package com.hbsi;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
//Main Class
public class GreedSnake extends KeyAdapter{
JFrame mainFrame;
Canvas paintCanvas;
JLabel labelScore;//計分牌
SnakeModel snakeModel=null;// 蛇
public static final int DEFAULT_WIDTH=500;
public static final int DEFAULT_HEIGHT=300;
public static final int nodeWidth=10;
public static final int nodeHeight=10;
//GreedSnake():初始化遊戲界面
public GreedSnake(){
//設置界面元素
mainFrame=new JFrame("貪吃蛇遊戲");
Container cp=mainFrame.getContentPane();
labelScore=new JLabel("所得分數為:",JLabel.CENTER);
cp.add(labelScore,BorderLayout.NORTH);
paintCanvas=new Canvas();
paintCanvas.setSize(DEFAULT_WIDTH+1,DEFAULT_HEIGHT+1);
paintCanvas.addKeyListener(this);
cp.add(paintCanvas,BorderLayout.CENTER);
JPanel panelButtom=new JPanel();
panelButtom.setLayout(new BorderLayout());
JLabel labelHelp;// 幫助信息
labelHelp=new JLabel("按 PageUP 或 PageDown 鍵改變速度",JLabel.CENTER);
panelButtom.add(labelHelp,BorderLayout.NORTH);
labelHelp=new JLabel("按 Enter 或 S 鍵重新開始遊戲",JLabel.CENTER);
panelButtom.add(labelHelp,BorderLayout.CENTER);
labelHelp=new JLabel("按 SPACE 鍵或 P 鍵暫停遊戲",JLabel.CENTER);
panelButtom.add(labelHelp,BorderLayout.SOUTH);
cp.add(panelButtom,BorderLayout.SOUTH);
mainFrame.addKeyListener(this);
mainFrame.pack();
mainFrame.setResizable(false);//設置窗口大小不能變化
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainFrame.setVisible(true);
begin();
}
//keyPressed():按鍵檢測
public void keyPressed(KeyEvent e){
int keyCode=e.getKeyCode();
if(snakeModel.running)
switch(keyCode){
case KeyEvent.VK_UP:
snakeModel.changeDirection(SnakeModel.UP);
break;
case KeyEvent.VK_DOWN:
snakeModel.changeDirection(SnakeModel.DOWN);
break;
case KeyEvent.VK_LEFT:
snakeModel.changeDirection(SnakeModel.LEFT);
break;
case KeyEvent.VK_RIGHT:
snakeModel.changeDirection(SnakeModel.RIGHT);
break;
case KeyEvent.VK_ADD:
case KeyEvent.VK_PAGE_UP:
snakeModel.speedUp();// 加速
break;
case KeyEvent.VK_SUBTRACT:
case KeyEvent.VK_PAGE_DOWN:
snakeModel.speedDown();// 減速
break;
case KeyEvent.VK_SPACE:
case KeyEvent.VK_P:
snakeModel.changePauseState();// 暫停或繼續
break;
default:
}
//重新開始
if(keyCode==KeyEvent.VK_S || keyCode==KeyEvent.VK_ENTER){
snakeModel.running=false;
begin();
}
}
//repaint（）：繪制遊戲界面（包括蛇和食物）
void repaint(){
Graphics g=paintCanvas.getGraphics();
//draw background
g.setColor(Color.LIGHT_GRAY);
g.fillRect(0,0,DEFAULT_WIDTH,DEFAULT_HEIGHT);
//draw the snake
g.setColor(Color.BLACK);
LinkedList na=snakeModel.nodeArray;
Iterator it=na.iterator();
while(it.hasNext()){
Node n=(Node)it.next();
drawNode(g,n);
}
// draw the food
g.setColor(Color.RED);
Node n=snakeModel.food;
drawNode(g,n);
updateScore();
}
//drawNode（）：繪畫某一結點（蛇身或食物）
private void drawNode(Graphics g,Node n){
g.fillRect(n.x*nodeWidth,n.y*nodeHeight,nodeWidth-1,nodeHeight-1);
}
//updateScore（）：改變計分牌
public void updateScore(){
String s="所得分數為: "+snakeModel.score;
labelScore.setText(s);
}
//begin（）：遊戲開始，放置貪吃蛇
void begin(){
if(snakeModel==null||!snakeModel.running){
snakeModel=new SnakeModel(this,DEFAULT_WIDTH/nodeWidth,
DEFAULT_HEIGHT/nodeHeight);
(new Thread(snakeModel)).start();
}
}
//main（）：主函數
public static void main(String[] args){
GreedSnake gs=new GreedSnake();
}
}
//Node:結點類
class Node{
int x;
int y;
Node(int x,int y){
this.x=x;
this.y=y;
}
}
//SnakeModel:貪吃蛇模型
class SnakeModel implements Runnable{
GreedSnake gs;
boolean[][] matrix;// 界面數據保存在數組裡
LinkedList nodeArray=new LinkedList();
Node food;
int maxX;//最大寬度
int maxY;//最大長度
int direction=2;//方向
boolean running=false;
int timeInterval=200;// 間隔時間（速度）
double speedChangeRate=0.75;// 速度改變程度
boolean paused=false;// 遊戲狀態
int score=0;
int countMove=0;
// UP和DOWN是偶數，RIGHT和LEFT是奇數
public static final int UP=2;
public static final int DOWN=4;
public static final int LEFT=1;
public static final int RIGHT=3;
//GreedModel():初始化界面
public SnakeModel(GreedSnake gs,int maxX,int maxY){
this.gs=gs;
this.maxX=maxX;
this.maxY=maxY;
matrix=new boolean[maxX][];
for(int i=0;i<maxX;++i){
matrix[i]=new boolean[maxY];
Arrays.fill(matrix[i],false);// 沒有蛇和食物的地區置false
}
//初始化貪吃蛇
int initArrayLength=maxX>20 ? 10 : maxX/2;
for(int i=0;i<initArrayLength;++i){
int x=maxX/2+i;
int y=maxY/2;
nodeArray.addLast(new Node(x,y));
matrix[x][y]=true;// 蛇身處置true
}
food=createFood();
matrix[food.x][food.y]=true;// 食物處置true
}
//changeDirection():改變運動方向
public void changeDirection(int newDirection){
if(direction%2!=newDirection%2){// 避免沖突
direction=newDirection;
}
}
//moveOn():貪吃蛇運動函數
public boolean moveOn(){
Node n=(Node)nodeArray.getFirst();
int x=n.x;
int y=n.y;
switch(direction){
case UP:
y–;
break;
case DOWN:
y++;
break;
case LEFT:
x–;
break;
case RIGHT:
x++;
break;
}
if((0<=x&&x<maxX)&&(0<=y&&y<maxY)){
if(matrix[x][y]){// 吃到食物或者撞到身體
if(x==food.x&&y==food.y){// 吃到食物
nodeArray.addFirst(food);// 在頭部加上一結點
//計分規則與移動長度和速度有關
int scoreGet=(10000-200*countMove)/timeInterval;
score+=scoreGet>0 ? scoreGet : 10;
countMove=0;
food=createFood();
matrix[food.x][food.y]=true;
return true;
}
else return false;// 撞到身體
}
else{//什麼都沒有碰到
nodeArray.addFirst(new Node(x,y));// 加上頭部
matrix[x][y]=true;
n=(Node)nodeArray.removeLast();// 去掉尾部
matrix[n.x][n.y]=false;
countMove++;
return true;
}
}
return false;//越界（撞到墻壁）
}
/*發瞭一份貪吃蛇遊戲的代碼，誰能幫我解釋一下，貪吃蛇程序的運行過程，運行步驟*/
//run():貪吃蛇運動線程
public void run(){
running=true;
while(running){
try{
Thread.sleep(timeInterval);
}
catch(Exception e){
break;
}
if(!paused){
if(moveOn()){// 未結束
gs.repaint();
}
else{//遊戲結束
JOptionPane.showMessageDialog(null,"GAME OVER",
"Game Over",JOptionPane.INFORMATION_MESSAGE);
break;
}
}
}
running=false;
}
//createFood():生成食物及放置地點
private Node createFood(){
int x=0;
int y=0;
do{
Random r=new Random();
x=r.nextInt(maxX);
y=r.nextInt(maxY);
}
while(matrix[x][y]);
return new Node(x,y);
}
//speedUp():加快蛇運動速度
public void speedUp(){
timeInterval*=speedChangeRate;
}
//speedDown():放慢蛇運動速度
public void speedDown(){
timeInterval/=speedChangeRate;
}
//changePauseState(): 改變遊戲狀態（暫停或繼續）
public void changePauseState(){
paused=!paused;
}
}