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