Graphics Extra

//Polygo using bresenham line
#include<stdio.h>
#include<graphics.h>
#include<math.h>
#define ROUND(a)((int)(a+0.5))
struct point
{
 int x,y;
}pol[10];
int n;
void DDA(int,int,int,int);
void Bresenham(int,int,int,int);
void readpoly()
{
 int i;
 for(i=0;i<n;i++)
 {
  printf("\nEnter the %d coordinates ",i+1);
  scanf("%d%d",&pol[i].x,&pol[i].y);
 }
}
void drawpolygonDDA()
{
 int i;
 for(i=0;i<n;i++)
  DDA(pol[i].x,pol[i].y,pol[(i+1)%n].x,pol[(i+1)%n].y);
}
void drawpolygonBres()
{
 int i;
 for(i=0;i<n;i++)
 {
  delay(500);
  Bresenham(pol[i].x,pol[i].y,pol[(i+1)%n].x,pol[(i+1)%n].y);
 }
}
int main()
{
 int xa,ya,xb,yb,choice,gd=DETECT,gm=VGAMAX;
 printf("\nEnter the no of sides ");
 scanf("%d",&n);
 readpoly();
 initgraph(&gd,&gm,NULL);
 printf("Press any key to draw traingle using Bresenham line
   drawing algortihm over the triangle drawn using
   DDA line drawing algorithm");
 drawpolygonDDA();
 getch();
 drawpolygonBres();
 while (!kbhit());
 closegraph();
 return 0;
}
void DDA(int xa,int ya,int xb,int yb)
{
 int dx,dy,steps,k;
 dx=xb-xa;
 dy=yb-ya;
 float x=xa,y=ya,xinc,yinc;
 if(abs(dx)>abs(dy))
  steps=abs(dx);
 else
  steps=abs(dy);
 xinc=dx/(float)steps;
 yinc=dy/(float)steps;
 putpixel(ROUND(x),ROUND(y),5);
 for(k=0;k<steps;k++)
 {
  x+=xinc;
  y+=yinc;
  putpixel(ROUND(x),ROUND(y),5);
 }
}
void Bresenham(int xa,int ya,int xb,int yb)
{
 int i,dx=xb-xa,dy=yb-ya,p,twod,twodd,s;
 float m=2;
 if(dx!=0)
  m=(float)dy/(float)dx;
 if(m>=-1&&m<=1)
 {
  if(xa>xb)
  {
   Bresenham(xb,yb,xa,ya);
   return;
  }
  p=2*dx-dy;
  if(dy<0)
  {
    s=-1;
       dy=-dy;
  }
  else
     s=1;
  putpixel(xa,ya,10);
  for(i=0;i<dy;i++)
  {
   while(p>0)
   {
    xa++;
    p-=2*dy;
    putpixel(xa,ya,10);
   }
   ya+=s;
   p+=2*dx;
   putpixel(xa,ya,10);
  }
 }
 else
 {
  if(ya>yb)
  {
   Bresenham(xb,yb,xa,ya);
   return;
  }
  p=2*dy-dx;
  if(dx<0)
   {
       s=-1;
       dx=-dx;
    }
  else
     s=1;
  putpixel(xa,ya,10);
  for(i=0;i<dx;i++)
  {
   while(p>0)
   {
    ya++;
    p-=2*dx;
    putpixel(xa,ya,10);
   }
   xa+=s;
   p+=2*dy;
   putpixel(xa,ya,10);
  }
 }
}

//Different shapes using flood fill
 # include <iostream.h>
 # include <graphics.h>
 # include    <conio.h>
 # include     <math.h>

 void show_screen( );

 void Flood_fill(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(175,175,40);

     Flood_fill(175,175,10,0);

       setcolor(15);
       settextstyle(0,0,1);
     outtextxy(150,225,"Circle");

       setcolor(15);
     Rectangle(375,145,475,205);

     Flood_fill(400,175,9,0);

       setcolor(15);
       settextstyle(0,0,1);
     outtextxy(390,215,"Rectangle");

       setcolor(15);
     Triangle(135,360,215,360,175,290);

     Flood_fill(175,325,8,0);

       setcolor(15);
       settextstyle(0,0,1);
     outtextxy(145,370,"Triangle");

       int polygon_points[14]={ 365,325, 400,290, 450,290, 485,325,
                        450,360, 400,360, 365,325 };

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

     Flood_fill(425,325,12,0);

       setcolor(15);
       settextstyle(0,0,1);
     outtextxy(395,370,"Polygon");

       getch( );
       return 0;
    }

 /*************************************************************************///---------------------------  Flood_fill( )  ---------------------------///*************************************************************************/void Flood_fill(constint x,constint y,
                   constint fill_color,constint old_color)
    {
       if(getpixel(x,y)==old_color)
      {
         putpixel(x,y,fill_color);

         Flood_fill((x+1),y,fill_color,old_color);
         Flood_fill((x-1),y,fill_color,old_color);
         Flood_fill(x,(y+1),fill_color,old_color);
         Flood_fill(x,(y-1),fill_color,old_color);
      }
    }

 /*************************************************************************///------------------------------  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(230,26,405,38);

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

     setcolor(11);
       outtextxy(237,29,"Flood 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.");
    }