Bresenham’s Line drawing Algorithm

# include <conio.h>

# include <graphics.h>

void main()

{

int dx,dy,x,y,p,x1,y1,x2,y2;

int gd,gm;

clrscr();

printf("\n\n\tEnter the co-ordinates of first point : ");

scanf("%d %d",&x1,&y1);

printf("\n\n\tEnter the co-ordinates of second point : ");

scanf("%d %d",&x2,&y2);

dx = (x2 - x1);

dy = (y2 - y1);

p = 2 * (dy) - (dx);

x = x1;

y = y1;

detectgraph(&gd,&gm);

initgraph(&gd,&gm,"c:\\tc2\\bgi");

putpixel(x,y,WHITE);

while(x <= x2)

{

if(p < 0)

{

x=x+1;

y=y;

p = p + 2 * (dy);

}

else

{

x=x+1;

y=y+1;

p = p + 2 * (dy - dx);

}

putpixel(x,y,WHITE);

}

getch();

closegraph();

}