scrollcanvas.java

这是一个用2D来模拟3D效果的卷轴动画 希望大家喜欢！

import java.io.IOException;

import javax.microedition.lcdui.*;
import javax.microedition.lcdui.game.*;


/**
 * The GameCanvas that dispalys the different background layers
 *
 * This code is part of the Tips & Tricks section at 
 * www.SonyEricsson.com/developer
 *
 * Written by J鰊s Weimarck, 2004
 */
public class ScrollCanvas extends GameCanvas implements Runnable {
  private boolean isRunning;
  
  private LayerManager layerManager;  
  
  // Sets the pixel speed of the backgrounds
  private static final int BACKGROUND_HORIZONTAL_MOVE = -2;
  private static final int FOREGROUND_HORIZONTAL_MOVE = -4;
  private int w = getWidth();
  private int h = getHeight();
  
  public ScrollCanvas() throws IOException {
    super(true);    
    w = getWidth();
    h = getHeight();
    
    // Create a LayerManager.
    layerManager = new LayerManager();
    layerManager.setViewWindow(96, 0, w, h);
   
    // The spaceship will get the first LayerManager index, thus being foremost 
    createSpaceship();
    
    // The Backgrounds will also be appended to the LayerManager
    createBackgrounds();
   
  }
  
  /**
   * Creates the individual backgrounds and adds them to a LayerManager
   */
  private void createBackgrounds()throws IOException {
      layerManager.append(createForegroundMountains());  
      layerManager.append(createBackgroundMountains());
  }
  
  private BackgroundLayer createForegroundMountains()throws IOException {
        Image backgroundImage = Image.createImage("/mountain.png");        
        int[] map = {
            0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,2,0,0,0,
            0,0,0,0,0,1,2,0,0,0,0,1,2,0,0,0,0,0,1,3,3,2,0,0,0,0,0,0,0,1,2,0,0,0,0,1,2,0,0,0,0,0,1,3,3,2,0,0
         };
         int maprows=2;
         int mapcols=48;

        BackgroundLayer background = new BackgroundLayer(mapcols, maprows, backgroundImage, 48, 48 );
        background.setHorizontalMove(FOREGROUND_HORIZONTAL_MOVE);
        background.setPosition(12, 176-(maprows*48));
        background.setCells(map,maprows, mapcols);
       return background;
  }
  
  private BackgroundLayer createBackgroundMountains()throws IOException {
        Image backgroundImage = Image.createImage("/mountain.png");  
          int[] map = {
            0,1,2,0,0,0,0,1,2,0,0,0,0,1,2,0,0,0,0,1,2,0,0,0,0,1,2,0,0,0,0,1,2,0,0,0,0,1,2,0,0,0,0,1,2,0,0,0,
            1,3,3,2,0,0,1,3,3,2,0,0,1,3,3,3,3,3,3,3,3,2,0,0,1,3,3,2,0,0,1,3,3,2,0,0,1,3,3,3,3,3,3,3,3,2,0,0
         };
         int maprows=2;
         int mapcols=48;
        BackgroundLayer background = new BackgroundLayer(mapcols, maprows, backgroundImage, 48, 48 );
        background.setHorizontalMove(BACKGROUND_HORIZONTAL_MOVE);
        background.setPosition(12, 176-(maprows*48));
        background.setCells(map,maprows, mapcols);
       return background;
  }

  
  
  private void createSpaceship()throws IOException {
    Image penguinImage = Image.createImage("/penguin.png");
    // Even though it's actually a penguin, lets call it a spaceship...
    Sprite spaceship = new Sprite(penguinImage, 48, 48);
    spaceship.setPosition(96 + (getWidth() - 48) / 2, 96);
    spaceship.defineReferencePixel(24, 24);

    layerManager.append(spaceship);
  }

  public void start() {
    isRunning = true;
    Thread t = new Thread(this);
    t.start();
  }
  
  public void run() {
    Graphics g = getGraphics();
    
    // Main game loop, do this to the bitter end (well, until the backgrounds has reached their ends)
    while (isRunning) {
      if (isShown()) {
        int keyStates = getKeyStates();

        // Move the spaceship
        if ((keyStates & UP_PRESSED) != 0) {
          layerManager.getLayerAt(0).move(0,-2);
        }else if ((keyStates & DOWN_PRESSED) != 0) {
          layerManager.getLayerAt(0).move(0,2);
        }
        
        // Move the Backgrounds
        scrollBackgrounds();
        
        // Stop the game when all background have scolled by...
        if(EndOfBackgrounds()){
            isRunning=false;
        }


        g.setColor(0x6600CC);
        g.fillRect(0, 0, w, h);
        layerManager.paint(g, 0, 0);
        flushGraphics();
      }
      
      try { 
          Thread.sleep(10);
      }catch (InterruptedException e) {System.out.println(e.getMessage());}
    }
  }
  
  public void stop() {
    isRunning = false;
  }
  

  /**
   * Scrolls the backgrounds individually
   */
  private void scrollBackgrounds(){ 
    BackgroundLayer background; 
    //Don't mind the first Layer of the LayerManager, it's the spaceship
   for(int i=1; i<layerManager.getSize(); i++){
     background = (BackgroundLayer)layerManager.getLayerAt(i);
     background.move();
   }

  }
  
  /**
   * Just checks if the backgrounds have reached their end.
   * Returns true if thats the case, false otherwise.
   */
  private boolean EndOfBackgrounds(){
     //Don't mind the first Layer of the LayerManager, it's the spaceship!
    for(int i=1; i<layerManager.getSize(); i++){
        if (((BackgroundLayer)layerManager.getLayerAt(i)).endOfBackground(w)){
            return true;
        }
    }
    return false;
  }

}