# include <iostream.h>
 # include <graphics.h>
 # include    <conio.h>
 # include     <math.h>


 void show_screen( );

 void BoundaryFill(constint,constint,constint,constint);

 void Circle(constint,constint,constint);
 void Triangle(constint,constint,constint,constint,constint,constint);
 void Rectangle(constint,constint,constint,constint);
 void Polygon(constint,constint []);
 void Line(constint,constint,constint,constint);


 int main( )
    {
       int driver=VGA;
       int mode=VGAHI;

       initgraph(&driver,&mode,"..\\Bgi");

       show_screen( );

       setcolor(15);
     Circle(175,175,50);

     BoundaryFill(175,175,10,15);

       setcolor(15);
       settextstyle(0,0,1);
     outtextxy(150,235,"Circle");

       setcolor(15);
     Rectangle(350,135,500,225);

     BoundaryFill(425,175,9,15);

       setcolor(15);
       settextstyle(0,0,1);
     outtextxy(390,235,"Rectangle");

       setcolor(15);
     Triangle(125,370,225,370,175,280);

     BoundaryFill(175,325,8,15);

       setcolor(15);
       settextstyle(0,0,1);
     outtextxy(145,380,"Triangle");

       int polygon_points[14]={ 340,330, 390,285, 460,285, 510,330,
                        460,375, 390,375, 340,330 };

       setcolor(15);
     Polygon(7,polygon_points);

     BoundaryFill(425,325,12,15);

       setcolor(15);
       settextstyle(0,0,1);
     outtextxy(397,380,"Polygon");

       getch( );
       return 0;
    }

 /*************************************************************************///---------------------------  BoundaryFill( )  -------------------------///*************************************************************************//* void BoundaryFill(const int x,const int y,                 const int fill_color,const int boundary_color)    {       if(getpixel(x,y)!=boundary_color && getpixel(x,y)!=fill_color)      {         putpixel(x,y,fill_color);         Boundary_fill((x+1),y,fill_color,boundary_color);         Boundary_fill((x-1),y,fill_color,boundary_color);         Boundary_fill(x,(y+1),fill_color,boundary_color);         Boundary_fill(x,(y-1),fill_color,boundary_color);      }    }*/struct Pixel
    {
       int x;
       int y;

       Pixel *Next;
    };

 Pixel *Entry=NULL;
 Pixel *Start=NULL;
 Pixel *Last=NULL;

 void insert_pixel(constint x,constint y)
    {
       Entry=new Pixel;

       Entry->x=x;
       Entry->y=y;

       Entry->Next=NULL;
       Last->Next=Entry;
       Last=Entry;
    }

 void BoundaryFill(constint _x,constint _y,
                  constint fill_color,constint boundary_color)
    {
       if(getpixel(_x,_y)==boundary_color || getpixel(_x,_y)==fill_color)
      return;

       int x=_x;
       int y=_y;

       Start=new Pixel;

       Start->x=x;
       Start->y=y;

       Start->Next=NULL;
       Last=Start;

       while(Start!=NULL)
      {
         putpixel(x,y,fill_color);

         if(getpixel((x-1),y)!=boundary_color &&
                   getpixel((x-1),y)!=fill_color&& (x-1)>=0)
        {
           putpixel((x-1),y,fill_color);

           insert_pixel((x-1),y);
        }

         if(getpixel(x,(y-1))!=boundary_color &&
                   getpixel(x,(y-1))!=fill_color&& (y-1)>=0)
        {
           putpixel(x,(y-1),fill_color);

           insert_pixel(x,(y-1));
        }

         if(getpixel((x+1),y)!=boundary_color &&
               getpixel((x+1),y)!=fill_color&& (x+1)<=getmaxx( ))
        {
           putpixel((x+1),y,fill_color);

           insert_pixel((x+1),y);
        }

         if(getpixel(x,(y+1))!=boundary_color &&
               getpixel(x,(y+1))!=fill_color&& (y-1)<=getmaxy( ))
        {
           putpixel(x,(y+1),fill_color);

           insert_pixel(x,(y+1));
        }

         Entry=Start;
         Start=Start->Next;

         x=Start->x;
         y=Start->y;

         delete Entry;
      }
    }

 /*************************************************************************///------------------------------  Circle( )  ----------------------------///*************************************************************************/void Circle(constint h,constint k,constint r)
    {
       int color=getcolor( );

       int x=0;
       int y=r;
       int p=(1-r);

       do
      {
         putpixel((h+x),(k+y),color);
         putpixel((h+y),(k+x),color);
         putpixel((h+y),(k-x),color);
         putpixel((h+x),(k-y),color);
         putpixel((h-x),(k-y),color);
         putpixel((h-y),(k-x),color);
         putpixel((h-y),(k+x),color);
         putpixel((h-x),(k+y),color);

         x++;

         if(p<0)
        p+=((2*x)+1);

         else
        {
           y--;
           p+=((2*(x-y))+1);
        }
      }
       while(x<=y);
    }

 /*************************************************************************///----------------------------  Triangle( )  ----------------------------///*************************************************************************/void Triangle(constint x_1,constint y_1,constint x_2,constint y_2,
                        constint x_3,constint y_3)
    {
       Line(x_1,y_1,x_2,y_2);
       Line(x_2,y_2,x_3,y_3);
       Line(x_3,y_3,x_1,y_1);
    }

 /*************************************************************************///---------------------------  Rectangle( )  ----------------------------///*************************************************************************/void Rectangle(constint x_1,constint y_1,constint x_2,constint y_2)
    {
       Line(x_1,y_1,x_2,y_1);
       Line(x_2,y_1,x_2,y_2);
       Line(x_2,y_2,x_1,y_2);
       Line(x_1,y_2,x_1,y_1);
    }

 /*************************************************************************///-----------------------------  Polygon( )  ----------------------------///*************************************************************************/void Polygon(constint n,constint coordinates[])
    {
       if(n>=2)
      {
         Line(coordinates[0],coordinates[1],
                         coordinates[2],coordinates[3]);

         for(int count=1;count<(n-1);count++)
        Line(coordinates[(count*2)],coordinates[((count*2)+1)],
                        coordinates[((count+1)*2)],
                        coordinates[(((count+1)*2)+1)]);
      }
    }

 /*************************************************************************///-------------------------------  Line( )  -----------------------------///*************************************************************************/void Line(constint x_1,constint y_1,constint x_2,constint y_2)
    {
       int color=getcolor( );

       int x1=x_1;
       int y1=y_1;

       int x2=x_2;
       int y2=y_2;

       if(x_1>x_2)
      {
         x1=x_2;
         y1=y_2;

         x2=x_1;
         y2=y_1;
      }

       int dx=abs(x2-x1);
       int dy=abs(y2-y1);
       int inc_dec=((y2>=y1)?1:-1);

       if(dx>dy)
      {
         int two_dy=(2*dy);
         int two_dy_dx=(2*(dy-dx));
         int p=((2*dy)-dx);

         int x=x1;
         int y=y1;

         putpixel(x,y,color);

         while(x<x2)
        {
           x++;

           if(p<0)
              p+=two_dy;

           else
              {
             y+=inc_dec;
             p+=two_dy_dx;
              }

           putpixel(x,y,color);
        }
      }

       else
      {
         int two_dx=(2*dx);
         int two_dx_dy=(2*(dx-dy));
         int p=((2*dx)-dy);

         int x=x1;
         int y=y1;

         putpixel(x,y,color);

         while(y!=y2)
        {
           y+=inc_dec;

           if(p<0)
              p+=two_dx;

           else
              {
             x++;
             p+=two_dx_dy;
              }

           putpixel(x,y,color);
        }
      }
    }

 /*************************************************************************///--------------------------  show_screen( )  ---------------------------///*************************************************************************/void show_screen( )
    {
       setfillstyle(1,1);
     bar(220,26,420,38);

       settextstyle(0,0,1);
     setcolor(15);
       outtextxy(5,5,"******************************************************************************");
       outtextxy(5,17,"*-**************************************************************************-*");
       outtextxy(5,29,"*-------------------------                           ------------------------*");
       outtextxy(5,41,"*-**************************************************************************-*");
       outtextxy(5,53,"*-**************************************************************************-*");

     setcolor(11);
       outtextxy(228,29,"Boundary Fill Algorithm");

     setcolor(15);

       for(int count=0;count<=30;count++)
          outtextxy(5,(65+(count*12)),"*-*                                                                        *-*");

       outtextxy(5,438,"*-**************************************************************************-*");
       outtextxy(5,450,"*-------------------------                          -------------------------*");
       outtextxy(5,462,"******************************************************************************");

     setcolor(12);
       outtextxy(229,450,"Press any Key to exit.");
    }