Implementation of Bresenhams algorithm - Line Updated

 1.a.) Implementation of Bresenhams algorithm - Line Updated

Program :


// This program will work for all input ....  0<m<1 and m>1 
// where 'm' is slope


#include "stdio.h"
#include "conio.h"
#include "math.h"
#include "graphics.h"
main()
{
int gd=DETECT,gm;
int xa,xb,ya,yb;
int dx,dy,x,y,xend,p,dxt,dyt,slope_pos,yend;
initgraph(&gd,&gm,"H:\\TC\\BGI");
printf("Enter the First End points(xa,ya):\n");
scanf("%d%d",&xa,&ya);
printf("Enter the Second End points(xb,yb):\n");
scanf("%d%d",&xb,&yb);


dxt=xb-xa;
dyt=yb-ya;
dx=abs(xb-xa);
dy=abs(yb-ya);


slope_pos=(dxt>0);
if(dyt<0)
slope_pos=!slope_pos;


if(dx>dy)   // slope => 0<m<1
{
p=2*dy-dx;
if(xa>xb)
{
x=xb;
y=yb;
xend=xa;
}
else
{
x=xa;
y=ya;
xend=xb;
}


    while(x<xend)
      {
      x=x+1;
      if(p<0)
      {
      p=p+2*dy;
      }
      else
      {
      if(slope_pos)
      y=y+1;
      else
      y=y-1;
      p=p+2*(dy-dx);
      }
      putpixel(x,y,6);
      }
      }
      else   // slope => m>1
      {
p=2*dx-dy;
if(ya>yb)
{
x=xb;
y=yb;
yend=ya;
}
else
{
x=xa;
y=ya;
yend=yb;
}
    while(y<yend)
      {
      y=y+1;
      if(p<0)
      {
      p=p+2*dx;
      }
      else
      {
      if(slope_pos)
      x=x+1;
      else
      x=x-1;
      p=p+2*(dx-dy);
      }
      putpixel(x,y,6);
      }
      }
    putpixel(xa,ya,4);
    putpixel(xb,yb,4);
   getch();
   return(0);
}


Output :

Enter The Two Left Endpoints(xa,ya):       50    60

Enter The Two Right Endpoints(xb,yb):    150 360

If you find any flaws in this inform to me .....

Computer Graphics Lab Programs - CS2405

Computer Graphics Lab Programs - CS2405

1.a.) Implementation of Bresenhams algorithm - Line

1.a.) Implementation of Bresenhams algorithm - Line Updated

1.b.) Implementation of Bresenhams algorithm - Circle

1.c.) Implementation of Bresenhams algorithm - Ellipse

Available Now .....

2. Implementation of Line, Circle and Ellipse Attributes

Available Soon .....

Implementation of Bresenhams algorithm - Ellipse

 1.c.) Implementation of Bresenhams algorithm - Ellipse  

Program : 

#include "stdio.h"

#include "conio.h"

#include "math.h"

#include "graphics.h"

main()

{

                    int gd=DETECT,gm;

                    int xcenter,ycenter,rx,ry;

                    int p,x,y,px,py,rx1,ry1,rx2,ry2;

                    initgraph(&gd,&gm,"h:\\tc\\bgi");

                    printf("Enter The Radius Value:\n");

                    scanf("%d%d",&rx,&ry);

                    printf("Enter The xcenter and ycenter Values:\n");

                    scanf("%d%d",&xcenter,&ycenter);

                    ry1=ry*ry;

                    rx1=rx*rx;

                    ry2=2*ry1;

                    rx2=2*rx1;

/* REGION 1 */

x=0;

                    y=ry;

                    plotpoints(xcenter,ycenter,x,y);

                    p=(ry1-rx1*ry+(0.25*rx1));

                    px=0;

                    py=rx2*y;

                    while(px<py)

                    {

                              x=x+1;

                             px=px+ry2;

                             if(p>=0)

                                       y=y-1;

                                       py=py-rx2;

                               if(p<0)

                                       p=p+ry1+px;

                              else

                                        p=p+ry1+px-py;

                    plotpoints(xcenter,ycenter,x,y);

/* REGION 2*/

                  

p=(ry1*(x+0.5)*(x+0.5)+rx1*(y-1)*(y-1)-rx1*ry1);

                   while(y>0)

                   {

                             y=y-1;

                             py=py-rx2;

                              if(p<=0)

                             {

                                       x=x+1;

                                       px=px+ry2;

                              }

                              if(p>0)

                                       p=p+rx1-py;

                             else

                                      p=p+rx1-py+px;

                     plotpoints(xcenter,ycenter,x,y);

                   }

               }

                    getch();

                    return(0);

            }

int plotpoints(int xcenter,int ycenter,int x,int y)

{

                    putpixel(xcenter+x,ycenter+y,6);

                    putpixel(xcenter-x,ycenter+y,6);

                    putpixel(xcenter+x,ycenter-y,6);

                    putpixel(xcenter-x,ycenter-y,6);

                    return;

}

Output :

Enter The Radius Value(Rx,Ry)           :     10      30

                   

Enter The xcenter and ycenter Values  :     300    150

Implementation of Bresenhams algorithm - Circle

 1.b.) Implementation of Bresenhams algorithm - Circle  

Program : 

#include "stdio.h"

#include "conio.h"

#include "math.h"

#include "graphics.h"

          main()

          {

                    int gd=DETECT,gm;

                    int xcenter,ycenter,radius;

                    int p,x,y;

                    initgraph(&gd,&gm,"h:\\tc\\bgi");

                    x=0;

                    printf("\n Enter The Radius Value: ");

                    scanf("%d",&radius);

                    y=radius;

                    printf("\n Enter The xcenter and ycenter Values: ");

                    scanf("%d%d",&xcenter,&ycenter);

                    plotpoints(xcenter,ycenter,x,y);

                    p=1-radius;

                    while(x<y)

                    {

                             if(p<0)

                                       x=x+1;

                             else

                              {

                                       x=x+1;

                                       y=y-1;

                             }

                             if(p<0)

                                       p=p+2*x+1;

                             else

                                       p=p+2*(x-y)+1;

                     plotpoints(xcenter,ycenter,x,y);

                   }

            getch();

            return(0);

          }

          int plotpoints(int xcenter,int ycenter,int x,int y) 

           {

                    putpixel(xcenter+x,ycenter+y,1);

                    putpixel(xcenter-x,ycenter+y,1);

                    putpixel(xcenter+x,ycenter-y,1);

                    putpixel(xcenter-x,ycenter-y,1);

                    putpixel(xcenter+y,ycenter+x,1);

                    putpixel(xcenter-y,ycenter+x,1);

                    putpixel(xcenter+y,ycenter-x,1);

                    putpixel(xcenter-y,ycenter-x,1);

                    return;

          }

Output :

Enter The Radius Value                       :     80

                   

Enter The xcenter and ycenter Values :      230    260

Implementation of Bresenhams algorithm - Line

 1.a.) Implementation of Bresenhams algorithm - Line  

Program : 


// Constraint : Slope must be 0 < m < 1

#include "stdio.h"

#include "conio.h"

#include "math.h"

#include "graphics.h"

main()

{

                    int gd=DETECT,gm;

                    int xa,xb,ya,yb;

                    int dx,dy,x,y,xend,p;

                    initgraph(&gd,&gm,"h:\\tc\\bgi");

                    printf("\n Enter The Two Left Endpoints(xa,ya): ");

                    scanf("%d%d",&xa,&ya);

                    printf("\n Enter The Two Right Endpoints(xb,yb): ");

                    scanf("%d%d",&xb,&yb);

                    dx=abs(xa-xb);

                    dy=abs(ya-yb);

                    p=2*dy-dx;

                    if(xa>xb)

                    {

                             x=xb;

                             y=yb;

                             xend=xa;

                    }

          else

{       

                             x=xa;

                              y=ya;

                              xend=xb;

}

      putpixel(x,y,6);

    while(x<xend)

      {

      x=x+1;

      if(p<0)

      {

      p=p+2*dy;

      }

      else                

      {

      y=y+1;

      p=p+2*(dy-dx);                

      }

      putpixel(x,y,6);

      }

   getch();

   return(0);

}

Output :

Enter The Two Left Endpoints(xa,ya):       234    124

Enter The Two Right Endpoints(xb,yb):    578    321