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someguy127

Member Since 26 Apr 2012
Offline Last Active May 15 2012 09:48 AM

Topics I've Started

Event Handling problems

15 May 2012 - 06:30 AM

Hi, I am working on one of my first games in java and I was having a big problem with the Event Handler where it would only work somewhere in the realm of 1/10 times. If anyone has any idea on how to solve this problem I'd be much obliged.

This is my game panel constructor, I have global variables called isRight, isDown etc... and in the main gameloop I check if they are true
in which case my character moves so many pixels
public GamePanel(){
  setFocusable(true);
  requestFocus();
  setPreferredSize(new Dimension(GWIDTH,GHEIGHT));
  makeGrid();
  setBackground(Color.white);
  addKeyListener(new KeyListener(){
  
   public void keyPressed(KeyEvent e) {
	switch(e.getKeyCode())
	{
	case KeyEvent.VK_RIGHT:
	 isRight = true;
	 System.out.println("Rightpressed");
	 break;
	case KeyEvent.VK_LEFT:
	 isLeft = true;
	 break;
	case KeyEvent.VK_UP:
	 isUp = true;
	 break;
	case KeyEvent.VK_DOWN:
	 isDown = true;
	default:
	 break;
	}
  
   }

   public void keyReleased(KeyEvent e) {
	switch(e.getKeyCode())
	{
	case KeyEvent.VK_RIGHT:
	 isRight = false;
	 System.out.println("Rightreleased");
	 break;
	case KeyEvent.VK_LEFT:
	 isLeft = false;
	 break;
	case KeyEvent.VK_UP:
	 isUp = false;
	 break;
	case KeyEvent.VK_DOWN:
	 isDown = false;
	default:
	 break;
	}
  
   }

   public void keyTyped(KeyEvent e) {
  
  
   }
  
  });
}
This here is the update methods and run() game loop, I don't think that the problem is in here because I put in a print statement in each of these methods and they ran consistently.
public void gameUpdate()
{
   //update game logic

   if(isRight){
	player.x += player.speed;
   }
   if(isLeft){
	player.x -=player.speed;
   }

}
public void run()
{
  while(running)
  {
  
   gameUpdate();
   gameRender();
   paintScreen();
   try{
	game.sleep(20);
   }
   catch(Exception e){}
  }
}

And Just incase it is not a problem with my constructor, here is my complete code if anyone is willing to look through it

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class GamePanel extends JPanel implements Runnable{

/**
  *
  */
private static final long serialVersionUID = 1L;
//double buffering
Image dbImage;
Graphics dbg;

Rectangle[] grid = new Rectangle[250];

//JPanel Vars
public static final int GWIDTH = 500, GHEIGHT = 500;
static final Dimension gameDim = new Dimension(GWIDTH,GHEIGHT);

public boolean isRight = false,isLeft = false, isUp = false,isDown=false;

private Thread game;
private volatile boolean running = false;

Player player = new Player();
public GamePanel(){
  setFocusable(true);
  requestFocus();
  setPreferredSize(new Dimension(GWIDTH,GHEIGHT));
  makeGrid();
  setBackground(Color.white);
  addKeyListener(new KeyListener(){
  
   public void keyPressed(KeyEvent e) {
    switch(e.getKeyCode())
    {
    case KeyEvent.VK_RIGHT:
	 isRight = true;
	 System.out.println("Rightpressed");
	 break;
    case KeyEvent.VK_LEFT:
	 isLeft = true;
	 break;
    case KeyEvent.VK_UP:
	 isUp = true;
	 break;
    case KeyEvent.VK_DOWN:
	 isDown = true;
    default:
	 break;
    }
   
   }
 
   public void keyReleased(KeyEvent e) {
    switch(e.getKeyCode())
    {
    case KeyEvent.VK_RIGHT:
	 isRight = false;
	 System.out.println("Rightreleased");
	 break;
    case KeyEvent.VK_LEFT:
	 isLeft = false;
	 break;
    case KeyEvent.VK_UP:
	 isUp = false;
	 break;
    case KeyEvent.VK_DOWN:
	 isDown = false;
    default:
	 break;
    }
   
   }

   public void keyTyped(KeyEvent e) {
   
   
   }
  
  });
  addMouseListener(new MouseListener(){
 
   public void mouseClicked(MouseEvent e) {
    // TODO Auto-generated method stub
   
   }
   @Override
   public void mouseEntered(MouseEvent e) {
    // TODO Auto-generated method stub
   
   }
   @Override
   public void mouseExited(MouseEvent e) {
    // TODO Auto-generated method stub
   
   }
   @Override
   public void mousePressed(MouseEvent e) {
    // TODO Auto-generated method stub
   
   }
   @Override
   public void mouseReleased(MouseEvent e) {
    // TODO Auto-generated method stub
   
   }
  
  });
 
}
private void makeGrid(){
  int x=0,y=0;
  for(int i = 0; i <grid.length;i++)
  {
   if(i % 16 != 0 | i ==0){
    grid[i] = new Rectangle(x,y,32,32);
    x+=32;
   }
   else{
    y+=32;
    x = 0;
    grid[i] = new Rectangle(x,y,32,32);
    x+=32;
   }
  }
}
private void startGame()
{
  if(game == null || !running){
   running = true;
   game = new Thread(this);
   game.start();
  
  }
}
public void stopGame()
{
  if(game != null || running)
  {
   running = false;
  }
}
public void addNotify()
{
  super.addNotify();
  startGame();
}
//Game Rendering
public void gameUpdate()
{
   //update game logic
 
   if(isRight){
    player.x += player.speed;
   }
   if(isLeft){
    player.x -=player.speed;
   }
 
}
private void gameRender()
{
  if(dbImage == null)
  {
   dbImage = createImage(GWIDTH,GHEIGHT);
   if(dbImage == null)
   {
    System.err.println("Error in Game Render");
    return;
   }
   else
   {
    dbg = dbImage.getGraphics();
   }
  }
  dbg.setColor(Color.WHITE);
  dbg.fillRect(0, 0, getWidth(),getHeight());
  //drawGAME
  draw(dbg);
}
public void draw(Graphics g)
{
  //draw things here
  g.setColor(Color.black);
  //player.draw(g);
  g.fillRect(player.x, player.y, player.width, player.height);
 
  g.setColor(Color.RED);
  for(int i = 0; i < grid.length; i++){
   g.drawRect(grid[i].x, grid[i].y, grid[i].width, grid[i].height);
  }
}

public void paintScreen()
{
  Graphics g;
  try{
   g = this.getGraphics();
   if(dbImage != null && g!= null){
    g.drawImage(dbImage,0,0, null);
   }
   Toolkit.getDefaultToolkit().sync();
   g.dispose();
  }
  catch(Exception e)
  {
   System.err.println("Error in paintScreen");
  }
 
}
//logic
public void run()
{
  while(running)
  {
  
   gameUpdate();
   gameRender();
   paintScreen();
   try{
    game.sleep(20);
   }
   catch(Exception e){}
  }
}
}

Language Comparison

28 April 2012 - 12:21 AM

Hey everyone I am new here, and I have begun the wonderful journey of being a game programmer.

first a little background, I am currently a college student studying Computer Science. I love programming, and more recently I love game programming. Unfortunately my school doesn't teach game programming as part of the core Computer Science Major so I have been tasked with learning this art on my own. What I have learned so far is the basic idea of Game loops, Movement, Collision etc.. just basic things you pick up from online tutorials. My languages so far have been Java, and C# with the XNA game library, I know the basics of both but when it comes to game programming I use C# because XNA takes care of the Visual aspect of it.

Well any way on to the main point of this topic, I know that every language has it's benefits and disadvantages, and I am looking for the ones that I would like to work with. So if you guys would be so kind as to pick some languages and give me the pros and cons of using it to make games, that would be great.

Also if there are any basic concepts of game programming I need to learn, please let me know.

Thanks a ton

-Someguy127

PARTNERS