ship.java

J2ME Game Programming的隋书源代码

/**
 * An Actor that moves and turns like a spaceship.
 */

import net.jscience.math.kvm.MathFP;

import javax.microedition.lcdui.Graphics;
import javax.microedition.lcdui.Image;

public class Ship extends Actor
{
   private static ImageSet yellowShipImageSet;
   private static ImageSet redShipImageSet;
   private static ImageSet droneSet;
   private static ImageSet shieldImageSet;
   private static ImageSet turretImageSet;
   private static ImageSet explosionSet;

   private static final int ENEMY_IGNORE_DISTANCE = 70;

   // ship instance
   private Sprite shipSprite;				// ship sprite graphics (this image is
   // different based on the type above
   private Sprite shieldSprite;			// shielding effects (same for all)
   private boolean firing;					// am I firing?
   private long timeLastFired;			// used to track when I can fire again
   private boolean showShields;			// are my shields showing?
   private int energy;						// current reactor core energy level
   private int energyMax;					// max level
   private int rechargeRate;				// recharge rate (energy per sec)
   private int msPerRecharge;				// how many MS to equal one recharge
   private long msSinceLastRecharge;	// multicycle counter for recharge
   private int firingDelay;				// reload time
   private boolean exploding;				// death becomes me
   private Sprite explodingSprite;		// exploding animation

   private int msPerAIUpdate;				// how many MS to equal one AI update
   private long msSinceLastAIUpdate;	// multicycle counter for AI update

   public Ship(World worldArg)
   {
      super(worldArg);

      if (yellowShipImageSet == null)
      {
         System.out.println("oops, ship used but imageset not initialized.");
         return;
      }

      shieldSprite = new Sprite(shieldImageSet, 0, 0);
      explodingSprite = new Sprite(explosionSet, 0, 0);
   }

   /**
    * Used as the ending warp tunnel graphics as well
    */
   public final static ImageSet getShieldImageSet()
   {
      return shieldImageSet;
   }

   public static ImageSet getYellowShipImageSet()
   {
      return yellowShipImageSet;
   }

   /**
    * Initialise an instance of a ship. May be called at any time to reuse this
    * instance of the object as another type.
    * @param typeArg
    */
   public final void init(int typeArg, int x, int y)
   {
      energy = energyMax;
      exploding = false;
      showShields = false;
      firing = false;

      firingDelay = 500;
      int alignedDiv = 16;
      int thrustFP = 0;
      int speed = 0;
      int maxVel = 0;
      int dir = 0;
      int bounceVelFP = Actor.FP_MINUS_05;
      int maxSpinRate = 23;

      energyMax = 1000;
      energy = energyMax;
      rechargeRate = 50;

      setType(typeArg);
      switch (getType())
      {
         case PLAYER_SHIP:
            shipSprite = new Sprite(yellowShipImageSet, 0, 0);
            speed = 2;
            maxVel = 2;
            thrustFP = MathFP.toFP("1.0");
            firing = StarAssault.getApp().isOptionAutoFire();
            break;
         case ENEMY_FIGHTER:
            shipSprite = new Sprite(redShipImageSet, 0, 0);
            speed = 1;
            maxVel = 1;
            thrustFP = MathFP.toFP("0.5");
            firing = true;
            firingDelay = 2000;
            break;
         case ENEMY_DRONE:
            shipSprite = new Sprite(droneSet, 0, 0);
            alignedDiv = 0;
            dir = Tools.getRand(0, 359);
            speed = maxVel = 1;
            thrustFP = 0;
            bounceVelFP = Actor.FP_MINUS_1;
            break;
         case ENEMY_TURRET:
            rechargeRate = 0;
            speed = 0;
            maxSpinRate = 5;
            energyMax = 200;
            firingDelay = 2000;
            shipSprite = new Sprite(turretImageSet, 0, 0);
            firing = true;
            break;
      }

      // ship settings
      if (rechargeRate > 0)
         msPerRecharge = 1000 / rechargeRate;
      msPerAIUpdate = 1000;

      reset();

      super.init(null, x, y, thrustFP, MathFP.toFP(speed),
                 MathFP.toFP(maxVel), dir, alignedDiv, bounceVelFP, maxSpinRate);
   }

   public final static void setup()
   {
      Image shipImage = ImageSet.loadClippedImage("/ship.png", 0, 0);
      Image explosionImage = ImageSet.loadClippedImage("/explode.png", 0, 0);
      Image droneImage = ImageSet.loadClippedImage("/mine.png", 0, 0);

      yellowShipImageSet = new ImageSet(16);
      redShipImageSet = new ImageSet(16);
      turretImageSet = new ImageSet(16);
      shieldImageSet = new ImageSet(1);
      explosionSet = new ImageSet(1);
      droneSet = new ImageSet(1);

      Image[] yellowDirImages = null;
      Image[] redDirImages = null;
      Image[] shieldImages = null;
      Image[] turretImages = null;

      Image[] explosionImages = ImageSet.extractFrames(explosionImage, 0, 0, 1, 4, 25, 25);
      explosionSet.addState(explosionImages, 500);

      Image[] droneImages = ImageSet.extractFrames(droneImage, 0, 0, 3, 2, 16, 16);
      droneSet.addState(droneImages, 800);

      //#ifdef nokia
      //# yellowDirImages = ImageSet.extractFrames(shipImage, 0, 0, 5, 1, 16, 16);
      //# yellowDirImages = ImageSet.getAxisReflections(yellowDirImages);
      //# redDirImages = ImageSet.extractFrames(shipImage, 0, 16, 5, 1, 16, 16);
      //# redDirImages = ImageSet.getAxisReflections(redDirImages);
      //# turretImages = ImageSet.extractFrames(shipImage, 0, 3 * 16, 5, 1, 16, 16);
      //# turretImages = ImageSet.getAxisReflections(turretImages);
      //# shieldImages = ImageSet.extractFrames(shipImage, 0, 2 * 16, 4, 1, 16, 16);
      //#else
      yellowDirImages = ImageSet.extractFrames(shipImage, 0, 0, 4, 4, 16, 16);
      redDirImages = ImageSet.extractFrames(shipImage, 4 * 16, 0, 4, 4, 16, 16);
      turretImages = ImageSet.extractFrames(shipImage, 8 * 16, 0, 4, 4, 16, 16);
      shieldImages = ImageSet.extractFrames(shipImage, 0, 4 * 16, 4, 1, 20, 20);
      //#endif

      // add the 16 states for the ship (representing the 16 directions)
      for (int i = 0; i < 16; i++)
      {
         Image[] yellowFrame = {yellowDirImages[i]};
         yellowShipImageSet.addState(yellowFrame, 0);

         Image[] redFrame = {redDirImages[i]};
         redShipImageSet.addState(redFrame, 0);

         Image[] turretFrame = {turretImages[i]};
         turretImageSet.addState(turretFrame, 0);
      }

      shieldImageSet.addState(shieldImages, 200);
   }

   public final int getWidth()
   {
      //#ifdef nokia
      //# return 14;
      //#else
      return 16;
      //#endif
   }

   public final int getHeight()
   {
      return getWidth();
   }

   public final void setFiring(boolean b)
   {
      firing = b;
   }

   public boolean isExploding()
   {
      return exploding;
   }

   public final void onCollision(Actor a)
   {
      if (a == null) return;

      if (a.getOwner() != this)
      {
         if (a.isBullet())
         {
            Bullet b = (Bullet) a;
            takeDamage(b.getDamage());
            a.setCollidable(false);
         }
      }

      // if we hit an enemy ship, then blow up the ship and cause
      // damage to the player
      if (!a.isBullet())
      {
         takeDamage(250);
      }

      if (this.getType() != PLAYER_SHIP)
      {
         exploding = true;
         setCollidable(false);

         // add to the score
         GameScreen.getGameScreen().incScore(100);

      }
   }

   public final void takeDamage(int damageLevel)
   {
      //#ifdef debug
      // disable damage when debugging
      //if (this.getType() == PLAYER_SHIP) return;
      //#endif
      energy -= damageLevel;
      showShields = true;

      if (energy < 0)
      {
         exploding = true;
         showShields = false;
      }
   }

   public final int getEnergy()
   {
      return energy;
   }

   public final int getEnergyMax()
   {
      return energyMax;
   }

   public final void cycle(long deltaMS)
   {
      super.cycle(deltaMS);

      if (getType() == ENEMY_DRONE)
         shipSprite.cycle(deltaMS);

      if (exploding)
      {
         explodingSprite.cycle(deltaMS);

         if (explodingSprite.getTotalCycles() > 0)
         {
            explodingSprite.reset();
            if (getType() != PLAYER_SHIP)
               suicide();

            GameScreen.getGameScreen().notifyShipDied(this);
         }
      }

      if (rechargeRate > 0 && energy < energyMax)
      {
         if (msSinceLastRecharge < msPerRecharge)
         {
            msSinceLastRecharge += deltaMS;
         }
         else
         {
            energy++;
            msSinceLastRecharge -= msPerRecharge;
            if (energy > energyMax) energy = energyMax;
         }
      }

      if (showShields)
      {
         shieldSprite.cycle(deltaMS);

         if (shieldSprite.getTotalCycles() > 0)
         {
            shieldSprite.reset();
            showShields = false;
         }
      }

      if (firing)
      {
         long timeSinceLastFire = (System.currentTimeMillis() - timeLastFired);
         if (timeSinceLastFire > firingDelay)
         {
            int[] nosePos = Actor.getProjectedPos(getCenterX(), getCenterY(),
                                                  getDirection(), 12);

            // get a bullet from the pool and init it to what we want
            Bullet b = getWorld().getBulletFromPool();
            b.init(Bullet.PLASMA_CANNON, this, nosePos[0], nosePos[1], getDirection());
            timeLastFired = System.currentTimeMillis();
         }
      }

      // do we have a brain?
      if (getType() > ENEMY_AI_START)
      {
         // keep the update rate on the AI brain down to a minimum
         if (msSinceLastAIUpdate < msPerAIUpdate)
            msSinceLastAIUpdate += deltaMS;
         else
         {
            msSinceLastAIUpdate -= msPerAIUpdate; // take off one update's worth

            // check the distance to the player
            int d = distanceTo(world.getPlayerShip());
            if (d < ENEMY_IGNORE_DISTANCE && d > 0)
            {
               // they are within distance so lets turn toward them
               int facingAngle = getFacingAngle(getX(), getY(), world.getPlayerShip().getX(),
                                                world.getPlayerShip().getY());
               //System.out.println(" xd=" + (getX() - world.getPlayerShip().getX()) +
               //						 " yd=" + (getY() - world.getPlayerShip().getY()) +
               //						 " angle=" + facingAngle);
               setTargetDirection(facingAngle);
            }
         }
      }
   }

   public final void suicide()
   {
      world.releaseShip(this);
   }

   public final void reset()
   {
      super.reset();
      exploding = false;
      energy = energyMax;
      showShields = false;
   }


   public final void render(Graphics g, int offsetX, int offsetY)
   {
      if (exploding)
      {
         explodingSprite.draw(g, getX() - offsetX - 2, getY() - offsetY - 2);

      }
      else
      {
         // for non-transparent graphics we show a larger version of the shields
         // under the ship (which has a slightly different visual effect)

         //#ifndef nokia
         if (showShields)
            shieldSprite.draw(g, getX() - offsetX - 2, getY() - offsetY - 2);
         //#endif

         if (getType() != ENEMY_DRONE)
         {
            int s = MathFP.toInt(MathFP.div(MathFP.toFP(getDirection()), Actor.FP_225));
            if (s != shipSprite.getCurrentState())
               shipSprite.setState(s, false);
         }

         shipSprite.draw(g, getX() - offsetX, getY() - offsetY);

         // with nokia we show the shields over the top of the ship
         //#ifdef nokia
         //# if (showShields)
            //# shieldSprite.draw(g, getX() - offsetX, getY() - offsetY);
         //#endif
      }
   }


}