Thread: How to write Java applets to create 2D games?

trying to make my player shoot.
when i hit space bar my player should shoot bullet and it should keep on going to right. but some some reason my when i hit space bar the bullet stays at one point and doesnt move.

i am trying to move bullet here. x is bullet x poistion and dx is bullet speed. note this method is in loop so it should move on bullet on right.

public void PLAYER_SHOOT_MOVE(Main m, Player p, Shoot s)
	{				
		x += dx;
	}/*** end of PLAYER_SHOOT method ***/

than i am print my bullet here. when user hit space bar. than variable hitSPACE get set to ture.

public void paint(Graphics g, Player p) 
	{
		if(hitSPACE == true)
		{
 
			g.drawImage(this.getSIMAGE(), p.getX(), p.getY(), width, height, null); 
		}
	}/*** paint method ***/

but the problem is that my bullet is not moving. any idea why this is hapening???




shoot.java

public class Shoot
{
	private int x;
	private int y;
	private int dx;
	private int width ;
	private int height;
 
	private boolean hitSPACE = false;  //user hit space bar
	private boolean dead = true;     //shoot is dead
 
	private static ImageIcon shoot_image = new ImageIcon("Image/shoot/bull2.png");
 
 
	public Shoot()
	{	
		 dx = 3;
		 width = 20;
		 height = 20;
	}
 
 
 
	/*** get/set methods ***/
	public static Image getSIMAGE()  
	{ return shoot_image.getImage(); }
 
	public int getX()
	{ return x; }
	public void setX(int value) 
	{ this.x =  value; }
 
	public int getY()
	{ return y; }
	public void setY(int value) 
	{ this.y =  value; }
 
	public int getWIDTH()
	{ return width; }
	public void setWIDTH(int value) 
	{ this.width =  value; }
 
	public int getHEIGHT()
	{ return height; }
	public void setHEIGHT(int value) 
	{ this.height =  value; }
 
	public boolean isDEAD()
	{ return dead; }
	public void setDEAD(boolean value)
	{ this.dead = value; }
 
 
	/*** Key pressed ***/
	public void hitSHOOT()  //user hit spacebar
	{
		hitSPACE = true;
		dead = true;
	}
	public void stopSHOOT()  //user stop spacebar
	{
		hitSPACE = false;
	}
 
 
 
	/******************/
	/*** LOOP METHOD ***/
	/*******************/
	public void PLAYER_SHOOT_MOVE(Main m, Player p, Shoot s)
	{				
		x += dx;
		System.out.println(x);
	}/*** end of PLAYER_SHOOT method ***/
 
 
	/*** paint method ***/
	public void paint(Graphics g, Player p) 
	{
		if(hitSPACE == true)
		{
 
			g.drawImage(this.getSIMAGE(), x, y, width, height, null); 
		}
	}/*** paint method ***/
}

main.java

public class Main extends Applet implements Runnable, KeyListener, MouseMotionListener, MouseListener
{
	//Double buffering variables
	Image dbImage;
	Graphics dbGraphics;
 
	Thread thread;
 
 
 
	//Class variables
	 Background background_class;
	 Score score_class;
	 Ground ground_class;
	 Sprite_Sheet sprite_sheet_class;
	 Player player_class;
	Platform platform_class[] = new Platform[5];
	Enemy  enemy_class;
	Item item_class[] = new Item[3];
	Shoot shoot_class;
 
 
	 //is if game is running or not
	 boolean running = true;
	 boolean mouseIn = false;
 
	 Container c;
 
 
 
 
	/*** init method ***/
	@Override
	public void init() 
	{
		setSize(900, 400);
		addKeyListener(this);
		addMouseListener(this);
		addMouseMotionListener(this);
 
	}/*** end of init method ***/
 
 
 
 
	/*** start method ***/
	@Override
	public void start()
	{	
		/*** set variables ***/
		Random r1 = new Random();
 
		sprite_sheet_class = new Sprite_Sheet(this);
		background_class = new Background();
		ground_class = new Ground(0, this.getHeight()-20,this.getSize().width, 20); //x, y, widith, height
		player_class = new Player(5, 250);  //x, y
		shoot_class = new Shoot();
		for(int i = 0; i < platform_class.length; i++)
		{ 
		  Random r = new Random();
		  platform_class[i] = new Platform(i*120, 300); //x,y --sub -40 so no cut off platform at bottom
		}
		//item_class = new Item_0_Background(200); //x print 1 item
		for(int i = 0; i < item_class.length; i++)
		{ item_class[i] = new Item_1_Fast(r1.nextInt(900)); } //x  - print 1 item than swich to 2nd item
 
		enemy_class = new Enemy(500, 345);   //x, y
		score_class = new Score(5,30);
 
 
		/*** play music in main ***/
		sprite_sheet_class.theme_music.loop();
 
 
 
		thread = new Thread(this); //start run method
		thread.start();
	}/*** end of start method ***/
 
 
 
	/*** run method ***/
 
	public void run()
	{
		while(player_class.isDEAD() == false) //if player is not dead keep going
		{
			Random r = new Random();
			background_class.BACKGROUND_MOVE(this);
 
			ground_class.GROUND_COLLISION(this, player_class);                         //ground + player collions
			player_class.PLAYER_MOVE(this, ground_class);                                  //player moves
			shoot_class.PLAYER_SHOOT_MOVE(this, player_class, shoot_class);  //player shoot bullet moves
			for(int i = 0; i < platform_class.length; i++)
			{ platform_class[i].PLATFORM_ANIMATION();
				platform_class[i].PLATFORM_COLLSION(this, player_class); }
			enemy_class.ENEMY_MOVE(this, sprite_sheet_class);
			enemy_class.PLAYER_ENEMY_COLLISION(this, player_class, enemy_class);          //player + enemy collision
			for(int i = 0; i < item_class.length; i++)
			{
			item_class[i].PLAYER_ITEM_COLLISION(this, score_class, player_class,  ground_class);
				if(item_class[i].getY() == 0)         //if item is top left coner
				{
					item_class[i] = null;                 //delete item
					item_class[i] = new Item_0_Background(r.nextInt(900)-50);//create new item
					int ra = r.nextInt(4);
					if(ra == 0)
					{
						item_class[i] = new Item_0_Background(r.nextInt(900)-10);  //create new item
					}
					else if(ra == 1)
					{
						item_class[i] = new Item_1_Fast(r.nextInt(900)-10);  //create new item
					}
					else if(ra == 2)
					{
						item_class[i] = new Item_2_SLOW(r.nextInt(900)-10); //	swich to different item
					}
					else if(ra == 3)
					{
						item_class[i] = new Item_3_Score(r.nextInt(900)-10);
					}
				}
			}
			//set score
			score_class.SCORE();
			score_class.health(player_class, enemy_class, sprite_sheet_class);
 
			/* msuic when player is dead */
			if(player_class.isDEAD() == true)
			{
				sprite_sheet_class.theme_music.stop();
				sprite_sheet_class.dead_music.play();
			}	
 
			repaint();
			try
			{
				Thread.sleep(10);
			}
			catch(InterruptedException e)
			{
				e.printStackTrace();
			}
		}
	}/*** end of run method ***/
 
 
 
 
 
 
 
	/*** update method ***/
	@Override
	public void update(Graphics g) 
	{
		if(dbImage == null) //if image is empty than create new image
		{
			dbImage = createImage(this.getSize().width, this.getSize().height);
			dbGraphics = dbImage.getGraphics();
		}
		dbGraphics.setColor(getBackground());  //set the background color
		dbGraphics.fillRect(0, 0, this.getSize().width, this.getSize().height);
		dbGraphics.setColor(getForeground());
		paint(dbGraphics);     //call paint method
		g.drawImage(dbImage, 0, 0, this);
	}/*** end of update method ***/
 
 
 
 
 
 
	/*** paint method ***/
	@Override
	public void paint(Graphics g) 
	{
		background_class.paint(g, this);
		ground_class.paint(g);             //call paint method from Ground class  //draw ground than player on top
 
		player_class.paint(g);             //call paint method from Player classr 
		for(int i = 0; i < platform_class.length; i++)
		{ platform_class[i].paint(g); }
		shoot_class.paint(g, player_class); //draw bullet
		if(enemy_class.isDEAD() == false)  //draw enemy if it's not dead
		{
			enemy_class.paint(g);
		}
		for(int i = 0; i < item_class.length; i++)
		{ item_class[i].paint(g); }
		score_class.paint(g, this, player_class);
 
	}/*** end of paint method ***/
 
 
 
 
 
 
	/*** stop method ***/
	@Override
	public void stop()
	{
 
	}/*** end of stop method ***/
 
	/*** destroy method ***/
	@Override
	public void destroy()
	{
	}/*** end of destroy method ***/
 
 
 
 
 
 
 
 
 
 
 
 
 
	/************** key *********************/
	@Override
	public void keyPressed(KeyEvent e)
	{
		int keys = e.getKeyCode();
		if(keys == KeyEvent.VK_RIGHT) 
		{
			player_class.hitRIGHT();
			sprite_sheet_class.running_music.loop();
		}
		else if(keys == KeyEvent.VK_LEFT)
		{
			player_class.hitLEFT();
			sprite_sheet_class.running_music.loop();
 
		}	
		else if (keys == KeyEvent.VK_UP)
		{
			player_class.hitJUMP(ground_class);
			sprite_sheet_class.jump_music.play();
 
		}
		else if(keys == KeyEvent.VK_SPACE)
		{
			shoot_class.hitSHOOT();
		}
	}
	@Override
	public void keyReleased(KeyEvent e)
	{
		int keys = e.getKeyCode();
		if(keys == KeyEvent.VK_RIGHT) 
		{
			player_class.stopRIGHT();
			sprite_sheet_class.running_music.stop(); 
		}
		else if(keys == KeyEvent.VK_LEFT)
		{
			player_class.stopLEFT();
			sprite_sheet_class.running_music.stop(); 
		}	
		else if(keys == KeyEvent.VK_SPACE)
		{
			shoot_class.stopSHOOT();
		}
 
	}
	@Override
	public void keyTyped(KeyEvent e){}
 
 
 
 
 
 
 
 
/*** mouse mostion ***/
	@Override
	public void mouseDragged(MouseEvent e) {}
	@Override
	public void mouseMoved(MouseEvent e) 
	{
			if(e.getX() > 270 && e.getX() < 460)
			{
				if(e.getY() > 310 && e.getY() < 350)
				{
					mouseIn = true;
				}
			}
 
 
			if(e.getX() < 280 || e.getX() > 460)
			{
					mouseIn = false;
 
			}
			if(e.getY() < 320 || e.getY() > 360)
			{
				mouseIn = false;
			}
	}
 
 
 
 
 
 
 
 
 
	/************    MOUSE  **********/
	@Override
	public void mousePressed(MouseEvent e)
	{
		//start game over
		if(mouseIn == true)
		{
			start();
		}
		//mouseIn = false;
	}
	public void mouseReleased(MouseEvent e){}
	public void mouseClicked(MouseEvent e){}
	public void mouseEntered(MouseEvent e){}
	public void mouseExited(MouseEvent e){}
 
 
 
 
}

You've posted several versions of this question several times now, and you always get the same response: you're going to have to boil your problem down to an SSCCE, just a single ball moving around on screen. Reposting all of your code again isn't making it more likely people will help you, it's making it less likely. I'll be happy to help you, but you have to get rid of all that extra code and condense it into a single class that we can copy and run.

You need to have a game loop called from a Timer that fires several times a second (30 fps should work). Each frame, you need to check the state of the input and update the moving Object's location and repaint everything. Once you have that working, we can go from there.

If you have a problem with this post feel free to report it. and i am not sure if you are trying to get the highest score of posting the most posts here. but you dont have to comment on every post.

2nd i already know i have to use timer but i do not understant it. you need to explain more on logic of timer. you said not to use main game loop. do you mean dont have to use run method and use some kind of timer method? i am using thread which slow down the frames too. ex Thread.sleep(10); isnt this the same things? if bullet is a image than why cant i do x+=dx?

I been using java for 4 weeks now and this is the first time learning about timers.

i wish there were a way to block people... it p*** me off when iam just trying to learn new stuff and people are making it more hard.

Originally Posted by hwoarang69

If you have a problem with this post feel free to report it.

I expressed my problem with your posts to you directly. The only person you're hurting is yourself. I'm trying to help you and to help you get help, but you keep posting questions that we can't really answer, and now immature bickering that isn't going to get you anywhere.

Originally Posted by hwoarang69

and i am not sure if you are trying to get the highest score of posting the most posts here. but you dont have to comment on every post.

I have a special interest in game development in Java, which is why your posts keep catching my eye. And I know from the structure of your post that nobody else is going to be able to help you, because you've structured your question in a pretty hard-to-answer way (as should be evidenced by the fact that his is the 5th time you've posted this question). Don't worry, I'll add you to my ignore list if this attitude continues.

Originally Posted by hwoarang69

2nd i already know i have to use timer but i do not understant it. you need to explain more on logic of timer. you said not to use main game loop. do you mean dont have to use run method and use some kind of timer method? i am using thread which slow down the frames too. ex Thread.sleep(10); isnt this the same things?

If the problem is that you don't understand Timers, then by all means, ask a specific question about them. Instead, you've simply reposted the same question without any mention of what you've looked into with Timers. Using Threads is certainly another way to go, but it introduces problems (tying up the EDT, doing gui work off the EDT, etc) that might not be great for a novice to deal with.

Originally Posted by hwoarang69

if bullet is a image than why cant i do x+=dx?

Dunno. Throw together an SSCCE and we can take a look at why that might be.

Originally Posted by hwoarang69

I been using java for 4 weeks now and this is the first time learning about timers.

Sounds like the basic tutorials and the API should be your best friend for the near future.

Originally Posted by hwoarang69

i was direct with you until other people start butting in.
...and yet here you are doing the same thing.

False. You've been asked to look into Timers and to put together an SSCCE. I'll be more than happy to help after you do that. Otherwise I'm going to lock this post. Up to you how you proceed from here.