c++ program to draw line using DDA LINE Algorithm.

#include<iostream.h>
#include<conio.h>
#include<graphics.h>
#include<math.h>

struct co_ordinate
{
 int x,y;
};

class ddaline
{
 public:
  co_ordinate point[2];
  void input_parameter()
   {
    cout<<"enter starting point co_ordinate:- ";
    cin>>point[0].x>>point[0].y;
    cout<<"enter ending point co_ordinate:- ";
    cin>>point[1].x>>point[1].y;
   }



  void draw_line();
 };//end of class ddaline
void ddaline :: draw_line()
 {
  int x,y,dx,dy,x_increament,y_increament,steps,i;

  dx=point[1].x-point[0].x;
  dy=point[1].y-point[0].y;

  if(abs(dx)>abs(dy))
    steps=dx;
  else
    steps=dy;

  x_increament=dx/steps;
  y_increament=dy/steps;

  x=point[0].x;
  y=point[0].y;

  putpixel(x,y,5);

  for(i=0;i<steps;i++)
   {
    x=x+x_increament;
    y=y+y_increament;
    putpixel(x,y,5);
  }
}//end of function drawline

void main()
{
 clrscr();
 ddaline d;
 int gdriver=DETECT,gmode;
 initgraph(&gdriver,&gmode,"");
 d.input_parameter();
 d.draw_line();
 getch();
}