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Bullet not travelling up! Java game

I'm a newbie in Java and I'm trying to make a ship fire a bullet. What I want is actually make the ship fire bullets as long as the Spacebar button is being held down.
I've successfully made the ship move here and there and also fire the bullet. However the bullet just won't go up. Here's my code -
package learningPackage;
import javax.swing.*;
import java.awt.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
public class Draw extends JFrame implements Runnable {
//Variables for the x and y coordinates, xDirection for modifying the values of x only.
int x, y, xDirection;
int bx, by;
Image dbImage;
Graphics dbGraphics;
boolean shot;
Rectangle bullet;
//Thread run
public void run() {
try {
while (true) {
move();
shoot();
//Setting sleep to 0 will make it light-speed!
Thread.sleep(5);
}
}
catch (Exception e) {
System.out.println("Error!");
}
}
//Ship move
//Ship moves only in one direction, x - axis
public void move() {
x += xDirection;
//Collision detection
if (x <= 10) {
x = 10;
}
if (x >= 415) {
x = 415;
}
}
//KeyListeners
public class AL extends KeyAdapter {
public void keyPressed(KeyEvent e) {
int keyCode = e.getKeyCode();
if (keyCode == e.VK_LEFT) {
xDirection = -2;
}
if (keyCode == e.VK_RIGHT) {
xDirection = 2;
}
if (keyCode == e.VK_SPACE) {
shot = true;
}
}
public void keyReleased(KeyEvent e) {
int keyCode = e.getKeyCode();
if (keyCode == e.VK_LEFT) {
xDirection = 0;
}
if (keyCode == e.VK_RIGHT) {
xDirection = 0;
}
if (keyCode == e.VK_SPACE) {
shot = false;
}
}
}
//Constructor for the game frame
public Draw() {
super("Game");
setSize(500, 500);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setResizable(false);
addKeyListener(new AL());
x = 200;
y = 465;
setVisible(true);
}
//Double - buffering
public void paint(Graphics g) {
dbImage = createImage(getWidth(), getHeight());
dbGraphics = dbImage.getGraphics();
paintComponent(dbGraphics);
g.drawImage(dbImage, 0, 0, this);
}
//All the graphics
public void paintComponent(Graphics g) {
bullet = new Rectangle(bx, by, 10, 10);
g.setColor(Color.RED);
//Ship rectangle
g.fillRect(x, y, 75, 25);
//Gun rectangle
g.fillRect(x + 32, y - 15, 10, 15);
//Setting the same values for bx and by as x and y so that the bullet will start from the Gun rectangle
bx = x + 32;
by = y - 15;
if (shot == true) {
g.setColor(Color.BLACK);
g.fillRect(bx, by, bullet.width, bullet.height);
}
repaint();
}
public void shoot() {
if (shot == true) {
by = by - 2;
}
if (by <= -5) {
//Resetting values
bx = x + 32;
by = y - 15;
bullet = new Rectangle(bx, by, 10, 10);
shot = false;
}
}
//Main method
public static void main(String[] args) {
Draw gameTry = new Draw();
Thread t1 = new Thread(gameTry);
t1.start();
}
}
Here's what happens when I just move the ship, working perfectly fine -
Here's what happens when I hold down space -
(Sorry for not being able to embed pics in the post itself, I'm new to Stack Overflow as well!)
I was actually coping this code from a tutorial but since the tutorial-code wasn't working out, I decided to do this on my own, but I can't do it on my own as well!
Help will definitely be appreciated!

The reason for the bullet not moving becomes appearant when you compare your shoot() method, and the paintComponent method.
Shoot checks if you have the shot boolean set, and if so, moves the bullet y position up by 2.
When the bullet leaves the top of the screen, it resets the "bullet".
This is all fine, it does what it's supposed to.
public void shoot() {
if (shot == true) {
by = by - 2; //this is fine, it moves the bullet up
}
if (by <= -5) {
//Resetting values
bx = x + 32;
by = y - 15;
bullet = new Rectangle(bx, by, 10, 10);
shot = false;
}
}
Then comes paintComponent, which is executed time your game is "painted" to the screen.
It defines a rectangle for the bullet at its current position,
draws the ship,
Then overwrites the bullet's x and y position so it sits on top of the ship.
That is where your problem is
public void paintComponent(Graphics g) {
bullet = new Rectangle(bx, by, 10, 10);
g.setColor(Color.RED);
g.fillRect(x, y, 75, 25);
g.fillRect(x + 32, y - 15, 10, 15);
//you are messing with bx and by here.
//probably because you wanted the bullet to be in the
//same position as the ship.
//this means they will be put back into the same position
//for every time your game is painted to the screen.
//my advice is, do *not* do this here.
bx = x + 32;
by = y - 15;
if (shot == true) {
g.setColor(Color.BLACK);
g.fillRect(bx, by, bullet.width, bullet.height);
}
repaint();
}

Java Mario game collision between enemy and blocks

I'm begginer in java game programming and I have a small actually big problem (for me) with game.
I'm trying making collision between enemy and blocks it doesnt work and i dont know why. It should worked but it just slow game on one fps per second and dont do anything.
I have main class called Game
with this main Init() function
public void init(){
WIDTH = getWidth();
HEIGHT = getHeight();
tex = new Texture();
BufferImageLoader loader = new BufferImageLoader();
level = loader.loadImage("/level.png"); // loading level
cloud = loader.loadImage("/cloud.png"); // loading clouds
handler = new Handler();
cam = new Camera(0,0);
LoadImageLevel(level);
this.addKeyListener(new KeyInput(handler));
}
and than LoadImageLevel function where I read level.png pixel by pixel and by the differents color I'm setting position of every objects.
private void LoadImageLevel (BufferedImage image){
int w = image.getWidth();
int h = image.getHeight();
//System.out.println(w + " , " + h);
for(int xx = 0; xx < h; xx++){
for(int yy = 0; yy < w ; yy++){
int pixel = image.getRGB(xx, yy);
int red = (pixel >> 16) & 0xff;
int green = (pixel >> 8) & 0xff;
int blue = (pixel) & 0xff;
if(red == 255 && green == 255 && blue == 255)
handler.addObject(new Block(xx*32,yy*32,1,ObjectId.Block));
if(red == 0 && green == 0 && blue == 255)
handler.addObject(new Player(xx*32,yy*32,1,handler,ObjectId.Player));
if(red == 0 && green == 255 && blue == 0)
handler.addObject(new Enemy(xx*32,yy*32,handler,ObjectId.Enemy));
}
}
}
In class Player is two important functions tick and collision where in tick is collison called.
public class Player extends GameObject{
private float width = 32, // 48
height = 64; // 96
private float gravity = 0.5f;
private final float MAX_SPEED = 10;
private int facing = 1;
private int last = 0; // last position left or right
private Handler handler;
Texture tex = Game.getInstance();
private int type;
private Animation playerWalk, playerWalkLeft,jump;
public Player(float x, float y,int type , Handler handler ,ObjectId id) {
super(x, y, id);
this.handler = handler;
this.type = type;
playerWalk = new Animation(2,tex.player[2],tex.player[3],
tex.player[4],tex.player[5]);
playerWalkLeft = new Animation(2,tex.player[7],tex.player[8],
tex.player[9],tex.player[10]);
jump = new Animation(2,tex.player[11],tex.player[12]);
}
public void tick(LinkedList<GameObject> object) {
x += velX;
y += velY;
if(velX < 0) facing = -1;
else if(velX > 0) facing = 1;
if(falling || jumping){
velY += gravity;
if(velY > MAX_SPEED){
velY = MAX_SPEED;
}
}
Collision(object);
//System.out.println(velX + " " + velY);
playerWalk.runAnimation();
playerWalkLeft.runAnimation();
jump.runAnimation();
}
private void Collision(LinkedList<GameObject> object){
for(int i = 0; i < handler.object.size();i++){
GameObject tempObject = handler.object.get(i);
if(tempObject.getId() == ObjectId.Block ){
if(getBoundsTop().intersects(tempObject.getBounds())){
y = tempObject.getY() + 32;
velY = 0;
}
if(getBounds().intersects(tempObject.getBounds())){
y = tempObject.getY() - height;
velY = 0;
falling = false;
jumping = false;
}else
falling = true;
if(getBoundsRight().intersects(tempObject.getBounds())){
x = tempObject.getX() - width;
}
if(getBoundsLeft().intersects(tempObject.getBounds())){
x = tempObject.getX() + 35;
}
}
/* new */
}
}
public void render(Graphics g) {
/*
g.setColor(Color.blue);
g.fillRect((int)x,(int)y,(int)width,(int)height);
Graphics2D g2d = (Graphics2D) g;
g.setColor(Color.red);
g2d.draw(getBounds());
g2d.draw(getBoundsRight());
g2d.draw(getBoundsLeft());
g2d.draw(getBoundsTop());
*/
if(velX != 0){
if (facing == 1){
playerWalk.drawAnimation(g,(int) x, (int)y,32,64);
last = 1;
}
else{
playerWalkLeft.drawAnimation(g,(int) x, (int)y,32,64);
last = 0;
}
}
else
if (last == 1)
g.drawImage(tex.player[1], (int)x,(int) y,32,64,null);
else
g.drawImage(tex.player[6], (int)x,(int) y,32,64,null); // 6 ,32,64
//System.out.println("Y: " + y); // 513 je max
if (y >= 513){
g.setColor(Color.red);
g.drawString("Game Over", (int) x, 200);
}
}
public Rectangle getBounds() {
return new Rectangle((int) ((int)x+(width/2)-((width/2)/2)),(int) ((int)y+(height/2)),(int)width/2,(int)height/2);
}
public Rectangle getBoundsTop() {
return new Rectangle((int) ((int)x+(width/2)-((width/2)/2)),(int)y,(int)width/2,(int)height/2);
}
public Rectangle getBoundsRight() {
return new Rectangle((int) ((int)x+width-5),(int)y+5,(int)5,(int)height-10);
}
public Rectangle getBoundsLeft() {
return new Rectangle((int)x,(int)y+5,(int)5,(int)height-10);
}
Player dont have any problem with block collision.
public class Block extends GameObject {
Texture tex = Game.getInstance();
private int type;
public Block(float x, float y,int type,ObjectId id) {
super(x, y, id);
this.type = type;
}
public void tick(LinkedList<GameObject> object) {
}
public void render(Graphics g) {
if(type == 0)
g.drawImage(tex.block[0], (int) x, (int) y ,null);
if(type == 1)
g.drawImage(tex.block[1], (int) x, (int) y ,null);
}
public Rectangle getBounds() {
return new Rectangle((int)x,(int)y,32,32);
}
}
But when i tried created Enemy class and make it same like in Player class I mean collision it just make game slower and nothing else.
public class Enemy extends GameObject{
private Handler handler;
public Enemy(float x, float y,Handler handler, ObjectId id) {
super(x, y, id);
this.handler = handler;
}
public void tick(LinkedList<GameObject> object) {
for(int i = 0; i < handler.object.size();i++){
GameObject tempObject = handler.object.get(i);
if(tempObject.getId() == ObjectId.Block ){
if(getBoundsTop().intersects(tempObject.getBounds())){
}
if(getBounds().intersects(tempObject.getBounds())){
}
if(getBoundsRight().intersects(tempObject.getBounds())){
}
if(getBoundsLeft().intersects(tempObject.getBounds())){
}
}
}
}
public void render(Graphics g) {
g.setColor(Color.red);
g.fillRect((int)x,(int) y, 32, 32);
}
public Rectangle getBoundsTop() {
return new Rectangle((int)x,(int)y,32,32);
}
public Rectangle getBoundsLeft() {
return new Rectangle((int)x,(int)y,32,32);
}
public Rectangle getBoundsRight() {
return new Rectangle((int)x,(int)y,32,32);
}
public Rectangle getBounds() {
return new Rectangle((int)x,(int)y,32,32);
}}
I know that bounds should not have return same "new Rectangle" and that theres no any movements of enemy anyway when i set in tick method x--; for just trying if enemy stop when it come to the edge of block but it doesnt work i dont know whats wrong with it i spend more than two days with fixing this. If it can help you there is a link for whole project (Eclipse) You can download it from dropbox
I just wanted to have an enemy which move left and right and have collison with block it means when he "touch" by his left side to the block he "turn around" and move to right side until he "touch" by his right side etc... other collisions between Player and Enemy is not problem for me. But just this.
I'm so thankful for every advice :)

The problem is with your getBounds() method.
You are saying in getBounds() method to return a rectangle with width=32 and height=32. And since your rectangle is 32 by 32 (as mentioned in fillrect(x,y,32,32) ) so getBounds() returns with the intersection in height and width.
In other words, try not to collide the returned Top left bottom or right bounds with themselves.
And in enemy(), you are declaring set.color = red while in loading you are using green. Try red==255, green==0, blue==0 instead of if(red == 0 && green == 255 && blue == 0)

Asteroid game NullPointerException error

I am having some serious problems with my Asteroid game. I'm trying to call my Game.java run() method in my main method in Asteroid.java but I keep getting the same error:
Exception in thread "main" java.lang.NullPointerException
at asteroids.Asteroids.main(Asteroids.java:15)
Java Result: 1
Can someone help me figure out why this is happening?
here is my code:
Asteroids.java
package asteroids;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.Point2D;
import java.util.ArrayList;
import java.io.IOException;
#SuppressWarnings("serial")
public class Asteroids {
Game game = null;
public static void main(String[] args){
new Asteroids ().game.run ();
}
}
//NEW Game.java//
package asteroids;
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.Point2D;
import java.util.ArrayList;
//#SuppressWarnings("serial")
public class Game extends Applet implements Runnable, KeyListener {
//timing variables
Thread thread;
long startTime, endTime, framePeriod;
//graphics variables
Image img;
Dimension dim;
int width, height;
Graphics g;
//text items
int level, lives, score;
SpaceShip ship;
boolean shipCollision, shipExplode;
//ArrayList to hold asteroids
ArrayList<Asteroid> asteroids = new ArrayList<>();
int numOfAsteroids = 1;
//ArrayList to hold the lasers
ArrayList<Laser> lasers = new ArrayList<>();
final double rateOfFire = 10; //limits rate of fire
double rateOfFireRemaining; //decrements rate of fire
//ArrayList to hold explosion particles
ArrayList<AsteroidExplosion> explodingLines = new ArrayList<>();
//ArrayList to hold ship explosions
ArrayList<ShipExplosion> shipExplosion = new ArrayList<>();
public void Game ()
{
init();
}
public void init() {
resize(900,700); //set size of the applet
dim = getSize(); //get dimension of the applet
width = dim.width;
height = dim.height;
framePeriod = 25; //set refresh rate
addKeyListener(this); //to get commands from keyboard
setFocusable(true);
ship = new SpaceShip(width/2, height/2, 0, .15, .5, .15, .98); //add ship to game
shipCollision = false;
shipExplode = false;
level = numOfAsteroids;
lives = 3;
addAsteroids();
img = createImage(width, height); //create an off-screen image for double-buffering
g = img.getGraphics(); //assign the off-screen image
thread = new Thread(this);
thread.start();
}
#Override
public void paint(Graphics gfx) {
Graphics2D g2d = (Graphics2D) g;
//give the graphics smooth edges
RenderingHints rh = new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
rh.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
g2d.setRenderingHints(rh);
g2d.setColor(Color.BLACK);
g2d.fillRect(0, 0, width, height); //add a black background
//add text for lives, score, and level
g2d.setColor(Color.WHITE);
g2d.drawString("Level : " + level, 10, 690);
g2d.drawString("Lives : " + lives, 110, 690);
g2d.drawString("Score : " + score, 210, 690);
for(Asteroid a: asteroids) { //draw asteroids
a.draw(g2d);
}
for(Laser l : lasers) { //draw lasers
l.draw(g2d);
}
for(AsteroidExplosion e : explodingLines) {
e.draw(g2d);
}
for(ShipExplosion ex : shipExplosion)
ex.draw(g2d);
ship.draw(g2d); //draw ship
if(shipCollision) {
shipExplosion.add(new ShipExplosion(ship.getX(), ship.getY(), 10, 10));
ship.setX(width/2);
ship.setY(height/2);
shipCollision = false;
lives--;
}
gfx.drawImage(img, 0, 0, this); //draw the off-screen image (double-buffering) onto the applet
}
#Override
public void update(Graphics gfx) {
paint(gfx); //gets rid of white flickering
}
#Override
public void run(){
for( ; ; ) {
startTime = System.currentTimeMillis(); //timestamp
ship.move(width, height); //ship movement
for(Asteroid a : asteroids) { //asteroid movement
a.move(width, height);
}
for(Laser l : lasers) { //laser movement
l.move(width, height);
}
for(int i = 0 ; i<lasers.size() ; i++) { //laser removal
if(!lasers.get(i).getActive())
lasers.remove(i);
}
for(AsteroidExplosion e : explodingLines) { //asteroid explosion floating lines movement
e.move();
}
for(int i = 0 ; i<explodingLines.size(); i++) { //asteroid explosion floating lines removal
if(explodingLines.get(i).getLifeLeft() <= 0)
explodingLines.remove(i);
}
for(ShipExplosion ex : shipExplosion){ //ship explosion expansion
ex.expand();
}
for(int i = 0 ; i<shipExplosion.size() ; i++) {
if(shipExplosion.get(i).getLifeLeft() <= 0)
shipExplosion.remove(i);
}
rateOfFireRemaining--;
collisionCheck();
if(asteroids.isEmpty()) {
numOfAsteroids++;
addAsteroids();
level = numOfAsteroids;
}
repaint();
try {
endTime = System.currentTimeMillis(); //new timestamp
if(framePeriod - (endTime-startTime) > 0) //if there is time left over after repaint, then sleep
Thread.sleep(framePeriod - (endTime - startTime)); //for whatever is remaining in framePeriod
} catch(InterruptedException e) {}
}
}
#Override
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
//fires laser
if(key == KeyEvent.VK_SPACE) {
if(rateOfFireRemaining <= 0 ) {
lasers.add(ship.fire());
rateOfFireRemaining = rateOfFire;
}
}
if(key == KeyEvent.VK_UP)
ship.setAccelerating(true);
if(key == KeyEvent.VK_RIGHT)
ship.setTurningRight(true);
if(key == KeyEvent.VK_LEFT)
ship.setTurningLeft(true);
if(key == KeyEvent.VK_DOWN)
ship.setDecelerating(true);
}
#Override
public void keyReleased(KeyEvent e) {
int key = e.getKeyCode();
if(key == KeyEvent.VK_UP)
ship.setAccelerating(false);
if(key == KeyEvent.VK_RIGHT)
ship.setTurningRight(false);
if(key == KeyEvent.VK_LEFT)
ship.setTurningLeft(false);
if(key == KeyEvent.VK_DOWN)
ship.setDecelerating(false);
}
#Override
public void keyTyped(KeyEvent e) {
}
public void addAsteroids() {
int numAsteroidsLeft = numOfAsteroids;
int size;
for(int i=0 ; i<numOfAsteroids ; i++) { //add asteroids to game
//randomize starting position
int asteroidX = (int)(Math.random() * width) + 1;
int asteroidY = (int)(Math.random() * height) + 1;
//randomize speed and direction
double xVelocity = Math.random() + 1; //horizontal velocity
double yVelocity = Math.random() + 1; //vertical velocity
//used starting direction
int xDirection = (int)(Math.random() * 2);
int yDirection = (int)(Math.random() * 2);
//randomize horizontal direction
if (xDirection == 1)
xVelocity *= (-1);
//randomize vertical direction
if (yDirection == 1)
yVelocity *= (-1);
//if there are more then four asteroids, any new ones are MEGA asteroids
if(numAsteroidsLeft > 4) {
size = 2;
} else { size = 1;
}
asteroids.add(new Asteroid(size, asteroidX, asteroidY, 0, .1, xVelocity, yVelocity));
numAsteroidsLeft--;
//Make sure that no asteroids can appear right on top of the ship
//get center of recently created asteroid and ship and check the distance between them
Point2D asteroidCenter = asteroids.get(i).getCenter();
Point2D shipCenter = ship.getCenter();
double distanceBetween = asteroidCenter.distance(shipCenter);
//if asteroid center is within 80 pixels of ship's center, remove it from the ArrayList and rebuild it
if(distanceBetween <= 80) {
asteroids.remove(i);
i--;
numAsteroidsLeft++;
}
}
}
public void collisionCheck() {
//cycle through active asteroids checking for collisions
for(int i = 0 ; i < asteroids.size() ; i++) {
Asteroid a = asteroids.get(i);
Point2D aCenter = a.getCenter();
//check for collisions between lasers and asteroids
for(int j = 0 ; j < lasers.size() ; j++) {
Laser l = lasers.get(j);
Point2D lCenter = l.getCenter();
double distanceBetween = aCenter.distance(lCenter);
if(distanceBetween <= (a.getRadius() + l.getRadius())) {
//split larger asteroids into smaller ones, remove smaller asteroids from screen
if(a.getRadius() >= 60) {
for(int k = 0 ; k < 3 ; k++)
explodingLines.add(a.explode());
split(i);
score += 200;
} else if(a.getRadius() >= 30){
for(int k = 0 ; k < 3 ; k++)
explodingLines.add(a.explode());
split(i);
score += 100;
} else {
for(int k = 0 ; k < 3 ; k++)
explodingLines.add(a.explode());
asteroids.remove(i);
score += 50;
}
lasers.remove(j); //remove laser from screen
}
}
//check for collisions between ship and asteroid
Point2D sCenter = ship.getCenter();
double distanceBetween = aCenter.distance(sCenter);
if(distanceBetween <= (a.getRadius() + ship.getRadius())) {
shipCollision = true;
shipExplode = true;
}
}
}
public void split(int i) {
Asteroid a = asteroids.get(i);
double bigAsteroidX = a.getX();
double bigAsteroidY = a.getY();
int size = (a.getSize() / 2);
asteroids.remove(i);
for(int j = 0 ; j<2 ; j++) {
//randomize speed and direction
double xVelocity = Math.random() + 1; //horizontal velocity
double yVelocity = Math.random() + 1; //vertical velocity
//used randomize starting direction
int xDirection = (int)(Math.random() * 2);
int yDirection = (int)(Math.random() * 2);
//randomize horizontal direction
if (xDirection == 1)
xVelocity *= (-1);
//randomize vertical direction
if (yDirection == 1)
yVelocity *= (-1);
asteroids.add(new Asteroid(size, bigAsteroidX, bigAsteroidY, 0, .1, xVelocity, yVelocity));
}
}
}
//Edit Update//
Okay I tried a lot of stuff and discovered that even though the game works when I debug Game.java and it doesn't work when I run it through Asteroids.java. I found that img = createIimg = createImage(width, height); and g = img.getGraphics(); are returning null and that GraphicsEnvironment.isHeadless() is returning true. How should I change my to fix this issue?
Error
Exception in thread "main" java.lang.NullPointerException
at asteroids.Game.init(Game.java:67)
at asteroids.Game.Game(Game.java:45)
at asteroids.Asteroids.main(Asteroids.java:15)
Java Result: 1

You have the var "game" null, and you tried to call the method "run" on this var (game.run); obviously if "game" is null, you can't get the method, and throws nullpointer exception.
Game game=new Game();
that's all you need. Your final code is:
Game game = new Game();//<----- here is the change
public static void main(String[] args){
new Asteroids ().game.run ();
}

This thing is null.
new Asteroids ().game
That's why you get this NullPointerException when you call run on it.

Game game = null;
public static void main(String[] args){
new Asteroids ().game.run ();
}
The prgram is running from the main method. game is null.
Maybe you should have
Game game = new Game(); // instead of null

Try it may be help
Game game = null;
public static void main(String[] args){
If( Asteroids ().game != null ){
new Asteroids ().game.run ();
}
}

Java (swing) paint only what's viewable on the screen

I am making a tile based platformer game in java. I render a map which is stored in a 2 dimensional array but when this array is very big my game starts to become slow. I realised that I had to only render the part of the map that is viewable, I tried to do that but i wrote very hacky code that only worked partly so I removed it. How can I do this properly? Here is my code (without the hacky stuff). Also how could I use System.nanoTime() rather than System.currentTimeMillis()?
package sexy_robot_from_another_dimension;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.TexturePaint;
import java.awt.image.BufferedImage;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Timer;
import java.util.TimerTask;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class Game extends JPanel
{
int playerX = 50;
int playerY = 50;
static boolean up = false;
static boolean down = false;
static boolean right = false;
static boolean left = false;
int playerSpeed = 1;
String[][] map;
int blockSize = 20;
int jumpLoop = 0;
int maxJumpLoop = 280;
static BufferedImage block, player;
int playerWidth = 20;
int playerHeight = 35;
int cameraX = 0;
int cameraY = 0;
long nextSecond = System.currentTimeMillis() + 1000;
int frameInLastSecond = 0;
int framesInCurrentSecond = 0;
public Game()
{
super();
try
{
map = load("/maps/map1.txt");
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
Timer timer = new Timer();
TimerTask task = new TimerTask()
{
#Override
public void run()
{
if(up)
{
if((!playerIsOnBlock(playerX, playerY).equals("0")) || (!playerIsOnBlock(playerX + (playerWidth - 1), playerY).equals("0")))
{
timeToJump();
}
}
if(down)
{
}
if(right)
{
if((playerIsLeftBlock(playerX, playerY).equals("0")) && (playerIsLeftBlock(playerX, playerY + (playerHeight/2 - 1)).equals("0")) && (playerIsLeftBlock(playerX, playerY + (playerHeight - 1)).equals("0")))
{
playerX += playerSpeed;
}
}
if(left)
{
if((playerIsRightBlock(playerX, playerY).equals("0")) && (playerIsRightBlock(playerX, playerY + (playerHeight/2 - 1)).equals("0")) && (playerIsRightBlock(playerX, playerY + (playerHeight - 1)).equals("0")))
{
playerX -= playerSpeed;
}
}
repaint();
}
};
timer.scheduleAtFixedRate(task, 0, 10);
Timer timerGrav = new Timer();
TimerTask taskGrav = new TimerTask()
{
#Override
public void run()
{
if((playerIsOnBlock(playerX, playerY).equals("0")) && (playerIsOnBlock(playerX + (playerWidth - 1), playerY).equals("0")))
{
playerY += playerSpeed;
repaint();
}
}
};
timerGrav.scheduleAtFixedRate(taskGrav, 0, 6);
}
void timeToJump()
{
if(jumpLoop == 0)
{
jumpLoop = 1;
Timer timer = new Timer();
TimerTask task = new TimerTask()
{
#Override
public void run()
{
if((playerIsBelowBlock(playerX, playerY).equals("0")) && (playerIsBelowBlock(playerX + (playerWidth - 1), playerY).equals("0")))
{
playerY -= playerSpeed;
jumpLoop++;
repaint();
}
else
{
jumpLoop = maxJumpLoop;
}
if(jumpLoop == maxJumpLoop)
{
jumpLoop = 0;
cancel();
}
}
};
timer.scheduleAtFixedRate(task, 0, 3);
}
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
long currentTime = System.currentTimeMillis();
if (currentTime > nextSecond)
{
nextSecond += 1000;
frameInLastSecond = framesInCurrentSecond;
framesInCurrentSecond = 0;
}
framesInCurrentSecond++;
g.drawString(frameInLastSecond + " fps", 10, 20);
cameraX = -playerX + getWidth()/2;
cameraY = -playerY + getHeight()/2;
g.translate(cameraX, cameraY);
for (int x = 0; x < map.length; x++)
{
for (int y = 0; y < map[0].length; y++)
{
switch(map[x][y])
{
case "0":
break;
case "1":
if(block != null)
{
TexturePaint tp0 = new TexturePaint(block, new Rectangle(0, 0, blockSize, blockSize));
g2.setPaint(tp0);
}
g.fillRect(y*blockSize, x*blockSize, 20, 20);
break;
}
}
}
g.setColor(Color.BLACK);
if(player != null)
{
TexturePaint tp0 = new TexturePaint(player, new Rectangle(playerX, playerY, playerWidth, playerHeight));
g2.setPaint(tp0);
}
g.fillRect(playerX, playerY, playerWidth, playerHeight);
g.setColor(Color.black);
g.setFont(new Font("Droid Sans Mono", Font.PLAIN, 12));
g.drawString("Sexy!", playerX - 5, playerY - 10);
}
boolean outOfMap(int x, int y)
{
y -= blockSize - 1;
x -= blockSize - 1;
if((y/blockSize <= map.length - 2) && (y/blockSize >= 0) && (x/blockSize <= map[0].length-2) && (x/blockSize >= 0))
{
return false;
}
return true;
}
String playerIsOnBlock(int x, int y)
{
y += playerHeight;
if(!outOfMap(x, y))
{
if(map[y/blockSize][x/blockSize] != "0")
{
return map[y/blockSize][x/blockSize];
}
}
return "0";
}
String playerIsBelowBlock(int x, int y)
{
y -= playerSpeed;
if(!outOfMap(x, y))
{
if(map[y/blockSize][x/blockSize] != "0")
{
return map[y/blockSize][x/blockSize];
}
}
return "0";
}
String playerIsLeftBlock(int x, int y)
{
x += playerWidth;
if(!outOfMap(x, y))
{
if(map[y/blockSize][x/blockSize] != "0")
{
return map[y/blockSize][x/blockSize];
}
}
return "0";
}
String playerIsRightBlock(int x, int y)
{
x -= playerSpeed;
if(!outOfMap(x, y))
{
if(map[y/blockSize][x/blockSize] != "0")
{
return map[y/blockSize][x/blockSize];
}
}
return "0";
}
String[][] load(String file) throws IOException
{
BufferedReader br = new BufferedReader(new InputStreamReader(getClass().getResourceAsStream(file)));
int lines = 1;
int length = br.readLine().split(" ").length;
while (br.readLine() != null) lines++;
br.close();
br = new BufferedReader(new InputStreamReader(getClass().getResourceAsStream(file)));
String[][] map = new String[lines][length];
for (int i = 0; i < lines; i++)
{
String line = br.readLine();
String[] parts = line.split(" ");
for (int y = 0; y < length; y++)
{
map[i][y] = parts[y];
}
}
br.close();
return map;
}
}
Thank you!

It seems your camera is centered on the player, then there are two ways of doing this, I like the first way, it is a bit cleaner:
1th: Create a rectangle that bounds your cameras view, and check if the map x,y is within this view, render only if true.
Rectangle cameraView = new Rectangle(playerX - getWidth() / 2, playerY - getHeight() / 2, getWidth(), getHeight());
for (int x = 0; x < map.length; x++) {
for (int y = 0; y < map[0].length; y++) {
if (!cameraView.contains(x*blockSize, y*blockSize))
continue;
switch (map[x][y]) {
case "0":
break;
case "1":
if (block != null) {
TexturePaint tp0 = new TexturePaint(block, new Rectangle(0, 0, blockSize, blockSize));
g2.setPaint(tp0);
}
g.fillRect(y * blockSize, x * blockSize, 20, 20);
break;
}
}
}
The second option is to simply calculate the distance to the center of the screen (playerX,playerY) from each map[x][y] and skip all map[x][y] that falls outside your viewing bounds, this is a bit uglier to code and I really don't recommend this, the rectangle option above should be fast enough.
Edit:
#JasonC That is true, I didn't consider for instance when an x value is definitely outside the view, it will still go into the y loop through all the y values. One can simply create a dummy variable in the x-loop and do the following check
for (int x = 0; x < map.length; x++) {
int dummyY = playerY
if(!cameraView.contains(x,dummyY))
continue;
....
//rest of code ommitted
Another optimization you can do is considering not setting a TexturePaint (expensive operation) but instead simply drawing the image of the block:
g.fillRect(y * blockSize, x * blockSize, 20, 20);
Replaced with
g.drawImage(block, y*blockSize, x*blockSize, null);
The same with the playerimage.

Set the clipping region to the visible area with Graphics.setClip(), that will prevent most rendering operations from taking effect outside that region.
For drawing operations where this isn't sufficient (perhaps you also want to avoid doing calculations or something for objects outside the clipping area), test your objects bounds against the clipping rectangle and skip the object if it doesn't intersect.
See Graphics.setClip().
A further optimization can be done by, for example, calculating the range of blocks on your map that is definitely outside of the visible area, and excluding that from your for loop (no sense testing blocks against the clipping region if you know they are outside already). Take the clipping region, transform it to map index coordinates, then you will know where in your map the visible area is and you can just iterate over that subsection of the map.

Java ball object doesn't bounce off of drawn rectangles like it's supposed to.

Sorry for the awful title. The purpose of the Java applet is as such: A ball is bouncing around the screen. The size and speed of this ball can be changed via scrollbars. The user can press and drag the mouse on the screen to draw rectangles. The ball will bounce off of these rectangles as well. The bounds of these rectangles are stored in a vector. When a rectangle is clicked, it (and all other rectangles at that point) are removed from the vector (and the screen).
The problem I'm having is two-fold: One, when I click a rectangle to remove it, it doesn't get removed, but that can be solved later.
Two: The ball doesn't bounce off of the rectangles like it's supposed to. When I draw a rectangle in either the same row or column as the ball, the ball bounces around inside of a tiny rectangle, like it's stuck.
Here's my code to detect if the ball is hitting the boundaries of either the applet or any of the rectangles:
public void move()
{
//if it will hit the right or left boundary, flip the x direction and set it
if (loc.x+size >= boundx || loc.x <= 0)
{ dx *= -1; }
//if it will hit the top or bottom boundray, flip the y direction and set it
if (loc.y+size >= boundy || loc.y <= 0)
{ dy *= -1; }
for (int i = 0; i < r.size(); i++)
{
temp = new Rectangle(r.elementAt(i));
int rx = temp.x;
int ry = temp.y;
int rh = temp.height;
int rw = temp.width;
//If the ball hits either side of the rectangle, change the x direction
if((loc.x > rx && loc.x > ry && loc.x < (ry + rh))||(loc.x < (rx + rw) && loc.x > rx && loc.x <(ry + rh)))
{dx *= -1;}
//If the ball hits either the top or bottom, change the y direction
if((loc.y > ry && loc.y > rx && loc.y < (rx + rw))||(loc.y < (ry + rh) && loc.y > ry && loc.y <(rx + rw)))
{dy *= -1;}
}
//Increment or decrement the location of the ball based on the X and Y directions.
loc.x += dx;
loc.y += dy;
}
If you want to view the code in its entirety, it's here: http://ideone.com/R1hpBx
Thanks in advance for all the wonderful help.

I finally found a edge detection system I like...
Basically, the magic happens here...
// Detect if we collided with any one (collision is the rectangle, bounds is us)
if (collision.intersects(bounds)) {
// Determine the intersect of the collision...
insect = collision.intersection(bounds);
// Flags...
boolean vertical = false;
boolean horizontal = false;
boolean isLeft = false;
boolean isTop = false;
// Left side...
if (insect.x == collision.x) {
horizontal = true;
isLeft = true;
// Right side
} else if (insect.x + insect.width == collision.x + collision.width) {
horizontal = true;
}
// Top
if (insect.y == collision.y) {
vertical = true;
isTop = true;
// Bottom
} else if (insect.y + insect.height == collision.y + collision.height) {
vertical = true;
}
// Technically, we can really only collide with a single edge...more or less
if (horizontal && vertical) {
// Basically, we try and give precedence to the longer edge...
if (insect.width > insect.height) {
horizontal = false;
} else {
vertical = false;
}
}
// We collided with a horizontal side...
if (horizontal) {
dx *= -1;
// Move the ball to the approriate edge so we don't get caught...
if (isLeft) {
bounds.x = collision.x - bounds.width;
} else {
bounds.x = collision.x + collision.width;
}
// We collided with a vertical side...
} else if (vertical) {
dy *= -1;
// Move the ball to the approriate edge so we don't get caught...
if (isTop) {
bounds.y = collision.y - bounds.height;
} else {
bounds.y = collision.y + collision.height;
}
}
}
Now, I only have a single obstacle, but I doubt it would take much effort to get it working with a series of obstacles... ;)
public class TestBouncingBall {
private Rectangle insect;
public static void main(String[] args) {
new TestBouncingBall();
}
public TestBouncingBall() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new BallPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class BallPane extends JLayeredPane {
private Ball ball;
private Timer timer;
private Rectangle world;
public BallPane() {
// world = new Rectangle(random(400), random(400), random(100), random(100));
world = new Rectangle(100, 100, 200, 200);
ball = new Ball();
ball.setSize(ball.getPreferredSize());
ball.setLocation(10, 10);
add(ball);
timer = new Timer(16, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
ball.move(getBounds(), world);
invalidate();
repaint();
}
});
timer.setRepeats(true);
timer.setCoalesce(true);
timer.start();
}
protected int random(int max) {
return (int) Math.round(Math.random() * max);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(Color.GRAY);
g2d.fill(world);
if (insect != null) {
g2d.setColor(Color.RED);
g2d.fill(insect);
}
g2d.dispose();
}
}
public class Ball extends JPanel {
public int maxSpeed = 10;
private BufferedImage beachBall;
private int dx = 10 - (int)Math.round(Math.random() * (maxSpeed * 2)) + 1;
private int dy = 10 - (int)Math.round(Math.random() * (maxSpeed * 2)) + 1;
private int spin = 20;
private int rotation = 0;
public Ball() {
try {
beachBall = ImageIO.read(getClass().getResource("/ball.png"));
} catch (IOException ex) {
ex.printStackTrace();
}
setOpaque(false);
}
#Override
public Dimension getPreferredSize() {
Dimension size = beachBall == null ? new Dimension(48, 48) : new Dimension(beachBall.getWidth(), beachBall.getHeight());
size.width += 4;
size.height += 4;
return size;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (beachBall != null) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ALPHA_INTERPOLATION, RenderingHints.VALUE_ALPHA_INTERPOLATION_QUALITY);
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setRenderingHint(RenderingHints.KEY_COLOR_RENDERING, RenderingHints.VALUE_COLOR_RENDER_QUALITY);
g2d.setRenderingHint(RenderingHints.KEY_DITHERING, RenderingHints.VALUE_DITHER_ENABLE);
g2d.setRenderingHint(RenderingHints.KEY_FRACTIONALMETRICS, RenderingHints.VALUE_FRACTIONALMETRICS_ON);
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2d.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
g2d.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL, RenderingHints.VALUE_STROKE_PURE);
int x = (getWidth() - beachBall.getWidth()) / 2;
int y = (getHeight() - beachBall.getHeight()) / 2;
AffineTransform transform = g2d.getTransform();
AffineTransform at = new AffineTransform();
at.translate(getX(), getY());
at.rotate(Math.toRadians(rotation), getWidth() / 2, getHeight() / 2);
g2d.setTransform(at);
g2d.drawImage(beachBall, x, y, this);
g2d.setTransform(transform);
g2d.dispose();
}
}
public void move(Rectangle world, Rectangle collision) {
Rectangle bounds = getBounds();
bounds.x += dx;
bounds.y += dy;
if (bounds.x < 0) {
bounds.x = 0;
dx *= -1;
}
if (bounds.y < 0) {
bounds.y = 0;
dy *= -1;
}
if (bounds.x + bounds.width > world.width) {
bounds.x = world.width - bounds.width;
dx *= -1;
}
if (bounds.y + bounds.height > world.height) {
bounds.y = world.height - bounds.height;
dy *= -1;
}
if (collision.intersects(bounds)) {
insect = collision.intersection(bounds);
boolean vertical = false;
boolean horizontal = false;
boolean isLeft = false;
boolean isTop = false;
if (insect.x == collision.x) {
horizontal = true;
isLeft = true;
} else if (insect.x + insect.width == collision.x + collision.width) {
horizontal = true;
}
if (insect.y == collision.y) {
vertical = true;
isTop = true;
} else if (insect.y + insect.height == collision.y + collision.height) {
vertical = true;
}
if (horizontal && vertical) {
if (insect.width > insect.height) {
horizontal = false;
} else {
vertical = false;
}
}
System.out.println("v = " + vertical + "; h = " + horizontal);
if (horizontal) {
dx *= -1;
if (isLeft) {
bounds.x = collision.x - bounds.width;
} else {
bounds.x = collision.x + collision.width;
}
} else if (vertical) {
dy *= -1;
if (isTop) {
bounds.y = collision.y - bounds.height;
} else {
bounds.y = collision.y + collision.height;
}
}
}
rotation += spin;
setBounds(bounds);
repaint();
}
}
}