一个功能简单的贪吃蛇游戏

拼搏现实的明天。 2022-05-24 06:25 219阅读 0赞

1.创建一个基于对话框的程序

2.添加如下所示的编辑框，文本框

![70][]

并设置这几个按钮位置属性如下

![70 1][]

3.准备一张背景图，放入res文件夹内，这样，准备工作就做好了，现在来添加代码了

4.添加Gdi+支持（见前文）

5.在主对话框类中添加两个结构

struct Snake
    {
    	int x;//位置
    	int y;
    	int direction;//方向
    	
    };
    
    struct Food
    {
    	int x;
    	int y;//位置
    
    };

添加共有成员

int m_width;//游戏区宽度
    	int m_height ;//游戏区高度
    	Image* img;//背景图
    	
    	list<Snake>snake;//蛇
    	Food food;//食物

别忘记添加对list的支持

#include<list>
    using std::list;

初始化背景图

在主对话框构造函数中

img = Image::FromFile(_T("res/bkg.jpg"));

6.添加宏，4个方向宏，2个蛇大小宏

#define SNAKE_LEFT 3
    #define SNAKE_UP 1
    #define SNAKE_RIGHT 2
    #define SNAKE_DOWN 0
    
    #define SNAKE_WIDTH 20
    #define SNAKE_HEIGHT 20

7.添加定时器消息，初始化在InitInstance（）函数中

SetTimer(0, 1000, NULL);
    
    	srand(300);
    	//蛇位置初始化
    	Snake snakes;
    	snakes.x = rand() % 300;
    	snakes.y = rand() % 300;
    	snakes.direction = rand() % 3;
    	for (int i = 0; i < 5; i++)
    	{
    		snakes.x += SNAKE_WIDTH;
    		snake.push_back(snakes);
    	}
    	//食物初始化
    	srand(2000);
    	food.x = rand() % m_width;
    	food.y = rand() % m_height;

8.添加绘制蛇主体和食物的函数DrawSnake（）

void CSnakeDlg::DrawSnake(Graphics & gh)
    {
    	SolidBrush brush(Color(120,0,0,0));
    	
    	IsHit();
    
    	gh.FillRectangle(&brush, RectF(food.x, food.y, SNAKE_WIDTH, SNAKE_HEIGHT));//绘制食物
    
    	for (auto &i : snake)
    	{
    		gh.FillRectangle(&brush, RectF(i.x, i.y, SNAKE_WIDTH, SNAKE_HEIGHT));//绘制蛇
    	}
    }

再添加碰撞检测函数IsHit（）

void CSnakeDlg::IsHit()
    {
    	SnakeRun();
    	Snake head = snake.back();
    	if (head.x<0 || head.x>m_width || head.y<0 || head.y>m_height)//撞墙判断
    		OnCancel();
    }

每一帧蛇移动一次，只动蛇头和蛇尾

void CSnakeDlg::SnakeRun()
    {
    //只动蛇头和蛇尾，推断出下一步蛇头的位置，压入列表中 ，然后删除蛇尾
    	//蛇头是尾元素
    	Snake snakes = snake.back();
    	Snake head;
    	switch (snakes.direction)
    	{
    	case SNAKE_LEFT:
    		head.direction = snakes.direction;
    		head.x = snakes.x - SNAKE_WIDTH;
    		head.y = snakes.y;
    		break;
    	case SNAKE_DOWN:
    		head.direction = snakes.direction;
    		head.x = snakes.x;
    		head.y = snakes.y+ SNAKE_HEIGHT;
    		break;
    	case SNAKE_RIGHT:
    		head.direction = snakes.direction;
    		head.x = snakes.x + SNAKE_WIDTH;
    		head.y = snakes.y;
    		break;
    	case SNAKE_UP:
    		head.direction = snakes.direction;
    		head.x = snakes.x ;
    		head.y = snakes.y- SNAKE_HEIGHT;
    		break;
    	}
    	snake.push_back(head);
    	if(!IsEat())//没有吃到食物就弹出头部
    	snake.pop_front();
    	
    }

是否吃到食物判断

bool CSnakeDlg::IsEat()
    {
    	Snake snakes = snake.back();
    	PointF ptCenter1, ptCenter2;
    	ptCenter1.X = snakes.x + SNAKE_WIDTH/2;
    	ptCenter1.Y = snakes.y + SNAKE_HEIGHT/2;
    	ptCenter2.X = food.x + SNAKE_WIDTH/2;
    	ptCenter2.Y = food.y + SNAKE_HEIGHT/2;
    	PointF pt = ptCenter1 - ptCenter2;
    	if(pt.X<SNAKE_WIDTH&&pt.X>-SNAKE_WIDTH&&pt.Y<SNAKE_HEIGHT&&pt.Y>-SNAKE_HEIGHT)
    	
    	{
    
    		food.x = rand() % m_width;
    		food.y = rand() % m_height;
    
    		return true;
    	}
    	return false;
    }

9.添加WM\_SIZE消息

获取对话框的大小并保存

void CSnakeDlg::OnSize(UINT nType, int cx, int cy)
    {
    	CDialogEx::OnSize(nType, cx, cy);
    	m_width = cx-100;
    	m_height = cy;
    
    	// TODO: 在此处添加消息处理程序代码
    }

10，添加对按键的支持

添加虚函数PreTranslateMessage（），该函数在Windows处理之前拦截按键消息

BOOL CSnakeDlg::PreTranslateMessage(MSG* pMsg)
    {
    	Snake &head = snake.back();
    	// TODO: 在此添加专用代码和/或调用基类
    	switch (pMsg->wParam)
    	{
    	case VK_LEFT:
    		if (head.direction != SNAKE_RIGHT)//方向不能相反
    			head.direction = SNAKE_LEFT;
    		break;
    	case VK_RIGHT:
    		if (head.direction != SNAKE_LEFT)
    			head.direction = SNAKE_RIGHT;
    		break;
    	case VK_UP:
    		if (head.direction != SNAKE_DOWN)
    			head.direction = SNAKE_UP;
    		break;
    	case VK_DOWN:
    		if (head.direction != SNAKE_UP)
    			head.direction = SNAKE_DOWN;
    		break;
    	}
    	return CDialogEx::PreTranslateMessage(pMsg);
    }

11.利用双缓冲将该游戏绘制出来

void CSnakeDlg::OnPaint()
    {
    	if (IsIconic())
    	{
    		CPaintDC dc(this); // 用于绘制的设备上下文
    
    		SendMessage(WM_ICONERASEBKGND, reinterpret_cast<WPARAM>(dc.GetSafeHdc()), 0);
    
    		// 使图标在工作区矩形中居中
    		int cxIcon = GetSystemMetrics(SM_CXICON);
    		int cyIcon = GetSystemMetrics(SM_CYICON);
    		CRect rect;
    		GetClientRect(&rect);
    		int x = (rect.Width() - cxIcon + 1) / 2;
    		int y = (rect.Height() - cyIcon + 1) / 2;
    
    		// 绘制图标
    		dc.DrawIcon(x, y, m_hIcon);
    	}
    	else
    	{
    		CDC* pDC = this->GetDC();
    		CBitmap bmp;
    		CDC m_dcMemory;
    		m_dcMemory.CreateCompatibleDC(pDC);
    		bmp.CreateCompatibleBitmap(pDC, m_width, m_height);
    		m_dcMemory.SelectObject(&bmp);
    		Graphics gh(m_dcMemory.GetSafeHdc());
    		{
    			gh.DrawImage(img, 0, 0, m_width, m_height);//背景
    
    			DrawSnake(gh);
    		}
    		pDC->BitBlt(0, 0, m_width, m_height, &m_dcMemory, 0, 0, SRCCOPY);
    		CDialogEx::OnPaint();
    	}
    }

12.利用计时器将做出流畅游戏

void CSnakeDlg::OnTimer(UINT_PTR nIDEvent)
    {
    	// TODO: 在此添加消息处理程序代码和/或调用默认值
    	OnPaint();
    	CDialogEx::OnTimer(nIDEvent);
    }

游戏完成

该游戏还有许多不完善的地方

得分功能没有设计；小蛇自我碰撞检测没有设计，游戏开始暂停也没有设计

效果

![70 2][]

[70]: /images/20220524/50ccea34e1534f89819709d4169dc731.png
[70 1]: /images/20220524/bd7541de2b3e49119a54c2ddfbc69594.png
[70 2]: /images/20220524/35864294d8564f2cb1b52146d9f491cd.png