im really new in Java. I just need to explain how to declare 2D array of objects, i have something like:
package breakout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.Color;
import java.awt.Font;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JOptionPane;
public class Breakout extends JPanel {
public class Ball {
private
int x = 400;
int y = 300;
int speed = 2;
int dirx = 1;
int diry = -1;
public
void bounce(int px, int py, int lx, int ly) {
if ((x + 10 >= 800 && dirx == 1) || (x <= 0 && dirx == -1))
dirx *= -1;
if (y <= 0 && diry == -1)
diry *= -1;
if (y + 10 >= py && y <= py + ly && diry == 1 && x + 10 >= px && x <= px + lx)
diry *= -1;
}
int getX() {
return x;
}
int getY() {
return y;
}
void setDirx(){
dirx *= -1;
}
void setDiry(){
diry *= -1;
}
void move() {
x += speed*dirx;
y += speed*diry;
}
void paint(Graphics2D g) {
g.fillOval(x,y,10,10);
}
}
public class Paddle {
private
int x = 400;
int y = 520;
int width = 100;
int height = 6;
int speed = 6;
int dirL = 0;
int dirR = 0;
public
void move() {
x -= speed*dirL;
x += speed*dirR;
}
void stop() {
if (x <= 0)
x = 0;
if (x + width >= 800)
x = 800 - width;
}
int getX() {
return x;
}
int getY() {
return y;
}
int getWidth() {
return width;
}
int getHeight() {
return height;
}
void paint(Graphics2D g) {
g.fillRect(x,y,width,height);
}
public void keyReleased(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_LEFT)
dirL = 0;
else if (e.getKeyCode() == KeyEvent.VK_RIGHT)
dirR = 0;
else {
dirL = 0;
dirR = 0;
}
}
public void keyPressed(KeyEvent e) {
switch(e.getKeyCode()) {
case KeyEvent.VK_LEFT:
dirL = 1;
break;
case KeyEvent.VK_RIGHT:
dirR = 1;
break;
}
}
}
public class Brick {
private
int x;
int y;
int width;
int height;
boolean alive;
boolean inX = false,inY = false;
public
void setUpBrick(int px, int py, int w, int h, boolean al) {
x = px;
y = py;
width = w;
height = h;
alive = al;
}
void setAlive(boolean alive) {
this.alive = alive;
}
void paint(Graphics2D g) {
if (alive)
g.fillRect(x,y,width,height);
}
boolean collision(int bx, int by) {
if (alive) {
if (bx + 10 >= x && bx <= x + width && by + 10 >= y && by <= y + height) {
setAlive(false);
return true;
} else return false;
}
else return false;
}
void inAreaX(int bx) {
if (bx + 10 >= x && bx <= x + width) {
System.out.println("inAreaX");
inX = true;
} else {
inX = false;
}
}
void inAreaY(int by) {
if (by + 10 >= y && by <= y + height) {
System.out.println("inAreaY");
inY = true;
} else {
inY = false;
}
}
boolean isInAreaX () {
if (inX)
return true;
else return false;
}
boolean isInAreaY () {
if (inY)
return true;
else return false;
}
}
Ball ball = new Ball();
Paddle paddle = new Paddle();
Brick[][] brick = new Brick[8][4];
for (int i = 0; i < 8; i++) {
for (int j = 0; j < 4; j++) {
brick[i][j].setUpBrick(j * 101, i * 51, 100, 50, true);
}
}
void bounce() {
for (int i = 0; i < 8; i++) {
for (int j = 0; j < 4; j++) {
brick[i][j].inAreaX(ball.getX());
brick[i][j].inAreaY(ball.getY());
if (brick[i][j].collision(ball.getX(), ball.getY())) {
if (brick[i][j].isInAreaX()) {
ball.setDiry();
} else if (brick[i][j].isInAreaY()) {
ball.setDirx();
}
}
}
}
}
void move() {
ball.bounce(paddle.getX(), paddle.getY(), paddle.getWidth(),paddle.getHeight());
ball.move();
paddle.move();
paddle.stop();
bounce();
}
public Breakout() {
addKeyListener(new KeyListener() {
public void keyTyped(KeyEvent e) {
}
public void keyReleased(KeyEvent e) {
paddle.keyReleased(e);
}
public void keyPressed(KeyEvent e) {
paddle.keyPressed(e);
}
});
setFocusable(true);
}
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(Color.RED);
ball.paint(g2d);
g2d.setColor(Color.BLACK);
paddle.paint(g2d);
g2d.setColor(Color.ORANGE);
for (int i = 0; i < 8; i++)
for (int j = 0; j < 4; j++)
brick[i][j].paint(g2d);
}
public static void main(String[] args) throws InterruptedException {
JFrame window = new JFrame("Tennis");
Breakout game = new Breakout();
window.add(game);
window.setSize(800,600);
window.setVisible(true);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
while (true) {
game.move();
game.repaint();
Thread.sleep(10);
}
}
i need to inicialize 2d array of brick, but it says that first for is unexpected token. How to write it? Thank you.
Unless if I have miscounted your opening and closing braces, your for loop is not inside any method, it's directly in your class body. That's why you're getting unexpected token. You will probably want to move it into the Breakout constructor.
In order to create a 2D array in Java, you can create such an array like this:
Object testArray = new Object[10][10];
This array is now a 10*10 array with memory allocated for 100 Object references.
You can create pointers two Objects with a double for-loop:
for (int i = 0; i < testArray.length(); i++) {
for (int j = 0; j < testArray.length; j++) {
testArray[i][j] = Object; //here you input the objects that you want to point to
}
}
Move the logic from setUpBrick to a constructor.
public class Brick {
private int x;
private int y;
private int width;
private int height;
private boolean alive;
private boolean inX = false,inY = false;
public Brick(int px, int py, int w, int h, boolean al) {
x = px;
y = py;
width = w;
height = h;
alive = al;
}
...
}
Then change
brick[i][j].setUpBrick(j * 101, i * 51, 100, 50, true);
to
brick[i][j] = new Brick(j*101, i*51, 100, 50, true);
Also note that access modifiers don't apply to a whole section of your class. In your example,
private
int x;
int y;
int width;
int height;
boolean alive;
boolean inX = false,inY = false;
means that only x is going to be private. The rest of the members will get the default access modifier.
One more tip. A couple of your methods can be simplified.
boolean isInAreaY () {
if (inY)
return true;
else return false;
}
can be written as:
boolean isInAreaY() {
return inY;
}
Related
I created a very simple shooting game utilizing JPanel as shown in the code below. I also wanted to experiment with rotating the game and trying it out. I have one issue, where the game I was able to successfully rotate the game but the dimension seems to cut out, and I have to set each position of the enemy and myself to the rotated position.
I was wondering if there was a way to rotate the result as a whole, instead of simply rotating the shape so that the position of the ship and the missiles would also rotate all at once.
Edited code: added three lives to the player and tried implementing heart image with BufferedImage.
public class game extends JFrame{
public game(){
}
public static void main(String[] args){
new game();
}
public class MyJPanel extends JPanel implements ActionListener, MouseListener,
MouseMotionListener,KeyListener
{
//variables for player
int my_x;
int player_width,player_height;
private int lives = 3;
int heart_width, heart_height;
//variables for player's missiles
int my_missile_x, my_missile_y;
int missile_flag;
public static final int MY_Y = 600;
//variables for enemies' missiles
int e_missile_flag[];
int e_missile_x[];
int e_missile_y[];
int e_missile_move[];
Image image,image2;
Timer timer;
private BufferedImage heart;
public MyJPanel(){
missile_flag = 0;
/*** initialize enemies' info ***/
ImageIcon icon2 = new ImageIcon("enemy.jpg");
image2 = icon2.getImage();
enemy_width = image2.getWidth(this);
enemy_height = image2.getHeight(this);
try {
heart = ImageIO.read(getClass().getResource("heart.jpg"));
}catch(IOException e) {
}
heart_width = heart.getWidth(this);
heart_height = heart.getHeight(this);
n = 14; //number of enemies
enemy_x = new int[n];
enemy_y = new int[n];
enemy_move = new int[n];
enemy_alive = new int[n];
int distance = 40;
e_missile_flag = new int[n];
e_missile_x = new int[n];
e_missile_y = new int[n];
e_missile_move = new int[n];
// place enemies in 7x2
for (int i = 0; i < 7; i++) {
enemy_x[i] = (enemy_width + distance) * i + 50;
enemy_y[i] = 50;
}
for (int i = 7; i < n; i++) {
enemy_x[i] = (enemy_width + distance) * (i - 5) + 50;
enemy_y[i] = 100;
}
for (int i = 0; i < n; i++) {
enemy_alive[i] = 1; //all alive
enemy_move[i] = -10; //moves to left
}
for (int i = 0; i < n; i++) {
e_missile_flag[i] = 0;
e_missile_x[i] = 0;
e_missile_y[i] = 0;
e_missile_move[i] = 7 + n%3;
}
/*** setup system ***/
setBackground(Color.black);
setFocusable(true);
addMouseListener(this);
addMouseMotionListener(this);
addKeyListener(this);
timer = new Timer(50, this);
timer.start();
}
private void updateEnemiesPosition(){
//update enemies' position
Dimension dim = getSize();
for (int i = 0; i < n; i++) {
enemy_x[i] += enemy_move[i];
if ((enemy_x[i] < 0) || (enemy_x[i] > (dim.width - enemy_width))) {
enemy_move[i] = -enemy_move[i];
}
}
}
private void updateMyPosition() {
if(my_x < 0) {
my_x = 800;
}
if(my_x > 800) {
my_x = 0;
}
}
private void activateMyMissile(){
//shoot a missile
if(missile_flag == 0){
my_missile_x = my_x + player_width / 2;
my_missile_y = MY_Y; //MY_Y=400
missile_flag = 1;
}
}
private void updateMyMissile(){
//update missile position if alive
if (missile_flag == 1) {
my_missile_y -= 15;
if (0 > my_missile_y) {
missile_flag = 0;
}
}
}
private void activateEnemiesMissile(){
//activate enemies' missile if enemy is alive and its missile is not alive
for(int i = 0; i < n; i++){
if (enemy_alive[i] == 1 && e_missile_flag[i] == 0) {
e_missile_x[i] = enemy_x[i] + enemy_width/2;
e_missile_y[i] = enemy_y[i];
e_missile_flag[i] = 1;
}
}
}
private void updateEnemiesMissile(){
//update enemies' missile position if alive
Dimension dim = getSize();
for(int i = 0; i < n; i++){
if (e_missile_flag[i] == 1) {
e_missile_y[i] += e_missile_move[i];
if (e_missile_y[i] > dim.height) {
e_missile_flag[i] = 0;
}
}
}
}
private void checkHitToEnemy(){
for(int i = 0; i < n; i++){
if(missile_flag == 1 && enemy_alive[i] == 1){
if(
my_missile_x > enemy_x[i] &&
my_missile_x < (enemy_x[i] + enemy_width) &&
my_missile_y > enemy_y[i] &&
my_missile_y < (enemy_y[i] + enemy_height)
){
//hit
missile_flag = 0;
enemy_alive[i] = 0;
}
}
}
}
private boolean checkClear(){
int cnt = 0;
for(int i = 0; i < n; i++){
if(enemy_alive[i] == 0) cnt++;
}
return (n == cnt);
}
if(lives>0) {
int x = 0;
int y = getHeight()- heart.getHeight();
for(int index = 0; index < lives; index++) {
g.drawImage(heart, x, y, this);
x += heart.getWidth();
}
}
g2d.dispose();
}
public void actionPerformed(ActionEvent e){
if (e.getSource() == timer) {
updateEnemiesPosition();
updateMyPosition();
updateMyMissile();
updateEnemiesMissile();
activateEnemiesMissile();
if(checkHitToPlayer()){
System.out.println("===== Game Over =====");
System.exit(0);
}
checkHitToEnemy();
if(checkClear()){
System.out.println("===== Game Clear =====");
System.exit(0);
}
repaint();
}
}
public void mouseClicked(MouseEvent me)
{ }
public void mousePressed(MouseEvent me)
{
activateMyMissile();
}
public void mouseReleased(MouseEvent me)
{ }
public void mouseExited(MouseEvent me)
{ }
public void mouseEntered(MouseEvent me)
{ }
public void mouseMoved(MouseEvent me)
{ }
public void mouseDragged(MouseEvent me)
{ }
public void keyReleased(KeyEvent e){
}
public void keyTyped(KeyEvent e){
}
}
}
The original size of the component is going to be less then 800x500 (I say less then, because the actual size will be 800x500 - the frame decorations - this is why you should be setting the size of the window directly).
When you rotate it 90 degrees, it becomes (less then) 500x800. So, no, there's no "easy" way to resolve this, without making the game square.
I added...
g2d.setColor(Color.DARK_GRAY);
g2d.fillRect(0, 0, getWidth(), getHeight());
after the rotation, which highlights the issue.
To do this, you should override getPreferredSize of the JPanel and the call pack on the frame. This will ensure that that game canvas is sized to it's preferred size and the window decorations are then packed around it.
import java.awt.Color;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Lec12 extends JFrame {
public Lec12() {
setTitle("Game Example");
setDefaultCloseOperation(EXIT_ON_CLOSE);
MyJPanel myJPanel = new MyJPanel();
Container c = getContentPane();
c.add(myJPanel);
pack();
setVisible(true);
}
public static void main(String[] args) {
new Lec12();
}
public class MyJPanel extends JPanel implements ActionListener, MouseListener,
MouseMotionListener, KeyListener {
//variables for player
int my_x;
int player_width, player_height;
//variables for enemies
int enemy_width, enemy_height;
int n;
int enemy_x[];
int enemy_y[];
int enemy_move[];
int enemy_alive[];
//variables for player's missiles
int my_missile_x, my_missile_y;
int missile_flag;
public static final int MY_Y = 400;
//variables for enemies' missiles
int e_missile_flag[];
int e_missile_x[];
int e_missile_y[];
int e_missile_move[];
Image image, image2;
Timer timer;
public MyJPanel() {
/**
* * initialize player's info **
*/
my_x = 250;
ImageIcon icon = new ImageIcon("player.jpg");
image = icon.getImage();
player_width = image.getWidth(this);
player_height = image.getHeight(this);
missile_flag = 0;
/**
* * initialize enemies' info **
*/
ImageIcon icon2 = new ImageIcon("enemy.jpg");
image2 = icon2.getImage();
enemy_width = image2.getWidth(this);
enemy_height = image2.getHeight(this);
n = 14; //number of enemies
enemy_x = new int[n];
enemy_y = new int[n];
enemy_move = new int[n];
enemy_alive = new int[n];
int distance = 40;
e_missile_flag = new int[n];
e_missile_x = new int[n];
e_missile_y = new int[n];
e_missile_move = new int[n];
// place enemies in 7x2
for (int i = 0; i < 7; i++) {
enemy_x[i] = (enemy_width + distance) * i + 50;
enemy_y[i] = 50;
}
for (int i = 7; i < n; i++) {
enemy_x[i] = (enemy_width + distance) * (i - 5) + 50;
enemy_y[i] = 100;
}
for (int i = 0; i < n; i++) {
enemy_alive[i] = 1; //all alive
enemy_move[i] = -10; //moves to left
}
for (int i = 0; i < n; i++) {
e_missile_flag[i] = 0;
e_missile_x[i] = 0;
e_missile_y[i] = 0;
e_missile_move[i] = 7 + n % 3;
}
/**
* * setup system **
*/
setBackground(Color.black);
setFocusable(true);
addMouseListener(this);
addMouseMotionListener(this);
addKeyListener(this);
timer = new Timer(50, this);
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(800, 800);
}
private void updateEnemiesPosition() {
//update enemies' position
Dimension dim = getSize();
for (int i = 0; i < n; i++) {
enemy_x[i] += enemy_move[i];
if ((enemy_x[i] < 0) || (enemy_x[i] > (dim.width - enemy_width))) {
enemy_move[i] = -enemy_move[i];
}
}
}
private void updateMyPosition() {
if (my_x < 0) {
my_x = 800;
}
if (my_x > 800) {
my_x = 0;
}
}
private void activateMyMissile() {
//shoot a missile
if (missile_flag == 0) {
my_missile_x = my_x + player_width / 2;
my_missile_y = MY_Y; //MY_Y=400
missile_flag = 1;
}
}
private void updateMyMissile() {
//update missile position if alive
if (missile_flag == 1) {
my_missile_y -= 15;
if (0 > my_missile_y) {
missile_flag = 0;
}
}
}
private void activateEnemiesMissile() {
//activate enemies' missile if enemy is alive and its missile is not alive
for (int i = 0; i < n; i++) {
if (enemy_alive[i] == 1 && e_missile_flag[i] == 0) {
e_missile_x[i] = enemy_x[i] + enemy_width / 2;
e_missile_y[i] = enemy_y[i];
e_missile_flag[i] = 1;
}
}
}
private void updateEnemiesMissile() {
//update enemies' missile position if alive
Dimension dim = getSize();
for (int i = 0; i < n; i++) {
if (e_missile_flag[i] == 1) {
e_missile_y[i] += e_missile_move[i];
if (e_missile_y[i] > dim.height) {
e_missile_flag[i] = 0;
}
}
}
}
private void checkHitToEnemy() {
for (int i = 0; i < n; i++) {
if (missile_flag == 1 && enemy_alive[i] == 1) {
if (my_missile_x > enemy_x[i]
&& my_missile_x < (enemy_x[i] + enemy_width)
&& my_missile_y > enemy_y[i]
&& my_missile_y < (enemy_y[i] + enemy_height)) {
//hit
missile_flag = 0;
enemy_alive[i] = 0;
}
}
}
}
private boolean checkHitToPlayer() {
for (int i = 0; i < n; i++) {
if (e_missile_flag[i] == 1) {
if (e_missile_x[i] > my_x
&& e_missile_x[i] < (my_x + player_width)
&& e_missile_y[i] > MY_Y
&& e_missile_y[i] < (MY_Y + player_height)) {
e_missile_flag[i] = 0;
return true;
}
}
}
return false;
}
private boolean checkClear() {
int cnt = 0;
for (int i = 0; i < n; i++) {
if (enemy_alive[i] == 0) {
cnt++;
}
}
return (n == cnt);
}
public void paintComponent(Graphics g) {
super.paintComponent(g); //reset graphics
Graphics2D g2d = (Graphics2D) g.create();
System.out.println(getWidth() + "x" + getHeight());
int w2 = getWidth() / 2;
int h2 = getHeight() / 2;
g2d.rotate(-Math.PI / 2, w2, h2);
g2d.setColor(Color.DARK_GRAY);
g2d.fillRect(0, 0, getWidth(), getHeight());
//draw player
g2d.setColor(Color.BLUE);
g2d.fillRect(my_x, 400, 10, 10);
// g.drawImage(image, my_x, 400, this);
//draw enemies
for (int i = 0; i < n; i++) {
if (enemy_alive[i] == 1) {
g2d.setColor(Color.RED);
g2d.fillRect(enemy_x[i], enemy_y[i], 10, 10);
// g.drawImage(image2, enemy_x[i], enemy_y[i], this);
}
}
//draw players missiles
if (missile_flag == 1) {
g2d.setColor(Color.white);
g2d.fillRect(my_missile_x, my_missile_y, 2, 5);
}
//draw enemies' missiles
for (int i = 0; i < n; i++) {
if (e_missile_flag[i] == 1) {
g2d.setColor(Color.white);
g2d.fillRect(e_missile_x[i], e_missile_y[i], 2, 5);
}
}
g2d.dispose();
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == timer) {
updateEnemiesPosition();
updateMyPosition();
updateMyMissile();
updateEnemiesMissile();
activateEnemiesMissile();
if (checkHitToPlayer()) {
System.out.println("===== Game Over =====");
System.exit(0);
}
checkHitToEnemy();
if (checkClear()) {
System.out.println("===== Game Clear =====");
System.exit(0);
}
repaint();
}
}
public void mouseClicked(MouseEvent me) {
}
public void mousePressed(MouseEvent me) {
activateMyMissile();
}
public void mouseReleased(MouseEvent me) {
}
public void mouseExited(MouseEvent me) {
}
public void mouseEntered(MouseEvent me) {
}
public void mouseMoved(MouseEvent me) {
}
public void mouseDragged(MouseEvent me) {
}
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
switch (key) {
case KeyEvent.VK_S:
my_x = my_x + 10;
break;
case KeyEvent.VK_W:
my_x = my_x - 10;
break;
case KeyEvent.VK_DOWN:
my_x = my_x + 10;
break;
case KeyEvent.VK_UP:
my_x = my_x - 10;
break;
case KeyEvent.VK_X:
if (missile_flag == 0) {
my_missile_x = my_x + player_width / 2;
my_missile_y = MY_Y;// MY_Y=400
missile_flag = 1;
}
break;
}
}
public void keyReleased(KeyEvent e) {
}
public void keyTyped(KeyEvent e) {
}
}
}
Also, beware, transformations of this nature are accumulative. You should, instead, take a snapshot of the Graphics context and dispose of it once you're done (see the above for an example).
Also, have look at How to Use Key Bindings as it will help resolve the focus issues related to KeyListener
I am a beginner at Java programming. I am trying to create a checkers game in which players can move their own pieces. The problem is that when one piece is moved, all of them move it. I would really appreciate some help. Thanks!!!
Main Class
package Checkers_Own;
import resources.DrawingBoard;
import resources.Timer;
public class Game {
public static void main(String[] args) {
Board[][] boards = new Board[8][8];
DrawingBoard board = new DrawingBoard(840, 640);
Timer timer = new Timer();
for(int i = 0; i < 8; i++){
for(int j = 0; j < 8; j++){
if(i % 2 == 1){
if(j % 2 == 1)boards[i][j] = new Board(true, i, j);
else boards[i][j] = new Board(false, i, j);
}
else if(i % 2 == 0){
if(j % 2 == 1)boards[i][j] = new Board(false, i, j);
else boards[i][j] = new Board(true, i, j);
}
}
}
for(int i = 5; i < 8; i++) for(int j = 0; j < 8; j++) if(!boards[j][i].isWhite) PiecesManager.add1(new Pieces(true, j, i));
for(int i = 0; i < 8; i++) for(int j = 0; j < 3; j++) if(!boards[i][j].isWhite) PiecesManager.add2(new Pieces(false, i, j));
PiecesManager.properties(board);
while(true){
board.clear();
for(int i = 0; i < 8; i++) for(int j = 0; j < 8; j++) boards[i][j].draw(board);
PiecesManager.draw(board);
PiecesManager.move();
board.repaint();
timer.pause(30);
}
}
}
Pieces
package Checkers;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import resources.DrawingBoard;
public class Pieces implements MouseMotionListener, MouseListener{
boolean side1, changed = false;
int x, y, lastX, lastY, dx, dy;
public Pieces(boolean side1, int x, int y){
this.side1 = side1;
this.x = (x * 80) + 10;
this.y = (y * 80) + 10;
}
public void draw(DrawingBoard board){
Graphics2D g = board.getCanvas();
if(side1){
g.setColor(Color.blue);
g.fillOval(x, y, 60, 60);
}
else{
g.setColor(Color.red);
g.fillOval(x, y, 60, 60);
}
}
public Pieces moved(){
if(changed){
return this;
}
return null;
}
public void move(){
if(changed){
x += dx;
y += dy;
}
changed = false;
}
public void mousePressed(MouseEvent e) {
lastX = e.getX();
lastY = e.getY();
}
public void mouseDragged(MouseEvent e) {
int mx = e.getX();
dx = mx - lastX;
lastX = mx;
int my = e.getY();
dy = my - lastY;
lastY = my;
if(mx != x || my != y) changed = true;
}
public void mouseMoved(MouseEvent e) {}
public void mouseClicked(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
}
Board
package Checkers_Own;
import java.awt.Color;
import java.awt.Graphics2D;
import resources.DrawingBoard;
public class Board {
boolean isWhite;
private int x, y;
public Board(boolean isWhite, int x, int y){
this.isWhite = isWhite;
this.x = x * 80;
this.y = y * 80;
}
public void draw(DrawingBoard board){
Graphics2D g = board.getCanvas();
if(isWhite){
g.setColor(Color.white);
g.fillRect(x, y, 80, 80);
}
else{
g.setColor(Color.black);
g.fillRect(x, y, 80, 80);
}
}
}
PiecesManager
package Checkers_Own;
import resources.DrawingBoard;
public class PiecesManager {
private static int size1, size2;
private static Pieces[] p1 = new Pieces[12];
private static Pieces[] p2 = new Pieces[12];
public static void draw(DrawingBoard board){
for(int i = 0; i < size1; i++) p1[i].draw(board);
for(int i = 0; i < size2; i++) p2[i].draw(board);
}
public static void move(){
for(int i = 0; i < p1.length; i++) if(p1[i].moved() == p1[i]) p1[i].move();
for(int i = 0; i < p2.length; i++) if(p2[i].moved() == p2[i]) p2[i].move();
}
public static void add1(Pieces piece){
p1[size1] = piece;
size1 ++;
}
public static void add2(Pieces piece){
p2[size2] = piece;
size2 ++;
}
public static void properties(DrawingBoard board){
for(int i = 0; i < p1.length; i++){
board.addMouseListener(p1[i]);
board.addMouseMotionListener(p1[i]);
}
for(int i = 0; i < p2.length; i++){
board.addMouseListener(p2[i]);
board.addMouseMotionListener(p2[i]);
}
}
}
I can draw lines, but the thickness is constant. I need to change the thickness when I press a button. In this example pressing 'w' will increase the thickness and pressing 'q' will decrease the thickness.
import java.awt.*;
import java.applet.*;
import sun.swing.SwingUtilities2;
public class draw extends Applet {
boolean isBlack = true;
Point startPoint;
Point points[];
int numPoints;
boolean drawing;
int n = 0;
#Override
public void init() {
startPoint = new Point(0, 0);
points = new Point[10000];
drawing = false;
resize(300, 400);
}
#Override
public void paint(Graphics g) {
if (n == 0) {
g.setColor(Color.red);
}
if (n == 1) {
g.setColor(Color.green);
}
if (n == 2) {
g.setColor(Color.blue);
}
if (n == 3) {
g.setColor(Color.black);
}
int oldX = startPoint.x;
int oldY = startPoint.y;
for (int i = 0; i < numPoints; ++i) {
g.drawLine(oldX, oldY, points[i].x, points[i].y);
oldX = points[i].x;
oldY = points[i].y;
}
}
#Override
public boolean keyDown(Event evt, int key) {
char keyChar = (char) key;
if (keyChar == 'w') {
n++;
if (n > 3) {
n = 0;
}
}
if (keyChar == 'q') {
n--;
if (n < 0) {
n = 3;
}
}
return true;
}
#Override
public boolean mouseDown(Event evt, int x, int y) {
if (!drawing) {
startPoint.x = x;
startPoint.y = y;
}
drawing = !drawing;
return true;
}
#Override
public boolean mouseMove(Event evt, int x, int y) {
if ((drawing) && (numPoints < 10000)) {
points[numPoints] = new Point(x, y);
++numPoints;
repaint();
}
return true;
}
}
But I can't calculate the thickness of the line, how would I do that?
You need to use the Graphics2D package:
Graphics2D g2 = SwingUtilities2.getGraphics2D(g);
g2.setStroke(new BasicStroke(n));
g2.drawLine(oldX, oldY, points[i].x, points[i].y);
I think that's is all you need. It's been awhile since I've worked with it.
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()
I am designing a simple java 2d game.where an aircraft shoots missiles and they hit alien ships.(pictures are attached for a better understanding).
Now I need to detect when the missile hits the alien ship. So as to count the number of total hits. I used the rectangle1.intersects(rec2)method, but instead of giving me an integer 1 as the answer (after the boolean of course) it gives me some funny answer. I guess like how much the two rectangles intersect...
Also when adding new aliens in an arraylist I use the following: I add new aliens every two seconds, but this slows down the game very much.
So please guide me on these two issues.
There is a game class (contains the main frame), board class (the panel on which I draw) alient, missile and craft class. Below I am giving the the actionPerformed() of the panel class which gets called by a timer every 2ms (the rest of the code is below).
///CODE TO BE FOCUSED ON
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
import javax.swing.*;
public class game extends JFrame {
static long z;
game()
{
add(new board());
setBounds(0, 0, 500, 500);
setVisible(true);
setLayout(null);
setLocationRelativeTo(null);
setTitle("\t\t...................::::~~~~'S GAME~~~~:::::...............");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
public static void main(String[] args) {
new game();
z = System.currentTimeMillis();
}
}
class board extends JPanel implements ActionListener
{
Timer t = new Timer(5, this);
public ArrayList alien_list;
craft craft_list = new craft();
Label l = new Label();
int total_hits = 0;
public board() {
setFocusable(true);
setLayout(null);
setDoubleBuffered(true);
setBackground(Color.BLACK);
addKeyListener(craft_list);
l.setBounds(0, 0, 150, 30);
l.setBackground(Color.GREEN);
add(l);
t.start();
alien_list = new ArrayList();
alien_list.add(new alien(0, 100));
alien_list.add(new alien(0, 150));
alien_list.add(new alien(0, 200));
}
public void paint(Graphics g) {
super.paint(g);
Graphics2D g1 = (Graphics2D) g;
long z = (System.currentTimeMillis() - game.z) / 1000;
if (z >= 60)
{
remove(l);
g.setColor(Color.red);
g1.drawString("time up", 100, 100);
} else
{
g1.drawImage(craft_list.getImage(), craft_list.getX(),
craft_list.getY(), null);
ArrayList a = craft_list.getmissile();
for (int i = 0; i < a.size(); i++) {
missile m = (missile) a.get(i);
g1.drawImage(m.getImage(), m.getX(), m.getY(), null);
}
l.setText("time elapsed:" + " " + +z + " " + "hits:" + " "
+ total_hits);
for (int i = 0; i < alien_list.size(); i++) {
alien m = (alien) alien_list.get(i);
g1.drawImage(m.getImage(), m.getX(), m.getY(), null);
}
}
}
public void actionPerformed(ActionEvent e) {
ArrayList a = craft_list.getmissile();
for (int i = 0; i < a.size(); i++) {
missile m = (missile) a.get(i);
if (m.visible == true)
m.move();
else
a.remove(i);
}
long z = (System.currentTimeMillis() - game.z) / 1000;
if (z % 3 == 0)
alien_list.add(new alien(-10, 100));
for (int j = 0; j < alien_list.size(); j++) {
alien m = (alien) alien_list.get(j);
if (m.visible == true)
m.move();
else
alien_list.remove(j);
}
craft_list.move();
collison();
repaint();
}
public void collison() {
ArrayList a = craft_list.getmissile();
for (int i = 0; i < a.size(); i++) {
missile m = (missile) a.get(i);
Rectangle r1 = m.getBounds();
for (int j = 0; j < alien_list.size(); j++) {
alien l = (alien) alien_list.get(j);
Rectangle r2 = l.getBounds();
if (r1.intersects(r2)) {
total_hits++;
m.setVisible(false);
l.setVisible(false);
}
}
}
}
}
class craft extends KeyAdapter
{
int x = 250;
int y = 400;
ArrayList m = new ArrayList();
Image i;
int dx, dy;
craft() {
ImageIcon i1 = new ImageIcon("1a.jpg");
i = i1.getImage();
}
public Image getImage() {
return i;
}
public int getX() {
return x;
}
public int getY() {
return y;
}
public void move() {
x += dx;
y += dy;
if (x < 0)
x = 0;
if (x > 450)
x = 450;
if (y > 420)
y = 420;
if (y < 200)
y = 200;
}
public void keyPressed(KeyEvent k)
{
int key = k.getKeyCode();
if (key == KeyEvent.VK_SPACE) {
fire();
}
if (key == KeyEvent.VK_LEFT) {
dx = -1;
}
if (key == KeyEvent.VK_RIGHT) {
dx = 1;
}
if (key == KeyEvent.VK_UP) {
dy = -1;
}
if (key == KeyEvent.VK_DOWN) {
dy = 1;
}
}
public void keyReleased(KeyEvent e) {
int key = e.getKeyCode();
if (key == KeyEvent.VK_LEFT) {
dx = 0;
}
if (key == KeyEvent.VK_RIGHT) {
dx = 0;
}
if (key == KeyEvent.VK_UP) {
dy = 0;
}
if (key == KeyEvent.VK_DOWN) {
dy = 0;
}
}
public void fire() {
m.add(new missile(getX() + 13, getY() - 6));
}
public ArrayList getmissile() {
return m;
}
public Rectangle getBounds() {
return new Rectangle(x, y, i.getWidth(null), i.getHeight(null));
}
}
class missile {
Image i;
int x, y;
public boolean visible;
missile(int x, int y) {
this.x = x;
this.y = y;
visible = true;
ImageIcon i1 = new ImageIcon("1c.jpg");
i = i1.getImage();
}
public Image getImage() {
return i;
}
public int getX() {
return x;
}
public int getY() {
return y;
}
public void move() {
y--;
if (y < 0)
visible = false;
}
public Rectangle getBounds() {
return new Rectangle(x, y, i.getWidth(null), i.getHeight(null));
}
public void setVisible(boolean t) {
this.visible = t;
}
}
class alien {
Image i;
int x, y;;
public boolean visible;
public alien(int x, int y)
{
this.x = x;
this.y = y;
ImageIcon i1 = new ImageIcon("b.jpg");
i = i1.getImage();
visible = true;
}
public int getX() {
return x;
}
public int getY() {
return y;
}
public Image getImage() {
return i;
}
public void move() {
x++;
if (x > 500)
visible = false;
}
public Rectangle getBounds() {
return new Rectangle(x, y, i.getWidth(null), i.getHeight(null));
}
public void setVisible(boolean t) {
this.visible = t;
}
}
Ok, your code format is kind of unreadable and invites everybody to oversee otherwise obvious bugs. That is what I have seen so far for your performance issue:
getBounds() creates a new Rectangle instance every time it gets called. You should update the bounds rectangle at the last line of your move() and just return the rectangle instance instead of creating a new one.
Reuse Image or ImageIcon objects. There is no need to load the same jpg file over and over again in a constructor. Make it static or use a image cache.
Instead of o++ in fire() you should use o = m.size(). Mainly because you never call o--, you only remove the rocket from the ArrayList.
And at that point everybody loses track of what o and m means. Name your variables better! o should be amountOfRockets and m should be listOfRockets.
When you use Eclipse, press ctrl + shift + f to format the code which I highly recommend. After that go through your code and name the variables correctly. That means you should give them a descriptive name. And finally: let the name of your classes start with an upper case.
Very likely that this will not yet remove all issues but it will at least help us to understand and read your code easier... which might lead us to a solution...
Update:
You still haven't done 1. and 2. I suggested but you did 3.
Here is what 1. should be as a sample for the Alien class:
private Rectangle bounds
//constructor
Alien() {
// your stuff and the bounds:
bounds = new Rectangle(x, y, i.getWidth(null), i.getHeight(null));
}
public void move() {
bounds.x++;
if (bounds.x > 500)
visible = false;
}
public Rectangle getBounds() {
return bounds;
}
You need to implement that for the Rocket class as well.
What I still don't get is where you remove the old Alien objects. Just setting their visibility is not enough. You should remove them from the list of your Alien objects. Otherwise you will loop through objects that are not there anymore.