J2ME RPG游戏边学边做(二)

juney Post at 2006/8/11 15:21:00

在写第二篇之前首先感谢favoyang在前一篇给我提出的几点建议。
 1、public void moveDown() throws IOException
 {
  //英雄下移,并改为相应的图片
  setImage(Image.createImage("/hero_down.png"), 17, 26);
  nextFrame();
  this.y = Math.min(braveCanvas.getHeight(), y + 1);
 }
   在io包中的读取是非常耗内存的,所以Image.createImage("/hero_down.png")放在线程的循环中确实不好,
现在已经改成图象在BraveCanvas类中创建(下面的代码已更改),然后由moveDown(Image image)方法接收传递
进来的图象。

 2、RPG是个大工程,一个人的力量是很难完成的,我只想实现基本的RPG功能,比如人物的对话,场景的
转换,战斗等等,希望大家多多给予帮助。

  这一篇我将给游戏加入地图,以下是该篇所需要的图片:
        background.png

       foreground.png

  一个RPG中的游戏地图是非常大而且多的,为了方便以后的维护,我创建了一个Scene类,该类主要是产
生游戏所需要的地图。

Scene.java
package brave;

import javax.microedition.lcdui.game.TiledLayer;
import javax.microedition.lcdui.Image;

public class Scene
{
 public static TiledLayer createTiledLayerByBackground(Image image)
 {
  //使用TiledLayer创建地图
  TiledLayer tiledLayer = new TiledLayer(10, 8, image, 48, 64);
  tiledLayer.fillCells(0, 0, 10, 8, 2);
  return tiledLayer;
 }
}

 

修改BraveCanvas类,加入地图

BraveCanvas.java

package brave;

import javax.microedition.lcdui.game.GameCanvas;
import javax.microedition.lcdui.Graphics;
import java.io.IOException;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.TiledLayer;


public class BraveCanvas extends GameCanvas implements Runnable
{
 private boolean sign;
 private Graphics g;
 private Hero hero;
 private Image upimage;
 private Image downimage;
 private Image leftimage;
 private Image rightimage;
 private TiledLayer backgroundMap;

 public BraveCanvas()
 {
  super(true);
 }

 public void startup()
 {
  this.sign = true;
  try
  {
   //产生地图
   backgroundMap = Scene.createTiledLayerByBackground(
    Image.createImage("/background.png"));
   
   //改正上一篇的错误
   upimage = Image.createImage("/hero_up.png");
   downimage = Image.createImage("/hero_down.png");
   leftimage = Image.createImage("/hero_left.png");
   rightimage = Image.createImage("/hero_right.png");

   hero = new Hero(upimage, 17, 26);
   hero.setFrameSequence(new int[]{1, 1, 0, 0, 1, 1, 2, 2});
   hero.setBraveCanvas(this);
   hero.init(40,40);
  }
  catch(Exception e)
  {
   e.printStackTrace();
  }
  Thread thread = new Thread(this);
  thread.start();
 }

 public void run()
 {
  g = getGraphics();
  while(sign)
  {
   try
   {
    input(g);
    paint(g);
    Thread.sleep(15);
   }
   catch(Exception e)
   {
    e.printStackTrace();
   }
  }
 }

 public void input(Graphics g) throws IOException
 {
  int keystates = getKeyStates();
  switch(keystates)
  {
   case UP_PRESSED:
    //由这里传入需要改变的图片
    hero.moveUp(upimage);

    break;
   case DOWN_PRESSED:
    hero.moveDown(downimage);
    break;
   case LEFT_PRESSED:
    hero.moveLeft(leftimage);
    break;
   case RIGHT_PRESSED:
    hero.moveRight(rightimage);
    break;
  }
  hero.afresh();
 }

 public void paint(Graphics g)
 {
  g.setColor(0x000000);
  g.fillRect(0, 0, getWidth(), getHeight());
  g.setColor(0xffffff);
  //显示地图
  backgroundMap.paint(g);

  hero.paint(g);
  flushGraphics();
 }
}


  现在我们的英雄虽然能在草地上行走了,但感觉给他移动的空间太小了。而且我们在创建背景地图的时
候,地图大小明明是512*480的。好,接下来我们要做的就是让英雄可以在更大的天地中活动。这里就需要一
个BraveManager类来管理这些屏幕上的Sprite和TiledLayer,该类继承LayerManager。

BraveManager.java

package brave;

import javax.microedition.lcdui.game.LayerManager;

public class BraveManager extends LayerManager
{
 private BraveCanvas braveCanvas;

 public void setBraveCanvas(BraveCanvas braveCanvas)
 {
  this.braveCanvas = braveCanvas;
 }

 public void afresh()
 {
  //确定当前试图的坐标
  //这里用一个比较简单的算法来使英雄永远在屏幕的中央
  int viewX = Math.max(0, getLayerAt(0).getX() - braveCanvas.getWidth()/2);
  int viewY = Math.max(0, getLayerAt(0).getY() - braveCanvas.getHeight()/2);
  viewX = Math.min(viewX, getLayerAt(1).getWidth() - braveCanvas.getWidth());
  viewY = Math.min(viewY, getLayerAt(1).getHeight() - braveCanvas.getHeight());
  setViewWindow(viewX, viewY, braveCanvas.getWidth(), braveCanvas.getHeight());
 }
}


修改BraveCanvas类

BraveCanvas.java

package brave;

import javax.microedition.lcdui.game.GameCanvas;
import javax.microedition.lcdui.Graphics;
import java.io.IOException;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.TiledLayer;


public class BraveCanvas extends GameCanvas implements Runnable
{
 private boolean sign;
 private Graphics g;
 private Hero hero;
 private Image upimage;
 private Image downimage;
 private Image leftimage;
 private Image rightimage;
 private TiledLayer backgroundMap;
 //创建Layer管理视图类
 private BraveManager braveManager;

 public BraveCanvas()
 {
  super(true);
 }

 public void startup()
 {
  this.sign = true;
  try
  {
   backgroundMap = Scene.createTiledLayerByBackground(
    Image.createImage("/background.png"));
   upimage = Image.createImage("/hero_up.png");
   downimage = Image.createImage("/hero_down.png");
   leftimage = Image.createImage("/hero_left.png");
   rightimage = Image.createImage("/hero_right.png");
   //创建Layer管理视图类
   braveManager = new BraveManager();
   braveManager.setBraveCanvas(this);

   hero = new Hero(upimage, 17, 26);
   hero.setFrameSequence(new int[]{1, 1, 0, 0, 1, 1, 2, 2});
   hero.setBraveCanvas(this);
   hero.setBraveManager(braveManager);
   hero.init(0,0);

  }
  catch(Exception e)
  {
   e.printStackTrace();
  }
  Thread thread = new Thread(this);
  thread.start();
 }

 public void run()
 {
  g = getGraphics();
  //插入图层
  braveManager.insert(hero, 0);
  braveManager.insert(backgroundMap, 1);

  while(sign)
  {
   try
   {
    input(g);
    paint(g);
    Thread.sleep(15);
   }
   catch(Exception e)
   {
    e.printStackTrace();
   }
  }
 }

 public void input(Graphics g) throws IOException
 {
  int keystates = getKeyStates();
  switch(keystates)
  {
   case UP_PRESSED:
    hero.moveUp(upimage);
    break;
   case DOWN_PRESSED:
    hero.moveDown(downimage);
    break;
   case LEFT_PRESSED:
    hero.moveLeft(leftimage);
    break;
   case RIGHT_PRESSED:
    hero.moveRight(rightimage);
    break;
  }
  hero.afresh();
  //刷新视图的位置
  braveManager.afresh();
 }

 public void paint(Graphics g)
 {
  g.setColor(0x000000);
  g.fillRect(0, 0, getWidth(), getHeight());
  g.setColor(0xffffff);
  //显示视图
  braveManager.paint(g, 0, 0);
  flushGraphics();
 }
}


这样英雄就可以在地图上任何地方行动了,不过还得改一个小地方:
不知道大家还记的不,在Hero类中,我们定义英雄移动的范围最大为屏幕的尺寸。
这显然是不行的,最大的移动范围应改成地图的大小:
this.y = Math.min(braveManager.getLayerAt(1).getHeight(), y + 1);
this.x = Math.min(braveManager.getLayerAt(1).getWidth(), x + 1);

代码如下:

Hero.java

package brave;

import javax.microedition.lcdui.game.Sprite;
import javax.microedition.lcdui.Image;
import java.io.IOException;
import javax.microedition.lcdui.Graphics;

public class Hero extends Sprite
{
 private int x;
 private int y;

 private BraveCanvas braveCanvas;
 private BraveManager braveManager;

 public Hero(Image image, int frameWidth, int frameHeight)
 {
  super(image, frameWidth, frameHeight);
 }

 public void setBraveCanvas(BraveCanvas braveCanvas)
 {
  this.braveCanvas = braveCanvas;
 }

 public void setBraveManager(BraveManager braveManager)
 {
  this.braveManager = braveManager;
 }

 public void setManager(BraveCanvas braveCanvas)
 {
  this.braveCanvas = braveCanvas;
 }

 public void init(int x, int y)
 {
  this.x = x;
  this.y = y;
 }

 public void afresh()
 {
  setPosition(this.x, this.y);
 }

 public void moveUp(Image image) throws IOException
 {
  setImage(image, 17, 26);
  nextFrame();
  this.y = Math.max(0, y - 1);
 }

 public void moveDown(Image image) throws IOException
 {
  setImage(image, 17, 26);
  nextFrame();
  this.y = Math.min(braveManager.getLayerAt(1).getHeight(), y + 1);
 }

 public void moveLeft(Image image) throws IOException
 {
  setImage(image, 17, 26);
  nextFrame();
  this.x = Math.max(0, x - 1);

 }

 public void moveRight(Image image) throws IOException
 {
  setImage(image, 17, 26);
  nextFrame();
  this.x = Math.min(braveManager.getLayerAt(1).getWidth(), x + 1);
 }
}

现在英雄的移动范围大了,但只英雄一人,也太孤单了,我们给他创造一个小镇吧。
修改Scene类如下:

Scene.java
package brave;

import javax.microedition.lcdui.game.TiledLayer;
import javax.microedition.lcdui.Image;

public class Scene
{
 public static TiledLayer createTiledLayerByBackground(Image image)
 {
  TiledLayer tiledLayer = new TiledLayer(10, 8, image, 48, 64);
  tiledLayer.fillCells(0, 0, 10, 8, 2);
  return tiledLayer;
 }

 public static TiledLayer createTiledLayerByForeground(Image image)
 {
  TiledLayer tiledLayer = new TiledLayer(30, 32, image, 16, 16);
  // 30 * 32
  int[] maplist =
  {
    //0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

26 27 28 29
   0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0

,0 ,0 ,0 ,0 ,0 ,//0
   0

,28,29,29,29,29,29,29,29,29,29,29,29,29,29,29,29,29,29,29,29,29,29,29,29,29,29,29,30,0 ,//1
   0 ,34,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0

,0 ,0 ,0 ,36,0 ,//2
   0 ,34,0 ,1 ,2 ,3 ,4 ,5 ,0 ,0 ,0 ,1 ,2 ,3 ,3 ,26,3 ,3 ,4 ,5 ,0 ,0 ,1 ,2 ,3

,4 ,5 ,0 ,36,0 ,//3
   0 ,34,0 ,7 ,8 ,46,10,11,0 ,0 ,0 ,7 ,8 ,47,31,32,33,47,10,11,0 ,0 ,7 ,8

,46,10,11,0 ,36,0 ,//4
   0 ,34,0 ,13,14,15,16,17,0 ,0 ,0 ,13,14,14,37,38,39,14,16,17,0 ,0

,13,14,15,16,17,0 ,36,0 ,//5
   0 ,34,0 ,19,20,21,22,23,6 ,0 ,0 ,19,20,20,43,44,45,20,20,23,0 ,0

,19,20,21,22,23,0 ,36,0 ,//6
   0 ,34,0 ,0 ,0 ,12,0 ,0 ,0 ,0 ,0 ,24,24,24,13,15,17,24,24,24,0 ,0 ,0 ,0

,12,0 ,0 ,0 ,36,0 ,//7
   0 ,34,0 ,0 ,0 ,12,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,19,21,23,0 ,0 ,0 ,0 ,0 ,0 ,0

,12,0 ,0 ,0 ,36,0 ,//8
   0 ,34,0 ,0 ,0 ,12,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,12,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0

,12,0 ,0 ,0 ,36,0 ,//9
   0 ,34,0 ,0 ,0

,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,0 ,0 ,0 ,36,0 ,//10
   0 ,34,0 ,0 ,0 ,0 ,0 ,0 ,0 ,12,25,25,25,25,25,25,25,25,25,25,12,0 ,0 ,0 ,0

,0 ,0 ,0 ,36,0 ,//11
   0 ,34,0 ,1 ,2 ,3 ,4 ,5 ,0 ,12,25,25,25,25,25,25,25,25,25,25,12,0 ,1 ,2 ,3

,4 ,5 ,0 ,36,0 ,//12
   0 ,34,0 ,7 ,8 ,46,10,11,0 ,12,25,25,25,25,25,25,25,25,25,25,12,0 ,7 ,8

,46,10,11,0 ,36,0 ,//13
   0 ,34,0 ,13,14,15,16,17,0 ,12,25,25,25,25,25,25,25,25,25,25,12,0

,13,14,15,16,17,0 ,36,0 ,//14
   0 ,34,0 ,19,20,21,22,23,0 ,12,25,25,25,25,25,25,25,25,25,25,12,0

,19,20,21,22,23,0 ,36,0 ,//15
   0 ,34,0 ,0 ,0 ,12,0 ,0 ,0 ,12,25,25,25,25,25,25,25,25,25,25,12,0 ,0 ,0

,12,0 ,0 ,0 ,36,0 ,//16
   0 ,34,0 ,0 ,0 ,12,0 ,0 ,0 ,12,25,25,25,25,25,25,25,25,25,25,12,0 ,0 ,0

,12,0 ,0 ,0 ,36,0 ,//17
   0 ,34,0 ,0 ,0 ,12,0 ,0 ,0 ,12,25,25,25,25,25,25,25,25,25,25,12,0 ,0 ,0

,12,0 ,0 ,0 ,36,0 ,//18
   0 ,34,0 ,0 ,0

,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,0 ,0 ,0 ,36,0 ,//19
   0 ,34,0 ,0 ,0 ,0 ,0 ,0 ,0 ,12,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,12,0 ,0 ,0 ,0

,0 ,0 ,0 ,36,0 ,//20
   0 ,34,0 ,0 ,0 ,0 ,0 ,0 ,0 ,12,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,12,0 ,0 ,0 ,0

,0 ,0 ,0 ,36,0 ,//21
   0 ,34,0 ,1 ,2 ,3 ,4 ,5 ,0 ,12,0 ,0 ,0 ,0 ,1 ,3 ,5 ,0 ,0 ,0 ,12,0 ,1 ,2 ,3

,4 ,5 ,0 ,36,0 ,//22
   0 ,34,0 ,7 ,8 ,46,10,11,0 ,12,0 ,0 ,0 ,0 ,7 ,48,11,0 ,0 ,0 ,12,0 ,7 ,8

,46,10,11,0 ,36,0 ,//23
   0 ,34,0 ,13,14,15,16,17,0 ,12,0 ,0 ,0 ,6 ,13,15,17,0 ,0 ,0 ,12,0

,13,14,15,16,17,0 ,36,0 ,//24
   0 ,34,0 ,19,20,21,22,23,0 ,12,0 ,0 ,0 ,6 ,19,21,23,0 ,0 ,0 ,12,0

,19,20,21,22,23,0 ,36,0 ,//25
   0 ,34,0 ,0 ,0 ,12,0 ,0 ,0 ,12,18,0 ,0 ,0 ,0 ,12,0 ,0 ,0 ,0 ,12,0 ,0 ,0

,12,0 ,0 ,0 ,36,0 ,//26
   0 ,34,0 ,0 ,0

,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,12,0 ,0 ,0 ,36,0 ,//27
   0 ,34,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,12,12,12,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0

,0 ,0 ,0 ,36,0 ,//28
   0 ,34,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,12,12,12,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0

,0 ,0 ,0 ,36,0 ,//29
   0

,40,29,29,29,29,29,29,29,29,29,29,29,29,12,12,12,29,29,29,29,29,29,29,29,29,29,29,42,0 ,//30
   0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0

,0 ,0 ,0 ,0 ,0  //31
  };
  for(int i = 0 ; i < maplist.length ; i++)
  {
   int col = i % 30;
   int row = (i - col) / 30;
   tiledLayer.setCell(col, row, maplist[i]);
  }
  return tiledLayer;
 }
}


修改BraveCanvas类如下:

BraveCanvas.java

package brave;

import javax.microedition.lcdui.game.GameCanvas;
import javax.microedition.lcdui.Graphics;
import java.io.IOException;
import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.TiledLayer;


public class BraveCanvas extends GameCanvas implements Runnable
{
 private boolean sign;
 private Graphics g;
 private Hero hero;
 private Image upimage;
 private Image downimage;
 private Image leftimage;
 private Image rightimage;
 private TiledLayer backgroundMap;
 private TiledLayer foregroundMap;
 private BraveManager braveManager;

 public BraveCanvas()
 {
  super(true);
 }

 public void startup()
 {
  this.sign = true;
  try
  {
   backgroundMap = Scene.createTiledLayerByBackground(
    Image.createImage("/background.png"));
   //生成小镇地图
   foregroundMap = Scene.createTiledLayerByForeground(
    Image.createImage("/foreground.png"));

   upimage = Image.createImage("/hero_up.png");
   downimage = Image.createImage("/hero_down.png");
   leftimage = Image.createImage("/hero_left.png");
   rightimage = Image.createImage("/hero_right.png");
   braveManager = new BraveManager();
   braveManager.setBraveCanvas(this);
   hero = new Hero(upimage, 17, 26);
   hero.setFrameSequence(new int[]{1, 1, 0, 0, 1, 1, 2, 2});
   hero.setBraveCanvas(this);
   hero.setBraveManager(braveManager);
   hero.init(0,0);

  }
  catch(Exception e)
  {
   e.printStackTrace();
  }
  Thread thread = new Thread(this);
  thread.start();
 }

 public void run()
 {
  g = getGraphics();
  braveManager.insert(hero, 0);
  //插入小镇地图
  braveManager.insert(foregroundMap, 1);
  braveManager.insert(backgroundMap, 2);
  while(sign)
  {
   try
   {
    input(g);
    paint(g);
    Thread.sleep(15);
   }
   catch(Exception e)
   {
    e.printStackTrace();
   }
  }
 }

 public void input(Graphics g) throws IOException
 {
  int keystates = getKeyStates();
  switch(keystates)
  {
   case UP_PRESSED:
    hero.moveUp(upimage);
    break;
   case DOWN_PRESSED:
    hero.moveDown(downimage);
    break;
   case LEFT_PRESSED:
    hero.moveLeft(leftimage);
    break;
   case RIGHT_PRESSED:
    hero.moveRight(rightimage);
    break;
  }
  hero.afresh();
  braveManager.afresh();
 }

 public void paint(Graphics g)
 {
  g.setColor(0x000000);
  g.fillRect(0, 0, getWidth(), getHeight());
  g.setColor(0xffffff);
  braveManager.paint(g, 0, 0);
  flushGraphics();
 }
}

运行结果如图:

这一篇就写到这了。
现在终于有点RPG游戏的样子了,不过我们的英雄似乎可以穿墙走壁啊。在下一篇中我将加入碰撞检测和人
物对话。

写到这已经创建五个类了(j2ee写习惯了:)),不知道是不是多了,大家多提点意见。而且也有很多地方设
计的不是很合理,以后的开发也许会出现点问题,好在我只是单纯的实现功能。
在确定英雄始终在地图中央的那段程序,总感觉有点烦琐,不知道大家是怎么写的,希望各位高手指导指导。


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