Develop Reference

How to restart while loop in order to restart game?

I want the game to restart when the player pressed the y key on the keyboard after dying or getting hit by the small ball.
BoxX and BoxY are the coordinates for enemy balls
Ball holds the rectangle or hitbox for all the enemy balls
ReverseX and Y, IndexX and Y, and BallXchange and Y all have to do with the movement of the enemy balls.
Here is the code:
import javax.swing.JPanel;
import javax.swing.JFrame;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.event.*;
import java.util.ArrayList;
import java.awt.Font;
import java.awt.Color;
import java.io.File;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
public class GameNotes extends JPanel implements KeyListener{
int x1=1;
int y1=1;
int ballx = 40;
int bally = 60;
boolean gameRunning = true;
BufferedImage image;
int windowx = 500;
int windowy = 500;
int score = 0;
int rectX = (int)(Math.random()*400)+30;
int rectY = (int)(Math.random()*400)+30;
int enemyX = (int)(Math.random()*300)+100;
int enemyY = (int)(Math.random()*250)+100;
int count = 1;
int num = 0;
boolean reverseX = false;
boolean reverseY = false;
boolean right = false;
boolean left = false;
boolean up = false;
boolean down = false;
ArrayList<Integer> BoxX = new ArrayList<Integer>();
ArrayList<Integer> BoxY = new ArrayList<Integer>();
ArrayList<Rectangle> Ball = new ArrayList<Rectangle>();
ArrayList<Integer> ReverseX = new ArrayList<Integer>();
ArrayList<Integer> ReverseY = new ArrayList<Integer>();
ArrayList<Integer> BallYchange = new ArrayList<Integer>();
ArrayList<Integer> BallXchange = new ArrayList<Integer>();
ArrayList<Integer> indexY = new ArrayList<Integer>();
ArrayList<Integer> indexX = new ArrayList<Integer>();
public GameNotes(){
setFocusable(true);
JFrame frame = new JFrame("GameDemo");
frame.setSize(windowx, windowy);
frame.add(this);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
addKeyListener(this);
try{
image = ImageIO.read(new File("C:\\Users\\10021707\\Desktop\\Game\\b.jpg"));
}catch (Exception e){
System.out.println("image not found \n E000384JW29400119482938WJDI39");
}
game:
while(gameRunning){
try{
Thread.sleep(3);
}catch(Exception e){
System.out.println("error");
}
Rectangle r = new Rectangle (ballx,bally,20,20);
Rectangle r2 = new Rectangle (rectX,rectY,30,30);
Rectangle rE = new Rectangle (enemyX,enemyY,10,10);
if(count == 1){
BoxX.add(enemyX);
BoxY.add(enemyY);
Ball.add(rE);
ReverseX.add(1);
BallXchange.add(enemyX);
num++;
indexX.add(num);
count--;
}
//System.out.println("ReverseY" + ReverseY.size());
if(ballx >= 461)
ballx = 461;
if(ballx <= 0)
ballx = 0;
if(bally >= 432)
bally = 432;
if(bally <= 0)
bally = 0;
if(r.intersects(r2)){
score+=5;
rectX = (int)(Math.random()*400)+30;
rectY = (int)(Math.random()*400)+30;
enemyX = (int)(Math.random()*300)+50;
enemyY = (int)(Math.random()*300)+50;
BoxX.add(enemyX);
BoxY.add(enemyY);
int x = (int)(Math.random()*10)+1;
//System.out.println(x);
if(x > 5){
ReverseX.add(1);
BallXchange.add(enemyX);
num++;
indexX.add(num);
}
if(x <= 5){
ReverseY.add(1);
BallYchange.add(enemyY);
num++;
indexY.add(num);
}
Rectangle En = new Rectangle (enemyX,enemyY,10,10);
Ball.add(En);
//System.out.println(Ball);
}
for(int i = 0; i < Ball.size(); i++){
Rectangle w = new Rectangle (BoxX.get(i),BoxY.get(i),10,10);
Ball.set(i,w);
}
for(int i = 0; i < BoxX.size(); i++){
if(r.intersects(Ball.get(i))){
gameRunning = false;
}
}
//System.out.println(ReverseY);
for(int i = 0; i < ReverseX.size(); i++){
BallXchange.set(i,BallXchange.get(i)+ReverseX.get(i));
BoxX.set(indexX.get(i)-1,BallXchange.get(i));
if(BallXchange.get(i) >= 470 || BallXchange.get(i) <= 0){
ReverseX.set(i,ReverseX.get(i)*-1);
}
}
for(int i = 0; i < ReverseY.size(); i++){
BallYchange.set(i,BallYchange.get(i)+ReverseY.get(i));
BoxY.set(indexY.get(i)-1,BallYchange.get(i));
if(BallYchange.get(i) >= 445 || BallYchange.get(i) <= 0){
ReverseY.set(i,ReverseY.get(i)*-1);
}
}
if(right)
ballx++;
if(left)
ballx--;
if(up)
bally--;
if(down)
bally++;
repaint();
}
}
public void paintComponent(Graphics g){
super.paintComponent(g);
g.drawImage(image,0,0,null);
g.fillOval(ballx,bally,20,20);
g.fillRect(rectX,rectY,30,30);
for(int i = 0; i < BoxX.size(); i++){
g.fillOval(BoxX.get(i),BoxY.get(i),10,10);
}
if(!gameRunning){
g.setColor(getBackground());
g.clearRect(rectX,rectY,30,30);
g.fillRect(rectX,rectY,30,30);
for(int i = 0; i < BoxX.size(); i++){
g.clearRect(BoxX.get(i),BoxY.get(i),10,10);
g.fillOval(BoxX.get(i),BoxY.get(i),10,10);
g.fillRect(BoxX.get(i),BoxY.get(i),10,10);
}
BoxX.clear();
BoxY.clear();
Ball.clear();
ReverseX.clear();
ReverseY.clear();
BallXchange.clear();
BallYchange.clear();
indexX.clear();
indexY.clear();
g.setColor(Color.BLACK);
g.setFont(new Font("TimesRoman", Font.PLAIN, 30));
g.drawString("Game Over", 165, 200);
g.setFont(new Font("TimesRoman", Font.PLAIN, 25));
g.drawString("Do you want to play again?", 100, 230);
g.setFont(new Font("TimesRoman", Font.PLAIN, 20));
g.drawString("(y or n)", 200, 250);
}
if(gameRunning){
g.setFont(new Font("TimesRoman", Font.PLAIN, 25));;
g.drawString("Score: "+score, 100, 450);
}
/*for(int i = 0; i < Ball.size(); i++){
g.fillRect((int)Ball.get(i).getX(),(int)Ball.get(i).getY(),10,10);
}*/
}
public void keyReleased(KeyEvent e){
if(e.getKeyCode() == KeyEvent.VK_D || e.getKeyCode() == KeyEvent.VK_RIGHT)
right = false;
if(e.getKeyCode() == KeyEvent.VK_A || e.getKeyCode() == KeyEvent.VK_LEFT)
left = false;
if(e.getKeyCode() == KeyEvent.VK_W || e.getKeyCode() == KeyEvent.VK_UP)
up = false;
if(e.getKeyCode() == KeyEvent.VK_S || e.getKeyCode() == KeyEvent.VK_DOWN)
down = false;
}
public void keyPressed(KeyEvent e){
int key = e.getKeyCode();
if(gameRunning == false && key == e.VK_Y){
score = 0;
gameRunning = true;
}
if(e.getKeyCode() == KeyEvent.VK_D || e.getKeyCode() == KeyEvent.VK_RIGHT)
right = true;
if(e.getKeyCode() == KeyEvent.VK_A || e.getKeyCode() == KeyEvent.VK_LEFT)
left = true;
if(e.getKeyCode() == KeyEvent.VK_W || e.getKeyCode() == KeyEvent.VK_UP)
up = true;
if(e.getKeyCode() == KeyEvent.VK_S || e.getKeyCode() == KeyEvent.VK_DOWN)
down = true;
}
public void keyTyped(KeyEvent e){
}
public static void main (String [] samay){
GameNotes test = new GameNotes();
}
}
Any help would be appreciated!

As ordonezalex suggested in his comment you can take the while loop and put it in a method such as this:
public void runGame() {
while(gameRunning){
try{
Thread.sleep(3);
}catch(Exception e){
System.out.println("error");
}
Rectangle r = new Rectangle (ballx,bally,20,20);
Rectangle r2 = new Rectangle (rectX,rectY,30,30);
Rectangle rE = new Rectangle (enemyX,enemyY,10,10);
if(count == 1){
BoxX.add(enemyX);
BoxY.add(enemyY);
Ball.add(rE);
ReverseX.add(1);
BallXchange.add(enemyX);
num++;
indexX.add(num);
count--;
}
//System.out.println("ReverseY" + ReverseY.size());
if(ballx >= 461)
ballx = 461;
if(ballx <= 0)
ballx = 0;
if(bally >= 432)
bally = 432;
if(bally <= 0)
bally = 0;
if(r.intersects(r2)){
score+=5;
rectX = (int)(Math.random()*400)+30;
rectY = (int)(Math.random()*400)+30;
enemyX = (int)(Math.random()*300)+50;
enemyY = (int)(Math.random()*300)+50;
BoxX.add(enemyX);
BoxY.add(enemyY);
int x = (int)(Math.random()*10)+1;
//System.out.println(x);
if(x > 5){
ReverseX.add(1);
BallXchange.add(enemyX);
num++;
indexX.add(num);
}
if(x <= 5){
ReverseY.add(1);
BallYchange.add(enemyY);
num++;
indexY.add(num);
}
Rectangle En = new Rectangle (enemyX,enemyY,10,10);
Ball.add(En);
//System.out.println(Ball);
}
for(int i = 0; i < Ball.size(); i++){
Rectangle w = new Rectangle (BoxX.get(i),BoxY.get(i),10,10);
Ball.set(i,w);
}
for(int i = 0; i < BoxX.size(); i++){
if(r.intersects(Ball.get(i))){
gameRunning = false;
}
}
//System.out.println(ReverseY);
for(int i = 0; i < ReverseX.size(); i++){
BallXchange.set(i,BallXchange.get(i)+ReverseX.get(i));
BoxX.set(indexX.get(i)-1,BallXchange.get(i));
if(BallXchange.get(i) >= 470 || BallXchange.get(i) <= 0){
ReverseX.set(i,ReverseX.get(i)*-1);
}
}
for(int i = 0; i < ReverseY.size(); i++){
BallYchange.set(i,BallYchange.get(i)+ReverseY.get(i));
BoxY.set(indexY.get(i)-1,BallYchange.get(i));
if(BallYchange.get(i) >= 445 || BallYchange.get(i) <= 0){
ReverseY.set(i,ReverseY.get(i)*-1);
}
}
if(right)
ballx++;
if(left)
ballx--;
if(up)
bally--;
if(down)
bally++;
repaint();
}
}
Then replace the while loop with this:
runGame();
And each time you want to re-run the game you can use that again, as long as the boolean gameRunning is true.

There are a few things you would need to update in your code:
A. Create a boolean called programRunning and set it to true:
boolean gameRunning = true;
boolean programRunning = true;
B. Create a private void method called initGame() and place all the game initialization code there:
private void initGame()
{
x1=1;
y1=1;
ballx = 40;
bally = 60;
windowx = 500;
windowy = 500;
score = 0;
rectX = (int)(Math.random()*400)+30;
rectY = (int)(Math.random()*400)+30;
enemyX = (int)(Math.random()*300)+100;
enemyY = (int)(Math.random()*250)+100;
count = 1;
num = 0;
reverseX = false;
reverseY = false;
right = false;
left = false;
up = false;
down = false;
BoxX = new ArrayList<Integer>();
BoxY = new ArrayList<Integer>();
Ball = new ArrayList<Rectangle>();
ReverseX = new ArrayList<Integer>();
ReverseY = new ArrayList<Integer>();
BallYchange = new ArrayList<Integer>();
BallXchange = new ArrayList<Integer>();
indexY = new ArrayList<Integer>();
indexX = new ArrayList<Integer>();
}
C. Modify the following code under the section where you are assigning a JPG to the image variable:
try{
image = ImageIO.read(new File("C:\\Users\\10021707\\Desktop\\Game\\b.jpg"));
}catch (Exception e){
System.out.println("image not found \n E000384JW29400119482938WJDI39");
}
//CODE CHANGED BELOW THIS COMMENT
do {
initGame();
while (gameRunning) {
runGame();
}
} while (programRunning);
D. Create the runGame() method that contains all of your code within the while (gameRunning) loop:
private void runGame()
{
try{
Thread.sleep(3);
}catch(Exception e){
System.out.println("error");
}
Rectangle r = new Rectangle (ballx,bally,20,20);
Rectangle r2 = new Rectangle (rectX,rectY,30,30);
Rectangle rE = new Rectangle (enemyX,enemyY,10,10);
if(count == 1){
BoxX.add(enemyX);
BoxY.add(enemyY);
Ball.add(rE);
ReverseX.add(1);
BallXchange.add(enemyX);
num++;
indexX.add(num);
count--;
}
//System.out.println("ReverseY" + ReverseY.size());
if(ballx >= 461)
ballx = 461;
if(ballx <= 0)
ballx = 0;
if(bally >= 432)
bally = 432;
if(bally <= 0)
bally = 0;
if(r.intersects(r2)){
score+=5;
rectX = (int)(Math.random()*400)+30;
rectY = (int)(Math.random()*400)+30;
enemyX = (int)(Math.random()*300)+50;
enemyY = (int)(Math.random()*300)+50;
BoxX.add(enemyX);
BoxY.add(enemyY);
int x = (int)(Math.random()*10)+1;
//System.out.println(x);
if(x > 5){
ReverseX.add(1);
BallXchange.add(enemyX);
num++;
indexX.add(num);
}
if(x <= 5){
ReverseY.add(1);
BallYchange.add(enemyY);
num++;
indexY.add(num);
}
Rectangle En = new Rectangle (enemyX,enemyY,10,10);
Ball.add(En);
//System.out.println(Ball);
}
for(int i = 0; i < Ball.size(); i++){
Rectangle w = new Rectangle (BoxX.get(i),BoxY.get(i),10,10);
Ball.set(i,w);
}
for(int i = 0; i < BoxX.size(); i++){
if(r.intersects(Ball.get(i))){
gameRunning = false;
}
}
//System.out.println(ReverseY);
for(int i = 0; i < ReverseX.size(); i++){
BallXchange.set(i,BallXchange.get(i)+ReverseX.get(i));
BoxX.set(indexX.get(i)-1,BallXchange.get(i));
if(BallXchange.get(i) >= 470 || BallXchange.get(i) <= 0){
ReverseX.set(i,ReverseX.get(i)*-1);
}
}
for(int i = 0; i < ReverseY.size(); i++){
BallYchange.set(i,BallYchange.get(i)+ReverseY.get(i));
BoxY.set(indexY.get(i)-1,BallYchange.get(i));
if(BallYchange.get(i) >= 445 || BallYchange.get(i) <= 0){
ReverseY.set(i,ReverseY.get(i)*-1);
}
}
if(right)
ballx++;
if(left)
ballx--;
if(up)
bally--;
if(down)
bally++;
repaint();
}
E. Add this code to your keyPressed(KeyEvent e) method:
if (gameRunning == false && key == KeyEvent.VK_N)
{
programRunning = false;
System.exit(0); //Closes the application.
}

Just giving you the main idea :
do{
//All logic goes here
//At the end of the game take input from user in the form of 'Y|y' or 'N|n'
System.out.println("Do you want to continue : press 'Y' for yes and 'N' for no");
Scanner sc=new Scanner(System.in);
String choice=sc.nextLine();
} while(choice.equalsIgnoreCase("Y"))

JFrame won't call paint method?

So I made Pong in a applet for a project in school but I realized that I can't hand in the project without creating an HTML file, so I'm attempting to change all my code from a applet to a JFrame. It all works, but my paint method isn't being called, any help will be great. Thanks for the help but to be honest im new to programming so if someone could make the changes to my code and then explain what you did, that would be great
package pong;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
class Main extends JPanel implements Runnable, KeyListener{//whatever class holds you main method
private static final long serialVersionUID = 1L;
int width = 600;
int height = width *9/16;
int Pwidth = 10, Pheight = 50, Px = 30, Py = height / 2-Pwidth, Pv = 3;
int Ewidth = 10, Eheight = 50, Ex = width - Ewidth - 30, Ey = height / 2-Ewidth - 50;
double Ev = 2.7;
int Bwidth = 10, Bheight = 10, Bx = width / 2 + 50, By = height / 2, Bvx = 3, Bvy = 3;
int TimeD = 0;
int Ms = 0, sec = 0, min = 0;
int Pscore = 0, Escore = 0, Pwinx = 800, Pwiny = height / 2, Ewinx = 800, Ewiny = height / 2;
boolean Bleft = true, Bright = false, Bup = true, Bdown = false;
boolean Pup = false, Pdown = false;
boolean Pa = false;
String string = new String();
public static JFrame frame;//public and static so other classes can access it. Might want to use a getter and setter here
public Main(){
frame=new JFrame("Pong, A game re-made by Camron Warren");// Create new JFrame
frame.setSize(width,height);//Set the size of the window
frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);//Make sure all processes are closed when the window is closed
frame.setLocationRelativeTo(null);//Centers window
frame.setVisible(true);//Make the window visible
Thread th = new Thread(this);
addKeyListener(this);
th.start();
}
public static void main(String[] args){
new Main();//instantiate the Main class, this has to happen
}
#Override
public void run() {
while(true){
if(Pscore >= 5){
Pwinx = 100;
Py = height / 2 - Pheight / 2;
Bx = width / 2 - Bwidth;
By = height /2 - Bheight /2;
}
if(Escore >= 5){
Ewinx = 400;
Py = height / 2-Pwidth;
Bx = width / 2 - Bwidth;
By = height /2;
}
if(Escore >= 5 && Pa == true){
Pscore = 0;
Escore = 0;
Ewinx = 800;
Ms = 0;
sec = 0;
min = 0;
}
if(Pscore >= 5 && Pa == true){
Pscore = 0;
Escore = 0;
Pwinx = 800;
Ms = 0;
sec = 0;
min = 0;
}
//ball movement class
ballMovement();
//TIME COUNTER
Ms++;
if(Ms >= 60){
sec++;
Ms = 0;
}
if(sec >= 60){
min++;
sec = 0;
}
//BALLMOVEMENT
if(Bleft == true){
Bx-=Bvx;
}
if(Bright == true){
Bx+=Bvx;
}
if(Bup == true){
By-=Bvy;
}
if(Bdown == true){
By+=Bvy;
}
//BALLHITBOX
if(By <= 0){
Bup = false;
Bdown = true;
}
if(By + Bheight >= height){
Bdown = false;
Bup = true;
}
//SCORE SYSTEM
if(Bx <= 0){
Escore++;
Bx = width / 2 - Bwidth;
By = height / 2;
}
if(Bx+Bwidth >= width){
Pscore++;
Bx = width /2 - Bwidth;
By = height / 2;
}
//PHITBOX
if(Bx+Bwidth >= Px && Bx <= Px+Pwidth && By+Bheight >= Py && By <= Py+Pheight){
System.out.println("Phit");
Bleft = false;
Bright = true;
}
//EHITBOX
if(Bx+Bwidth >= Ex && Bx <= Ex + Ewidth && By+Bheight >= Ey && By <= Ey + Eheight){
System.out.println("Ehit");
Bright = false;
Bleft = true;
}
//PMOVEMENT
if(Pup == true){
Py-=Pv;
}
if(Pdown == true){
Py+=Pv;
}
//PHITBOX/APPLETHITBOX
if(Py <= 0){
Py = 0;
}
if(Py + Pheight >= height){
Py = height - Pheight;
}
//EHITBOX/APPLETHITBOX
if(Ey <= 0){
Ey = 0;
}
if(Ey + Eheight >= height){
Ey = height - Eheight;
}
//REPAINT
repaint();
try {
Thread.sleep(17);
} catch (InterruptedException e){
e.printStackTrace();
}
}
}
public void ballMovement()
{
if(By >= Ey)
{
Ey += Ev;
}
if(By <= Ey)
{
Ey -= Ev;
}
}
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
if(key == KeyEvent.VK_W){
Pup = true;
}
if(key == KeyEvent.VK_S){
Pdown = true;
}
if(key == KeyEvent.VK_UP){
Pup = true;
}
if(key == KeyEvent.VK_DOWN){
Pdown = true;
}
if(key == KeyEvent.VK_F1){
Pa = true;
}
}
public void keyReleased(KeyEvent e) {
int key = e.getKeyCode();
if(key == KeyEvent.VK_W){
Pup = false;
}
if(key == KeyEvent.VK_S){
Pdown = false;
}
if(key == KeyEvent.VK_UP){
Pup = false;
}
if(key == KeyEvent.VK_DOWN){
Pdown = false;
}
if(key == KeyEvent.VK_F1){
Pa = false;
}
}
#Override
public void keyTyped(KeyEvent arg0) {}
#SuppressWarnings("deprecation")
public void update(Graphics g) {
Graphics offgc;
Image offscreen = null;
Dimension d = size();
offscreen = createImage(d.width, d.height);
offgc = offscreen.getGraphics();
offgc.setColor(getBackground());
offgc.fillRect(0, 0, d.width, d.height);
offgc.setColor(getForeground());
paint(offgc);
g.drawImage(offscreen, 0, 0, this);
}
#Override
public void paint(Graphics g){
g.setColor(Color.green);
g.fillRect(Px, Py, Pwidth, Pheight);
g.setColor(Color.RED);
g.fillRect(Ex, Ey, Ewidth, Eheight);
g.setColor(Color.BLACK);
g.fillOval(Bx, By, Bwidth, Bheight);
g.setColor(Color.BLACK);
g.drawRect(0, 0, width - 1, height - 1);
g.drawString("Score: " + Pscore, 20, 20);
g.drawString("Score " + Escore , width - 60, 20);
g.drawString("Time played: " + min + ": " + sec, width / 2 - 50, 20);
g.setColor(Color.BLACK);
g.fillRect(width / 2, height, 1, height);
g.setColor(Color.BLACK);
g.drawLine(width / 2, 0, width / 2, height);
g.setColor(Color.BLACK);
g.drawString("Pong: a game re-made by Camron Warren", 10, height - 10);
g.drawString("Congrat's, you win!", Pwinx, Pwiny);
g.drawString("Press F1 to play again!", Pwinx, Pwiny + 10);
g.drawString("Enemy win's", Ewinx, Ewiny);
g.drawString("Press F1 to play again!", Ewinx, Ewiny + 10);
}
}

Why collision algorithm in my applet game does not work properly ?

This is my game project. It's very simple version of "Flappy Bird" and I have some serious problems with how the collisions algorithm works. I wrote 2 separate code fragments for collision, for wall1 and wall2. The problem begins when the ball is trying to go through a hole because somehow the program is detecting a collision with a wall. I'm almost positive that the collision algorithm was written correctly because I have been checking it all day.
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Random;
import java.util.Timer;
import java.util.logging.Level;
import java.util.logging.Logger;
public class Game extends Applet implements KeyListener, Runnable {
Image bground;
Random generator = new Random();
int r1;
int wall1x;
int wall1y;
int wall1long;
int wall2x;
int wall2y;
int wall2long;
Timer timer;
private Image i;
private Graphics doubleG;
int r2;
int blok_x1 = 800;
int blok_y1;
int blok_x = 800;
int blok_y = 0;
int blok_x_v = 2;
int ballX = 20;
int ballY = 20;
int dx = 0;
int dyclimb = 1;
int dyrise = 1;
double gravity = 3;
double jumptime = 0;
int FPS = 100;
public int tab[];
public boolean grounded = true, up = false;
boolean OVER = false;
#Override
public void init() {
bground = getImage(getCodeBase(), "12.png");
this.setSize(600, 400);
tab = new int[100];
for (int t = 0; t < 100; t++) {
tab[t] = generator.nextInt(380) + 1;
}
addKeyListener(this);
}
#Override
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_LEFT) {
ballX -= 10;
}
if (e.getKeyCode() == KeyEvent.VK_RIGHT) {
ballX += 10;
}
if (e.getKeyCode() == KeyEvent.VK_UP) {
ballY -= 10;
up = true;
}
if (e.getKeyCode() == KeyEvent.VK_DOWN) {
ballY += 10;
}
}
#Override
public void paint(Graphics g) {
g.drawImage(bground, 0, 0, this);
if (OVER == false) {
for (int i = 0; i < 100; i++) {
g.setColor(Color.green);
wall1x = blok_x + i * 400;
wall1y = blok_y;
wall1long = tab[i];
g.fillRect(wall1x, wall1y, 20, wall1long);
g.setColor(Color.green);
wall2x = blok_x1 + i * 400;
wall2y = tab[i] + 60;
wall2long = 400 - tab[i];
g.fillRect(wall2x, wall2y, 20, wall2long);
g.setColor(Color.green);
}
g.setColor(Color.red);
g.fillOval(ballX, ballY, 20, 20);
} else {
g.drawString("GAME OVER", 300, 300);
}
}
#Override
public void update(Graphics g) {
if (i == null) {
g.setColor(Color.green);
i = createImage(this.getSize().width, this.getSize().height);
doubleG = i.getGraphics();
g.setColor(Color.green);
}
doubleG.setColor(getBackground());
g.setColor(Color.green);
doubleG.fillRect(0, 0, this.getSize().width, this.getSize().height);
doubleG.setColor(getForeground());
g.setColor(Color.green);
paint(doubleG);
g.drawImage(i, 0, 0, this);
}
#Override
public void run() {
int time = 10;
while (true) {
if (up == true) {
ballY -= dyclimb;
time--;
} else {
ballY += dyrise;
}
if (time == 0) {
time = 10;
up = false;
}
blok_x--;
blok_x1--;
if (ballX > 600 || ballX < 0 || ballY > 400 || ballY < 0) {
OVER = true;
}
for (int i = 0; i < 100; i++) { // collision algorithm
wall1x = blok_x + i * 400;
wall1y = blok_y;
wall1long = tab[i];
if (ballX + 20 >= wall1x && ballX <= wall1x + 20 && ballY <= wall1y + wall1long && ballY >= wall1x - 20) { //wall1
OVER = true;
}
}
for (int i = 0; i < 100; i++) {
wall2x = blok_x1 + i * 400;
wall2y = tab[i] + 60;
wall2long = 400 - tab[i];
if (ballX + 20 >= wall2x && ballX <= wall2x + 20 && ballY <= wall2y + wall2long && ballY >= wall2x - 20) { //wall2
OVER = true;
}
}
repaint();
try {
Thread.sleep(17);
} catch (InterruptedException ex) {
Logger.getLogger(NewApplet.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
#Override
public void start() {
Thread thread = new Thread(this);
thread.start();
}
#Override
public void keyTyped(KeyEvent e) {
}
#Override
public void keyReleased(KeyEvent e) {
}
}

Use Rectangle class. There's a method called Intersect or Intersection or something like that.
Say you have one object moving. Make a Rectangle to match the object in position(basically an invisible cover for the object).
Do the same things with another object.
When both are to collide, use the intersection method to check on the collision by using the rectangles.
These might help
http://docs.oracle.com/javase/7/docs/api/java/awt/Rectangle.html
Java method to find the rectangle that is the intersection of two rectangles using only left bottom point, width and height?
java.awt.Rectangle. intersection()

Finding cause of jitter in collision detection

I'm looking for help in finding the source of jitter when using collision detection.
I've implemented a java game (using eclipse and slick2d) and have been loosely following this guide:
http://katyscode.wordpress.com/2013/01/18/2d-platform-games-collision-detection-for-dummies
but of course changing bits where necessary to suit my game and java not cpp.
From the research I have done I think the root cause of my jitter is coming from rounding errors.
Despite that being my main suspect, I still haven't been able to identify where it's occurring.
Sorry if the indentation isn't quite right there, had a little trouble using the code block recognition.
Basically I'm creating variables in the class.
In init() I set up most of the resources.
In render() all the drawing takes place. Note the graphics translation so the camera follows the player.
In update I'm of course updating the position of the player according to user input, gravity and friction.
I also call my collision detection from this method.
Collision detection is working on a penetration resolution method.
(Yes I know I'm exhaustively comparing with every single world object. I will be improving my efficiency with AABB's when I have sorted more fundamental problems out. Like jitter!)
My method first calculates how much the player expects to move in each axis, then for each world object it checks for intersection with the players bounding points (floating point values that represent coordinates around the player). It checks this in each direction and uses the result to determine in which axis the collision occurred, if any, so that the appropriate action can be taken.
Sorry it's a put load of code, but it's collision detection after all, which isn't a small thing.
Here is my Play class where all the updating goes on for the game:
package GameFiles;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.newdawn.slick.*;
import org.newdawn.slick.state.*;
import java.awt.Rectangle;
//import java.awt.geom.Rectangle2D;
public class Play extends BasicGameState{
static int tileSize = 32;
File levelMap;
SpriteSheet spriteSheet;
int[][] currentMap;
Image[] groundTiles = new Image[4];
//List<Rectangle2D> levelBounds = new ArrayList<Rectangle2D>();
List<Rectangle> levelBounds = new ArrayList<Rectangle>();
Player player;
float playerX, playerY;
int dir;
float acc, mov, friction, gravity;
float runSpeed;
float maxAcc;
boolean inAir, jumping, keyDown;
boolean exitFlag;
int mapHeight, mapWidth;
float mapX, mapY;
float speedX, speedY;
int worldObjectCount;
int iterations;
public Play(int state){
}
public void init(GameContainer gc, StateBasedGame sbg) throws SlickException{
playerX = Game.scrWidth/2;
playerY = Game.scrHeight - tileSize - tileSize;
player = new Player(playerX, playerY);
levelMap = new File("maps/lvl1.txt");
spriteSheet = new SpriteSheet("res/tiles/tilesets/DungeonCrawlTilesetBW.png", tileSize, tileSize);
try
{
currentMap = readMap(levelMap);
}
catch (IOException e)
{
System.out.println("Array size mismatch when copying arrays.");
e.printStackTrace();
}
levelBounds.clear();
for(int x = 0; x < mapWidth; x++)
{
for(int y = 0; y < mapHeight; y++){
if(currentMap[x][y] == 1){
levelBounds.add(new Rectangle(x*tileSize, Game.scrHeight - mapHeight*tileSize + y*tileSize, tileSize, tileSize));
//levelBounds.add(new Rectangle2D.Float(x*tileSize, Game.scrHeight - mapHeight*tileSize + y*tileSize, tileSize, tileSize));
System.out.println("Added new bounding box: " + (x*tileSize) + ", " + (Game.scrHeight - mapHeight*tileSize + y*tileSize) + ", " + tileSize);
}
}
}
worldObjectCount = levelBounds.size();
System.out.println("World object count: " + worldObjectCount);
groundTiles[0] = spriteSheet.getSubImage(4, 16);
groundTiles[1] = spriteSheet.getSubImage(13, 19);
dir = 1;
acc = 0.0f;
mov = 0.0f;
friction = 4f;
gravity = 4f;
runSpeed = 0.6f;
maxAcc = -1f;
inAir = false;
jumping = false;
keyDown = false;
exitFlag = false;
speedX = 0.0f;
speedY = 0.0f;
iterations = 3;
}
public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException{
//determine cameraX and cameraY
float cameraX, cameraY;
cameraX = player.getX() - Game.scrWidth/2;
cameraY = player.getY() - (Game.scrHeight/2 - tileSize - tileSize);
g.translate(-cameraX, -cameraY);
player.render(g);
for(int x = 0; x < mapWidth; x++)
{
for(int y = 0; y < mapHeight; y++){
if(currentMap[x][y] == 1){
groundTiles[0].draw(x*tileSize, Game.scrHeight - mapHeight*tileSize + y*tileSize);
}
}
}
g.translate(cameraX, cameraY);
}
public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException{
Input input = gc.getInput();
float secondsElapsed = delta/1000.0f;
checkCollisions(secondsElapsed);
player.setX((player.getX() + speedX));
player.setY((player.getY() - speedY));
//check inputs
checkKeyEvents(input);
//slow down / friction
if(!keyDown){
if(mov < 0)
mov += friction * secondsElapsed;
else
mov -= friction * secondsElapsed;
}
speedX = mov;
if (speedX > 0 && speedX < friction * secondsElapsed) speedX = 0;
if (speedX < 0 && speedX > -friction * secondsElapsed) speedX = 0;
//jump or fall
acc -= gravity * secondsElapsed;
if (acc < maxAcc){
acc = maxAcc;
}
speedY = acc;
//exit when exitFlag true
if(exitFlag){
gc.exit();
}
}
public void checkCollisions(float secondsElapsed){
boolean contactX = true, contactYbottom = true, contactYtop = true;
// Keep iterating the contact solver until the maximum number of iterations is reached
// or no collisions are detected
for (int iteration = 0; iteration < iterations && (contactX || contactYbottom || contactYtop); iteration++)
{
float nextMoveX = speedX * secondsElapsed;
float nextMoveY = speedY * secondsElapsed;
contactX = contactYbottom = contactYtop = false;
float projectedMoveX, projectedMoveY, originalMoveX, originalMoveY;
originalMoveX = nextMoveX;
originalMoveY = nextMoveY;
for (int o = 0; o < worldObjectCount && !contactX && !contactYbottom && !contactYtop; o++)
{
for (int dir = 0; dir < 6; dir++)
{
//top, bottom, left, left, right, right.
if (dir == 0 && nextMoveY < 0) continue;
if (dir == 1 && nextMoveY > 0) continue;
if (dir == 2 && nextMoveX > 0) continue;
if (dir == 3 && nextMoveX > 0) continue;
if (dir == 4 && nextMoveX < 0) continue;
if (dir == 5 && nextMoveX < 0) continue;
projectedMoveX = (dir >= 2? nextMoveX : 0);
projectedMoveY = (dir < 2? nextMoveY : 0);
float[][] collisionPoint = player.getBounds();
Rectangle curRect = new Rectangle(levelBounds.get(o).x, levelBounds.get(o).y, levelBounds.get(o).width, levelBounds.get(o).height);
//Rectangle2D curRect = levelBounds.get(o).getBounds2D();
while (curRect.contains(collisionPoint[dir][0] + projectedMoveX, collisionPoint[dir][1] + projectedMoveY)
|| curRect.intersects(collisionPoint[dir][0] + projectedMoveX, collisionPoint[dir][1] + projectedMoveY, 1, 1))
{
if (dir == 0) projectedMoveY += 0.05f; //top collision
if (dir == 1) projectedMoveY -= 0.05f; //bottom collision
if (dir == 2) projectedMoveX += 0.05f; //left collision
if (dir == 3) projectedMoveX += 0.05f;
if (dir == 4) projectedMoveX -= 0.05f; //right collision
if (dir == 5) projectedMoveX -= 0.05f;
}
if (dir >= 2 && dir <= 5)
nextMoveX = projectedMoveX;
if (dir >= 0 && dir <= 1)
nextMoveY = projectedMoveY;
}
if (nextMoveY > originalMoveY && originalMoveY != 0)
{
contactYtop = true;
}
if (nextMoveY < originalMoveY && originalMoveY != 0)
{
contactYbottom = true;
}
if (Math.abs(nextMoveX - originalMoveX) > 0.01f)
{
contactX = true;
}
if (contactX && contactYtop && speedY > 0)
speedY = nextMoveY = 0;
}
if (contactYbottom || contactYtop)
{
player.setY(player.getY() + nextMoveY);
speedY = 0;
acc = 0;
if (contactYbottom)
jumping = false;
}
if (contactX)
{
player.setX(player.getX() + nextMoveX);
speedX = 0;
mov = 0;
}
}//end collisions
}
public int[][] readMap(File level) throws IOException, SlickException{
BufferedReader br = new BufferedReader(new FileReader(level));
mapWidth = Integer.parseInt(br.readLine());
mapHeight = Integer.parseInt(br.readLine());
int[][] map = new int[mapWidth][mapHeight];
for(int row = 0; row < mapHeight; row++)
{
String line = br.readLine();
if(line == null || line.isEmpty())
{
System.out.println("Line is empty or null");
}
else
{
String[] tileValues = line.split(",");
for(int col = 0; col < mapWidth; col++)
{
map[col][row] = Integer.parseInt(tileValues[col]);
}
}
}
br.close();
return map;
}
public void checkKeyEvents(Input input){
//key input events
if(input.isKeyPressed(Input.KEY_DOWN)){
}
if(input.isKeyPressed(Input.KEY_UP)){
if(!jumping){
acc = 1f;
}
jumping = true;
}
if(input.isKeyDown(Input.KEY_LEFT) && !input.isKeyDown(Input.KEY_RIGHT)){
keyDown = false;
mov -= 0.006f;
if (mov < -runSpeed){
mov = -runSpeed;
}
}
if(input.isKeyDown(Input.KEY_RIGHT) && !input.isKeyDown(Input.KEY_LEFT)){
keyDown = false;
mov += 0.006f;
if (mov > runSpeed){
mov = runSpeed;
}
}
if(input.isKeyPressed(Input.KEY_ESCAPE)){
exitFlag = true;
}
}
public int getID(){
return 1;
}
}
Since I can't predict what more info a potential helper might need, I'll leave it at that for now, but of course I can provide any more info when/where needed.
Thanks,
J.

AffineTransform mouse aiming rotation stutter on 90 degrees

EDIT:
OH!!!!!
it works!!!
It seems that at one point it was fixed However the wrong HTML file was opening up so the wrong code was running. I feel stupid, that should have been obvious.
But THANKYOU!!!
Its so awesome to actually get some help with this stuff. whenever i ask for some help anywhere else or even ask my teacher im usually ignored or get useless advice.
(end of edit)
Im making a game for my final project in a java class. I just got mouse aiming to work using AffineTransform, however When ever the player object rotates to 90 degrees(or a multiple of it), it does this weird stutter thing.
Heres the code im specifically concerned with.
g2.drawImage(img, x_pos,y_pos,this);
AffineTransform oldTransform = g2.getTransform();
g2.setTransform(AffineTransform.getRotateInstance(radAngle,x_pos + (img.getWidth() / 2),y_pos+(img.getHeight() / 2)));
Could someone please help me figure out how to fix this? my project is due tomorrow so im slim on time.
Here are the images i use
Heres the code.
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.lang.Math.*;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import javax.imageio.ImageIO;
import java.io.*;
import java.net.URL;
public class Game extends Applet implements Runnable, KeyListener, MouseMotionListener
{
int x_pos = 250;
int y_pos = 250;
float x_speed = 0;
float y_speed = 0;
int radius = 20;
int appletsize_x = 800;
int appletsize_y = 600;
int x = 0;
int y = 0;
int up = 0;
int down= 0;
int left = 0;
int right= 0;
int mouse_x;
int mouse_y;
int tracking_angle;
private BufferedImage dbImage;
private Graphics dbg;
private Image curser;
BufferedImage img = null;
BufferedImage round = null;
AffineTransform at = new AffineTransform();
double radAngle;
public void init()
{
try {
URL url = new URL(getCodeBase(), "Player.png");
img = ImageIO.read(url);
} catch (IOException e) {System.out.println("Cant find player image");
}
try {
URL url = new URL(getCodeBase(), "round.png");
round = ImageIO.read(url);}
catch (IOException e) {}
setBackground (Color.blue);
setFocusable(true);
addKeyListener( this );
curser = getImage(getDocumentBase(), "mouse.png");
addMouseMotionListener(this);
try
{
Toolkit tk = Toolkit.getDefaultToolkit();
Cursor c = tk.createCustomCursor( curser,new Point( 5, 5 ), "Inodrop" );
setCursor( c );
}
catch( IndexOutOfBoundsException x )
{}
}
public class Shot {
int x_loc = -50;
int y_loc = -50;
public Shot(){
if(x_loc < 0){
x_loc = x_pos;}
if(y_loc < 0){
y_loc = y_pos;}
paint(dbg);}
public void paint(Graphics g){
System.out.println("hi");
Graphics2D g2d = (Graphics2D)g;
Graphics g2D = round.getGraphics();
g2d.drawImage(round, x_loc,y_loc,null);}}
public void start ()
{
Thread th = new Thread (this);
th.start ();
}
public void stop()
{
}
public void destroy()
{
}
public void mouseMoved(MouseEvent e){
//get position of mouse
mouse_x = e.getX();
mouse_y = e.getY();
double x_dist = mouse_x - x_pos;
double y_dist = mouse_y - y_pos;
if (x_dist == 0) {
radAngle = 90;
} else if ((x_dist == 0) && (y_dist == 0)) {
radAngle = 0;
} else {
radAngle = Math.atan(y_dist / x_dist);
}
tracking_angle = (int)(Math.sin(radAngle) * 100);
//System.out.println(Math.toRadians(tracking_angle));
}
public void mouseDragged(MouseEvent e){}
public void keyReleased(KeyEvent r)
{
//Left
if (r.getKeyCode() == 39 ){
x = 0;
left = 0;
Shot shoot = new Shot();
}
//Right
if (r.getKeyCode() == 37){
x = 0;
right = 0;
}
//Down
if (r.getKeyCode() == 38 ) {
//y_speed = 0;
down = 0;}
//Up
if (r.getKeyCode() == 40 ) {
//y_speed = 0;
up = 0;}
//move();
}
public void keyTyped(KeyEvent t){}
public void keyPressed(KeyEvent r){
//Left
if (r.getKeyCode() == 39 ){
left = 1;}
//Right
if (r.getKeyCode() == 37){
right = 1;}
//Down
if (r.getKeyCode() == 38 ) {
down = 1;}
//Up
if (r.getKeyCode() == 40 ) {
up = 1;}
//move();
}
public void run ()
{
Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
while (true)
{
if (left == 1 && x_speed < 11){
x = 0;
x_speed += 1;
}
//Right
if (right == 1 && x_speed > -11){
x = 0;
x_speed -= 1;
}
//Down
if (down == 1 && y_speed > -11) {
y_speed -= 1;}
//Up
if (up == 1 && y_speed < 11) {
y_speed += 1;}
if( x == 0 && x_speed > 0){
x_speed -=.2;}
if( x == 0 && x_speed < 0){
x_speed +=.2;}
if( y == 0 && y_speed > 0){
y_speed -=.2;}
if( y == 0 && y_speed < 0){
y_speed +=.2;}
if (x_pos > appletsize_x - radius && x_speed > 0)
{
x_pos = radius;
}
else if (x_pos < radius && x_speed < 0)
{
x_pos = appletsize_x + radius ;
}
//System.out.println(y_pos);
if (y_pos > appletsize_y - radius && y_speed > 0){
y_speed = 0;}
else if ( y_pos < radius && y_speed < 0 ){
y_speed = 0;}
x_pos += (int)x_speed;
y_pos += (int)y_speed;
repaint();
try
{
Thread.sleep (15);
}
catch (InterruptedException ex)
{
}
Thread.currentThread().setPriority(Thread.MAX_PRIORITY);
}
}
public void update (Graphics g)
{
if (dbImage == null)
{
dbImage = new BufferedImage(this.getSize().width, this.getSize().height, BufferedImage.TYPE_INT_RGB);
dbg = dbImage.getGraphics ();
}
dbg.setColor (getBackground ());
dbg.fillRect (0, 0, this.getSize().width, this.getSize().height);
dbg.setColor (getForeground());
paint (dbg);
g.drawImage (dbImage, 0, 0, this);
}
public void paint (Graphics g)
{
//g = img.getGraphics();
Graphics2D g2 = (Graphics2D)g;
g2.drawImage(img, x_pos,y_pos,this);
AffineTransform oldTransform = g2.getTransform();
g2.setTransform(AffineTransform.getRotateInstance(radAngle,x_pos + (img.getWidth() / 2),y_pos+(img.getHeight() / 2)));
System.out.println(img.getWidth());
}
}

double x_dist = mouse_x - x_pos;
double y_dist = mouse_y - y_pos;
double radAngle = Math.atan(y_dist / x_dist);
tracking_angle = (int) (Math.sin(radAngle) * 100);
I think the error is somewhere in this part. You're definitely dividing by 0 here if x_dist is 0. Better do something like this:
if (x_dist == 0) {
radAngle = 90;
} else {
radAngle = Math.atan(y_dist / x_dist);
}
EDIT: Additionally, I think you should throw away the tracking_angle line completely and just do this later:
g2.setTransform(AffineTransform.getRotateInstance(rad_angle,
x_pos + (img.getWidth() / 2),y_pos+(img.getHeight() / 2)));
Also you should change that new code you posted in the comments:
double radAngle;
if (x_dist == 0) {
radAngle = 90;
} else if (y_dist == 0) {
radAngle = 90;
} else {
radAngle = Math.atan(y_dist / x_dist);
}
You are solving this for x_dist == 0 or y_dist == 0 (which isn't an edge case), but not for the case that both are 0 where you simply can't compute an angle and I think you should go with 0. So use this instead:
double radAngle;
if (x_dist == 0) {
radAngle = 90;
} else if ((x_dist == 0) && (y_dist == 0)) {
radAngle = 0;
} else {
radAngle = Math.atan(y_dist / x_dist);
}
Also, as trashgod pointed out, you're ignoring exceptions, for example:
try {
URL url = new URL(getCodeBase(), "Player.png");
img = ImageIO.read(url);
} catch (IOException e) {
}
You should not just continue in such cases but f.e. display an useful error message and quit the program, in any case do something instead of just catching the exception and continue as if nothing happened.

I haven't tested this, but try:
double radAngle = Math.atan2(y_dist, x_dist);