//文件名：SnakeMIDlet .java
package snake;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class SnakeMIDlet extends MIDlet {
SnakeCanvas displayable = new SnakeCanvas();
public SnakeMIDlet() {
Display.getDisplay(this).setCurrent(displayable);
}
public void startApp() {}
public void pauseApp() {}
public void destroyApp(boolean unconditional) {}
}
//文件名：SnakeCanvas.java
package snake;
import java.util.*;
import javax.microedition.lcdui.*;
/**
* 贪吃蛇游戏
*/
public class SnakeCanvas extends Canvas implements Runnable{
/**存储贪吃蛇节点坐标,其中第二维下标为0的代表x坐标，第二维下标是1的代表y坐标*/
int[][] snake = new int[200][2];
/**已经使用的节点数量*/
int snakeNum;
/**贪吃蛇运动方向,0代表向上，1代表向下,2代表向左,3代表向右*/
int direction;
/*移动方向*/
/**向上*/
private final int DIRECTION_UP = 0;
/**向下*/
private final int DIRECTION_DOWN = 1;
/**向左*/
private final int DIRECTION_LEFT = 2;
/**向右*/
private final int DIRECTION_RIGHT = 3;
/**游戏区域宽度*/
int width;
/**游戏区域高度*/
int height;
/**蛇身单元宽度*/
private final byte SNAKEWIDTH = 4;
/**是否处于暂停状态,true代表暂停*/
boolean isPaused = false;
/**是否处于运行状态,true代表运行*/
boolean isRun = true;
/**时间间隔*/
private final int SLEEP_TIME = 300;
/**食物的X坐标*/
int foodX;
/**食物的Y坐标*/
int foodY;
/**食物的闪烁控制*/
boolean b = true;
/**Random对象*/
Random random = new Random();
public SnakeCanvas() {
//初始化
init();
width = this.getWidth();
height = this.getHeight();
//启动线程
new Thread(this).start();
}
/**
* 初始化开始数据
*/
private void init(){
//初始化节点数量
snakeNum = 7;
//初始化节点数据
for(int i = 0;i < snakeNum;i++){
snake[i][0] = 100 - SNAKEWIDTH * i;
snake[i][1] = 40;
}
//初始化移动方向
direction = DIRECTION_RIGHT;
//初始化食物坐标
foodX = 100;
foodY = 100;
}
protected void paint(Graphics g) {
//清屏
g.setColor(0xffffff);
g.fillRect(0,0,width,height);
g.setColor(0);
//绘制蛇身
for(int i = 0;i < snakeNum;i++){
g.fillRect(snake[i][0],snake[i][1],SNAKEWIDTH,SNAKEWIDTH);
}
//绘制食物
if(b){
g.fillRect(foodX,foodY,SNAKEWIDTH,SNAKEWIDTH);
}
}
private void move(int direction){
//蛇身移动
for(int i = snakeNum - 1;i > 0;i--){
snake[i][0] = snake[i - 1][0];
snake[i][1] = snake[i - 1][1];
}
//第一个单元格移动
switch(direction){
case DIRECTION_UP:
snake[0][1] = snake[0][1] - SNAKEWIDTH;
break;
case DIRECTION_DOWN:
snake[0][1] = snake[0][1] + SNAKEWIDTH;
break;
case DIRECTION_LEFT:
snake[0][0] = snake[0][0] - SNAKEWIDTH;
break;
case DIRECTION_RIGHT:
snake[0][0] = snake[0][0] + SNAKEWIDTH;
break;
}
}
/**
* 吃掉食物，自身增长
*/
private void eatFood(){
//判别蛇头是否和食物重叠
if(snake[0][0] == foodX && snake[0][1] == foodY){
snakeNum++;
generateFood();
}
}
/**
* 产生食物
* 说明：食物的坐标必须位于屏幕内，且不能和蛇身重合
*/
private void generateFood(){
while(true){
foodX = Math.abs(random.nextInt() % (width - SNAKEWIDTH + 1))
/ SNAKEWIDTH * SNAKEWIDTH;
foodY = Math.abs(random.nextInt() % (height - SNAKEWIDTH + 1))
/ SNAKEWIDTH * SNAKEWIDTH;
boolean b = true;
for(int i = 0;i < snakeNum;i++){
if(foodX == snake[i][0] && snake[i][1] == foodY){
b = false;
break;
}
}
if(b){
break;
}
}
}
/**
* 判断游戏是否结束
* 结束条件：
* 1、蛇头超出边界
* 2、蛇头碰到自身
*/
private boolean isGameOver(){
//边界判别
if(snake[0][0] < 0 || snake[0][0] > (width - SNAKEWIDTH) ||
snake[0][1] < 0 || snake[0][1] > (height - SNAKEWIDTH)){
return true;
}
//碰到自身
for(int i = 4;i < snakeNum;i++){
if(snake[0][0] == snake[i][0]
&& snake[0][1] == snake[i][1]){
return true;
}
}
return false;
}
/**
* 事件处理
*/
public void keyPressed(int keyCode){
int action = this.getGameAction(keyCode);
//改变方向
switch(action){
case UP:
if(direction != DIRECTION_DOWN){
direction = DIRECTION_UP;
}
break;
case DOWN:
if(direction != DIRECTION_UP){
direction = DIRECTION_DOWN;
}
break;
case LEFT:
if(direction != DIRECTION_RIGHT){
direction = DIRECTION_LEFT;
}
break;
case RIGHT:
if(direction != DIRECTION_LEFT){
direction = DIRECTION_RIGHT;
}
break;
case FIRE:
//暂停和继续
isPaused = !isPaused;
break;
}
}
/**
* 线程方法
* 使用精确延时
*/
public void run(){
try{
while (isRun) {
//开始时间
long start = System.currentTimeMillis();
if(!isPaused){
//吃食物
eatFood();
//移动
move(direction);
//结束游戏
if(isGameOver()){
break;
}
//控制闪烁
b = !b;
}
//重新绘制
repaint();
long end = System.currentTimeMillis();
//延时
if(end - start < SLEEP_TIME){
Thread.sleep(SLEEP_TIME - (end - start));
}
}
}catch(Exception e){}
}
}
