line clipping program

#include
#include
#include
#include
struct wind
{
int xmin,ymin;
int xmax,ymax;
};
struct point
{
int x,y;
char code[5];
};

void gencode(struct wind w,struct point p)
{
if(p.x p.code[0]='1'; else p.code[0]='0';
if(p.x>w.xmax)
p.code[1]='1'; else p.code[1]='0';
if(p.y p.code[2]='1'; else p.code[2]='0';
if(p.y>w.ymax)
p.code[3]='1'; else p.code[3]='0';

}


struct point clipline(struct wind w,struct point p,struct point pt)
{
int i,flag=0;
float m=(p.y-pt.y)/(p.x-pt.x);
gencode(w,p);
while(!flag)
{
flag=1;
if(p.code[0] == '1')
{
p.y+=(w.xmin-p.x)*m;
p.x=w.xmin;
gencode(w,p);
flag=0;
}
else if(p.code[1] == '1')
{
p.y+=(w.xmax-p.x)*m;
p.x=w.xmax;
gencode(w,p);
flag=0;
}
else if(p.code[2] == '1')
{
p.x+=(w.ymin-p.y)/m;
p.y=w.ymin;
gencode(w,p);
flag=0;
}
else if(p.code[3] == '1')
{
p.x+=(w.ymax-p.y)/m;
p.y=w.ymax;
gencode(w,p);
flag=0;
}

}
cout< getch();
return p;
}



void main()
{

int gdriver=DETECT,gm;
struct point p1,p2;
struct wind w;

initgraph(&gdriver,&gm," ");
printf("Window ");
scanf("%d%d%d%d",&w.xmin,&w.ymin,&w.xmax,&w.ymax);
printf("Line ");
scanf("%d%d%d%d",&p1.x,&p1.y,&p2.x,&p2.y);
p1=clipline(w,p1,p2);
p2=clipline(w,p2,p1);
rectangle(w.xmin,w.ymin,w.xmax,w.ymax);
printf("%d%d%d%d",p1.x,p1.y,p2.x,p2.y);
line(p1.x,p1.y,p2.x,p2.y);
getch();
closegraph();
}