/*AIM:TO IMPLEMENT LIANG BARSKY LINE CLIPPING ALGORITHM
  NAME:HARSH HEMRAJANI
  BATCH:C12
  ROLL NO:33
*/
import java.util.*;
import java.applet.Applet;
import java.awt.*;
class Clipper
{
    int WXmin,WYmin,WXmax,WYmax;
    double u1,u2;
    public Clipper(Rectangle r)     //Constructor initializes window parameters
    {
        WXmax=(int)r.getMaxX();
        WXmin=(int)r.getMinX();
        WYmax=(int)r.getMaxY();
        WYmin=(int)r.getMinY();
    }
    public void clip(Point p1,Point p2,Graphics g) //Clips the line
    {
        int dx,dy,a,b;
        boolean done=false;
        g.drawRect(WXmin,WYmin,WXmax-WXmin,WYmax-WYmin);    //Drawing window
        u1=0;u2=1;
        dx=p2.x-p1.x;
        dy=p2.y-p1.y;
        a=p1.x;b=p1.y;
        if(clipTest(-dx,p1.x-WXmin))
            if(clipTest(dx,WXmax-p1.x))
                if(clipTest(-dy,p1.y-WYmin))
                    if(clipTest(dy,WYmax-p1.y))
                    {
                        done=true;
                        if(u1>0)
                        {
                            p1.x=a+(int)(u1*(double)dx);
                            p1.y=b+(int)(u1*(double)dy);
                        }
                        if(u2<1)
                        {
                            p2.x=a+(int)(u2*(double)dx);
                            p2.y=b+(int)(u2*(double)dy);
                        }
                        if(u1==0 && u2==1)
                        {
                            System.out.println("Line is completely inside");
                            g.drawLine(p1.x,p1.y,p2.x,p2.y);
                            return;
                        }
                    }
        if(!done)
        {
            System.out.println("Line is completely outside the window");
            return;
        }
        System.out.println("\nCo-ordinates of clipped line:");
        System.out.println(p1.x+" "+p1.y);
        System.out.println(p2.x+" "+p2.y);
        g.drawLine(p1.x,p1.y,p2.x,p2.y);
    }
    private boolean clipTest(double p,double q)
    {
        double r=q/p;
        boolean okay=true;
        if(p<0)
        {
            if(r>u2)
                okay=false;
            else if(r>u1)
                u1=r;
        }
        else if(p>0)
        {
            if(r<u1)
                okay=false;
            else if(r<u2)
                u2=r;
        }
        else if(q<0)
            okay=false;
        return okay;
    }
}
public class LiangClip extends Applet
{
    Point p1,p2; Clipper win;
    public void init()
    {
        this.setSize(800, 800);
        Scanner sc=new Scanner(System.in);
        System.out.println("Enter the parameters of clipping window:");
        System.out.print("Left top point:");
        int rx=sc.nextInt();
        int ry=sc.nextInt();
        System.out.print("Width:");
        int w=sc.nextInt();
        System.out.print("Height:");
        int h=sc.nextInt();
        Rectangle r=new Rectangle(rx,ry,w,h);
        win=new Clipper(r);
        System.out.println("\nEnter the end points of a line:");
        p1=new Point(sc.nextInt(),sc.nextInt());
        p2=new Point(sc.nextInt(),sc.nextInt());
    }
    public void paint(Graphics g)
    {
        win.clip(p1,p2,g);
    }
}
/*OUTPUT:
Enter the parameters of clipping window:
Left top point:
225 225
Width:180
Height:135

Enter the end points of a line:
125 400
420 180
Co-ordinates of clipped line:
225 326
359 225
*/