Canyon.java

import java.util.*;     // for Random function
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;   // for JFrame

public class Canyon {

    /**
    *   Program:    Canyon.java by Chris Clarke
    *   Created:    Nov 2006
    *   Purpose:    Popular arcade game
    *   Notes:      Left and right cursor keys steer pod, p = pause
    *   Modified:   01.09.2012 (JFrame)
    */

    public static void main(String[] args) {
        CanyonJFrame frame = new CanyonJFrame();
        frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
}

class CanyonJFrame extends JFrame implements KeyListener {
    public CanyonJFrame() {
        setTitle("Canyon by Chris Clarke");
        initWall();
        addKeyListener(this);
        // Set to a reasonable size.
        setSize(MAX_X, MAX_Y);
    }

    public void initWall() {
        wall = new boolean[MAX_WIDTH][MAX_HEIGHT];
        start = true;
    }

    public void generateRow() {
        if (start) {
            wall[leftWall][MAX_HEIGHT-1]=true;
            wall[rightWall][MAX_HEIGHT-1]=true;
            start = false;
        } else {
            Random r = new Random();
            int addition = r.nextInt(3)-1;  // -1, 0 or 1

            if ((leftWall>0)&&(addition==-1)) {
                leftWall--;
                rightWall--;
            }
            if ((rightWall<MAX_WIDTH-1)&&(addition==1)) {
                leftWall++;
                rightWall++;
            }
            if ((r.nextInt(100)>92)&&(rightWall-leftWall>5))
                // decrease the gap
                rightWall--;

            // shuffle up previous rows
            for (int x=0; x<MAX_WIDTH; x++)
                for (int y=0; y<MAX_HEIGHT-1; y++)
                    wall[x][y] = wall[x][y+1];
            // create current row
            for (int x=0; x<MAX_WIDTH; x++)
                if ((x==leftWall)||(x==rightWall))
                    wall[x][MAX_HEIGHT-1] = true;
                else
                    wall[x][MAX_HEIGHT-1] = false;
        }
    }

    public boolean outsideGap(int objX) {
        // is pod outside the gap?
        boolean[] outsideGap = new boolean[MAX_WIDTH];
        boolean flag=true;
        for (int x=0; x<MAX_WIDTH; x++)
            outsideGap[x] = true;
        for (int x=0; x<MAX_WIDTH; x++) {
            if (wall[x][10])
                flag=!flag;
            outsideGap[x] = flag;
        }
        if (outsideGap[objX])
            return true;
        else
            return false;
    }

    public void paint(Graphics g) {
        generateRow();
        // delete all
        g.setColor(Color.WHITE);
        g.fillRect(0,0,1024,768);
        g.setColor(Color.BLACK);
        for (int x=0; x<MAX_WIDTH; x++)
            for (int y=0; y<MAX_HEIGHT-1; y++)
                if (wall[x][y])
                    // draw wall row by row
                    g.fillRect(100+SQR_SIZE*x,
                     100+SQR_SIZE*y, SQR_SIZE, SQR_SIZE);
        // draw falling object
        g.setColor(Color.ORANGE);
        g.fillRect(100+SQR_SIZE*objectX, 100+SQR_SIZE*10, SQR_SIZE, SQR_SIZE);
        // hit the side
        if (wall[objectX][10])
            // game over
            ends(g);
        if ((score>=(MAX_HEIGHT-1)-10)&&(outsideGap(objectX)))
            // game over
            ends(g);
        // short pause
        try {
            Thread.sleep(200);
        }
        catch (InterruptedException e) {}

        score++;
        if (paused) {
            g.setFont(new Font("Arial", Font.BOLD, 36));
            g.drawString("Game Paused - press c to continue...", 100, 100);
        } else
            repaint();
    }

    public void ends(Graphics g) {
        g.setFont(new Font("Arial", Font.BOLD, 72));
        g.drawString("Game Over", 350, 300);
        g.drawString("Score = "+score, 350, 500);
        // long pause
        try {
            Thread.sleep(4000);
        }
        catch (InterruptedException e) {}
        // close program
        System.exit(0);
    }

    public void keyPressed(KeyEvent e) {
        // Check if any keys have been pressed and take appropriate action.
        int keyCode = e.getKeyCode();

        if (keyCode == KeyEvent.VK_LEFT)
            // move object left
            if (objectX>0)
                objectX--;
        if (keyCode == KeyEvent.VK_RIGHT)
            // move object right
            if (objectX<MAX_WIDTH-1)
                objectX++;
        if (keyCode == KeyEvent.VK_P)
            // The letter 'p' pressed
            paused = true;
        if (keyCode == KeyEvent.VK_C) {
            // The letter 'c' pressed to continue after a pause
            paused = false;
            // continue
            repaint();
        }
    }

    public void keyReleased(KeyEvent e) {}

    public void keyTyped(KeyEvent e) {}

    boolean[][] wall;
    boolean     start;
    boolean     paused;

    public static final int MAX_X = 1024;
    public static final int MAX_Y = 768;
    public static final int MAX_WIDTH = 50;
    public static final int MAX_HEIGHT = 45;
    public static final int SQR_SIZE = 18;

    int leftWall = 10, rightWall = MAX_WIDTH-10;
    int objectX=MAX_WIDTH/2;    // position of object
    int score = 0;
}