[Jayree]

Hi there guys, i've got an assignment in university due tomorrow. And im struggling on finishing my code. Its 2D btw.

Basically we have to make a Lunar Lander type game (Accelerating, gravity, crash zone, land pad etc).

Ive done all the gravity, acceleration.

But i'm having trouble making the certain areas of my screen a crash zone and land pad.

The crash zone is basically all the floor (no including the land pad). so that when the image hits the crash zone it changes to an explosiong gif,

And the land pad i need to have the lander speed low enough and it to land on the land pad to be a successfull landing if that makes sense?

Basically I can't get my head around how i tell it that the floor area is solid and is a crash zone and that the land pad is solid and able to land on?

Lunar Lander

sort of like that game but not as many complex cliffs etc.

Any helps appreciated cheers - Jay.

/**
 * Write a description of class LunarLander here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */

//Functionality
import javax.swing.JFrame;      // window functionality
import java.awt.Color;          // RGB color stuff

import javax.swing.Timer;       // import timer functionality
import java.awt.event.*;        // functionality for the event fired by the timer

import java.awt.*;              // Graphics stuff from the AWT library, e.g. Graphics
import javax.swing.*;           // Graphics stuff from the Swing library, e.g. JLabel
import java.awt.image.BufferedImage; // Graphics drawing canvas
import java.awt.event.KeyEvent;
import java.util.Random;
public class LunarLander extends JFrame{

    // The Java window
    private static JFrame window;
    
    // Graphics "Handle"
    private static Graphics gr; 
    
    // Image Storage
    private static Image theBackground; // Background Image
    private static Image theLander; // PNG of the Lunar Lander
    private static Image theBang; // Animated Explosion
    public static Random randomGen= new Random();
    
    private static int landerX = randomGen.nextInt(800 - 50), landerY = 50; // Starting position of the lander
    private static boolean  explosion=false; // Sets explosion to false
    public static int speedY = 0;
    public static int speedX = 0;
    public static double speedStopping = 1;
    public static int speedAccelerating = 2;
    public static int topLandingSpeed = 5;
    
    
    // Main Method, Create window
    public static void main(String[] args) {
        
        //Window Setup
        window = new JFrame(); // Renames the new window
        
        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // Sets the X to close
        window.setTitle("Moon Lander, Can you be the first man on the moon!"); // Title Name
        window.setSize(800, 600); // Window Size
        window.setResizable(true); // Disables resizable window
        window.setLocationRelativeTo(null); // Sets location to top of the screen
        
        BufferedImage canvas=new BufferedImage(800,600,BufferedImage.TYPE_INT_ARGB); // Creates A Canvas
        gr=canvas.getGraphics(); // Creates handle for drawing on the canvas
        JLabel label=new JLabel(new ImageIcon(canvas)); // Creates label to draw on
        window.add(label);
        
        window.setVisible(true); // Displays above
        
        //Loading Images
        theBackground = GameImage.loadImage("Images//Background.png"); // Loads background
        theLander = GameImage.loadImage("Images//LunarLander.png"); // Loads lander
        theBang = GameImage.loadImage("Images//explosion.gif"); // Loads Explosion
             
        GameKeyboard.initialise(); // Starts keyboard input
        
        
        
        //Timer Setup
        ActionListener taskPerformer = new ActionListener()
            {
                public void actionPerformed(ActionEvent evt) // Calls the actionPerformed() method
                {
                    doTimerAction();
                }    
            };
        Timer ScreenTimer = new Timer(75, taskPerformer); // Creates Timer
        ScreenTimer.start(); // Starts Timer
    }
    
    // Method to draw all needed images, then timer resets to display on the screen
    private static void doTimerAction() {
        
        gr.drawImage(theBackground, 0, 0, null); // Overwrites everything with the background image
        
        // User Instructions
        gr.setColor( Color.red );  // Sets colour red
        gr.setFont(new Font("Arial", Font.BOLD, 16)); // Sets font
        gr.drawString("Arrow keys to move, land on the platform to win", 200,200); // Output and location
        

        
        // Get keys pressed from the keyboard
        char key= GameKeyboard.getKey();
        int specialKey=GameKeyboard.getSpecialKey();
        
        
        //Keyboard Binding
        
        
        if (landerY >= 500){
            gr.drawImage(theBang, landerX, landerY, null);
            gr.setColor( Color.red );  // Sets colour red
        gr.setFont(new Font("Arial", Font.BOLD, 16)); // Sets font
        gr.drawString("You have crashed! Restart game!", 200,400);
        }else{  
            
            
        if (specialKey == 38){
            speedY -= speedAccelerating;
        }else{ 
            speedY += speedStopping;
        }  
        
        if (specialKey == 37){
            speedX -= speedAccelerating;
        }else{
            speedX += speedStopping;
        }
            
        if (specialKey == 39){
            speedX += speedAccelerating;
        }else{
            speedX -= speedStopping;
        }
        
        landerX += speedX;
        landerY += speedY;
        

        

        gr.setColor( Color.red );  // Sets colour red
        gr.setFont(new Font("Arial", Font.BOLD, 16)); // Sets font
        gr.drawString("speedX" + speedX + "speedY" + speedY + "speedAccelerating" +speedAccelerating + "speedStopping" + speedStopping + "landerY" + landerY + "landerX" + landerX, 200,400);
        gr.drawImage(theLander, landerX, landerY, null); // Draws lander and its position
        
    }    
    window.repaint();  // Re paints everything onto the screen
    }    
}

[NormR]

how i tell it that the floor area is solid and is a crash zone and that the land pad is solid and able to land on?

What values can the program look at to make that decision?

There are missing classes when compiling for testing.

[Jayree]

Oops forgot to post them.

/* 
 * This class implements a simple keyboard event dispatcher. Normally a Java application attaches so
 * called 'KeyListeners' to individual objects such as text input fields. In a game, however, we want
 * all parts of the game window to respond to keyboard inputs without having to click on them first.
 * We also don't want the repetitive task of attaching a 'KeyListenr' to each and every object that
 * may appear in the game.
 * The drawback of this apprach is that it is now tricky to use a standard text input field - alas,
 * that is probably not really what we want anyway.
 * 
 * USAGE:
 * ======
 * In the game class just add this line:
 *         GameKeyboard.initialise();
 *         
 * You can then interrogate two variables: 'key' and 'specialKey' like this:
 *         if(GameKeyboard.getKey() == 'q') {  ...
 *         if(GameKeyboard.getSpecialKey() == 38) { // 'up' arrow key is 38, down is 40, ...
 */


import java.awt.*;              // Graphics stuff from the AWT library, her for the KeyEventDispatcher
import java.awt.event.*;        // Event handler, here for keyboard events

public class GameKeyboard implements KeyEventDispatcher {

    // The variable 'key' and 'specialKey' are private but can be accessed via the public
    // 'get' methods 'getKey()' and 'getSpecialKey()'. These are coded below.
    // These can be interrogated from the main application
    private static char key=' ';
    private static int  specialKey=0;

    // This constant is public so that other classes can check if a key has been pressed.
    // e.g.  if(kbd.getKey() != kbd.NONE) {...
    public final int NONE=0;

    private static GameKeyboard kbd;

    // Attach a keyboard focus manager to the keyboard event dispatcher
    // Don't worry if you don't understand this. Just leave it as it is.
    public GameKeyboard() {
        KeyboardFocusManager manager = KeyboardFocusManager.getCurrentKeyboardFocusManager();
        manager.addKeyEventDispatcher( this );    
    }

    // This is the method that actually checks the keyboard for key strokes and sets the two
    // private variables of this class ('key' and 'specialKey') to its values accordingly.
    public boolean dispatchKeyEvent(KeyEvent e) {


        // To start with, let's reset both variables
        key= NONE;
        specialKey= NONE;

        // Read the special keys (e.g. arrow keys, Shift, Alt, ...)
        specialKey= e.getKeyCode();

        // Only if no special character was pressed, check for normal keys, otherwise you
        // get the scan codes of the special keys
        if(specialKey == NONE) {
            key = e.getKeyChar();
        }

        // If a key is going up, reset the two variables.
        if (e.getID() == KeyEvent.KEY_RELEASED) {
            key= NONE;
            specialKey= NONE;
        } 

        return false;
    }

    public static void initialise() {
        GameKeyboard kbd= new GameKeyboard();
    }

    public static char getKey() {
        return key;
    }

    public static int getSpecialKey() {
        return specialKey;
    }
    
}

/*
 * This is a very simple class that encapsulates the loading
 * of images only.
 * 
 * Access from other classes: 
 *     Image myImg = GameImage.loadImage("C://MyImage.gif");
 */

import java.awt.*;              // Graphics stuff from the AWT library, here: Image
import java.io.File;            // File I/O functionality (for loading an image)
import javax.swing.ImageIcon;   // All images are used as "icons"



public class GameImage
{
    public static Image loadImage(String imagePathName) {
        
        // All images are loades as "icons"
        ImageIcon i = null;
        
        // Try to load the image
        File f = new File(imagePathName);
        
        
        if(f.exists()) {  // Success. Assign the image to the "icon"
            i = new ImageIcon(imagePathName);
        }
        else {           // Oops! something is wrong.
            System.out.println("\nCould not find this image: "+imagePathName+"\nAre file name and/or path to the file correct?");            
            System.exit(0);
        }
        
        // Done. Either return the image or "null"
        return i.getImage();
        
    } // End of loadImages method

}

Basically its all begginer stuff, I have the images braught in via the gameImage class, displayed then moved around by co ordinates.
The keyboard input is listened to by the keyboard class (W,A,D etc)

I just cant figure out how to make the lander its self colide with certain areas of the 800x600 screen.

[NormR]

how to make the lander its self colide with certain areas of the 800x600 screen

Compare the lander's location with the location of the areas it can collide with.
It helps to see by using a piece of paper to draw the objects and label their locations in x and y values and then see what comparisons are needed to detect when there is a collision.