1.SDL簡(jiǎn)介

?SDL（Simple DirectMediaLayer）是一套開放源代碼的跨平臺(tái)多媒體開發(fā)庫，使用C語言寫成。SDL提供了數(shù)種控制圖像、聲音、輸出入的函數(shù)，讓開發(fā)者只要用相同或是相似的代碼就可以開發(fā)出跨多個(gè)平臺(tái)（Linux、Windows、MacOS X等）的應(yīng)用軟件?，F(xiàn)SDL多用于開發(fā)游戲、模擬器、媒體播放器等多媒體應(yīng)用領(lǐng)域。

2.貪吃蛇游戲

2.1 實(shí)現(xiàn)原理

貪吃蛇游戲?qū)崿F(xiàn)方式很多，可以通過鏈表方式實(shí)現(xiàn)，也可以通過結(jié)構(gòu)體數(shù)組方式實(shí)現(xiàn)。結(jié)構(gòu)體主要用來保村蛇身的坐標(biāo)位置和長(zhǎng)度。移動(dòng)蛇身則通過不斷遍歷結(jié)構(gòu)體數(shù)組，刷新屏幕窗口即可。

2.2 效果展示

2.2 繪制蛇身函數(shù)

/*繪制食物*/
static void SDL_Drawfood(int x,int y,int stat)
{
	SDL_Rect rect;
	rect.x=x;
	rect.y=y;
	rect.w=15;
	rect.h=15;
	if(stat)/*1表示繪制*/
	{
		SDL_RenderCopy(render,food_sdltext,NULL,&rect);
	}
	else SDL_RenderFillRect(render,&rect);/*0表示清空*/
}

2.3 繪制食物函數(shù)

/*繪制食物*/
static void SDL_Drawfood(int x,int y,int stat)
{
	SDL_Rect rect;
	rect.x=x;
	rect.y=y;
	rect.w=15;
	rect.h=15;
	if(stat)/*1表示繪制*/
	{
		SDL_RenderCopy(render,food_sdltext,NULL,&rect);
	}
	else SDL_RenderFillRect(render,&rect);/*0表示清空*/
}

2.4 判斷是否碰到墻和蛇身函數(shù)

/*判讀蛇頭是否咬到自己或者碰到墻壁*/
static int SDL_GetSnakedeath(struct SNAKE *buff,int cnt)
{
	int i=0;
	int x=buff[cnt-1].x;
	int y=buff[cnt-1].y;
	if((x>800-20 || y>480-20) || (x<0 || y<100))//判斷是否撞墻
	{
		return 1;
	}
	
	for(i=0;i

	

	2.5 移動(dòng)蛇身函數(shù)

	
/*******************動(dòng)態(tài)移動(dòng)蛇身********************************/
static void Snake_Move(int x,int y)
{
  int i=0;
  SDL_DrawSnake(snake_info[0].x,snake_info[0].y,0);//清除蛇尾
  for(i=0;i

	

	2.6 獲取方向鍵和游戲開始函數(shù)

	
/*******************控制方向,判斷游戲是否結(jié)束********************/
int SnakeGameStart(void)
{
	SDL_Surface *text1_surface;
	SDL_Texture * texture;
	SDL_Rect dstrect;
	static int start_stop=0;/*暫停與開始*/
	int count=0;
	int x=0;
	int y=120;
	int stat=0;
	int  food_x,food_y;
	char buff[20];
	SDL_Rect rect={0,100,800,380};
	SDL_RenderFillRect(render,&rect);

	//創(chuàng)建蛇身1
	snake_info[node_cnt].x=x;
	snake_info[node_cnt].y=y;
	node_cnt++;
	//創(chuàng)建蛇身2
	snake_info[node_cnt].x=x+20;
	snake_info[node_cnt].y=y; 
	node_cnt++;
	snake_info[node_cnt].x=x+20*2;
	snake_info[node_cnt].y=y; 
	//保存蛇頭坐標(biāo)
	x=snake_info[node_cnt].x;
	y=snake_info[node_cnt].y;
	node_cnt++;
	SDL_DrawSnakebody(snake_info,node_cnt,1);//繪制蛇身
	
	  //生成實(shí)物坐標(biāo)
  	food_x=((rand()%800)/20)*20;
  	food_y=((rand()%380)/20)*20+100;
 	SDL_Drawfood(food_x,food_y,1);
	bool quit= true;
	SDL_Event event;/*獲取事件*/
	int key_value=4;
	int res=0;
	while(quit)
	{
		while(SDL_PollEvent(&event))
		{
			if(event.type==SDL_QUIT)
			{
				quit=false;
				continue;
			}
			if(event.type==SDL_KEYDOWN)//鍵盤事件
			{
				//printf("key=%dn",event.key.keysym.sym);
				if(event.key.keysym.sym==SDLK_UP)key_value=1;
				else if(event.key.keysym.sym==SDLK_DOWN)key_value=2;
				else if(event.key.keysym.sym==SDLK_LEFT)key_value=3;
				else if(event.key.keysym.sym==SDLK_RIGHT)key_value=4;
				else if(event.key.keysym.sym==SDLK_q)key_value=5;/*退出*/
				else if(event.key.keysym.sym==SDLK_SPACE)/*空格鍵*/
				{
					start_stop=!start_stop;
				}
				else if(event.key.keysym.sym==SDLK_EQUALS)/*加速*/
				{
					if(movi_speed>100)movi_speed-=100;
				}
				else if(event.key.keysym.sym==SDLK_MINUS)/*減速*/
				{
					
					if(movi_speed<600)movi_speed+=100;
				}
			}
		}
		if(snake_info[node_cnt-1].x==food_x && snake_info[node_cnt-1].y==food_y)//判斷是否吃到食物
	    {
			count+=5;
			snprintf(buff,sizeof(buff),"%d",count);
			/*創(chuàng)建字體顯示表面*/
			text1_surface=TTF_RenderUTF8_Blended(ttffont,buff,color);
			/*創(chuàng)建紋理*/
			texture=SDL_CreateTextureFromSurface(render,text1_surface);
			/*將surface拷貝到渲染器*/
			dstrect.x=80+235;/*顯示的起始位置*/
			dstrect.y=25;/*顯示的起始位置*/
			dstrect.w=text1_surface->w;/*顯示的寬度*/
			dstrect.h=text1_surface->h;/*顯示的高度*/
			SDL_RenderFillRect(render,&dstrect);
			SDL_RenderCopy(render,texture,NULL,&dstrect);
			SDL_FreeSurface(text1_surface);/*釋放surface*/
			SDL_DestroyTexture(texture);/*釋放紋理*/
			node_cnt++;
	      if(stat&1<<0 || stat&1<<1)//向上或向下時(shí)y+5
	      {
	        snake_info[node_cnt].x=food_x;
	        snake_info[node_cnt].y=food_y+20; 
	      }
	      else //向左或向右時(shí)
	      {
	        snake_info[node_cnt].x=food_x+20;
	        snake_info[node_cnt].y=food_y; 
	      }
		  food_x=((rand()%800)/20)*20;
	      while(1)//保證重新生成的實(shí)物不再蛇身上
	      {
	        if(SDL_GetSnakeFoodX(food_x,node_cnt)==0)break;
			if(food_x<780)food_x+=20;
			else food_x=0;
	      }
		  food_y=((rand()%380)/20)*20+100;
	      while(1)
	      {
	        if(SDL_GetSnakeFoodY(food_y,node_cnt)==0)break;
			if(food_y<460)food_y+=20;
			else food_y=100;
	      }
	      SDL_Drawfood(food_x,food_y,1);
	    }
		if(start_stop)
		{
			continue;/*暫停*/
		}
	    switch(key_value)
	    {
	      case UP://上 
			stat&=~(0x3<<2);//清除左右標(biāo)志 
			if(stat&1<<1){
				y+=20;
			}//向下時(shí)不能直接向上,保持向下
			else
			{
				stat|=1<<0;//向上
				y-=20;
			}
			Snake_Move(x,y);
	        break;
	      case DOWM://下
			stat&=~(0x3<<2);//清除左右標(biāo)志 
			if(stat&1<<0)
			{
				y-=20;
			}//在向上時(shí)不能直接向下,保持向下
			else
			{
				stat|=1<<1;//向下標(biāo)志位
				y+=20;
			}
			Snake_Move(x,y); 
			break;
	      case LEFT://左
			stat&=~(0x3<<0);//清除上下標(biāo)志  
			if(stat&1<<3){
				x+=20;
			}//向右時(shí)不能直接向左，保持向右
			else
			{
				stat|=1<<2;//向左
				x-=20;   
			}
			Snake_Move(x,y);   
			break; 
	      case RIGHT://右 
			stat&=~(0x3<<0);//清除上下標(biāo)志  
			if(stat&1<<2){
				x-=20; 
			}//向左時(shí)不能直接向右，保持向左
			else
			{
				stat|=1<<3;
				x+=20;      
			}
			Snake_Move(x,y);
			break;   
		  case QUIT:
		  {
			node_cnt=0;
			/*創(chuàng)建字體顯示表面*/
			text1_surface=TTF_RenderUTF8_Blended(ttffont,"正在退出游戲，請(qǐng)稍等。。",color);
			/*創(chuàng)建紋理*/
			texture=SDL_CreateTextureFromSurface(render,text1_surface);
			/*將surface拷貝到渲染器*/
			dstrect.x=800/2-text1_surface->w/2;/*顯示的起始位置*/
			dstrect.y=480/2-text1_surface->h/2;/*顯示的起始位置*/
			dstrect.w=text1_surface->w;/*顯示的寬度*/
			dstrect.h=text1_surface->h;/*顯示的高度*/
			SDL_RenderFillRect(render,&dstrect);
			SDL_RenderCopy(render,texture,NULL,&dstrect);
			SDL_FreeSurface(text1_surface);/*釋放surface*/
			SDL_DestroyTexture(texture);/*釋放紋理*/
			SDL_RenderPresent(render);
		  	quit=false;
			SDL_Delay(2000);
			res= 2;
			quit=false;
		  } 
		  break;	
	    }
		
		if(SDL_GetSnakedeath(snake_info,node_cnt))
		{
			node_cnt=0;
			res= 1;
			/*創(chuàng)建字體顯示表面*/
			text1_surface=TTF_RenderUTF8_Blended(ttffont,"游戲結(jié)束！",color);
			/*創(chuàng)建紋理*/
			texture=SDL_CreateTextureFromSurface(render,text1_surface);
			/*將surface拷貝到渲染器*/
			dstrect.x=800/2-text1_surface->w/2;/*顯示的起始位置*/
			dstrect.y=480/2-text1_surface->h/2-30;/*顯示的起始位置*/
			dstrect.w=text1_surface->w;/*顯示的寬度*/
			dstrect.h=text1_surface->h;/*顯示的高度*/
			SDL_RenderFillRect(render,&dstrect);
			SDL_RenderCopy(render,texture,NULL,&dstrect);
			SDL_FreeSurface(text1_surface);/*釋放surface*/
			SDL_DestroyTexture(texture);/*釋放紋理*/
			/*創(chuàng)建字體顯示表面*/
			text1_surface=TTF_RenderUTF8_Blended(ttffont,"請(qǐng)按 Space 重新開始游戲 ",color);
			/*創(chuàng)建紋理*/
			texture=SDL_CreateTextureFromSurface(render,text1_surface);
			/*將surface拷貝到渲染器*/
			dstrect.x=800/2-text1_surface->w/2;/*顯示的起始位置*/
			dstrect.y=480/2-text1_surface->h/2+30;/*顯示的起始位置*/
			dstrect.w=text1_surface->w;/*顯示的寬度*/
			dstrect.h=text1_surface->h;/*顯示的高度*/
			SDL_RenderCopy(render,texture,NULL,&dstrect);
			SDL_FreeSurface(text1_surface);/*釋放surface*/
			SDL_DestroyTexture(texture);/*釋放紋理*/
			SDL_RenderPresent(render);
			quit=false;
			continue;
		}
		SDL_RenderPresent(render);
		SDL_Delay(movi_speed);
	}
	return res;
}


	

	2.7 主函數(shù)

	
int main(int argc,char *argv[])
{

	SDL_Init(SDL_INIT_VIDEO);
	SDL_Window *window=SDL_CreateWindow("SDL test",SDL_WINDOWPOS_CENTERED,SDL_WINDOWPOS_CENTERED,800,480,SDL_WINDOW_SHOWN);
	/*創(chuàng)建渲染器*/
	render=SDL_CreateRenderer(window,-1,SDL_RENDERER_ACCELERATED);
	/*設(shè)置透明度*/
	SDL_SetRenderDrawBlendMode(render,SDL_BLENDMODE_BLEND);
	/*設(shè)置渲染器顏色*/
	SDL_SetRenderDrawColor(render, 255, 255, 255, 255);
	/*清空渲染器*/
	SDL_RenderClear(render);
	SDL_SetRenderDrawColor(render, 255,0, 0, 255);
	int i=0;
	for(i=0;i<3;i++)
	{
		SDL_RenderDrawLine(render,0,96+i,800,96+i);
	}
	SDL_SetRenderDrawColor(render, 255, 255, 255, 255);
	SDL_RenderPresent(render);
	surface=IMG_Load("bg6.png");
	sdltext=SDL_CreateTextureFromSurface(render,surface);
	food_surface=IMG_Load("food.jpg");
	food_sdltext=SDL_CreateTextureFromSurface(render,food_surface);
	/*TTF初始化*/
	TTF_Init();
	/*打開字庫*/
	ttffont=TTF_OpenFont("simkai.ttf",50);
	if(ttffont==NULL)
	{
		printf("simkai.ttf open failedn");
		return 0;
	}

	/*創(chuàng)建字體顯示表面*/
	SDL_Surface *text1_surface=TTF_RenderUTF8_Blended(ttffont,"當(dāng)前得分:",color);
	/*創(chuàng)建紋理*/
	SDL_Texture * texture=SDL_CreateTextureFromSurface(render,text1_surface);
	/*將surface拷貝到渲染器*/
	SDL_Rect dstrect;
	dstrect.x=80;/*顯示的起始位置*/
	dstrect.y=25;/*顯示的起始位置*/
	dstrect.w=text1_surface->w;/*顯示的寬度*/
	dstrect.h=text1_surface->h;/*顯示的高度*/
	SDL_RenderCopy(render,texture,NULL,&dstrect);
	SDL_FreeSurface(text1_surface);/*釋放surface*/
	SDL_DestroyTexture(texture);/*釋放紋理*/
	
	/*創(chuàng)建字體顯示表面*/
	text1_surface=TTF_RenderUTF8_Blended(ttffont,"Space 開始/暫停 ",color);
	/*創(chuàng)建紋理*/
	texture=SDL_CreateTextureFromSurface(render,text1_surface);
	/*將surface拷貝到渲染器*/
	dstrect.x=800/2-text1_surface->w/2;/*顯示的起始位置*/
	dstrect.y=150;/*顯示的起始位置*/
	dstrect.w=text1_surface->w;/*顯示的寬度*/
	dstrect.h=text1_surface->h;/*顯示的高度*/
	SDL_RenderCopy(render,texture,NULL,&dstrect);
	SDL_FreeSurface(text1_surface);/*釋放surface*/
	SDL_DestroyTexture(texture);/*釋放紋理*/

	/*創(chuàng)建字體顯示表面*/
	text1_surface=TTF_RenderUTF8_Blended(ttffont,"+/- 移速 ",color);
	/*創(chuàng)建紋理*/
	texture=SDL_CreateTextureFromSurface(render,text1_surface);
	/*將surface拷貝到渲染器*/
	dstrect.x=800/2-text1_surface->w/2;/*顯示的起始位置*/
	dstrect.y=210;/*顯示的起始位置*/
	dstrect.w=text1_surface->w;/*顯示的寬度*/
	dstrect.h=text1_surface->h;/*顯示的高度*/
	SDL_RenderCopy(render,texture,NULL,&dstrect);
	SDL_FreeSurface(text1_surface);/*釋放surface*/
	SDL_DestroyTexture(texture);/*釋放紋理*/


	/*創(chuàng)建字體顯示表面*/
	text1_surface=TTF_RenderUTF8_Blended(ttffont,"Q 退出",color);
	/*創(chuàng)建紋理*/
	texture=SDL_CreateTextureFromSurface(render,text1_surface);
	/*將surface拷貝到渲染器*/
	dstrect.x=800/2-text1_surface->w/2;/*顯示的起始位置*/
	dstrect.y=270;/*顯示的起始位置*/
	dstrect.w=text1_surface->w;/*顯示的寬度*/
	dstrect.h=text1_surface->h;/*顯示的高度*/
	SDL_RenderCopy(render,texture,NULL,&dstrect);
	SDL_FreeSurface(text1_surface);/*釋放surface*/
	SDL_DestroyTexture(texture);/*釋放紋理*/

	/*創(chuàng)建字體顯示表面*/
	text1_surface=TTF_RenderUTF8_Blended(ttffont,"貪吃蛇小游戲",color);
	/*創(chuàng)建紋理*/
	texture=SDL_CreateTextureFromSurface(render,text1_surface);
	/*將surface拷貝到渲染器*/
	dstrect.x=800/2-text1_surface->w/2;/*顯示的起始位置*/
	dstrect.y=330;/*顯示的起始位置*/
	dstrect.w=text1_surface->w;/*顯示的寬度*/
	dstrect.h=text1_surface->h;/*顯示的高度*/
	SDL_RenderCopy(render,texture,NULL,&dstrect);
	SDL_FreeSurface(text1_surface);/*釋放surface*/
	SDL_DestroyTexture(texture);/*釋放紋理*/
	SDL_RenderPresent(render);
	int stat=0;
	bool quit= true;
	SDL_Event event;/*獲取事件*/
AA:
	quit= true;
	while(quit)
	{
		while(SDL_PollEvent(&event))
		{
			if(event.type==SDL_QUIT)
			{
				quit=false;
				continue;
			}
			if(event.type==SDL_KEYDOWN)//鍵盤事件
			{
				if(event.key.keysym.sym==SDLK_q)
				{
					quit=false;
					continue;
				}
				else if(event.key.keysym.sym==SDLK_SPACE)
				{
					quit=false;
					stat=1;
					continue;
				}
			}
		}
	}
	if(stat)
	{
		stat=0;
		if(SnakeGameStart()==1)goto AA;
	}
	SDL_FreeSurface(surface);
	SDL_DestroyRenderer(render);
	SDL_DestroyWindow(window);/*銷毀窗口*/
	SDL_Quit();/*關(guān)閉SDL*/
	return 0;
}


	

	2.8 程序編譯

	
CFLAGS =-I/home/wbyq/src_pack/SDL2-2.0.14/_install/include -I/home/wbyq/src_pack/SDL2-2.0.14/_install/include/SDL2 -L/home/wbyq/src_pack/SDL2-2.0.14/_install/lib
CFLAGS +=-L/home/wbyq/src_pack/SDL2_image-2.0.5/_install/lib -I/home/wbyq/src_pack/SDL2_image-2.0.5/_install/include -I/home/wbyq/src_pack/SDL2_image-2.0.5/_install/include/SDL2

CFLAGS +=-I/home/wbyq/src_pack/SDL2_ttf-2.0.15/_install/include/SDL2 -L/home/wbyq/src_pack/SDL2_ttf-2.0.15/_install/lib
CFLAGS+=-lSDL2 -lpthread -lm -ldl -lSDL2_image -lSDL2_ttf
app:
	gcc sdl_test.c  $(CFLAGS)




	審核編輯：湯梓紅