Java究竟怎么玩？

   示例程序下載地址：http://download.csdn.net/source/999273（源碼在jar內）

 AVG，即Adventure Game，可以直譯為[冒險游戲]。但是通常情況下我們說AVG是指[文字冒險游戲]，也有人更直白的解釋成自己選擇路線和結局的電子小說，與硬砍硬殺的RPG或者揉破鍵盤的ACT不同，AVG多以解謎或文字游戲等腦力攻關推動劇情發展。現在日本流行的ADV，可以看作是AVG英文全稱的不同縮寫方式，大體上講，AVG == ADV。

 由于商業化需要，現代主流的AVG往往是GalGame，也就是少女游戲，或稱少女戀愛游戲，但GalGame != AVG，只是下屬分支中的一環罷了，AVG包含GalGame，但GalGame并不能完全代表AVG/ADV。另外關于GalGame的詳細介紹，在若木民喜《只有神才知道的世界》中演繹的相當生動，有興趣的可以自己去看看~

  就技術角度而言，AVG開發可以算得所有游戲類型中最容易的。一款簡單AVG游戲的制作難度甚至在貪食蛇、俄羅斯方塊之下。由于實現的簡易性，導致AVG的開發重心往往著重于策劃及美工，程序員的作用則微乎其微。同時也正因AVG開發的門坎約等于0，所以此類型的同人游戲之多即可堪稱世界之冠。另外，AVG開發工具普及的也促進了AVG的量產化。利用工具，即始是小說作者、漫畫家等非軟件專業出身的人士，往往也能輕易制作出頂級的AVG大作。（順便一提，目前我所見過最好的AVG制作工具是鬼子的livemaker，采用類似思維導圖的方式構造整個游戲，很多輕小說作者乃至網絡漫畫家用它制作自己作品的宣傳游戲。但就技術角度上說，livemaker的開發依舊沒什么難度......）

 由于AVG的大泛濫，通常僅有文字、圖片及語音的AVG往往無法滿足用戶需求（H除外-_-）。我們每每可在AVG游戲類型后發現個+號，比如《櫻花大戰》是AVG+SLG，《生化危機》是AVG+ACT。所以客觀上說，AVG開發僅僅能進行字圖的交互是不夠的，還要解決多模塊組件的協調問題。

 在Java桌面應用開發中,我們都知道繪圖是極為簡單的，有Image、Graphics兩個對象就可以Paint一個圖形，即使圖形對象再多，最后它們也必須統一在一個Paint中，所以Java中不存在圖像的交互問題。

但問題在于，圖像的顯示可以統一，但是觸發圖像變化的事件卻是很難統一的。比如現在有需求如下，在AVG模式中，觸發鍵盤事件上、下、左、右時為控制畫面的前進、后退，切換模式到SLG模式后，設定上、下、左、右是光標移動，那么如果我要在程序中實現，就必須記錄當前模式，而后根據不同模式調用事件，再反饋到圖形上。如果只有幾個事件的區別，我們當然可以很容易用分支來實現；問題是，隨著游戲規模的加大，這些分支將成幾何倍數增多，單純的分支判定到最后只能忙于應付，落個費力不討好。

其實在這時，我們大可以使用一些技巧來輕松解決問題。

示例如下：

首先，我們構造一個接口，命名為IControl，繼承鼠標及鍵盤監聽，并在其中設定兩個抽象方法：

    package org.loon.simple.avg; import java.awt.Graphics; import java.awt.event.KeyListener; import java.awt.event.MouseListener; import java.awt.event.MouseMotionListener; /** * Copyright 2008 - 2009 * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. * * @project loonframework * @author chenpeng * @email：ceponline@yahoo.com.cn * @version 0.1 */ public interface IControl extends MouseListener, MouseMotionListener, KeyListener { public abstract void draw(final Graphics g); public abstract IControl invoke(); }

  而后，再構造一個接口，命名為IAVG，同樣繼承鼠標及鍵盤監聽，并在其中設定三個抽象方法，用以操作IControl接口：

    package org.loon.simple.avg; import java.awt.Graphics; import java.awt.event.KeyListener; import java.awt.event.MouseListener; import java.awt.event.MouseMotionListener; /** * Copyright 2008 - 2009 * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. * * @project loonframework * @author chenpeng * @email：ceponline@yahoo.com.cn * @version 0.1 */ public interface IAVG extends MouseListener, MouseMotionListener, KeyListener { public abstract void draw(final Graphics g); public abstract IControl getControl(); public abstract void setControl(final IControl control); } 

     再后，制作一個顯示圖像用組件，命名為AVGCanva，繼承自Canvas。

     package org.loon.simple.avg; import java.awt.Canvas; import java.awt.Graphics; /** * Copyright 2008 - 2009 * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. * * @project loonframework * @author chenpeng * @email：ceponline@yahoo.com.cn * @version 0.1 */ public class AVGCanvas extends Canvas { /** * */ private static final long serialVersionUID = 1982278682597393958L; private boolean start; private IAVG avg; public AVGCanvas(IAVG handler) { this.avg = handler; this.start = false; this.addKeyListener(handler); this.addMouseListener(handler); this.addMouseMotionListener(handler); } public void update(Graphics g) { paint(g); } public void paint(Graphics g) { if (this.start) { this.avg.draw(g); } } public void startPaint() { this.start = true; } public void endPaint() { this.start = false; } }

     這段代碼中的paint方法中并沒有現成的方法，而是調用了IAVG接口的draw。緊接著，我們再設定一個AVGFrame用以加載AVGCanvas。

    package org.loon.simple.avg; import java.awt.Color; import java.awt.Dimension; import java.awt.Frame; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; /** * Copyright 2008 - 2009 * * Licensed under the Apache License, Version 2.0 (the "License"); you may not * use this file except in compliance with the License. You may obtain a copy of * the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations under * the License. * * @project loonframework * @author chenpeng * @email：ceponline@yahoo.com.cn * @version 0.1 */ public class AVGFrame extends Frame implements Runnable { /** * */ private static final long serialVersionUID = 198284399945549558L; private IAVG avg; private AVGCanvas canvas; private boolean fps; private String titleName; private Thread mainLoop; public AVGFrame(String titleName, int width, int height) { this(new AVG(), titleName, width, height); } public AVGFrame(IAVG avg, String titleName, int width, int height) { super(titleName); Lib.WIDTH = width; Lib.HEIGHT = height; this.avg = avg; this.titleName = titleName; this.addKeyListener(avg); this.setPreferredSize(new Dimension(width + 5, height + 25)); this.initCanvas(Lib.WIDTH, Lib.HEIGHT); this.pack(); this.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); this.setResizable(false); this.setLocationRelativeTo(null); this.setVisible(true); } public void run() { gameLoop(); } /** * 開始循環窗體圖像 * */ private synchronized void gameLoop() { canvas.startPaint(); long second = 0L; int moveCount = 0; // 循環繪制 for (;;) { long start = System.currentTimeMillis(); this.paintScreen(); long end = System.currentTimeMillis(); long time = end - start; long sleepTime = 20L - time; if (sleepTime < 0L) sleepTime = 0L; try { Thread.sleep(sleepTime); } catch (InterruptedException e) { e.printStackTrace(); } if (this.fps) { moveCount++; second += System.currentTimeMillis() - start; if (second >= 1000L) { this.setTitle(new StringBuilder(titleName).append(" FPS:") .append(moveCount).toString()); moveCount = 0; second = 0L; } } } } /** * 啟動游戲循環 * */ public void mainLoop() { this.mainLoop = new Thread(this); this.mainLoop.start(); } /** * 初始化背景帆布 * * @param width * @param height */ private void initCanvas(final int width, final int height) { canvas = new AVGCanvas(avg); canvas.setBackground(Color.black); canvas.setPreferredSize(new Dimension(width, height)); this.add(canvas); } public IAVG getAVG() { return this.avg; } protected void processWindowEvent(WindowEvent e) { super.processWindowEvent(e); } public synchronized void paintScreen() { canvas.repaint(); } public boolean isShowFPS() { return fps; } public void setShowFPS(boolean fps) { this.fps = fps; } public Thread getMainLoop() { return mainLoop; } public String getTitleName() { return titleName; } }

  我們可以看到，在本例鼠標鍵盤事件及圖像繪制完全通過接口方式實現。此時，只要讓不同組件統一實現IControl接口，便可以輕松轉換事件及圖像的繪制。也正是我們都再熟悉不過的MVC模式中，通過Event導致Controller改變Model及View的基本原理。

   下一回，我們將具體講解一個AVG游戲實現的基本流程。

  示例代碼界面如下圖：

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   示例程序下載地址：http://download.csdn.net/source/999273（源碼在jar內）