SimpleCG小游戏开发系列(2)--贪吃蛇

一、前言

? ? ? ? 在之前的C语言小游戏开发系列我们已经介绍了扫雷游戏的开发，本篇我们继续此系列第二篇，同样是比较简单但好玩的一个游戏--贪吃蛇。因为有了之前的游戏框架，我们只需要直接搬来原来的框架即可，可以省去不少活。

先看看游戏效果预览

下面进行详细的逻辑介绍。

二、玩法介绍

????????贪吃蛇是一款经典的游戏，玩家需要控制一条蛇在屏幕上移动，不断吃掉食物并成长，同时要避免碰到墙壁或自己的身体。蛇在移动过程中会遇到食物，玩家需要让蛇的头部碰到食物，蛇就会自动将食物吞下，并且蛇的长度会相应增加。碰到墙壁或自己的身体就游戏结束。

三、主要逻辑及难点说明

? ? ? ? 贪吃蛇游戏的核心逻辑在于蛇的移动和食物的生成。蛇的移动需要精确控制，避免蛇的头部碰到自己的身体或者墙壁，食物的生成需要有一定的随机性，使得游戏有一定的变化性。

? ? ? ? 我们首先将游戏分三个场景进行绘制，分别是开始前的菜单显示、游戏进行中的场景显示、以及游戏结束界面的显示。我们可以直接用一个全局整型变量g_nGameState来区分场景。在游戏进行时我们主要绘制蛇行走的地图，这个在前面扫雷游戏中有所介绍，大同小异，主要就是一个一维数组实现的二维平面。

int		g_nMap[ C_MAP_WIDTH * C_MAP_HEIGHT]		= {0};

然后是蛇的表示，我们用一个坐标数组来表示蛇身体所处地图位置。

POINT	g_ptSnake[C_SNAKE_MAXLEN];

?地图绘制就是根据地图表示的地形绘制出相应内容

for(j=0;j<C_MAP_HEIGHT;++j)
	{
		for(i=0;i<C_MAP_WIDTH;++i)
		{
			switch( g_nMap[j*C_MAP_WIDTH+i] )
			{
			case enumMAPTYPE_STONE:
				solidrectangle( i*C_IMAGE_BLOCK, j*C_IMAGE_BLOCK, i*C_IMAGE_BLOCK+C_IMAGE_BLOCK, j*C_IMAGE_BLOCK+C_IMAGE_BLOCK);
				break;
			case enumMAPTYPE_FOOD:
				setfillcolor(RGB(0xAA,0x0,0x0));
				solidcircle( i*C_IMAGE_BLOCK+10, j*C_IMAGE_BLOCK+10, 5);
				setfillcolor(RGB(0xAA,0xAA,0xAA));
				break;
			}
			
		}
	}

蛇的行走就只需要根据当前方向进行坐标移动就可以了

switch( g_nSnakDir )
	{
	case enumDIR_LEFT:
		SnakeMoveTo(g_ptSnake[0].x-1,g_ptSnake[0].y);
		break;
	case enumDIR_RIGHT:
		SnakeMoveTo(g_ptSnake[0].x+1,g_ptSnake[0].y);
		break;
	case enumDIR_UP:
		SnakeMoveTo(g_ptSnake[0].x,g_ptSnake[0].y-1);
		break;
	case enumDIR_DOWN:
		SnakeMoveTo(g_ptSnake[0].x,g_ptSnake[0].y+1);
		break;
	}

以上就是贪吃蛇涉及的主要设计难点，都比较容易理解，就不展开讨论了。

?四、主体逻辑的所有源代码

????????以下就是贪吃蛇的全部主要代码，只是示例程序，所以只设置了一关、有兴趣的同学可以自行扩展代码。

// GameSnake.cpp : 定义控制台应用程序的入口点。
//

#include "../import/include/SimpleCG.h"
#include "GameUI.h"


#ifdef _DEBUG
#pragma comment(lib,"../import/lib/SimpleCG_MDd.lib")
#else
#ifdef _WIN64
#pragma comment(lib,"../import/lib/x64/MTRelease/SimpleCG_MT64.lib")
#else
#pragma comment(lib,"../import/lib/SimpleCG_MT.lib")
#endif
#endif


#define C_SNAK_VERSION			1001

#define C_IMAGE_WIDTH			640
#define C_IMAGE_HEIGHT			480
#define C_IMAGE_BLOCK			20
#define C_MAP_WIDTH				C_IMAGE_WIDTH/C_IMAGE_BLOCK
#define C_MAP_HEIGHT			C_IMAGE_HEIGHT/C_IMAGE_BLOCK
#define C_SNAKE_MAXLEN			50
enum ENUM_GAMESTATE
{
	  enumGS_MENU
	, enumGS_RUNNING
	, enumGS_GAMEOVER
};
enum ENUM_MAPTYPE
{
	  enumMAPTYPE_NULL
	, enumMAPTYPE_STONE
	, enumMAPTYPE_FOOD
};
enum ENUM_DIRECTION
{
	  enumDIR_LEFT
	, enumDIR_RIGHT
	, enumDIR_UP
	, enumDIR_DOWN
};
int		g_nMap[ C_MAP_WIDTH * C_MAP_HEIGHT]		= {0};
int		g_nSnakDir								= enumDIR_LEFT;
POINT	g_ptSnake[C_SNAKE_MAXLEN];
int		g_nSnakLen								= 2;
int		g_nGameState							= enumGS_MENU;
char	g_nTitle[] = { 0x4f,0x49,0x49,0x79,0x0,0x7f,0xe,0x30,0x7f,0x0,0x7e,0x9,0x9,0x7e,0x0,0x7f,0x8,0x14,0x63,0x0,0x7f,0x49,0x49,0x49 };
char	g_pGame[] = { 0x7f,0x41,0x5d,0x49,0x7b,0x0,0x7c,0x12,0x11,0x12,0x7c,0x0,0x7f,0x2,0x4,0x2,0x7f,0x0,0x7f,0x49,0x49,0x49,0x49 };
char	g_pOver[] = { 0x7f,0x41,0x41,0x41,0x7f,0x0,0x1f,0x20,0x40,0x20,0x1f,0x0,0x7f,0x49,0x49,0x49,0x49,0x0,0x7f,0x9,0x19,0x29,0x46 };
int		g_nMenu = 0;
int		g_nScore = 0;
int		g_nSpeed = 1;
LRESULT OnKeyDown(HWND hWnd, WPARAM wParam, LPARAM lParam);
LRESULT OnLButtonDown( HWND hWnd, WPARAM wParam, int nX, int nY );
LRESULT OnRButtonDown( HWND hWnd, WPARAM wParam, int nX, int nY );
LRESULT OnMouseMove( HWND hWnd, WPARAM wParam, int nX, int nY );
//绘制标题
void DrawTitle( int nX, int nY, char *pTitle, int nSize);
void MakeFood()
{
	bool bFoodSet = false;
	int nRand = 0;
	while(!bFoodSet)
	{
		nRand=rand()%(C_MAP_WIDTH*C_MAP_HEIGHT);
		if(g_nMap[nRand] == enumMAPTYPE_NULL )
		{
			g_nMap[nRand] = enumMAPTYPE_FOOD;
			bFoodSet = true;
		}
	}
}
//初始化游戏
void InitGame(HWND hWnd)
{
	int i=0;
	int j=0;
	for(j=0;j<C_MAP_HEIGHT;++j)
	{
		for(i=0;i<C_MAP_WIDTH;++i)
		{
			if(i==0||i==C_MAP_WIDTH-1||j==0||j==C_MAP_HEIGHT-1)
			{
				g_nMap[j*C_MAP_WIDTH+i] = enumMAPTYPE_STONE;
			}
			else
			{
				g_nMap[j*C_MAP_WIDTH+i] = enumMAPTYPE_NULL;
			}
			
		}
	}
	g_nSpeed = 1;
	g_nSnakLen = 2;
	g_ptSnake[0].x = 10;
	g_ptSnake[0].y = 10;
	g_ptSnake[1].x = 11;
	g_ptSnake[1].y = 10;
	g_nSnakDir = enumDIR_LEFT;
	srand(GetTickCount());
	MakeFood();
	//按键处理初始化
	//SetKeyboardProcess( enumINMSG_KEYDOWN, OnKeyDown );
	GetKeyboardInput()->onKeyDown		= OnKeyDown;
	GetMouseInput()->onMouseDownLeft	= OnLButtonDown;
	GetMouseInput()->onMouseDownRight	= OnRButtonDown;
	GetMouseInput()->onMouseMove		= OnMouseMove;
	g_nGameState = enumGS_MENU;
}
//移动蛇
void SnakeMoveTo(int x, int y)
{
	int i=0;
	if(x<0 || y<0 || x>=C_MAP_WIDTH || y>=C_MAP_HEIGHT )
		return;
	//GetFood
	if(g_nMap[y*C_MAP_WIDTH+x]==enumMAPTYPE_FOOD)
	{
		g_nMap[y*C_MAP_WIDTH+x]=enumMAPTYPE_NULL;
		g_ptSnake[g_nSnakLen].x = g_ptSnake[g_nSnakLen-1].x;
		g_ptSnake[g_nSnakLen].y = g_ptSnake[g_nSnakLen-1].y;
		if( g_nSnakLen<C_SNAKE_MAXLEN-1)
			g_nSnakLen++;

		g_nScore += 10 * g_nSpeed;
		g_nSpeed = g_nSnakLen / 5 + 1;
		MakeFood();
	}
	else if(g_nMap[y*C_MAP_WIDTH+x]==enumMAPTYPE_STONE )//dead
	{
		g_nGameState = enumGS_GAMEOVER;
		return;
	}
	for(i=g_nSnakLen-1;i>0;--i)
	{
		if( g_ptSnake[i].x==x && g_ptSnake[i].y==y )
		{
			g_nGameState = enumGS_GAMEOVER;
			return;
		}
		g_ptSnake[i].x = g_ptSnake[i-1].x;
		g_ptSnake[i].y = g_ptSnake[i-1].y;
	}
	g_ptSnake[0].x = x;
	g_ptSnake[0].y = y;
}
//按方向移动
void MoveFoward()
{
	switch( g_nSnakDir )
	{
	case enumDIR_LEFT:
		SnakeMoveTo(g_ptSnake[0].x-1,g_ptSnake[0].y);
		break;
	case enumDIR_RIGHT:
		SnakeMoveTo(g_ptSnake[0].x+1,g_ptSnake[0].y);
		break;
	case enumDIR_UP:
		SnakeMoveTo(g_ptSnake[0].x,g_ptSnake[0].y-1);
		break;
	case enumDIR_DOWN:
		SnakeMoveTo(g_ptSnake[0].x,g_ptSnake[0].y+1);
		break;
	}
}
//更新游戏状态
void UpdateGame( UINT nElapse )
{
	static int s_nLastTick = 0;
	int nWait = 9-g_nSpeed;
	if(nWait<0)
		nWait = 1;
	if( ( nElapse - s_nLastTick )<nWait*50 )
		return;
	switch(g_nGameState)
	{
	case enumGS_MENU:
		break;
	case enumGS_RUNNING:
		s_nLastTick = nElapse;
		MoveFoward();
		break;
	case enumGS_GAMEOVER:
		break;
	}
	
}
//绘制地图
void DrawMap()
{
	int i=0;
	int j=0;
	setfillcolor(RGB(0xAA,0xAA,0xAA));
	for(j=0;j<C_MAP_HEIGHT;++j)
	{
		for(i=0;i<C_MAP_WIDTH;++i)
		{
			switch( g_nMap[j*C_MAP_WIDTH+i] )
			{
			case enumMAPTYPE_STONE:
				solidrectangle( i*C_IMAGE_BLOCK, j*C_IMAGE_BLOCK, i*C_IMAGE_BLOCK+C_IMAGE_BLOCK, j*C_IMAGE_BLOCK+C_IMAGE_BLOCK);
				break;
			case enumMAPTYPE_FOOD:
				setfillcolor(RGB(0xAA,0x0,0x0));
				solidcircle( i*C_IMAGE_BLOCK+10, j*C_IMAGE_BLOCK+10, 5);
				setfillcolor(RGB(0xAA,0xAA,0xAA));
				break;
			}
			
		}
	}
}
//绘制标题
void DrawTitle( int nX, int nY, char *pTitle, int nSize)
{
	int i=0;
	int j=0;
	for(i=0;i<nSize;++i)
	{
		int nNum = pTitle[i];
		for(j=0;j<8;++j)
		{
			if(nNum&0x1)
			{
				solidrectangle( nX+i*C_IMAGE_BLOCK, nY+j*C_IMAGE_BLOCK, nX+i*C_IMAGE_BLOCK+C_IMAGE_BLOCK, nY+j*C_IMAGE_BLOCK+C_IMAGE_BLOCK);
				
			}
			nNum>>=1;
		}
	}                                                                                                                                                                               
}
//绘制蛇
void DrawSnake()
{
	int i=0;
	setfillcolor(RGB(0x0,0xAA,0x0));
	for(i=0; i<g_nSnakLen; ++i)
	{
		solidrectangle( g_ptSnake[i].x*C_IMAGE_BLOCK, g_ptSnake[i].y*C_IMAGE_BLOCK, g_ptSnake[i].x*C_IMAGE_BLOCK+C_IMAGE_BLOCK, g_ptSnake[i].y*C_IMAGE_BLOCK+C_IMAGE_BLOCK);
	}
}
void DrawMenu()
{
	setfillcolor(RGB(0x0,0xAA,0x0));
	DrawTitle( 60, 60, g_nTitle, sizeof(g_nTitle)/sizeof(g_nTitle[0]));
	
	DrawButton( 200, 260, 120, 30, RGB(0x0,0xDD,0x0), 0, _T("开始游戏"));
	DrawButton( 200, 300, 120, 30, RGB(0x0,0xDD,0x0), 0, _T("退出游戏"));
	setlinecolor(0);
	fillcircle( 180, g_nMenu * 40 + 260 + 15, 10 );
}
//绘制游戏
void RenderGame()
{
	clearrectangle(0,0,C_IMAGE_WIDTH, C_IMAGE_HEIGHT);
	switch(g_nGameState)
	{
	case enumGS_MENU:
		DrawMenu();
		break;
	case enumGS_RUNNING:
		DrawMap();
		DrawSnake();
		RenderUI();
		break;
	case enumGS_GAMEOVER:
		DrawTitle( 100, 60, g_pGame, sizeof(g_pGame)/sizeof(g_pGame[0]));
		DrawTitle( 100, 220, g_pOver, sizeof(g_pOver)/sizeof(g_pOver[0]));
		
		settextcolor(0);
		printfRectEx( 0, 380, C_IMAGE_WIDTH, 20, SCG_TEXT_MIDDLE, _T("分数: %d"), g_nScore );
		//outtextRectEx( 0, 400, C_IMAGE_WIDTH, 100, _T("Press any key to continue..."), SCG_TEXT_MIDDLE);
		outtextRectEx( 0, 400, C_IMAGE_WIDTH, 100, _T("按任意键继续..."), SCG_TEXT_MIDDLE);
		break;
	}
}
//按键消息响应函数
LRESULT OnKeyDown(HWND hWnd, WPARAM wParam, LPARAM lParam)
{
	switch( g_nGameState )
	{
	case enumGS_MENU:
		switch( wParam )
		{
		case VK_DOWN:
			if( g_nMenu<1 )
				++g_nMenu;
			break;
		case VK_UP:
			if( g_nMenu> 0 )
				--g_nMenu;
			break;
		case VK_SPACE:
		case VK_RETURN:
			if( g_nMenu == 1)
				PostQuitMessage(0);
			else
				g_nGameState = enumGS_RUNNING;
			break;
		}
		break;
	case enumGS_RUNNING:
		switch( wParam )
		{
		case VK_DOWN:
			if(g_nSnakDir == enumDIR_LEFT || g_nSnakDir == enumDIR_RIGHT)
			{
				g_nSnakDir = enumDIR_DOWN;
				
				MoveFoward();
			}
			return 1;
			break;
		case VK_UP:
			if(g_nSnakDir == enumDIR_LEFT || g_nSnakDir == enumDIR_RIGHT)
			{
				g_nSnakDir = enumDIR_UP;
				
				MoveFoward();
			}
			return 1;
			break;
		case VK_LEFT:
			if(g_nSnakDir == enumDIR_UP || g_nSnakDir == enumDIR_DOWN)
			{
				g_nSnakDir = enumDIR_LEFT;
				
				MoveFoward();
			}
			return 1;
			break;
		case VK_RIGHT:
			if(g_nSnakDir == enumDIR_UP || g_nSnakDir == enumDIR_DOWN)
			{
				g_nSnakDir = enumDIR_RIGHT;
				
				MoveFoward();
			}
			return 1;
			break;
		}
		break;
	case enumGS_GAMEOVER:
		InitGame(NULL);
		break;
	}
	
	return 0;
}

LRESULT OnLButtonDown( HWND hWnd, WPARAM wParam, int nX, int nY )
{
	switch( g_nGameState )
	{
	case enumGS_MENU:
		if( g_nMenu == 1)
			PostQuitMessage(0);
		else
			g_nGameState = enumGS_RUNNING;
		break;
	case enumGS_RUNNING:
		switch(g_nSnakDir )
		{
		case enumDIR_LEFT:
			g_nSnakDir = enumDIR_DOWN;
			break;
		case enumDIR_RIGHT:
			g_nSnakDir = enumDIR_UP;
			break;
		case enumDIR_UP:
			g_nSnakDir = enumDIR_LEFT;
			break;
		case enumDIR_DOWN:
			g_nSnakDir = enumDIR_RIGHT;
			break;
		}
		break;
	case enumGS_GAMEOVER:
		InitGame(NULL);
		break;
	}
	return false;
}
LRESULT OnRButtonDown( HWND hWnd, WPARAM wParam, int nX, int nY )
{
	if( g_nGameState == enumGS_RUNNING)
	{
		switch(g_nSnakDir )
		{
		case enumDIR_LEFT:
			g_nSnakDir = enumDIR_UP;
			break;
		case enumDIR_RIGHT:
			g_nSnakDir = enumDIR_DOWN;
			break;
		case enumDIR_UP:
			g_nSnakDir = enumDIR_RIGHT;
			break;
		case enumDIR_DOWN:
			g_nSnakDir = enumDIR_LEFT;
			break;
		}
	}
	return false;
}
LRESULT OnMouseMove( HWND hWnd, WPARAM wParam, int nX, int nY )
{
	if( g_nGameState == enumGS_MENU)
	{
		if( nY>=300)
			g_nMenu = 1;
		else
			g_nMenu = 0;
	}
	return false;
}
int _tmain(int argc, _TCHAR* argv[])
{
	SCG_GameLoopInfo info;
	info.nFPS				= 60;
	info.nHeight			= C_IMAGE_HEIGHT;
	info.nWidth				= C_IMAGE_WIDTH;
	info.pFunDrawProcess	= RenderGame;
	info.pFunFrameUpdate	= UpdateGame;
	info.pFunInitGame		= InitGame;
	info.pFunInput			= NULL;

	if( !StartGameLoopEx( &info ))
		return 1;
	return 0;
}

五、代码及相关图形库下载

贪吃蛇完整VS2010工程可在以下地址下载。

gamesnake · master · b2b160 / SimpleCG_Demo · GitCode

编译此程序需安装SimpleCG库，安装方法如下：?

SimpleCG库安装方法

如果只想执行程序可在如下地址下载?

贪吃蛇执行程序