贪吃蛇
贪吃蛇这一款小游戏，在以前的诺基亚手机中基本都会带有这款，曾经风靡一时。
那么我们如何将这一款小游戏实现出来呢？
在这里，我们会使用到javaFX图形化编程，将图形化界面打印出来，通过用户的实际操作，来控制游戏，如下图：
这就是，游戏最终实现的情况。
我们可以通过蛇的速度来控制游戏难度，通过控制方向左右移动，实现游戏的逻辑，最后完成。
首先我们会导入很多的包，大多数都是javafx的，因为需要图形化界面，我们需要导入它，javafx是jdk自带的。
import javafx.animation.AnimationTimer;
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.input.KeyEvent;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.text.Font;
import javafx.stage.Stage;
import java.util.Arrays;
import java.util.Random;
我们定义贪吃蛇的身体初始为3，食物随机生成，每次吃完食物速度会增加，同时获得一分，当头部撞墙，或者头部撞到身体后，游戏结束。当游戏结束，按R从新开始游戏。
具体看源码，参照注释阅读：
源码：
public class Point {
public int x;
public int y;
public Point(int x, int y) {
this.x = x;
this.y = y;
}
}
package snake;
import javafx.animation.AnimationTimer;
import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.canvas.Canvas;
import javafx.scene.canvas.GraphicsContext;
import javafx.scene.input.KeyEvent;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.text.Font;
import javafx.stage.Stage;
import java.util.Arrays;
import java.util.Random;
public class SnakeAPP extends Application {
//定义变量
//游戏区域大小，格子的的宽和高
private static final int WIDTH = 20;
private static final int HEIGHT = 20;
//绘制图形的时候，格子所占的大小
private static final int GRID_SIZE = 40;
private static final int CANVAS_WIDTH = WIDTH * GRID_SIZE;
private static final int CANVAS_HEIGHT = HEIGHT * GRID_SIZE;
//定义游戏本身
//移动速度
//speed,每秒的帧数
private static int speed;
//食物
private static Point food = new Point(-1, -1);
//蛇,最多长1000节
private static Point[] snake = new Point[1000];
//现在多少节
private static int snakeLength = 0;
//朝向
enum Direction {
UP, LEFT, DOWN, RIGHT
}
private static Direction direction;
//随机生成器
private static Random random = new Random();
//游戏结束标志
private static boolean gameOver;
//初始化游戏数据
private static void newGame() {
speed = 3;
//蛇的初始有3节
Arrays.fill(snake, null);
snakeLength = 0;
snake[snakeLength++] = new Point(WIDTH / 2, HEIGHT / 2);
snake[snakeLength++] = new Point(WIDTH / 2, HEIGHT / 2);
snake[snakeLength++] = new Point(WIDTH / 2, HEIGHT / 2);
//生成食物
newFood();
direction = Direction.LEFT;
//游戏未结束
gameOver = false;
}
//在地图上随机生成食物
private static void newFood() {
//1，不能生成在外面
//2.不能和蛇的身体碰撞
int x, y;
do {
x = random.nextInt(WIDTH);
y = random.nextInt(HEIGHT);
} while (isCollision(x, y));
food.x = x;
food.y = y;
}
private static boolean isCollision(int x, int y) {
//遍历蛇
//不要用foreach
for (int i = 0; i < snakeLength; i++) {
Point point = snake[i];
if (point.x == x && point.y == y) {
return true;
}
}
return false;
}
//每一帧做的动作
private static void frame() {
//移动身体
for (int i = snakeLength - 1; i >= 1; i--) {
//变成前一个坐标
snake[i].x = snake[i - 1].x;
snake[i].y = snake[i - 1].y;
}
//移动头
Point head = snake[0];
switch (direction) {
case UP:
head.y--;
break;
case DOWN:
head.y++;
break;
case LEFT:
head.x--;
break;
case RIGHT:
head.x++;
break;
}
//判断头是否出边界
if (head.x < 0 || head.x >= WIDTH || head.y < 0 || head.y >= HEIGHT) {
gameOver = true;
return;
}
//判断是否碰到身体
for (int i = 1; i < snakeLength; i++) {
Point point = snake[i];
if (head.x == point.x && head.y == point.y) {
gameOver = true;
return;
}
}
//判断是否吃到食物
// 如果吃到食物
// 1.身体增加1节 2.重新生成食物 3. 速度增加
if (head.x == food.x && head.y == food.y) {
snake[snakeLength++] = new Point(-1, -1);
newFood();
speed++;
}
}
//每一帧绘制工作，渲染
private static void render(GraphicsContext gc) {
//1.从新绘制背景
gc.setFill(Color.BLACK);
gc.fillRect(0, 0, CANVAS_WIDTH, CANVAS_HEIGHT);
//2.蛇的绘制
for (int i = 0; i < snakeLength; i++) {
Point point = snake[i];
gc.setFill(Color.GREEN);
gc.fillRect(point.x * GRID_SIZE + 1, point.y * GRID_SIZE + 1, GRID_SIZE - 2, GRID_SIZE - 2);
}
//3.食物的绘制
gc.setFill(Color.YELLOW);
gc.fillOval(food.x * GRID_SIZE + 1, food.y * GRID_SIZE + 1, GRID_SIZE, GRID_SIZE);
//3.进行游戏结束绘制
if (gameOver) {
gc.setFill(Color.RED);
gc.setFont(new Font(40));
gc.fillText("游戏结束,按R继续", 200, 200);
}
//得分
gc.setFill(Color.AQUAMARINE);
gc.setFont(new Font(20));
gc.fillText("当前得分"+ (speed-3)+"分", 40, 40);
//作者
gc.setFill(Color.AQUA);
gc.setFont(new Font(15));
gc.fillText("版本：v1.0 作者：H485301267 ", 20, 740);
}
@Override
public void start(Stage primaryStage) throws Exception {
//游戏的初始化
newGame();
Pane pane = new Pane();
Canvas canvas = new Canvas(CANVAS_WIDTH, CANVAS_HEIGHT);
pane.getChildren().add(canvas);
Scene scene = new Scene(pane);
final GraphicsContext gc = canvas.getGraphicsContext2D();
AnimationTimer timer = new AnimationTimer() {
long lastTiick;
@Override
public void handle(long now) {
if (gameOver) {
return;
}
if (lastTiick == 0 || now - lastTiick > 1e9 / speed) {
lastTiick = now;
frame();
render(gc);
}
}
};
timer.start();
scene.setOnKeyPressed(new EventHandler<KeyEvent>() {
@Override
public void handle(KeyEvent event) {
switch (event.getCode()) {
case W:
case UP:
if (direction != Direction.DOWN) {
direction = Direction.UP;
}
break;
case A:
case LEFT:
if (direction != Direction.RIGHT) {
direction = Direction.LEFT;
}
break;
case S:
case DOWN:
if (direction != Direction.UP) {
direction = Direction.DOWN;
}
break;
case D:
case RIGHT:
if (direction != Direction.LEFT) {
direction = Direction.RIGHT;
}
break;
case R:
if (gameOver) {
newGame();
}
break;
}
}
});
primaryStage.setScene(scene);
primaryStage.setTitle("贪吃蛇");
primaryStage.setResizable(false);
primaryStage.sizeToScene();
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}