贪吃蛇小游戏的简单实现——Java

逃离我推掉我的手 2022-10-29 09:03 239阅读 0赞

### 贪吃蛇 ###

*  贪吃蛇
 *   *  源码：

# 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：  
![在这里插入图片描述][2021021016390339.gif_pic_center]  
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);
        }
    }

[2021021016390339.gif_pic_center]: /images/20221024/10ebf514f6b847ac90cb43124420f12f.png