35. LIANG BARSKY LINE CLIPPING ALGORITHM

Code:

#include<iostream.h>

# include<conio.h>

# include<graphics.h>

void main() {

int gd=DETECT,gm;

initgraph(&gd,&gm,"C:\\TC\\BGI");

int x1,y1,x2,y2,xmax,xmin,ymax,ymin,xx1,yy1,xx2,yy2,dx,dy,i;

int p[4],q[4];

float t1,t2,t[4];

cout<<"Enter the lower co-ordinates of window";

cin>>xmin>>ymin;

cout<<"Enter the upper co-ordinates of window";

cin>>xmax>>ymax;

setcolor(RED);

rectangle(xmin,ymin,xmax,ymax);

cout<<"Enter x1:";

cin>>x1;

cout<<"Enter y1:";

cin>>y1;

cout<<"Enter x2:";

cin>>x2;

cout<<"Enter y2:";

cin>>y2;

line(x1,y1,x2,y2);

dx=x2-x1;

dy=y2-y1;

p[0]=-dx;

p[1]=dx;

p[2]=-dy;

p[3]=dy;

q[0]=x1-xmin;

q[1]=xmax-x1;

q[2]=y1-ymin;

q[3]=ymax-y1;

for(i=0;i<4;i++)

{ if(p[i]!=0)

{t[i]=(float)q[i]/p[i];}

else

if(p[i]==0 && q[i]<0)

cout<<"line completely outside the window";

else

if(p[i]==0 && q[i]>=0)

cout<<"line completely inside the window";

}

if (t[0]>t[2])

{t1=t[0];}

else

{t1=t[2];}

if (t[1]<t[3])

{t2=t[1];}

else

{t2=t[3];}

if (t1<t2)

{xx1=x1+t1*dx;

xx2=x1+t2*dx;

yy1=y1+t1*dy;

yy2=y1+t2*dy;

cout<<"line after clipping:";

setcolor(WHITE);

line(xx1,yy1,xx2,yy2);}

else

{cout<<"line lies out of the window";}

getch();

}

OUTPUT:

Need the code??

Download Link= https://www.dropbox.com/s/jhbmpn6dfzypnl4/Liang%20barsky.docx