//To use Frame and Graphics import java.io.*; import java.awt.*; import java.awt.image.*; import javax.imageio.*; //To use Geometry import java.awt.geom.*; //To use a Listener for closing window import java.awt.event.*; import java.util.LinkedList.*; import java.util.*; import java.awt.image.BufferedImage; import java.awt.event.KeyEvent; import java.awt.event.KeyListener; //------------------------------------------------------------------- //Extend the Frame Class to build our Graphics Frame public class TestGraphics extends Frame implements WindowListener { private Image dbImage; private Graphics buffer; // Variable needed to get key states private static GameKey game_key=new GameKey(); //Variable for maximum number of box enemies private static int maxBoxes=100; //arrays for enemy boxes private static int[] x=new int[maxBoxes]; private static int[] y=new int[maxBoxes]; private static int[] xVel=new int[maxBoxes]; private static int[] yVel=new int[maxBoxes]; private static int[] energy=new int [maxBoxes]; private static boolean[] enemyExists=new boolean[maxBoxes]; //Variable used for maximum number of bullets private static int maxBullets=100; //arrays for player bullets private static int[] bulletX=new int[maxBullets]; private static int[] bulletY=new int[maxBullets]; private static boolean[] bulletExists=new boolean[maxBullets]; //variable to check is another bullet can be fired yet private static int bulletTimer=0; //variable to adjust the rotation of enemy boxes private static double spin=0.01; //variable used for keeping the games score, timing the appearance //of enemies, the rate at which enemies are generated private static int score=0; private static int gameTimer=0; private static int speedUp=100; private static int speedUpCounter=0; private static BufferedImage img = null; //variables for player coordinates private static int playerX=220; private static int playerY=550; //a random number generator object private static Random generator = new Random(); //has the game started? private static boolean start=true; //variables for total time in 'Jiffies' that has elapsed private static int bigTimer=0; //number of hits a player can take before dying private static int playerHits=3; //constructor TestGraphics() { super("Asteroid Belter"); //add a listener for THIS window addWindowListener(this); } //main method for game public static void main(String args[]) { //assign default values to the box enemies for(int i=0;i=50){ do rand=generator.nextInt(maxBullets); while(bulletExists[rand]==true); bulletX[rand]=playerX; bulletY[rand]=playerY; bulletExists[rand]=true; energy[rand]=3; bulletTimer=0; } } //create a new asteroid by giving it a random x Value and a //y Velue that is off the screen. Setting it's enemyExists[] variable to //true means that the enemy will be updated and drawn. also reset the gameTimer variable if (gameTimer % speedUp ==0){ do rand=generator.nextInt(maxBoxes); while(enemyExists[rand]==true); y[rand]=-20; x[rand]=generator.nextInt(460) + 10; enemyExists[rand]=true; yVel[rand]=generator.nextInt(1) + 1; gameTimer=0; if (speedUp > 20) speedUpCounter++; } //set the colour to black and draw the score, //remaining hits and time on screen g2.setColor(black); g2.drawString("Score: "+score,10,50); g2.drawString("Hits: "+playerHits, 10,75); g2.drawString("time: "+(10000-bigTimer),10,100); //set the colour to green and begin the loop that //draws bullets g2.setColor(green); for (int i=0;i=480) xVel[i]=-xVel[i]; if (x[i]<=0) xVel[i]=-xVel[i]; //increase the y Velocity by a given ammount //if the y coordinate is greater than the height of the screen //plus the size of the enemy then set the eneimes enemyExists[] //value to false so it is no longer drawn y[i]=y[i]+yVel[i]; if (y[i]>=620){ y[i] = -20; enemyExists[i]=false; } //in an enemy collides with the player ship then //reduce the players hits by one and remove the enemoy from the screen. //if the enemyExists[] value is not set to false then the enemy Collision //would reduce the players hits to 0 in the next two frames, making the //game unfair. if (rectsOverlap(x[i],y[i],30,30,playerX-10,playerY-10,20,20)==true){ enemyExists[i]=false; playerHits--; } //rotate the enemy square around it's centre by the spin value g2.rotate((Math.PI*2/360)*spin+i,x[i]+15,y[i]+15); //set the colour to red g2.setColor(red); //draw the enemy on screen g2.drawRect(x[i],y[i],30,30); } //return the graphics object's transformation state to it's //original un-transformed stae g2.setTransform(currentState); } //this part of the code controls the players movement, either //increasing or decreasing the players x value, and also keeping it within the //graphics frame if(game_key.key_left) { playerX--; if (playerX<20) playerX=20; } if(game_key.key_right) { playerX++; if(playerX>460) playerX=460; } //set the colour to blue and draw the player ojn the screen g2.setColor(blue); g2.drawRect(playerX-10,playerY-10,20,20); //call the repaint() method repaint(); } //if the game ended, with either the time having //run out or the players lives having been reduced to less than 0 if (start==false) { //draw the game over text and final score on screen g2.setColor(black); g2.scale(3, 5); g2.drawString("Game Over",10,50); g2.drawString("You Scored: "+score,10,70); g2.setTransform(currentState); } } //update method handles the double buffering that allows the smooth //movement of the graphics public void update(Graphics g) { if (dbImage == null){ // initialize buffer to same size (component) dbImage = createImage(this.getSize().width, this.getSize().height); //put image into buffer buffer = dbImage.getGraphics (); } // get background colour buffer.setColor(getBackground()); // clear screen (fill with background colour) buffer.fillRect(0, 0, this.getSize().width, this.getSize().height); // draw elements into the buffer using paint() paint(buffer); // draw image on the screen g.drawImage(dbImage, 0, 0, this); } //the rectsOverlap method returns true id two rectangular graphical objects are occupying the same space on the screen public static boolean rectsOverlap(int x0,int y0,int w0,int h0,int x2,int y2,int w2,int h2) { if ((x0 > (x2 + w2)) || ((x0 + w0) < x2)) return false; if(y0 > (y2 + h2) ||(y0 + h0) < y2) return false; return true; } //this class handles keyboard input in order to allow a user to move the players ship around the screen public static class GameKey implements KeyListener // Keyboard input { public boolean key_right,key_left,key_up,key_down,key_z,key_x; public void keyTyped(KeyEvent e){} public void keyPressed(KeyEvent e) { if(e.getKeyCode() == e.VK_DOWN) key_down = true; if(e.getKeyCode() == e.VK_UP) key_up = true; if(e.getKeyCode() == e.VK_LEFT) key_left = true; if(e.getKeyCode() == e.VK_RIGHT) key_right = true; if(e.getKeyCode() == e.VK_Z) key_z = true; if(e.getKeyCode() == e.VK_X) key_x = true; } public void keyReleased(KeyEvent e) { if(e.getKeyCode() == e.VK_DOWN) key_down = false; if(e.getKeyCode() == e.VK_UP) key_up = false; if(e.getKeyCode() == e.VK_LEFT) key_left = false; if(e.getKeyCode() == e.VK_RIGHT) key_right = false; if(e.getKeyCode() == e.VK_Z) key_z = false; if(e.getKeyCode() == e.VK_X) key_x = false; } } //code for the various window things etc. public void windowActivated(WindowEvent event) { } public void windowDeactivated(WindowEvent event) { } public void windowClosed(WindowEvent event) { } public void windowDeiconified(WindowEvent event) { } public void windowIconified(WindowEvent event) { } public void windowOpened(WindowEvent event) { } public void windowClosing(WindowEvent event) { System.exit(0); } }