RITIKA_S.CPP

#include<iostream.h>
#include<conio.h>
#include<graphics.h>

int k,xmin,ymin,xmax,ymax,arr[20],m;
void clipl (int x1, int y1, int x2, int y2)
{
    if(x2-x1)
        m=(y2-y1)/(x2-x1);
    else
        m=100000;
    if(x1 >= xmin && x2 >= xmin)
    {
        arr[k]=x2;
        arr[k+1]=y2;
        k+=2;
    }
    if(x1 < xmin && x2 >= xmin)
    {
        arr[k]=xmin;
        arr[k+1]=y1+m*(xmin-x1);
        arr[k+2]=x2;
        arr[k+3]=y2;
        k+=4;
    }
    if(x1 >= xmin && x2 < xmin)
    {
        arr[k]=xmin;
        arr[k+1]=y1+m*(xmin-x1);
        k+=2;
    }
}

void clipt(int x1, int y1, int x2, int y2)
{
    if(y2-y1)
        m=(x2-x1)/(y2-y1);
    else
        m=100000;
    if(y1 <= ymax && y2 <= ymax)
    {
        arr[k]=x2;
        arr[k+1]=y2;
        k+=2;
    }
    if(y1 > ymax && y2 <= ymax)
    {
        arr[k]=x1+m*(ymax-y1);
        arr[k+1]=ymax;
        arr[k+2]=x2;
        arr[k+3]=y2;
        k+=4;
    }
    if(y1 <= ymax && y2 > ymax)
    {
        arr[k]=x1+m*(ymax-y1);
        arr[k+1]=ymax;
        k+=2;
    }
}

void clipr(int x1, int y1, int x2, int y2)
{
    if(x2-x1)
        m=(y2-y1)/(x2-x1);
    else
        m=100000;
    if(x1 <= xmax && x2 <= xmax)
    {
        arr[k]=x2;
        arr[k+1]=y2;
        k+=2;
    }
    if(x1 > xmax && x2 <= xmax)
    {
        arr[k]=xmax;
        arr[k+1]=y1+m*(xmax-x1);
        arr[k+2]=x2;
        arr[k+3]=y2;
        k+=4;
    }
    if(x1 <= xmax && x2 > xmax)
    {
        arr[k]=xmax;
        arr[k+1]=y1+m*(xmax-x1);
        k+=2;
    }
}

void clipb(int x1, int y1, int x2, int y2)
{
    if(y2-y1)
        m=(x2-x1)/(y2-y1);
    else
        m=100000;
    if(y1 >= ymin && y2 >= ymin)
    {
        arr[k]=x2;
        arr[k+1]=y2;
        k+=2;
    }
    if(y1 < ymin && y2 >= ymin)
    {
        arr[k]=x1+m*(ymin-y1);
        arr[k+1]=ymin;
        arr[k+2]=x2;
        arr[k+3]=y2;
        k+=4;
    }
    if(y1 >= ymin && y2 < ymin)
    {
        arr[k]=x1+m*(ymin-y1);
        arr[k+1]=ymin;
        k+=2;
    }
}
 
void main()
{
    int gd=DETECT,gm,n,poly[20];
    int xi,yi,xf,yf,polyy[20];
    initgraph(&gd,&gm,"C:\\TurboC3\\BGI");
    setcolor(WHITE);
    cout<<"Enter the Minimum Coordinates of visible window : x : ";
    cin>>xmin;
    cout<<"y : ";
    cin>>ymin;
    cout<<"Enter the Maximum Coordinates of visible window : x : ";
    cin>>xmax;
    cout<<"y : ";
    cin>>ymax;
    cout<<"Enter the number of side of Polygon to be clipped : ";
    cin>>n;
    cout<<"Enter the coordinates :";
    for(int i=0 ; i < 2*n ; i++)
       cin>>polyy[i];

    polyy[i]=polyy[0];
    polyy[i+1]=polyy[1];
    for(i=0 ; i < 2*n+2 ; i++)
        poly[i]=polyy[i];

    clrscr();
    rectangle(xmin,ymax,xmax,ymin);
    cout<<"\tUNCLIPPED POLYGON";
    setcolor(WHITE);
    fillpoly(n,poly);
    getch();
    clrscr();
    k=0;
    for(i=0;i < 2*n;i+=2)
        clipl(polyy[i],polyy[i+1],polyy[i+2],polyy[i+3]);
    n=k/2;
    for(i=0;i < k;i++)
        polyy[i]=arr[i];
    polyy[i]=polyy[0];
    polyy[i+1]=polyy[1];
    k=0;
    for(i=0;i < 2*n;i+=2)
        clipt(polyy[i],polyy[i+1],polyy[i+2],polyy[i+3]);
    n=k/2;
    for(i=0;i < k;i++)
        polyy[i]=arr[i];
    polyy[i]=polyy[0];
    polyy[i+1]=polyy[1];
    k=0;
    for(i=0;i < 2*n;i+=2)
        clipr(polyy[i],polyy[i+1],polyy[i+2],polyy[i+3]);
    n=k/2;
    for(i=0;i < k;i++)
        polyy[i]=arr[i];
    polyy[i]=polyy[0];
    polyy[i+1]=polyy[1];
    k=0;
    for(i=0;i < 2*n;i+=2)
        clipb(polyy[i],polyy[i+1],polyy[i+2],polyy[i+3]);
    for(i=0;i < k;i++)
        poly[i]=arr[i];
    if(k)
        fillpoly(k/2,poly);
    setcolor(RED);
    rectangle(xmin,ymax,xmax,ymin);
    cout<<"CLIPPED POLYGON";
    getch();
    closegraph();
}