Thread: bounding box collision

hi im trying to make a packman style game for an assignment but the problem im having is i cant remove the munchies which the monster is supposed to eat,
im trying to make an array that will remove the munchies. ive made an array called munchie that i want setting to 1 if it is to be draw and if it is 0 then the munchie will disapear, ive highlighted in green the bit im having problems with.

i hope im making sence

please help thankyou

import javax.swing.*;
import java.applet.AudioClip;
import java.awt.*;
 
/**
 *
 * <p>Title: MonsterGame</p>
 * <p>An interactive animation with Munchies and user-controlled Monster</p>
 * <p>Copyright: Copyright (c) 2005</p>
 * @author Cathy French
 * @version 1.2   September 2006
 */
public class MonsterGame extends ICGGSPanel
{
    // game constants
    private final int NUM_MUNCHIES = 5;   // the number of munchies to be displayed
 
    // game information
    private  int score;  // player score (not currently used)
    private  int boardWidth, boardHeight;  // game board dimensions
 
    // Munchie data
    private  int[] munchieXPos;  // x coordinate of top left corner of each munchie image
    private int[] munchieYPos;   // y coordinate of top left corner of each munchie image
    private int[] munchieAnimationCount;  // current animation counter for each munchie
    private  Image munchieImage1, munchieImage2;  // the images to display
    private int munchieWidth, munchieHeight;  // munchie dimensions
 
 
    // Monster data
    private  int monsterXPos, monsterYPos;  // coordinates of top left corner of monster
    private int monsterSize;  // size of monster
    private  int monsterSpeed;  // monster speed in pixels per frame
    private  Color monsterColour;  
    private  int monsterDirection;  // direction monster is moving
    private  int monsterAnimationCount;  // animation counter for monster
    private AudioClip monsterBumpWallSound;  // sound to play when monster hits a wall
 
 
 
    int[]munchie;
 
    int arcAngle;
    int startAngle = 0;
    int startAngle2;
    /**
     * Constructor - creates a game using the two images and audio clip
     * @param image1 Image - the first image for the munchies
     * @param image2 Image - the second image for the munchies
     * @param theAudio AudioClip - sound to be played when the monster hits a wall
     */
    public MonsterGame(Image image1, Image image2, AudioClip theAudio)
    {
        // initialise Munchie information
        // create the arrays, need one "slot" for each munchie
        munchieXPos = new int[NUM_MUNCHIES];
        munchieYPos = new int[NUM_MUNCHIES];
        munchieAnimationCount = new int[NUM_MUNCHIES];
        // store the munchie images
        munchieImage1 = image1;
        munchieImage2 = image2;
        // the munchie is the same size as the loaded image
        munchieWidth = image1.getWidth(null);
        munchieHeight = image1.getHeight(null);
 
 
        // initialise the Monster information
        monsterColour = Color.red;
        monsterBumpWallSound = theAudio;
        monsterSize = 30;
 
        // initialise background colour
        this.setBackground(Color.WHITE);
    }
 
    /**
     * Use to reset the game
     * sets score to zero
     * sets up Monster and munchies in random positions
     */
 
    public void resetGame()
    {
        // make the game board the same size as the panel
        boardWidth = this.getWidth();
        boardHeight = this.getHeight();
        score = 0;
        // reset the Monster to a random position and direction
        monsterXPos = (int)(Math.random() * (boardWidth - monsterSize));
        monsterYPos = (int)(Math.random() * (boardHeight - monsterSize));
        monsterDirection = (int)(Math.random() * 4) + 1;
        monsterSpeed = 5;
        monsterAnimationCount = 0;
 
        // reset all the munchies to random positions and different animation counts
        for (int i = 0; i < NUM_MUNCHIES; i++) {
            munchieXPos[i] = (int)(Math.random() * (boardWidth - munchieWidth));
            munchieYPos[i] = (int)(Math.random() * (boardHeight - munchieHeight));
            munchieAnimationCount[i] = i % 10;
        }
 
    }
 
    /**
     * overrides superclass method
     * processes user input
     * @param input int - code for the lastest user input
     */
    public void processInput(int input)
    {
         if (input > 0 && input < 5)  // if the input is a valid direction
            monsterDirection = input;  // set the current direction to the input
    }
 
    /**
     * overrides superclass method
     * updates the game objects
     */
    public void update()
    {
        // update moster direction and animation
         switch (monsterDirection)
        {
          case Input.RIGHT:
              startAngle2 = startAngle = 10;
              // monster is moving right, increase its X-coordinate
              monsterXPos = monsterXPos + monsterSpeed;
              if (monsterXPos > (boardWidth - monsterSize)) // has the monster hit the right wall?
              {
                  monsterXPos = boardWidth - monsterSize;  // move it back to just touching right wall
                  monsterBumpWallSound.play();  // play an appropriate sound
 
              }
 
              monsterDirection = Input.NONE;
 
              break;
 
              case Input.LEFT:
                  startAngle2 = startAngle = 185;
                  monsterXPos = monsterXPos - monsterSpeed;
if (monsterXPos < 0) // has the monster hit the right wall?
              {
                  monsterXPos = 0;  // move it back to just touching right wall
                  monsterBumpWallSound.play();  // play an appropriate sound
              }
 
                  monsterDirection = Input.NONE;
 
                  break;
 
                  case Input.DOWN:
                      startAngle2 = startAngle = 280;
              //monster is moving right, increase its X-coordinate
              monsterYPos = monsterYPos + monsterSpeed;
              if (monsterYPos > (boardWidth - monsterSize)) // has the monster hit the right wall?
              {
                  monsterYPos = boardWidth - monsterSize;  // move it back to just touching right wall
                  monsterBumpWallSound.play();  // play an appropriate sound
              }
 
              monsterDirection = Input.NONE;
 
               break;
 
              case Input.UP:
                  startAngle2 = startAngle = 100;
                  monsterYPos = monsterYPos - monsterSpeed;
                        if (monsterYPos < 0) // has the monster hit the right wall?
                            {
                                monsterYPos = 0;  // move it back to just touching right wall
                                monsterBumpWallSound.play();  // play an appropriate sound
                            }
 
                  monsterDirection = Input.NONE;
 
 
              // to do - fill in appropriate code for other directions
        }
 
 
 
 
         if (monsterAnimationCount < 5)
        {
 
            // for frames 0 to 4, his mouth gradually closes
            arcAngle = 310 + 10 * monsterAnimationCount;
            startAngle2 = startAngle2 - 5*monsterAnimationCount;
        }
        else
        {
 
             //for frames 5 to 9, it opens again
            arcAngle = 310 + (10  - monsterAnimationCount) * 10;
            startAngle2 = startAngle2 - (10 - monsterAnimationCount) * 5;
        }
 
 
 
 
 
         // increment the monster animation counter 
       monsterAnimationCount++;
       if (monsterAnimationCount >= 10)  // when the counter gets to 10, set it back to 0
           monsterAnimationCount = 0;
 
       // update each munchie animation
        for (int i = 0; i < NUM_MUNCHIES; i++)
        {
           // increment the animation counter 
            munchieAnimationCount[i]++;
            if (munchieAnimationCount[i] >= 10) // when the counter gets to 10, set it back to 0
                munchieAnimationCount[i] = 0;
        }
    }
 
 
    /**
     * called by system after repaint() call (or Applet moved or resized)
     * @param g Graphics  object for painting on
     */
    public boolean collisionDetection(int xPos1, int yPos1, int Height1, int Width1, int xPos2, int yPos2, int Height2, int Width2)
{
 
int bottom1, bottom2;
int top1, top2;
int left1, left2;
int right1,right2;
 
left1= xPos1;
left2 =xPos2;
right1 = xPos1+Width1;
right2 = xPos2+Width2;
top1 = yPos1;
top2 = yPos2;
bottom1 = yPos1+Height1;
bottom2 = yPos2+Height2;
 
if (bottom1 < top2) return(true);
if (top1 > bottom2) return(true);
 
if (right1 < left2) return(true);
if (left1 > right2) return(true);
 
return (false);
}
 
 
public void paintComponent(Graphics g)
 
{
 
super.paintComponent(g); // paint the default panel
 
// paint each of the Munchies in turn
//if(munchie > 0 )
{
 
for (int i = 0; i < NUM_MUNCHIES; i++)
 
  [COLOR="lime"]if(munchie[i]>1 )[/COLOR]
 
{
Image im; // this is the image to be displayed
if (munchieAnimationCount[i] < 5)
{
im = munchieImage1;
}
else
{
// display the second image when the counter is between 5 and 9
im = munchieImage2;
}
 
// draw the image in the correct position
g.drawImage(im, munchieXPos[i], munchieYPos[i], null);
}
 
g.setColor(monsterColour);
g.fillArc(monsterXPos, monsterYPos, monsterSize, monsterSize, startAngle, arcAngle);
g.setColor(Color.BLACK);
g.drawRect(0, 0, boardWidth-1, boardHeight-1);
 
 
 
//then to implement:
for(int i=0;i<NUM_MUNCHIES;i++)
 
{
boolean Flag = collisionDetection(monsterXPos, monsterYPos, monsterSize,monsterSize ,munchieXPos[i],munchieYPos[i],20,20);
 
if (Flag==false)
{
[COLOR="Lime"]munchie[i]=0;[/COLOR]
 
score=score+100;
Flag=true;
}
}
}
}
}

First, if this is the code in its entirety, it doesn't look like the array munchie is allocated (eg munchie = new int[NUM_MUNCHIES] )
Second:

Originally Posted by beechy34

ive made an array called munchie that i want setting to 1 if it is to be draw and if it is 0 then the munchie will disapear

if ( munchie[i]>1 ){
//draw image
}

The conditional above does not follow the guidelines you laid out for 1 to draw, 0 to not draw...perhaps try

if ( munchie[i] == 1 ){
//draw image
}

Hope this helps

hay thats helped me alot thanks,
but the munchies still wont disapear when the monster goes over them.
here is an explanation of what someone told me should happen

the flag gets set to false if their's been a collision so that particular munchie gets set a value of one. If you go up to your Draw section and just add a line checking whether the value is larger than 0 before the munchie is drawn, it shouldn't render it to the screen.

here is the code again but just a small piece

public boolean collisionDetection(int xPos1, int yPos1, int Height1, int Width1, int xPos2, int yPos2, int Height2, int Width2)
{
 
int bottom1, bottom2;
int top1, top2;
int left1, left2;
int right1,right2;
 
left1= xPos1;
left2 =xPos2;
right1 = xPos1+Width1;
right2 = xPos2+Width2;
top1 = yPos1;
top2 = yPos2;
bottom1 = yPos1+Height1;
bottom2 = yPos2+Height2;
 
if (bottom1 < top2) return(true);
if (top1 > bottom2) return(true);
 
if (right1 < left2) return(true);
if (left1 > right2) return(true);
 
return (false);
}
 
 
public void paintComponent(Graphics g)
 
{
    int munchie[]= new int[NUM_MUNCHIES];
 
super.paintComponent(g); // paint the default panel
 
// paint each of the Munchies in turn
//if(munchie > 0 )
{
 
for (int i = 0; i < NUM_MUNCHIES; i++)
 
  if(munchie[i]==0 )
 
{
Image im; // this is the image to be displayed
if (munchieAnimationCount[i] < 5)
{
im = munchieImage1;
}
else
{
// display the second image when the counter is between 5 and 9
im = munchieImage2;
}
 
// draw the image in the correct position
g.drawImage(im, munchieXPos[i], munchieYPos[i], null);
}
 
g.setColor(monsterColour);
g.fillArc(monsterXPos, monsterYPos, monsterSize, monsterSize, startAngle, arcAngle);
g.setColor(Color.BLACK);
g.drawRect(0, 0, boardWidth-1, boardHeight-1);
 
 
 
//then to implement:
for(int i=0;i<NUM_MUNCHIES;i++)
 
{
boolean Flag = collisionDetection(monsterXPos, monsterYPos, monsterSize,monsterSize ,munchieXPos[i],munchieYPos[i],20,20);
 
if (Flag==false)
{
munchie[i]=1;
 
 
//score=score+100;
Flag=true;
}
}
}
}
}

please help me thanks