function.c

本人自己编写的Linux下的象棋程序

	    {
	        if((x == x0 - 1) && y == y0)
	       {
			return  try_move(x0, y0, x, y, screen, qipan_screen);
	       }	     	    
	    }	
    }	   	   
    return -1;	
}


//马的运动规则
int horse_rules(int x0, int y0 ,int x, int y, SDL_Surface *screen, SDL_Surface *qipan_screen)
{
    if(x >=0 && x<=9 && y >= 0 && y <= 8)
    {
    
	 if((x == (x0 + 2) && y == (y0 + 1) )
	  || (x == (x0 + 2) && y == (y0 - 1) ))
	 {
	     if(qipan[x0+1][y0] == 0)
	     {
		return try_move(x0, y0, x, y, screen, qipan_screen);
	    }	 
	 }
	 else if ((x == (x0 - 2) && y == (y0 + 1) ) 
	          || (x == (x0 - 2) && y == (y0 -1) ))
	 {
	     if(qipan[x0-1][y0] == 0)
	     {
		return try_move(x0, y0, x, y, screen, qipan_screen);
	     }	 
	 }
        else if((x == (x0 + 1) && y == (y0 - 2) )
	         || (x == (x0 - 1) && y == (y0 - 2)))
        {
	    if(qipan[x0][y0-1] == 0)
	    {
		return try_move(x0, y0, x, y, screen, qipan_screen);	    
	    }	
	}
	else if((x == (x0 + 1) && y == (y0 + 2) ) 
	         || (x == (x0 - 1) && y == (y0 + 2) ))
	{
	    if(qipan[x0][y0+1] == 0)
	    {
		return try_move(x0, y0, x, y, screen, qipan_screen);
	    }	
	}	
    }	
    return -1;
}


//象的运动规则
int elf_rules(int x0, int y0 ,int x, int y, SDL_Surface *screen, SDL_Surface *qipan_screen)
{
    if(x >=0 && x<= 9 && y >= 0 && y<= 8)     
    {
        if((x0 <= 4 && x > 4) || (x0 > 4 && x <=4))
	    return -1;
	        
        if(x == (x0 - 2) && y ==(y0 - 2))
	{
	    if(qipan[x0-1][y0-1] == 0)
	    {
		return try_move(x0, y0, x, y, screen, qipan_screen);
	    }
	} 
	else if(x == (x0 + 2) && y == (y0 - 2))
	{	  
	       if(qipan[x0+1][y0-1] == 0)
	       {
			return try_move(x0, y0, x, y, screen, qipan_screen);
		       	    	       
	       }	     	 	   
	}
	else if(x == (x0 - 2) && y == (y0 + 2))
	{
	       if(qipan[x0-1][y0+1] == 0)
	       {
			return try_move(x0, y0, x, y, screen, qipan_screen);     	       	       
	       }
	   }
	   else if( x == (x0 + 2) && y == (y0 + 2))
          {
	       if(qipan[x0+1][y0+1] == 0)
	       {
			return try_move(x0, y0, x, y, screen, qipan_screen);	       	       
	       }	  
	  }	  	
    }
    return -1;	           
}

//士的运动规则
int nurse_rules(int x0, int y0 ,int x, int y, SDL_Surface *screen, SDL_Surface *qipan_screen)
{
    if((y >= 3 && y <= 5) && ((x >= 0 && x <= 2) || (x >= 7 && x <= 9)))
    {
        if(x == (x0 + 1) && y == (y0 + 1) || x == (x0 + 1) && y == (y0 - 1)
	   || x == (x0 - 1) && y == (y0 + 1) || x == (x0 - 1) && y == (y0 - 1))
        {
         	return try_move(x0, y0, x, y, screen, qipan_screen);
        }
    }
    return -1;
}

//将帅的运动规则
int master_rules(int x0, int y0 ,int x, int y, SDL_Surface *screen, SDL_Surface *qipan_screen)
{
    if((y >= 3 && y <= 5) && ((x >= 0 && x <= 2) || (x >= 7 && x <= 9)))
    {
        if(x == (x0 + 1) && y == y0  || x == x0 && y == (y0 - 1)
	   || x == (x0 - 1) && y == y0 || x == x0  && y == (y0 +1))
        {
	     if((qipan[x][y] != 0) && !friend(qipan[x0][y0] ,qipan[x][y]) || qipan[x][y] == 0)
             {    
             	move(x0, y0, x, y, screen, qipan_screen);
                return 0;	    	
	    }    
        }
    }
    return -1;
}


//移动,吃子
int move(int x0,int y0, int x, int y, SDL_Surface *screen, SDL_Surface *qipan_screen)
{
    	display_qizi(x, y, &qizi[qipan[x0][y0]], screen, qipan_screen);
    	SDL_Rect clip;
    	clip.x = y0*60+10;
    	clip.y = x0*60+10;
    	clip.w = 60;
    	clip.h = 60;
	display_surface( clip.x, clip.y, qipan_screen, screen, &clip );
	qipan[x][y] = qipan[x0][y0];
        qipan[x0][y0] = 0;
}


int try_move(int x0,int y0, int x, int y, SDL_Surface *screen, SDL_Surface *qipan_screen)
{
	 if((qipan[x][y] != 0) && !friend(qipan[x0][y0] ,qipan[x][y]) || qipan[x][y] == 0)
         {    
	
	 	if (qipan[x][y] == RC_MAS || qipan[x][y] == BC_MAS)
		{
		        move(x0, y0, x, y, screen, qipan_screen);
			return 1;		
		}
		else
		{
			move(x0, y0, x, y, screen, qipan_screen);
                	return 0;
		}
	 }
	 return -1;	 
}

void flash_qizi(int x0, int y0, SDL_Surface *screen)
{
	int i, j;
	int startx = y0*60+10;
	int starty = x0*60+10;/* Here p is the address to the pixel we want to set */
	int w = qizi[qipan[x0][y0]].image->w;
	int centerx = startx + w / 2;
	int centery = starty + w / 2;
	Uint32 red_color = SDL_MapRGB(screen->format, 255, 0, 0);
	for(i = 0; i < w; i++)
	{
		for(j = 0; j < w; j++)
		{
			if(sqrt(pow(startx+i - centerx, 2) + pow(starty+j - centery, 2)) > w / 2 + 3)
			{
				putpixel(screen, startx+i, starty+j, red_color);
			}
		}
	}
} 



void change_to(int x0,int y0, int x, int y, 
	SDL_Surface *screen, SDL_Surface *qipan_screen)
{
    	SDL_Rect clip;
    	clip.x = y0*60+10;
    	clip.y = x0*60+10;
    	clip.w = 60;
    	clip.h = 60;
	display_surface( clip.x, clip.y, qipan_screen, screen, &clip );	
    	display_qizi(x0, y0, &qizi[qipan[x0][y0]], screen, qipan_screen);
	flash_qizi(x, y, screen);
}


Uint32 getpixel(SDL_Surface *surface, int x, int y)
{
    int bpp = surface->format->BytesPerPixel;
    /* Here p is the address to the pixel we want to retrieve */
    Uint8 *p = (Uint8 *)surface->pixels + y * surface->pitch + x * bpp;

    switch(bpp) {
    case 1:
        return *p;

    case 2:
        return *(Uint16 *)p;

    case 3:
        if(SDL_BYTEORDER == SDL_BIG_ENDIAN)
            return p[0] << 16 | p[1] << 8 | p[2];
        else
            return p[0] | p[1] << 8 | p[2] << 16;

    case 4:
        return *(Uint32 *)p;

    default:
        return 0;       //shouldn't happen, but avoids warnings 
    }
}


void putpixel(SDL_Surface *surface, int x, int y, Uint32 pixel)
{
    int bpp = surface->format->BytesPerPixel;
    // Here p is the address to the pixel we want to set 
    Uint8 *p = (Uint8 *)surface->pixels + y * surface->pitch + x * bpp;

    switch(bpp) {
    case 1:
        *p = pixel;
        break;

    case 2:
        *(Uint16 *)p = pixel;
        break;

    case 3:
        if(SDL_BYTEORDER == SDL_BIG_ENDIAN) {
            p[0] = (pixel >> 16) & 0xff;
            p[1] = (pixel >> 8) & 0xff;
            p[2] = pixel & 0xff;
        } else {
            p[0] = pixel & 0xff;
            p[1] = (pixel >> 8) & 0xff;
            p[2] = (pixel >> 16) & 0xff;
        }
        break;

    case 4:
        *(Uint32 *)p = pixel;
        break;
    }
}


void start_again(SDL_Surface *qipan_screen, SDL_Surface *screen)
{
	init_qipan();
	display_qipan(qipan_screen , screen);
}

void display_end(SDL_Surface *screen)
{
    SDL_Surface *end;
    end = (SDL_Surface *)load_image(END);
    display_surface(185,275,end,screen,NULL);
    if( SDL_Flip( screen ) == -1 )
    {
        return ; 	    
    }
    SDL_FreeSurface( end );
}



void  display_window(SDL_Surface *screen)
{
    SDL_Surface *window;
    window = (SDL_Surface *)load_image(WINDOW);
    display_surface(550,0,window,screen,NULL);
    if( SDL_Flip( screen ) == -1 )
    {
        return ; 	    
    }
    SDL_FreeSurface( window );
}



void  display_start1(SDL_Surface *screen)
{
    SDL_Surface *start;
    start = (SDL_Surface *)load_image(START1);
    display_surface(615,400,start,screen,NULL);
    if( SDL_Flip( screen ) == -1 )
    {
        return ; 	    
    }
    SDL_FreeSurface( start );
}


void  display_start2(SDL_Surface *screen)
{
    SDL_Surface *start;
    start = (SDL_Surface *)load_image(START2);
    display_surface(615,400,start,screen,NULL);
    if( SDL_Flip( screen ) == -1 )
    {
        return ; 	    
    }
    SDL_FreeSurface( start );
}