hscanvas.java

塞迪网校J2ME移动应用开发教程的所有源代码.

        // Start a new game
        newGame();

      // The game is over, so don't update anything
      return;
    }

    // Process user input to move the water layer and animate the player
    int keyState = getKeyStates();
    int xMove = 0, yMove = 0;
    if ((keyState & LEFT_PRESSED) != 0) {
      xMove = -4;
      playerSprite.setFrame(3);
    }
    else if ((keyState & RIGHT_PRESSED) != 0) {
      xMove = 4;
      playerSprite.setFrame(1);
    }
    if ((keyState & UP_PRESSED) != 0) {
      yMove = -4;
      playerSprite.setFrame(0);
    }
    else if ((keyState & DOWN_PRESSED) != 0) {
      yMove = 4;
      playerSprite.setFrame(2);
    }
    if (xMove != 0 || yMove != 0) {
      layers.setViewWindow(xView + xMove, yView + yMove, getWidth(),
        getHeight() - infoBar.getHeight());
      playerSprite.move(xMove, yMove);
    }

    // Check for a collision with the player and the land tiled layer
    if (playerSprite.collidesWith(landLayer, true)) {
      // Restore the original view window and player sprite positions
      layers.setViewWindow(xView, yView, getWidth(),
        getHeight() - infoBar.getHeight());
      playerSprite.move(-xMove, -yMove);
    }
    else {
      // If there is no collision, commit the changes to the view window position
      xView += xMove;
      yView += yMove;
    }

    for (int i = 0; i < 2; i++) {
      // Update the pirate and barrel sprites
      pirateSprite[i].update();
      barrelSprite[i].update();

      // Check for a collision with the player and the pirate sprite
      if (playerSprite.collidesWith(pirateSprite[i], true)) {
        // Play a wave sound for rescuing a pirate
        try {
          rescuePlayer.start();
        }
        catch (MediaException me) {
        }

        // Increase the number of pirates saved
        piratesSaved++;

        // Randomly place the pirate in a new location
        placeSprite(pirateSprite[i], landLayer);
      }

      // Check for a collision with the player and the barrel sprite
      if (playerSprite.collidesWith(barrelSprite[i], true)) {
        // Play a tone sound for gaining energy from a barrel
        try {
          Manager.playTone(ToneControl.C4 + 12, 250, 100);
        }
        catch (MediaException me) {
        }

        // Increase the player's energy
        energy = Math.min(energy + 5, 45);

        // Randomly place the barrel in a new location
        placeSprite(barrelSprite[i], landLayer);
      }
    }

    for (int i = 0; i < 5; i++) {
      // Update the mine and squid sprites
      mineSprite[i].update();
      squidSprite[i].update();

      // Check for a collision with the player and the mine sprite
      if (playerSprite.collidesWith(mineSprite[i], true)) {
        // Play a wave sound for hitting a mine
        try {
          minePlayer.start();
        }
        catch (MediaException me) {
        }

        // Decrease the player's energy
        energy -= 10;

        // Randomly place the mine in a new location
        placeSprite(mineSprite[i], landLayer);
      }

      // Check for a collision with the player and the squid sprite
      if (playerSprite.collidesWith(squidSprite[i], true)) {
        // Play a tone sound for hitting a squid
        try {
          Manager.playTone(ToneControl.C4, 250, 100);
        }
        catch (MediaException me) {
        }

        // Decrease the player's energy
        energy -= 5;
      }
    }

    // Update the enemy ship sprite
    enemyShipSprite.update();

    // Check for a collision with the player and the enemy ship sprite
    if (playerSprite.collidesWith(enemyShipSprite, true)) {
      // Play a wave sound for hitting the enemy ship
      try {
        minePlayer.start();
      }
      catch (MediaException me) {
      }

      // Decrease the player's energy
      energy -= 10;
    }

    // Check for a game over
    if (energy <= 0) {
      // Stop the music
      try {
        musicPlayer.stop();
      }
      catch (MediaException me) {
      }

      // Play a wave sound for the player ship sinking
      try {
        gameoverPlayer.start();
      }
      catch (MediaException me) {
      }

      // Hide the player ship sprite
      playerSprite.setVisible(false);

      gameOver = true;
    }

    // Update the animated water tiles
    if (++waterDelay > 3) {
      if (++waterTile[0] > 3)
        waterTile[0] = 1;
      waterLayer.setAnimatedTile(-1, waterTile[0]);
      if (--waterTile[1] < 1)
        waterTile[1] = 3;
      waterLayer.setAnimatedTile(-2, waterTile[1]);
      waterDelay = 0;
    }
  }

  private void draw(Graphics g) {
    // Draw the info bar with energy and pirate's saved
    g.drawImage(infoBar, 0, 0, Graphics.TOP | Graphics.LEFT);
    g.setColor(0, 0, 0); // black
    g.setFont(Font.getFont(Font.FACE_SYSTEM, Font.STYLE_PLAIN, Font.SIZE_MEDIUM));
    g.drawString("Energy:", 2, 1, Graphics.TOP | Graphics.LEFT);
    g.drawString("Pirates saved: " + piratesSaved, 88, 1, Graphics.TOP | Graphics.LEFT);
    g.setColor(32, 32, 255); // blue
    g.fillRect(40, 3, energy, 12);

    // Draw the layers
    layers.paint(g, 0, infoBar.getHeight());
    
    if (gameOver) {
      // Draw the game over message and score
      g.setColor(255, 255, 255); // white
      g.setFont(Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD, Font.SIZE_LARGE));
      g.drawString("GAME OVER", 90, 40, Graphics.TOP | Graphics.HCENTER);
      g.setFont(Font.getFont(Font.FACE_SYSTEM, Font.STYLE_BOLD, Font.SIZE_MEDIUM));
      if (piratesSaved == 0)
        g.drawString("You didn't save any pirates.", 90, 70, Graphics.TOP | Graphics.HCENTER);
      else if (piratesSaved == 1)
        g.drawString("You saved only 1 pirate.", 90, 70, Graphics.TOP | Graphics.HCENTER);
      else
        g.drawString("You saved " + piratesSaved + " pirates.", 90, 70, Graphics.TOP |
          Graphics.HCENTER);
    }

    // Flush the offscreen graphics buffer
    flushGraphics();
  }

  private void newGame() {
    // Initialize the game variables
    gameOver = false;
    energy = 45;
    piratesSaved = 0;

    // Show the player ship sprite
    playerSprite.setVisible(true);

    // Randomly place the player and adjust the view window
    placeSprite(playerSprite, landLayer);
    xView = playerSprite.getX() - ((getWidth() - playerSprite.getWidth()) / 2);
    yView = playerSprite.getY() - ((getHeight() - playerSprite.getHeight()) / 2);
    layers.setViewWindow(xView, yView, getWidth(), getHeight() - infoBar.getHeight());

    // Start the music (at the beginning)
    try {
      musicPlayer.setMediaTime(0);
      musicPlayer.start();
    }
    catch (MediaException me) {
    }
  }

  private void placeSprite(Sprite sprite, TiledLayer barrier) {
    // Initially try a random position
    sprite.setPosition(Math.abs(rand.nextInt() % barrier.getWidth()) -
      sprite.getWidth(), Math.abs(rand.nextInt() % barrier.getHeight()) -
      sprite.getHeight());

    // Reposition until there isn't a collision
    while (sprite.collidesWith(barrier, true)) {
      sprite.setPosition(Math.abs(rand.nextInt() % barrier.getWidth()) -
        sprite.getWidth(), Math.abs(rand.nextInt() % barrier.getHeight()) -
        sprite.getHeight());
    }
  }
}