DDA algorithm

Program 1: Draw a line using DDA Algorithm.

#include<iostream.h>

#include<conio.h>

#include<math.h>

#include<graphics.h>

void ddaline(int,int,int,int);

void main()

{

clrscr();

int gd=DETECT,gm;

initgraph(&gd,&gm,"d:\\turboc3");

int x1,x2,y1,y2;

cout<<"Enter Initial co-ordinates:(x1,y1)";

cout<<"\nx-axis:";

cin>>x1;

cout<<"y-axis:";

cin>>y1;

cout<<"Enter End co-ordinates:(x2,y2)";

cout<<"\nx-axis:";

cin>>x2;

cout<<"y-axis:";

cin>>y2;

ddaline(x1,x2,y1,y2);

getch();

}

void ddaline(int x1,int x2,int y1,int y2)

{

int dx,dy,steps,k;

float xincr,yincr,x=200,y=200;

dx=x2-x1;

dy=y2-y1;

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

{

steps=dx;

}

else

{

steps=dy;

}

xincr=dx/steps;

yincr=dy/steps;

putpixel(x,y,12);

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

{

x+=xincr;

y+=yincr;

putpixel(x,y,12);

}

}

Output:

Enter Initial co-ordinates:(x1,y1)

x-axis:100

y-axis:150

Enter End co-ordinates:(x2,y2)

x-axis:500

y-axis:150