int printf(const char *format, ...);

typedef struct {
    char x,y; 
} s;

char c[]={' ','\'','.',':',0x1b,'[','H'} ,
  M[ 1843]={4,5,6,} ,
  *m=&M[3],
  e;
int a,b;

s P[15],Q[15];
void
o(int x,int y){
  a=80*(y/2)+x,b= 1+(y&1);
  e?(m[a]|=b):(m[a]&=~b);

  printf("#0018:x %02x y %02x a %04x m[a] %02x\n",x,y,a,m[a]);
}
void
W(s*p,s*q){
  s t;
  t=*p;
  *p=*q;
  *q=t;
}
void
l(s p, s q){
  s t;
  int x=p.x-q.x,
      y=p.y-q.y,
      w,
      v;

printf("#0035:p.x %02x p.y %02x q.x %02x q.y %02x\n",p.x,p.y,q.x,q.y);

  x=x<0?-x:x;
  y=y<0?-y:y;
  if(y<x){
    if( q.x<p.x)
	W(&p,&q);
    v=p.y<=q.y?1:-1;
    w=(y%x)/2;
    for(; p.x<=q.x; p.x++){
      o(p.x, p.y);
      if((w-=y)<=0)
        w+=x,p.y+=v;
    }
  } else if(y){
    if(q.y<p.y) 
      W(&p,&q);
    v=!(p.  x>q.x)?1:-1;
    w=(x%y)/2;
    for(; p.y<=q.y; p.y++){
      o(p.x,q.y);
      if((w-=x)<=0)
	w+= y,
	p.x+=v;
    }
  }
}    extern int rand();
void
r(s*p,s q){
  p->x=((rand()%80)-q.x)/11;
  p->y=((rand()%48)-q.y)/11;
printf("#0066:r: p->x %02x p->y %02x\n",p->x,p->y);
}
void
d(s*p,s q,s r){
printf("#0070:d0: q->x %02x q->y %02x\n",q.x,q.y);
printf("#0071:d1: r->x %02x r->y %02x\n",r.x,r.y);
  p->x=q.x+r.x;
  p->y=q.y+r.y;
printf("#0074:d2: p->x %02x p->y %02x\n",p->x,p->y);
} extern void srand(int); 
int
main(int i,int j,int k){
  s R,S;
  int count;
  i=0,
    k=0;
  srand(512);
  for(count=0;count<400 ;count++){
    j=(i+1)%10;
    e=0;
    l(P[j],Q[j]);
printf("#0087:main0: p.x %02x p.y %02x q.x %02x q.y %02x\n",P[j].x,P[j].y,Q[j].x,Q[j].y);
    if(--k<=0){
      r(&R,P[i]);
      r(&S,Q[i ]);
printf("#0091:main1: R.x %02x R.y %02x S.x %02x S.y %02x\n",R.x,R.y,S.x,S.y);
      k=10;
    }
    d(&P[j],P[i],R);
printf("#0095:main2: p.x %02x p.y %02x q.x %02x q.y %02x\n",P[j].x,P[j].y,Q[i].x,Q[i].y);
    d(&Q[j],Q[i],S);
printf("#0097:main3: p.x %02x p.y %02x q.x %02x q.y %02x\n",P[j].x,P[j].y,Q[i].x,Q[i].y);
    i=j;
    e=1;
    l(P[j],Q[j]);
printf("#0101:main4: p.x %02x p.y %02x q.x %02x q.y %02x\n",P[j].x,P[j].y,Q[i].x,Q[i].y);
    b=83;
if (0)
    for (a=0; a<sizeof M; a++){
      if(--b<=0) 
        b=80,putchar('\n');
      putchar(c[M[a]]);
    }
  }
return 0;
}