Sunday, January 17, 2010

bresenhams line drawing algorithm

program:
#include"stdio.h"
#include"conio.h"
#include"stdlib.h"
#include"graphics.h"
#include"dos.h"
#include"math.h"

void main()
{
int driver,mode,k;
int xa,xb,ya,yb,dx,dy,x,y,i,p,dy2,dydx2;
clrscr();
printf("\n\tEnter(xa,ya)...");
scanf("%d%d",&xa,&ya);
printf("\n\tEnter(xb,yb)...");
scanf("%d%d",&xb,&yb);
x=xa;
y=ya;
driver=DETECT;
initgraph(&driver,&mode,"");
dx=abs(xb-xa);
dy=abs(yb-ya);
p=(2*dy)-dx;
dy2=2*dy;
dydx2=2*(dy-dx);
line(100,0,100,500);
line(0,100,500,100);
putpixel(x,y,2);
for(i=0;i<=dx;i++)
{
if(p<0)
{
x=x+1;
putpixel(x,y,2);
p+=dy2;
}
else
{
x=x+1;
y=y+1;
putpixel(x,y,2);
p+=dydx2;
}
}
getch();
}
output:


Enter(xa,ya)...100 100
Enter(xb,yb)...250 252