Draw a line using Bresenham's algorithm in Computer Graphic

 Draw a line using Bresenham's algorithm

#include<iostream.h>

#include<conio.h>

#include<math.h>

#include<graphics.h>

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

{

int dx=abs(x1-x2),dy=abs(y1-y2);

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

int p=2*dy-dx;

int x,y,xend;

if(x1>x2)

{

x=x2;

y=y2;

xend=x1;

}

else

{

x=x1;

y=y1;

xend=x2;

}

putpixel(x,y,12);

while(x<xend)

{

x++;

if(p<0)

p+=twody;

else

{

p+=twodydx;

y++;

}

putpixel(x,y,12);

}

}

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;

linebres(x1,y1,x2,y2);

getch();

}

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