C语言贪吃蛇

一、说明

• 编译环境：vs 2019
• 需要安装 eazyx（几秒钟就行）
• 代码注释详细
• 成像图
  

二、制作思路

1. 界面
   大小、颜色
2. 蛇的初始化
   蛇身形状、长度，出现在地图的位置，一开始往哪个方向移动
3. 食物的随机出现
   播种：srand((unsigned int)time(NULL));
   随机函数：rand()
4. 蛇的行动操作（移动和吃食物）
   WASD
   不能直接走与自身方向相反的方向，如：
    向右走时不能向左
5. 蛇死亡条件
   撞边界、撞自己
6. 得分的计算
   吃食物得分，打印在界面
7. 如何画蛇、画食物

三、代码

//在代码中取消 Unicode 编码的宏定义，让后续编译都以 MBCS 编码进行
#undef UNICODE
#undef _UNICODE

#include<stdio.h>
#include<conio.h> // _getch _kbhit
#include<time.h>
#include<graphics.h> //需安装easyX

//界面大小，可直接修改
#define M 600
#define N 400

typedef struct {
    
	int x, y;
}point;//坐标xy，与数学的坐标略有不同
struct snake {
    
	point xy[100];
	int position;
	int lenth;
}snake;
struct food {
    
	int flag = 0;//判断食物是否存在
	point fdxy;
	int grade = 0;
}food;

enum position {
     up, down, left, right };//枚举

//蛇，初始化蛇的位置
void startsnake()
{
    
	//蛇头
	snake.xy[0].x = 20;
	snake.xy[0].y = 0;

	snake.xy[1].x = 10;
	snake.xy[1].y = 0;

	snake.xy[2].x = 0;
	snake.xy[2].y = 0;

	//蛇初始化方向
	snake.position = right;

	snake.lenth = 3;
}

//画蛇（要安装easy_X），颜色会不断变化
void drawsnake()
{
    
	for (int i = 0; i < snake.lenth; i++)
	{
    
		setfillcolor(RGB(rand() % 255, rand() % 255, rand() % 255));
		fillrectangle(snake.xy[i].x, snake.xy[i].y, snake.xy[i].x + 10, snake.xy[i].y + 10);
	}
}

void movesnake()
{
    
	//蛇身往前移动一格
	for (int i = snake.lenth - 1; i > 0; i--)
	{
    
		snake.xy[i].x = snake.xy[i - 1].x;
		snake.xy[i].y = snake.xy[i - 1].y;
	}
	//蛇头方向移动
	switch (snake.position)
	{
    
	case up:
		snake.xy[0].y = snake.xy[0].y - 10; break;
	case down:
		snake.xy[0].y = snake.xy[0].y + 10; break;
	case left:
		snake.xy[0].x = snake.xy[0].x - 10; break;
	case right:
		snake.xy[0].x = snake.xy[0].x + 10; break;
	}
}

//随机生成食物
void showfood()
{
    
	food.fdxy.x = rand() % (M/10) * 10;//0~590
	food.fdxy.y = rand() % (N/10) * 10;//0~390
	//循环用于判断是否与蛇重合
	for (int i = 0; i < snake.lenth; i++)
	{
    
		if (snake.xy[i].x == food.fdxy.x && snake.xy[i].y == food.fdxy.y)
		{
    
			food.fdxy.x = rand() % 60 * 10;
			food.fdxy.y = rand() % 40 * 10;
		}
	}
}
//
void drawfood()
{
    
	setfillcolor(RGB(rand() % 255, rand() % 255, rand() % 255));
	fillrectangle(food.fdxy.x, food.fdxy.y, food.fdxy.x + 10, food.fdxy.y + 10);
}

void eatfood()
{
    
	if (snake.xy[0].x == food.fdxy.x && snake.xy[0].y == food.fdxy.y)
	{
    
		snake.lenth++;
		food.flag = 0;//这里看下main函数
		food.grade += 10;
	}
}

//键盘操作
void keydown()
{
    
	char dqown = _getch();
	switch (dqown)
	{
    
	case 'W':
	case 'w':
		if (snake.position != down)
			snake.position = up;
		break;
	case 'A':
	case 'a':
		if (snake.position != right)
			snake.position = left;
		break;
	case 'S':
	case 's':
		if (snake.position != up)
			snake.position = down;
		break;
	case 'D':
	case 'd':
		if (snake.position != left)
			snake.position = right;
		break;
	case '9':Sleep(5000);//按下 9 暂停 5 秒 (可自行更改)
	}
}

void showgrade()
{
    
	char Grade[20] = "";
	sprintf_s(Grade, "grade:%d", food.grade);
	outtextxy(250, 20, Grade);
}

//撞墙则死，碰自己不死
void dead()
{
    
	if (snake.xy[0].x == M || snake.xy[0].x < 0 || snake.xy[0].y < 0 || snake.xy[0].y == N)
	{
    
		char over[20] = "Game Over!";
		outtextxy(250, 50, over);
		system("pause");
		exit(0);
	}

}

int main()
{
    
	srand((unsigned int)time(NULL));//播种
	initgraph(M, N); //画面大小，可自行随意更改
	setbkcolor(RGB(110, 120, 119));//背景颜色

	//初始化蛇
	startsnake();
	drawsnake();

	while (1)
	{
    
		cleardevice();//清屏
		movesnake();
		drawsnake();
		if (food.flag == 0)//判断是否生成食物
		{
    
			showfood();
			food.flag = 1;
		}
		drawfood();
		if (_kbhit())//判断是否键盘操作
		{
    
			keydown();
		}
		eatfood();
		showgrade();
		dead();
		Sleep(100);//这个可以看作蛇的移动速度
	}
	return 0;
}