Java - Random placement of objects - java

I'm working on a rain simulator. My idea is that every drop should be an object but for some reason they will not show up on the JFrame. If I change the values of the coordinates for the rectangle they appear but not if I randomize the numbers. What is causing the objects to not appear?
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Rain extends RainDrop implements ActionListener{
//Change the following 2 lines of variables to change the graphics
static int width = 1000, height = 600;
int dropAmount = 650, speed = 10;
Timer tm = new Timer(speed, this);
RainDrop[] RainDrop = new RainDrop[650];
public Rain(){
for(int i = 0; RainDrop.length > i; i++){
RainDrop[i] = new RainDrop();
RainDrop[i].generateRain();
add(RainDrop[i]);
}
repaint();
}
public void paintComponent(Graphics g){
tm.start();
}
public void actionPerformed(ActionEvent e){
repaint();
}
public static void main(String[] args) {
JFrame f = new JFrame();
f.setLocation(100, 100);
f.setSize(width, height);
f.setTitle("Rain");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Rain Rain = new Rain();
f.add(Rain);
f.setResizable(true);
f.setVisible(true);
}
}
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JPanel;
.
public class RainDrop extends JPanel{
//Drop [0] is used to store x values
//Drop [1] is used to store y values
//Drop [2] is used to store height values
//Drop [3] is used to store width values
//Drop [4] is used to store velocity values
private int[] Drop = new int [5];
private int width = 1000, height = 600;
public RainDrop(){
}
public int[] generateRain(){
Drop [0] = (int) (Math.random() * width);
Drop [1] = (int) (Math.random() * height);
Drop [2] = (int) (Math.random() * 13);
Drop [3] = (int) (Math.random() * 4);
Drop [4] = (int) (Math.random() * 6);
if(Drop [2] < 5) Drop [2] += 9;
if(Drop [3] < 3) Drop [3] += 3;
if(Drop [3] == 5) Drop [3] = 4;
if(Drop [4] < 3) Drop [4] += 3;
return Drop;
}
public void paintComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.red);
g.fillRect(Drop [0], Drop [1], 5, 20);
}
}

The basic design is wrong. Rain should not extend RainDrop.
Rain should just be a JPanel with a paintComponent() method that paints a RainDrop object.
Create an ArrayList to hold RainDrop objects. Then you can start the Timer in the Rain panel. When the Timer fires you can iterate through all the RainDrop objects in the ArrayList and change the location of each RainDrop and then repaint() the panel.
Here is an example showing this basic approach. It show how to move balls around a panel:
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.util.*;
import javax.swing.*;
import javax.swing.Timer;
public class BallAnimation4
{
private static void createAndShowUI()
{
BallPanel panel = new BallPanel();
JFrame frame = new JFrame("BallAnimation4");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( panel );
frame.setSize(800, 600);
frame.setLocationRelativeTo( null );
//frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.setVisible( true );
panel.addBalls(5);
panel.startAnimation();
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
class BallPanel extends JPanel implements ActionListener
{
private ArrayList<Ball> balls = new ArrayList<Ball>();
public BallPanel()
{
setLayout( null );
setBackground( Color.BLACK );
}
public void addBalls(int ballCount)
{
Random random = new Random();
for (int i = 0; i < ballCount; i++)
{
Ball ball = new Ball();
ball.setRandomColor(true);
ball.setLocation(random.nextInt(getWidth()), random.nextInt(getHeight()));
ball.setMoveRate(32, 32, 1, 1, true);
// ball.setMoveRate(16, 16, 1, 1, true);
ball.setSize(32, 32);
balls.add( ball );
}
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
for (Ball ball: balls)
{
ball.draw(g);
}
}
public void startAnimation()
{
Timer timer = new Timer(75, this);
timer.start();
}
public void actionPerformed(ActionEvent e)
{
move();
repaint();
}
private void move()
{
for (Ball ball : balls)
{
ball.move(this);
}
}
class Ball
{
public Color color = Color.BLACK;
public int x = 0;
public int y = 0;
public int width = 1;
public int height = 1;
private int moveX = 1;
private int moveY = 1;
private int directionX = 1;
private int directionY = 1;
private int xScale = moveX;
private int yScale = moveY;
private boolean randomMove = false;
private boolean randomColor = false;
private Random myRand = null;
public Ball()
{
myRand = new Random();
setRandomColor(randomColor);
}
public void move(JPanel parent)
{
int iRight = parent.getSize().width;
int iBottom = parent.getSize().height;
x += 5 + (xScale * directionX);
y += 5 + (yScale * directionY);
if (x <= 0)
{
x = 0;
directionX *= (-1);
xScale = randomMove ? myRand.nextInt(moveX) : moveX;
if (randomColor) setRandomColor(randomColor);
}
if (x >= iRight - width)
{
x = iRight - width;
directionX *= (-1);
xScale = randomMove ? myRand.nextInt(moveX) : moveX;
if (randomColor) setRandomColor(randomColor);
}
if (y <= 0)
{
y = 0;
directionY *= (-1);
yScale = randomMove ? myRand.nextInt(moveY) : moveY;
if (randomColor) setRandomColor(randomColor);
}
if (y >= iBottom - height)
{
y = iBottom - height;
directionY *= (-1);
yScale = randomMove ? myRand.nextInt(moveY) : moveY;
if (randomColor) setRandomColor(randomColor);
}
}
public void draw(Graphics g)
{
g.setColor(color);
g.fillOval(x, y, width, height);
}
public void setColor(Color c)
{
color = c;
}
public void setLocation(int x, int y)
{
this.x = x;
this.y = y;
}
public void setMoveRate(int xMove, int yMove, int xDir, int yDir, boolean randMove)
{
this.moveX = xMove;
this.moveY = yMove;
directionX = xDir;
directionY = yDir;
randomMove = randMove;
}
public void setRandomColor(boolean randomColor)
{
this.randomColor = randomColor;
switch (myRand.nextInt(3))
{
case 0: color = Color.BLUE;
break;
case 1: color = Color.GREEN;
break;
case 2: color = Color.RED;
break;
default: color = Color.BLACK;
break;
}
}
public void setSize(int width, int height)
{
this.width = width;
this.height = height;
}
}
}

I can't get your code to show anything if I take the randoms out, but I do see that you're not actually painting the raindrops.
In Rain.java:
public void paintComponent(Graphics g) {
for (int i = 0; RainDrop.length > i; i++) {
RainDrop[i].generateRain();
RainDrop[i].paintComponent(g);
}
}
and put tm.start(); in your constructor. You don't need to start the timer every time you repaint

Related

Why does the JFrame glitch when multiple objects are painted?

I am making an asteroid game. Every so often an asteroid needs to be generated and fly across the screen. For some reason when more then 1 asteroid is created, the screen glitches out. If you maximize the screen you will be able to see the glitching. I have tried using paint instead of paintComponent. I have also tried extending JFrame instead of JPanel but that just makes it worse. The class below sets up the screen and handles the game loop
public class Game extends JPanel {
static ArrayList<Asteroids> rocks = new ArrayList<Asteroids>();
//This variable determines whether the game should keep running
static boolean running = true;
//Counter to access arraylist
static int counter = 0;
public static void main(String[] args) throws InterruptedException {
//Creating the window
JFrame frame = new JFrame("Asteroid Game");
frame.getContentPane().setBackground(Color.BLACK);
frame.setSize(1100, 1000);
frame.setLocationRelativeTo(null);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
Asteroids a = new Asteroids();
frame.add(a);
//Game loop
while(running) {
if(counter % 4 == 0) {
rocks.add(new Asteroids());
frame.add(rocks.get(rocks.size() - 1));
}
for(int i = 0; i < rocks.size(); i++) {
rocks.get(i).repaint();
rocks.get(i).move();
if(!rocks.get(i).isPosFine()) {
rocks.remove(i);
i--;
}
}
Thread.sleep(17);
counter++;
}
}
}
The class below sets up the asteroids
public class Asteroids extends JPanel {
//These arrays store the coordinates of the asteroid
private int[] xPos = new int[8];
private int[] yPos = new int[8];
//Determines whether asteroid should be generated from top or bottom
private int[] yGen = {-100, 1100};
//Determines the direction the asteroid shold go
int genLevel;
/**
* #param g Graphics
* This method paints the asteroid
*/
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D r = (Graphics2D)g;
r.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
r.setColor(Color.decode("#52575D"));
r.fillPolygon(xPos, yPos, 8);
}
/**
* This constructor sets up the asteroid location points
*/
public Asteroids() {
int x = (int)(Math.random() * (700 - 1) + 100);
int y = yGen[(int)(Math.random() * (1 + 1 - 0))];
updateAsteroids(x, y);
genLevel = y;
System.out.println("Created!");
}
/**
* #param x int
* #param y int
* This method generates the asteroid based on the points passed in
*/
public void updateAsteroids(int x, int y) {
xPos[0] = x;
xPos[1] = x + 20;
xPos[2] = x + 40;
xPos[3] = x + 35;
xPos[4] = x + 40;
xPos[5] = x + 4;
xPos[6] = x - 16;
xPos[7] = x - 20;
yPos[0] = y;
yPos[1] = y + 7;
yPos[2] = y + 20;
yPos[3] = y + 40;
yPos[4] = y + 80;
yPos[5] = y + 70;
yPos[6] = y + 40;
yPos[7] = y;
}
/**
* This moves the asteroid
*/
public void move() {
int moveSpeedx = (int)(Math.random() * (10 - 1) + 1);
int moveSpeedy = (int)(Math.random() * (10 - 1) + 1);
for(int i = 0; i < 8; i++) {
if(genLevel > 0) {
xPos[i] -= moveSpeedx;
yPos[i] -= moveSpeedy;
}
else {
xPos[i] += moveSpeedx;
yPos[i] += moveSpeedy;
}
}
}
/**
* #return if the asteroid should be kept on the screen or not
*/
public boolean isPosFine() {
for(int i = 0; i < 8; i++) {
if(xPos[i] > 1250 || xPos[i] < -150)
return false;
if(yPos[i] > 1250 || yPos[i] < - 150)
return false;
}
return true;
}
}```
Your biggest problem that I can see is that you made your Asteroids class extend JPanel, making it much heavier weight than it should be, and making it difficult for more than one to show and for them to interact well and easily.
I recommend that you:
Make Asteroid a non-component logical class,
one that knows how to draw itself by giving it a public void draw(Graphics2D g2) method
one that knows how to move itself in response to your game loop's tick
Create one JPanel just for drawing the entire animation
Give this JPanel a collection of Asteroid objects, say in an ArrayList
In this JPanel's paintComponent, loop through all Asteroids in the collection, calling each one's draw(...) method
Drive the whole animation in a Swing thread-safe and controllable way using a Swing Timer. In this timer's actionPerformed, tell each asteroid to move, and then call repaint() on the drawing JPanel
Don't call .repaint() within the loop, but rather after the loop is finished
Create a small BufferedImage sprite from your Shapes, and draw those as the asteroid
A simple example illustrating what I mean:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Polygon;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;
#SuppressWarnings("serial")
public class Game2 extends JPanel {
private static final int PREF_W = 1000;
private static final int PREF_H = 800;
private static final int TIMER_DELAY = 20;
private List<Asteroid2> asteroids = new ArrayList<>();
public Game2() {
setBackground(Color.BLACK);
int rows = 5;
int cols = 5;
for (int i = 0; i < rows; i++) {
for (int j = 0; j < cols; j++) {
Asteroid2 asteroid = new Asteroid2();
asteroid.setX(j * (PREF_W / cols));
asteroid.setY(i * (PREF_H / rows));
asteroids.add(asteroid);
}
}
new Timer(TIMER_DELAY, e -> {
for (Asteroid2 asteroid2 : asteroids) {
asteroid2.move();
}
repaint();
}).start();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (Asteroid2 asteroid : asteroids) {
asteroid.draw(g);
}
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
private static void createAndShowGui() {
Game2 mainPanel = new Game2();
JFrame frame = new JFrame("Game2");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
class Asteroid2 {
private static final int[] POLY_X = { 20, 40, 60, 55, 60, 24, 4, 0 };
private static final int[] POLY_Y = { 0, 7, 20, 40, 80, 70, 40, 0 };
private static final Color ASTEROID_COLOR = Color.decode("#52575D");
private Image image;
private int x;
private int y;
public Asteroid2() {
Polygon poly = new Polygon(POLY_X, POLY_Y, POLY_X.length);
image = new BufferedImage(60, 80, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = (Graphics2D) image.getGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(ASTEROID_COLOR);
g2.fill(poly);
g2.dispose();
}
public void move() {
x++;
y++;
}
public void setX(int x) {
this.x = x;
}
public void setY(int y) {
this.y = y;
}
public void draw(Graphics g) {
if (image != null) {
g.drawImage(image, x - 20, y, null);
}
}
}

How to set a colored background to a frame?

I am trying to add a background color such as red or blue, etc... I tried almost everything I found on other forum posts, nothing worked.
This is not my code. I took it from an open source and I am modifying it
import javax.swing.*;
import java.awt.*;
import java.util.ArrayList;
import java.awt.color.*;
public class main {
public static void main(String[] args) {
Program program = new Program();
program.run();
}
}
class Program {
private JFrame mainFrame;
private DrawPanel drawPanel;
private java.util.List<Ball> balls;
private int windowWidth = 640;
private int windowHeight = 480;
private String windowLabel = "Bounce Program";
void run() {
balls = new ArrayList<>();
/* Generate balls */
for (int i = 0; i < 50; i++) {
Ball ball = new Ball(
/* Random positions from 0 to windowWidth or windowHeight */
(int) Math.floor(Math.random() * windowWidth),
(int) Math.floor(Math.random() * windowHeight),
/* Random size from 10 to 30 */
(int) Math.floor(Math.random() * 20) + 10,
/* Random RGB colors*/
new Color(
(int) Math.floor((Math.random() * 256)),
(int) Math.floor((Math.random() * 256)),
(int) Math.floor((Math.random() * 256))
),
/* Random velocities from -5 to 5 */
(int) Math.floor((Math.random() * 10) - 5),
(int) Math.floor((Math.random() * 10) - 5)
);
balls.add(ball);
}
/* Initialize program */
mainFrame = new JFrame();
drawPanel = new DrawPanel();
mainFrame.getContentPane().add(drawPanel);
mainFrame.setTitle(windowLabel);
mainFrame.setSize(windowWidth, windowHeight);
mainFrame.setVisible(true);
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
while (true) {
for (Ball b: balls) {
b.update();
}
/* Give Swing 10 milliseconds to see the update! */
try {
Thread.sleep(10);
} catch (InterruptedException e) {
e.printStackTrace();
}
mainFrame.repaint();
}
}
class DrawPanel extends JPanel {
#Override
public void paintComponent(Graphics graphics) {
super.paintComponent(graphics);
for (Ball b: balls) {
b.draw(graphics);
}
}
}
class Ball {
private int posX, posY, size;
private Color color;
private int vx = 5;
private int vy = 5;
public Ball(int posX, int posY, int size, Color color, int vx, int vy) {
this.posX = posX;
this.posY = posY;
this.size = size;
this.color = color;
this.vx = vx;
this.vy = vy;
}
void update() {
if (posX > mainFrame.getWidth() || posX < 0) {
vx *= -1;
}
if (posY > mainFrame.getHeight() || posY < 0) {
vy *= -1;
}
if (posX > mainFrame.getWidth()) {
posX = mainFrame.getWidth();
}
if (posX < 0) {
posX = 0;
}
if (posY > mainFrame.getHeight()) {
posY = mainFrame.getHeight();
}
if (posY < 0) {
posY = 0;
}
this.posX += vx;
this.posY += vy;
}
void draw(Graphics g) {
g.setColor(color);
g.fillOval(posX, posY, size, size);
}
}
}
drawPanel = new DrawPanel();
You add a panel to the frame so you need to set the background of that panel:
drawPanel = new DrawPanel();
drawPanel.setBackground( Color.RED );

How do I paint multiple objetcs that move at different speeds in Java?

I am working on homework for class, and its late because I can't seem to understand the material despite all the research that I am doing. I am a beginner and do not know much in the way of java. Also, this is my first post so please be forgiving when you are reading this.
I am building on source code from my textbook, which I updated recently for past homework, but now I am trying to generate a class that draws multiple squares and moves those objects independently and at different speeds. They will all need to rebound off the walls as well. I followed the instructions and created two arrays that will hold the random x and y values between 1 and 10. However, I struggle with arrays and I am sure that I am not doing it correctly. So, I would love some feedback to see if I have it set up correctly.
I have a the jpanel pulling up and drawing, and as long as there is 1 square it is working fine bouncing off the walls, but things change when I draw more than one. The do not move independently and they also share the same speed. Some even disappear from time to time. This has really thrown me off. I appreciate any help!
In short, I am trying to paint new squares that all travel in different directions and at different speeds. Per the instructions we are suppose create and use a two arrays that handle the x and y values.
Here is what I have so far:
public class DotsPanel extends JPanel
{
private int delay = 15;
private final int SIZE = 7, IMAGE_SIZE = 3; // radius of each dot
private Timer timer;
private int x, y, i;
private ArrayList<Point> pointList;
static int [] xarray = new int [1000];
static int [] yarray = new int [1000];
Random rand = new Random();
//-----------------------------------------------------------------
// Constructor: Sets up this panel to listen for mouse events.
//-----------------------------------------------------------------
public DotsPanel()
{
pointList = new ArrayList<Point>();
int [] xarray = new int [1000];
int [] yarray = new int [1000];
timer = new Timer(delay, new ReboundListener());
addMouseListener (new DotsListener());
addMouseMotionListener (new DotsListener());
setBackground(Color.gray);
setPreferredSize(new Dimension(700, 500));
for(int i = 0; i < xarray.length; i++)
{
xarray[i] = rand.nextInt(7);
yarray[i] = rand.nextInt(7);
}
timer.start();
}
//-----------------------------------------------------------------
// Draws all of the dots stored in the list.
//-----------------------------------------------------------------
public void paintComponent(Graphics page)
{
super.paintComponent(page);
page.setColor(Color.BLUE);
for (Point spot : pointList)
{
page.fillRect(spot.x-SIZE, spot.y-SIZE, 25, 25);
page.drawString("Count: " + pointList.size(), 5, 15);
}
}
//*****************************************************************
// Represents the listener for mouse events.
//*****************************************************************
private class DotsListener implements MouseListener, MouseMotionListener
{
//--------------------------------------------------------------
// Adds the current point to the list of points and redraws
// the panel whenever the mouse button is pressed.
//--------------------------------------------------------------
public void mousePressed(MouseEvent event)
{
pointList.add(event.getPoint());
repaint();
}
public void mouseDragged(MouseEvent event)
{
// initially I had two xarray and yarray in here just like in
// mouseClicked
// but it did not change anything when removed
}
//--------------------------------------------------------------
// Provide empty definitions for unused event methods.
//--------------------------------------------------------------
public void mouseClicked(MouseEvent event)
{
xarray[i] = rand.nextInt(7);
yarray[i] = rand.nextInt(7);
}
public void mouseReleased(MouseEvent event) {}
public void mouseEntered(MouseEvent event) {}
public void mouseExited(MouseEvent event) {}
public void mouseMoved(MouseEvent e) {}
}
private class ReboundListener implements ActionListener
{
//--------------------------------------------------------------
// Updates the position of the image and possibly the direction
// of movement whenever the timer fires an action event.
//--------------------------------------------------------------
public void actionPerformed(ActionEvent event)
{
for (Point spot : pointList)
{
spot.x += xarray[i];
spot.y += yarray[i];
if (spot.x <= 0 || spot.x >= 700)
xarray[i] = xarray[i] * -1;
if (spot.y <= 0 || spot.y >= 500)
yarray[i] = yarray[i] * -1;
repaint();
}
}
}
}
However, I struggle with arrays and I am sure that I am not doing it correctly.
I wouldn't use Arrays.
Instead, have a Ball object manage its own state. Then you can have different color, speed, size etc for each Ball. Then when the Timer fires you just calculate the new position and repaint the Ball.
Here is an example to get you started:
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.util.*;
import javax.swing.*;
import javax.swing.Timer;
public class BallAnimation4
{
private static void createAndShowUI()
{
BallPanel panel = new BallPanel();
JFrame frame = new JFrame("BallAnimation4");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( panel );
frame.setSize(800, 600);
frame.setLocationRelativeTo( null );
//frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.setVisible( true );
panel.addBalls(5);
panel.startAnimation();
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
class BallPanel extends JPanel implements ActionListener
{
private ArrayList<Ball> balls = new ArrayList<Ball>();
public BallPanel()
{
setLayout( null );
setBackground( Color.BLACK );
}
public void addBalls(int ballCount)
{
Random random = new Random();
for (int i = 0; i < ballCount; i++)
{
Ball ball = new Ball();
ball.setRandomColor(true);
ball.setLocation(random.nextInt(getWidth()), random.nextInt(getHeight()));
ball.setMoveRate(32, 32, 1, 1, true);
// ball.setMoveRate(16, 16, 1, 1, true);
ball.setSize(32, 32);
balls.add( ball );
}
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
for (Ball ball: balls)
{
ball.draw(g);
}
}
public void startAnimation()
{
Timer timer = new Timer(75, this);
timer.start();
}
public void actionPerformed(ActionEvent e)
{
move();
repaint();
}
private void move()
{
for (Ball ball : balls)
{
ball.move(this);
}
}
class Ball
{
public Color color = Color.BLACK;
public int x = 0;
public int y = 0;
public int width = 1;
public int height = 1;
private int moveX = 1;
private int moveY = 1;
private int directionX = 1;
private int directionY = 1;
private int xScale = moveX;
private int yScale = moveY;
private boolean randomMove = false;
private boolean randomColor = false;
private Random myRand = null;
public Ball()
{
myRand = new Random();
setRandomColor(randomColor);
}
public void move(JPanel parent)
{
int iRight = parent.getSize().width;
int iBottom = parent.getSize().height;
x += 5 + (xScale * directionX);
y += 5 + (yScale * directionY);
if (x <= 0)
{
x = 0;
directionX *= (-1);
xScale = randomMove ? myRand.nextInt(moveX) : moveX;
if (randomColor) setRandomColor(randomColor);
}
if (x >= iRight - width)
{
x = iRight - width;
directionX *= (-1);
xScale = randomMove ? myRand.nextInt(moveX) : moveX;
if (randomColor) setRandomColor(randomColor);
}
if (y <= 0)
{
y = 0;
directionY *= (-1);
yScale = randomMove ? myRand.nextInt(moveY) : moveY;
if (randomColor) setRandomColor(randomColor);
}
if (y >= iBottom - height)
{
y = iBottom - height;
directionY *= (-1);
yScale = randomMove ? myRand.nextInt(moveY) : moveY;
if (randomColor) setRandomColor(randomColor);
}
}
public void draw(Graphics g)
{
g.setColor(color);
g.fillOval(x, y, width, height);
}
public void setColor(Color c)
{
color = c;
}
public void setLocation(int x, int y)
{
this.x = x;
this.y = y;
}
public void setMoveRate(int xMove, int yMove, int xDir, int yDir, boolean randMove)
{
this.moveX = xMove;
this.moveY = yMove;
directionX = xDir;
directionY = yDir;
randomMove = randMove;
}
public void setRandomColor(boolean randomColor)
{
this.randomColor = randomColor;
switch (myRand.nextInt(3))
{
case 0: color = Color.BLUE;
break;
case 1: color = Color.GREEN;
break;
case 2: color = Color.RED;
break;
default: color = Color.BLACK;
break;
}
}
public void setSize(int width, int height)
{
this.width = width;
this.height = height;
}
}
}
Since your Arrays only contain the Point you want to paint you don't have any information about the speed each point should be moved at. The best you could do is create a random amount each point should be moved each time its location is changed. This would give erratic movement as each time you move a point the distance would be random.
If you want more constant speed then you would need to create a second Array to contain the distance each point should move every time.
This starts to get messy creating a new Array every time you want a new property to be unique for the object you want to paint. That is why the approach to create a custom Object with multiple properties is easier to manage.

Score not Updating in Pong

I'm very confused as to why my scoreboard isn't updating on screen. The scores are increasing (I checked with debugger, also the ball is being centered). But the scoreboard isn't updating at all it constantly says "0 : 0"
Pong Class
package com.dheraxysgames.pong;
import java.awt.Dimension;
import javax.swing.JFrame;
public class Pong extends JFrame{
private static final long serialVersionUID = 1L;
//Set Resolution
public static final int width = 300,
height = width / 4 * 3,
scale = 3;
public Pong() {
Dimension size = new Dimension(width * scale, height * scale);
setSize(size);
setTitle("PONG");
setResizable(false);
setVisible(true);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
add(new GamePanel());
}
public static int getWindowWidth(){
return width * scale;
}
public static int getWindowHeight(){
return height * scale;
}
public static void main(String[] args) {
new Pong();
}
}
GamePanel Class
package com.dheraxysgames.pong;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JPanel;
import javax.swing.Timer;
public class GamePanel extends JPanel implements ActionListener, KeyListener {
private static final long serialVersionUID = 1L;
Ball ball = new Ball();
Player player = new Player();
AI ai = new AI(this);
public GamePanel(){
Timer time = new Timer(50, this);
time.start();
this.addKeyListener(this);
this.setFocusable(true);
}
private void update(){
player.update();
ai.update();
ball.update();
ball.checkCollision(player);
ball.checkCollision(ai);
}
public void paintComponent(Graphics g){
super.paintComponent(g);
g.setColor(Color.BLACK);
g.fillRect(0, 0, Pong.getWindowWidth(), Pong.getWindowHeight());
g.setColor(Color.WHITE);
Font font = new Font("IMMORTAL", Font.BOLD, 50);
g.setFont(font);
g.drawString(player.score + " : " + ai.score, Pong.getWindowWidth() / 2 - 60, 50);
player.paint(g);
ai.paint(g);
ball.paint(g);
}
public Ball getBall(){
return ball;
}
public void actionPerformed(ActionEvent e) {
update();
repaint();
}
//Keyboard
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_UP) player.setYVelocity(-10);
if (e.getKeyCode() == KeyEvent.VK_DOWN) player.setYVelocity(10);
}
public void keyReleased(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_UP) player.setYVelocity(0);
if (e.getKeyCode() == KeyEvent.VK_DOWN) player.setYVelocity(0);
}
public void keyTyped(KeyEvent e) {
}
}
Player Class
package com.dheraxysgames.pong;
import java.awt.Color;
import java.awt.Graphics;
public class Player {
public int score = 0;
private static int width = 50,
height = 150;
private int x = 800, y = (Pong.getWindowHeight() / 2) - (height / 2),
yV = 0;
public Player() {
}
public void update(){
y += yV;
}
public void paint(Graphics g){
g.setColor(Color.GREEN);
g.fillRect(x, y, width, height);
}
public int getX(){
return x;
}
public int getY(){
return y;
}
public int getWidth(){
return width;
}
public int getHeight(){
return height;
}
public void setYVelocity(int speed){
yV = speed;
}
}
AI Class
package com.dheraxysgames.pong;
import java.awt.Color;
import java.awt.Graphics;
public class AI {
public int score = 0;
private static int width = 50,
height = 150;
private GamePanel field;
private int x = 50, y = (Pong.getWindowHeight() / 2) - (height / 2),
yV = 0;
public AI(GamePanel game) {
this.field = game;
}
public AI(){
}
public void update(){
if(field.getBall().getY() < this.y) yV = -8;
if(field.getBall().getY() > this.y) yV = 8;
y += yV;
}
public void paint(Graphics g){
g.setColor(Color.GREEN);
g.fillRect(x, y, width, height);
}
public int getX(){
return x;
}
public int getY(){
return y;
}
public int getWidth(){
return width;
}
public int getHeight(){
return height;
}
public void setYVelocity(int speed){
yV = speed;
}
}
Ball Class
package com.dheraxysgames.pong;
import java.awt.Color;
import java.awt.Graphics;
public class Ball {
private int x = Pong.getWindowWidth() / 2, y = Pong.getWindowHeight() / 2,
xV = 10, yV = 10;
private static int size = 40;
Player player = new Player();
AI ai = new AI();
public void update() {
x += xV;
y += yV;
if (x < 0){
reverseXDirection();
player.score++;
x = Pong.getWindowWidth() / 2;
y = Pong.getWindowHeight() / 2;
}
if (x > Pong.getWindowWidth() - size){
reverseXDirection();
ai.score++;
x = Pong.getWindowWidth() / 2;
y = Pong.getWindowHeight() / 2;
}
if (y < 0 || y > Pong.getWindowHeight() - size - 38) reverseYDirection();
}
public void paint(Graphics g){
g.setColor(Color.GREEN);
g.fillOval(x, y, size, size);
}
private void reverseXDirection(){
xV = -xV;
}
private void reverseYDirection(){
yV = -yV;
}
public void checkCollision(Player p) {
if (this.x + size > p.getX() && this.x + size < p.getX() + p.getWidth()){
if (this.y + size > p.getY() && this.y + size < p.getY() + p.getHeight()){
reverseXDirection();
}
}
}
public void checkCollision(AI ai) {
if (this.x > ai.getX() && this.x < ai.getX() + ai.getWidth()){
if (this.y > ai.getY() && this.y < ai.getY() + ai.getHeight()){
reverseXDirection();
}
}
}
public int getX(){
return x;
}
public int getY(){
return y;
}
}
In you're Ball class the score you're updating is not the same score that is being checked in the GamePanel class.
Notice how in both classes you are calling
Player player = new Player();
AI ai = new AI();
player and ai in Ball are seperate instances from the player and ai in GamePanel.
You will need to get the player and ai from the GamePanel class and pass them to the Ball class. The easiest way to do this would probably be to give Ball a constructor like so
Player player;
AI ai;
public Ball(Player player, AI ai) {
this.player = player;
this.ai = ai;
}
And in your GamePanel class change:
Ball ball = new Ball();
Player player = new Player();
AI ai = new AI(this);
To this:
Player player = new Player();
AI ai = new AI(this);
Ball ball = new Ball(player, ai);
It's been a while since I've used java so I'm probably forgetting a simpler way to do this, but this should solve the problem.

Three Paddle Pong Hit Detection

I am creating yet another version of pong. This one uses 3 paddles for each person. I have spent almost two hours trying to figure out why the two other paddles are not detecting when the ball strikes the paddle. The original (top) paddle does detect the hit and properly updates the hit counter. I have tried separate if statements, else if statements etc., with no success. I created three Y variables to detect the position of all three paddles still no luck.
Any suggestions?
import java.awt.Point;
public class box {
private int xTopLeft, yTopLeft, width, height;
int xBall, yBall;
private int radius = 5;
int xBallVel, yBallVel;
int VELOCITY_MAG =5;
public Point ballLoc = new Point();
private int paddleY;
private int paddleYP2;
private int paddleYP3;
private int paddleWidth = 20;
private int paddleWidth2 = 20;
private int paddleWidth3 = 20;
int hitCount = 0;
int missCount = 0;
private boolean updating=true;
public int getBallRadius()
{
return radius;
}
public Point getBallLoc()
{
ballLoc.x = xBall;
ballLoc.y = yBall;
return ballLoc;
}
public box(int x, int y, int w, int h)
{
xTopLeft =x;
yTopLeft = y;
width =w;
height = h;
createRandomBallLocation();
}
public void updatePaddle(int y)
{
paddleY = y;
}
public void updatePaddleP2(int yp2)
{
paddleYP2 = yp2;
}
public void updatePaddleP3(int yp3)
{
paddleYP3 = yp3;
}
public int getPaddleWidth()
{
return paddleWidth ;
}
public int getPaddleWidth2()
{
return paddleWidth2 ;
}
public int getPaddleWidth3()
{
return paddleWidth3 ;
}
public int getPaddleY()
{
System.out.println(paddleY);
return paddleY;
}
public int getPaddleP2()
{
System.out.println(paddleYP2);
return paddleYP2;
}
public int getPaddleP3()
{
return paddleYP3;
}
public int getHitCount()
{
return hitCount;
}
public int getMissCount()
{
return missCount;
}
public int velMag()
{
return VELOCITY_MAG;
}
public void update()
{
if (!updating) return;
xBall = xBall + xBallVel;
yBall = yBall + yBallVel;
if (xBall + radius >= xTopLeft+width && xBallVel>=0)
if ((yBall >= paddleY-paddleWidth && yBall <= paddleY + paddleWidth)
|| (yBall >= paddleYP2-paddleWidth2 && yBall <= paddleYP2 + paddleWidth2 )
|| (yBall >= paddleYP3-paddleWidth3 && yBall <= paddleYP3 + paddleWidth3 ))
{
// hit paddles
xBallVel = - xBallVel;
hitCount++;
}
else if (xBall+radius >= xTopLeft + width)
{
xBallVel = - xBallVel;
}
if (yBall+radius >= yTopLeft + height && yBallVel >= 0)
{
yBallVel = - yBallVel;
}
if (yBall-radius <= yTopLeft && yBallVel <=0)
{
yBallVel = - yBallVel;
}
if (xBall-radius <= xTopLeft && xBallVel <= 0)
{
xBallVel = - xBallVel;
}
}
public void createRandomBallLocation()
{
xBall = xTopLeft + radius +
(int)((width-2*radius)*Math.random());
yBall = yTopLeft + radius +
(int)((height-2*radius)*Math.random());
xBallVel = velMag();
yBallVel = velMag();
}
}
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.image.BufferStrategy;
public class Pong extends JFrame
implements Runnable{
box box = null;
int top, left, width, height;
final int LINE_THICKNESS = 5;
Graphics bufferGraphics;
int sleep=25;
public Pong(String name)
{
super(name);
int windowWidth = 1024;
int windowHeight =768;
this.setSize(windowWidth, windowHeight);
this.setResizable(false);
this.setLocation(400, 150);
this.setVisible(true);
this.createBufferStrategy(4);
MyMouseClick mmc = new MyMouseClick();
addMouseListener(mmc);
MyMouseMotion mmm = new MyMouseMotion();
addMouseMotionListener(mmm);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Thread thread = new Thread(this);
thread.start();
}
public void run()
{
while(true)
{
try
{
if (box != null)
{
box.update();
repaint();
}
Thread.sleep(sleep);
}
catch (InterruptedException e)
{}
}
}
public void paint(Graphics g)
{
BufferStrategy bf = this.getBufferStrategy();
g = bf.getDrawGraphics();
Dimension d = getSize();
if (box ==null)
{
Insets insets = getInsets();
left = insets.left;
top = insets.top;
width = d.width-left - insets.right;
height = d.height - top - insets.bottom;
box = new box(left, top, width, height);
}
g.fillRect(0,0, d.width, d.height);
g.setColor(Color.BLUE);
g.setFont(new Font("Arial", 20, 30));
g.drawString("Hits: "+box.getHitCount(), 20, 60);
g.setColor(Color.red);
g.setFont(new Font("Arial", 20, 30));
g.drawString("Misses: "+box.getMissCount(), 20, 380);
g.fillRect(left, top, left+width, LINE_THICKNESS); // top of box
g.setColor(Color.white);
g.fillRect(left, top+height, left+width, LINE_THICKNESS); // bottom of box
g.drawLine(left, top, left, top+height); // left of box
g.drawLine(left+width, top, left+width, top+height); // right side
Point ballLoc = box.getBallLoc();
int radius = box.getBallRadius();
g.fillOval(ballLoc.x - radius, ballLoc.y-radius, 2*radius, 2*radius);
// Draw paddles Player 1
g.setColor(Color.yellow);
int yp = box.getPaddleY();
int yp2 = box.getPaddleP2();
int yp3 = box.getPaddleP3();
int yw = box.getPaddleWidth();
int yw2 = box.getPaddleWidth2();
int yw3 = box.getPaddleWidth3();
g.fillRect(left+width-5, yp-yw, 4, 50);
g.fillRect(left+width-5, (yp2-yw2)+280, 4, 50);
g.fillRect(left+width-5, (yp3-yw3)+140, 4, 50);
bf.show();
}
// *********************** Inner classes
class MyMouseClick extends MouseAdapter
{
public void mouseClicked(MouseEvent e)
{
box = null;
repaint();
}
}
class MyMouseMotion extends MouseMotionAdapter
{
public void mouseMoved(MouseEvent e)
{
int y = e.getY();
int y2 = e.getY();
int y3 = e.getY();
if (box != null)
{
box.updatePaddle(y);
box.updatePaddleP2(y2);
box.updatePaddleP3(y3);
repaint();
}
}
}
// ************************************
public static void main(String[] args) {
Pong t = new Pong("Three Paddle Pong");
t.setVisible(true);
} // end of main
}
In the paint method you do paint your 3 paddles at different y positions, but for the actual paddle positions, paddleYP? which are used for collision detection, you just set the 3 paddles to the same y in mouseMoved.

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