Help With Snake Game

[Amil Mehmedagic]

Hello!

I am trying to get the rat to stop when its centre falls within 5 pixels of the head of the snake. The head of the snake is the first element in an array of 25 snake objects. There's five classes to this application altogether and I am providing the Snake, Rat and SnakeRatPanel classes to help you on this.

I think the problem is in the moveRat method of the SnakeRatPanel class, as it is here where I am controlling the movement of the rat. The condition
to stop the rat when its centre is within 5 pixels of the snake's head

while (getX() > (snake.getX(0)+rat.getRadius()) || getY() > (snake.getY(0)+rat.getRadius()) || getX() < (snake.getX(0)-rat.getRadius()) || getY() < (snake.getY(0)-rat.getRadius()))  

doesn't do anything.

I appreciate your help on this one!
Below are the three classes: Rat, Snake and SnakeRatPanel:

public class Snake {

private int segs, segSize=10;
  private int [] x; 
  private int [] y; 
  private Color [] colour;
   
public Snake(int s) {
segs = s;
x = new int [segs];
y = new int [segs];
colour = new Color [segs];
int i=segs-1;
  while (!(i<0)) {
 
   x[i] = segSize*i;
   y[i] = 0;
   
   if (i%4==0) {colour[i]=Color.orange;} 
   if (i%4==1) {colour[i]=Color.yellow;} 
   if (i%4==2 || i%4==3) {colour[i]=Color.black;} 
   
   i=i-1;
  }
  colour[0]=Color.green;
}
 
public void move(int dir) {
int right=0, left=1, up=2, down=3;
  int i=segs-1; 
while (i!=0)  {
 x[i] = x[i-1];
   y[i] = y[i-1];
   i=i-1;
}
if(dir==right) {x[0] = x[0] + segSize;}
if(dir==left)  {x[0] = x[0] - segSize;}
if(dir==up)    {y[0] = y[0] - segSize;}
if(dir==down)  {y[0] = y[0] + segSize;}
}

public Color getColour(int i) {return colour[i];}
public int   getX(int i) {return x[i];}
  public int   getY(int i) {return y[i];}
  public int   getSize() {return segs;}
  public int   getSegSize() {return segSize;}
}
 
public class Rat {
private int north=0,east=1,south=2,west=3;
 
private int x, y;
private int orient;
private int radius=5;
private int step=5;
  private int side;
  private Color colour=Color.red;
  private double prob;
 
  public Rat(int sd, double p) {
side=sd;
orient=(int)(4*Math.random());
x=     (int)(side*Math.random());
y=     (int)(side*Math.random());
prob=p;
}
 

public void move () {
if      (orient==east) {  
    if (x+radius>side) {orient=west;}
      else {x=x+step;}}  
    else if (orient==west) {   
    if (x<radius) {orient=east;}
        else {x=x-step;}}
    else if (orient==south) {   
    if (y+radius>side) {orient=north;} 
        else {y=y+step;}}           
    else if (orient==north) {   
    if (y<radius) {orient=south;}
        else {y=y-step;}}
}
 
  
  public int      getX()      {return x;}
public int      getY()      {return y;}
public int      getRadius() {return radius;}
  public Color    getColour() {return colour;}
 
}
 
public class SnakeRatPanel extends JPanel {
  
private Snake snake;
private Rat rat;
private int size=25,side=500,delay;
private double prob=0.05;

  public SnakeRatPanel () {
   delay = DialogBox.requestInt("Delay rat by time in ms");
   snake = new Snake(size);
   rat   = new Rat(side,prob);
   setBackground(Color.white);     
   addKeyListener(new KeyAdapter() {
    public void keyPressed(KeyEvent evt) {
       moveSnake(evt);
    }
   });
  }
    
  private void moveSnake(KeyEvent e) {
int keyCode = e.getKeyCode();
if(keyCode==KeyEvent.VK_RIGHT) {snake.move(0);}
if(keyCode==KeyEvent.VK_LEFT)  {snake.move(1);}
if(keyCode==KeyEvent.VK_UP)    {snake.move(2);}
if(keyCode==KeyEvent.VK_DOWN)  {snake.move(3);} 
repaint();
  }
  
  public void moveRat() {
  
  //int count = 0;
  
  while (getX() > (snake.getX(0)+rat.getRadius()) || getY() > (snake.getY(0)+rat.getRadius()) || getX() < (snake.getX(0)-rat.getRadius()) || getY() < (snake.getY(0)-rat.getRadius()))  {
  //while (getX() < snake.getX(0)+rat.getRadius()) {
      rat.move();
  repaint();
    Delay.milliseconds(delay);
  }
  
  }
 
  public void paintComponent (Graphics g) {
   super.paintComponent(g);
   requestFocus();   
   g.translate(50,50);
   drawSnake(g);
   drawRat(g);
  }
    
  private void drawSnake (Graphics g) {
    int i=snake.getSize()-1;
   while (!(i<0)) {  
    g.setColor(snake.getColour(i));
   g.fillRect(snake.getX(i), snake.getY(i), 
             snake.getSegSize(), snake.getSegSize());
   i=i-1;
   }
  }
  
  private void drawRat (Graphics g) {
    g.setColor(rat.getColour());
    int r = rat.getRadius();
    g.fillOval(rat.getX()-r, rat.getY()-r, 2*r,2*r);
  }
  
}
  

[Stefan Wagner]

I modified it for my taste, and to get a better overview.

 public void moveRat () 
{
//int count = 0;
int rr;
int sy;
int sx;
int x, y;
do
{
rr = rat.getRadius ();
sy = snake.getY (0);
sx = snake.getX (0);
x = rat.getX ();
y = rat.getY ();
//while (getX () < snake.getX (0)+rat.getRadius ()) 
{
rat.move ();
repaint ();
delay (delayt);
}
System.out.print ("#> (" + x +  ", " + y + ")\t");
                System.out.println ("[(" +sx+  ", " +sy+ ") " +rr+ "] " );
}while (x > (sx + rr) || 
y > (sy + rr) || 
x < (sx - rr) || 
y < (sy - rr));
System.out.println ("#> hit !!! " );
}

Your getX () getY () where without specified object, so 'this' was asumed.
There is no SnakeRatPanel.getX () but a JPanel.getX () and that was called.
I guess you wanted to call rat.getX ();

An additional feature is my real sophisticated debug-code

[Amil Mehmedagic]

Thanks Stefan!

This is precisely what I wanted to accomplish! And thankx for the debug code too!