DRAW A LINE USING DDA ALGORITHM

DRAW A LINE USING DDA ALGORITHM

#include <graphics.h>

#include <stdlib.h>

#include <stdio.h>

#include <conio.h>

#include<dos.h>

#define ROUND(a)((int)(a+0.5))

int main(void)

{

   /* request auto detection */

   int gdriver = DETECT, gmode, errorcode;

   int xa,xb,ya,yb;

  // int y=0,x=0,i;

   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 value for x1,y1:\n");

 scanf("%d%d",&xa,&ya);

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

 scanf("%d%d",&xb,&yb);

 linedda(xa,ya,xb,yb);

 getch();

 closegraph();

  return 0;

}

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

{

int dx=xb-xa,dy=yb-ya,steps,k;

float xincr,yincr,x=xa,y=ya;

if(abs(dx)>abs(dy))

steps=abs(dy);

else

steps=abs(dy);

xincr=dx/(float)steps;

yincr=dy/(float)steps;

putpixel(ROUND(x),ROUND(y),GREEN);

for(k=0;k<steps;k++)

{

x+=xincr;

y+=yincr;

putpixel(ROUND(x),ROUND(y),GREEN);

}

}

OUTPUT:-

Enter the value for x1,y1:

100

100

Enter the value for x2,y2:

250

300