DRAW A LINE USING BRESENHAM ALGORITHM

DRAW A LINE USING BRESENHAM ALGORITHM

#include <graphics.h>

#include <stdlib.h>

#include <stdio.h>

#include <conio.h>

#include<dos.h>

void main()

{

   /* request auto detection */

   int gdriver = DETECT, gmode, errorcode;

   int xa,xb,ya,yb,x,y;

   char msg[25];

   /* initialize graphics and local variables */

   initgraph(&gdriver, &gmode, "");

   /* read result of initialization */

   errorcode = graphresult();

   /* an error occurred */

   if (errorcode != grOk)

   {

      printf("Graphics error: %s\n", grapherrormsg(errorcode));

      printf("Press any key to halt:");

      getch();

      exit(1);

  }

  printf("Enter the x1 and y1 value:\n");

  scanf("%d%d",&xa,&ya);

  printf("Enter the x2 and y2 value:\n");

  scanf("%d%d",&xb,&yb);

  linebres(xa,ya,xb,yb);

  getch();

  closegraph();

}

           

 void linebres(int xa,int ya,int xb,int yb)

{

            int dx=abs(xa-xb),dy=abs(ya-yb);

            int p=2*dy-dx;

            int twody=2*dy,twodxdy=2*(dy-dx);

            int x,y,xend;

            if(xa>xb)

            {

                    x=xb;y=yb;xend=xa;

            }

           

            else

            {

                        x=xa;y=ya;xend=xb;

            }

            putpixel(x,y,YELLOW);

            while(x<xend)

            {

                        x++;

                        if(p<0)

                                    p+=twody;

                        else

                        {

                                    y++;

                                    p+=twodxdy;

                        }

                        putpixel(x,y,YELLOW);

            }

}

OUTPUT:-

Enter the x1 and y1 value:

100

100

Enter the x2 and y2value:

250

300