fc.lino

define point {
  number x, y;
}

define line {
  point start, end, c;
  constraints { 
    (start + end) / 2 = c;
  }
  draw { &draw_line; }
}

define hline extends line {
  number y, len;
  constraints {
    y = start.y;
    y = end.y;
    len = end.x - start.x;
  }
}

define vline extends line {
  number x, len;
  constraints {
    x = start.x;
    x = end.x;
    len = end.y - start.y;
  }
}

define box {
  point n, s, e, w, ne, se, nw, sw, c;
  hline top, bottom;
  vline left, right;
  number ht, wd;
  constraints {
    nw = top.start;
    ne = top.end;
    sw = bottom.start;
    se = bottom.end;
    n  = (nw + ne)/2;
    s  = (sw + se)/2;
    w  = (nw + sw)/2;
    e  = (ne + se)/2;
    c  = (n  + s )/2;
    top.start    = left.start;
    top.end      = right.start;
    bottom.start = left.end;
    bottom.end   = right.end;
    ht = left.len;
    wd = top.len;
  } 
}

define square extends box {
  constraints { ht = wd; }
}

define ellipse extends box {
  draw { &draw_ellipse; }
}

define circle extends ellipse {
  constraints { ht = wd; }
}

box F, add, mul, c32, c59, C;

number hspace, vspace, boxht, boxwd;

line i, j, k1, k2, l, m;

point kk;


constraints {
     i.start = F.e;   i.end=add.nw;
     j.start = add.e; j.end=c32.w;
     l.start = c59.e; l.end=mul.sw;
     m.start = mul.e; m.end=C.w;

  boxht = 2; boxwd = boxht*2;

  F.ht = boxht; F.wd = boxwd;
  F.nw = (0, 0);

  add = F   + ( hspace,  vspace);
  c32 = add + ( hspace,  0);
  mul = add + ( 0,       vspace);
  C   = mul + ( hspace,  0);
  c59 = mul + (-hspace,  vspace);

  kk.x = add.sw.x - (hspace-boxwd) * 2/3;
  kk.y = (add.sw.y + mul.nw.y)/2;
  k1.start = kk;
  k1.end = add.sw;
  k2.start = kk;
  k2.end = mul.nw;

  hspace = 1 + boxwd;
  vspace = 1 + boxht;
}