The Net: Ultimate Internet Guide/WWLCD1.ISO/pc/java/de86gnzn/examples/boinkaroids/ship.java

Java Source | 1996-08-14 | 5.1 KB | 290 lines

/*
 *
 * Ship.java
 * @author    Mark G. Tacchi ([e-mail])
 * @version    0.8
 * Mar 11/1996
 *

* The ship is controlled by the user, it registers for specific keyboard
 * events to handle control.
 *
 * This Actor collides with Asteroids and Goobies.  It is responsible for
 * creating an explosion object.
 *
 */

import java.applet.Applet;
import java.applet.AudioClip;
import java.lang.Math;
import java.awt.*;

import com.next.gt.*;

public class Ship extends Actor implements EventHandler{

  //
  // Limit number of bullets on the screen at once
  //
  private static int         MAX_NUM_BULLETS= 5;
  public int                numBullets= 0;

  //
  // Animation.  ccw= 1, cw= -1
  //
  public int                animationDirection= 1;
  public boolean            isAnimating= true;

  //
  // Is thrusting
  //
  public boolean            thrusting= false;

Ship(Gamelet theOwner) {
  super();

  Image            theImage;
  owner= theOwner;


  //
  // play warp in sound
  //
  owner.play(owner.getCodeBase(), "sounds/warp.au");

  x= (owner.size().width/2.0);
  y= (owner.size().height/2.0);
  velocity_x= 0;
  velocity_y= 0;
  String    theImageName= "images/ship.gif";

  theImage= owner.getImage(owner.getCodeBase(), "images/ship.gif");
  setImage (theImage, 4, 24);

 isAnimating= false;

  int events[]=    {    Event.KEY_ACTION,
                      Event.KEY_ACTION_RELEASE,
                    Event.KEY_PRESS,
                    Event.KEY_RELEASE
                };


 owner.eventManager.registerForEventNotification(this,events);

} /*Ship()*/



/**
 * Handle keyboard events that control ship.
 */
public boolean handleRequestedEvent (Event theEvent) {
  switch(theEvent.id) {
  case Event.KEY_ACTION:
    switch(theEvent.key) {
      case Event.RIGHT:
        this.rotateRight(true);
        return true;
      case Event.LEFT:
        this.rotateLeft(true);
        return true;
      case Event.UP:                    //THRUST ON
        this.thrust(true);
        return true;
    } /*endSwitch*/
    break;
  case Event.KEY_ACTION_RELEASE:
    switch(theEvent.key) {
      case Event.RIGHT:
        this.rotateRight(false);
        return true;
      case Event.LEFT:
        this.rotateLeft(false);
        return true;
      case Event.UP:                    //THRUST OFF
        this.thrust(false);
        return true;
    } /*endSwitch*/
    break;
    case Event.KEY_PRESS:
      switch(theEvent.key) {
        case 32:
          this.fire();
          return true;
      } /*endSwitch*/
    break;
    case Event.KEY_RELEASE:
      switch(theEvent.key) {
        case 32:
          return true;
      } /*endSwitch*/
    break;
  } /*endSwitch*/

  return false;

} /*handleRequestedEvent*/



/**
 * If ship is thrusting, then velocity is increasing.  Use friction if
 * not thrusting.
 */
public void calculateNewVelocity() {
  if (thrusting) {
    velocity_x+= Math.cos(currentFrame*2*Math.PI/numFrames + Math.PI/2)*10;
    velocity_y+= Math.sin(currentFrame*2*Math.PI/numFrames - Math.PI/2)*10;
  }
  else {
    velocity_x*= 0.99;
    velocity_y*= 0.99;
  }

} /*calculateNewVelocity*/



/**
 * Animation of the ship is based on theta, display accordingly.
 */
public void calculateCurrentFrame() {
   if (isAnimating) {
     if (animationDirection== -1) {
       if (--currentFrame<=0) currentFrame= numFrames - 1;
     }
     else {
      if (++currentFrame>=numFrames) currentFrame= 0;
     }
    } /*endif*/

} /*calculateCurrentFrame*/



/**
 * Handle left rotation.
 */
public void rotateLeft (boolean keydown) {
  if (keydown) {
    isAnimating= true;
    animationDirection= 1;
  }
  else {
    isAnimating= false;
  }

} /*rotateLeft*/



/**
 * Handle right rotation.
 */
public void rotateRight (boolean keydown) {
  if (keydown) {
    animationDirection= -1;
    isAnimating= true;
  }
  else {
    isAnimating= false;
  }

} /*rotateRight*/



/**
 * Handle thrust.
 */
public void thrust (boolean keydown) {
  if (keydown) {
    thrusting= true;
  }
  else {
    thrusting= false;
  }

} /*thrust*/



/**
 * Fire bullet.
 */
public void fire() {

  if (numBullets<MAX_NUM_BULLETS) {
    Bullet aBullet;

    numBullets++;
    owner.play(owner.getCodeBase(), "sounds/bullet.au");
    aBullet= new Bullet(owner, this);
    owner.actorManager.addActor(aBullet);
  } /*endif*/

} /*fire*/



/**
 * Accessor methods (bullet uses this).
 */

/**
 * Ship's angle.
 */
public double getTheta() {
  return (currentFrame*2*Math.PI/numFrames + Math.PI/2);
} /*getTheta*/



/**
 * Ship's speed.
 */
public double getSpeed() {
  return Math.sqrt(velocity_x*velocity_x + velocity_y*velocity_y);
} /*getSpeed*/



/**
 * Handle collision with an actor.
 */
protected void collideWithActor (Actor theActor)
{
  String theActorClassName= theActor.getClass().getName();

  if (theActorClassName.equals("Asteroid") ||
      theActorClassName.equals("Goobie") ||
      theActorClassName.equals("Bigoobie") ) {
    explode();
  } /*endif*/

} /*collideWithActor*/



/**
 * Explode ship.
 */
public void explode()
{
  Explosion anExplosion;

  //
  // Tell the ActorManager that I'm gone, and an Explosion Actor
  // should be added.
  //
  owner.actorManager.removeActor(this);
  anExplosion= new Explosion(owner, this);
  owner.actorManager.addActor(anExplosion);

  //
  // Lower ship counter.
  //
  ((Boinkaroids)owner).decrementShipCount();

} /*explode*/


} /*Ship*/