model, which the list can modify and then the paint list which the paint method can use. This allows the thread to modifiy the model, while a paint process is underway.
To prevent any clash, I've added in a lock, which prevents one thread from modifying/accessing the paint list, while another thread has it locked.
Now. Down to the real problem. The main issue you're having isn't the amount of time between the updates, but the distance you are moving. Reduce the distance (to make it slower) and standarise the updates.
Most people won't notice anything much over 25fps, so trying to do much more then that is just wasting CPU cycles and starving the repaint manager, preventing it from actually updating the screen.
It's a balancing act to be sure...
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.locks.ReentrantLock;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestAnimation11 extends JPanel {
private ArrayList<Square> squares = new ArrayList<>();
private ReentrantLock lock;
public TestAnimation11() {
lock = new ReentrantLock();
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame();
frame.setSize(500, 500);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
frame.add(TestAnimation11.this);
Thread t = new Thread(new UpdateEngine());
t.start();
}
});
}
public static void main(String[] args) {
new TestAnimation11();
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Square[] paint = null;
lock.lock();
try {
paint = squares.toArray(new Square[squares.size()]);
} finally {
lock.unlock();
}
for (Square s : paint) {
g.setColor(Color.blue);
g.fillRect(s.getX(), s.getY(), 50, 50);
}
}
public class UpdateEngine implements Runnable {
private List<Square> model = new ArrayList<>(squares);
#Override
public void run() {
int ticks = 0;
List<Square> dispose = new ArrayList<>(25);
while (true) {
ticks++;
dispose.clear();
for (Square s : model) {
int objX = s.getX();
int desX = s.getDestX();
if (objX <= desX) {
dispose.add(s);
} else {
s.setX(s.getX() - 2);
}
}
model.removeAll(dispose);
if (ticks == 11) {
Square sqr = new Square();
sqr.moveTo(0);
model.add(sqr);
} else if (ticks >= 25) {
ticks = 0;
}
lock.lock();
try {
squares.clear();
squares.addAll(model);
} finally {
lock.unlock();
}
repaint();
try {
Thread.sleep(40);
} catch (Exception e) {
}
}
}
}
class Square {
public int x = 0, y = 0, destX = 0;
public Square() {
this.x = 400;
this.y = 100;
}
public void moveTo(int destX) {
this.destX = destX;
}
public int getX() {
return this.x;
}
public int getDestX() {
return this.destX;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return this.y;
}
}
}