// some useful functions
(
~grid = { 0 ! 60 } ! 60;

~at = { |coord|
   var col = ~grid.at(coord[0]);
   if(col.notNil) { col.at(coord[1]) }
};
~put = { |coord, value|
   var col = ~grid.at(coord[0]);
   if(col.notNil) { col.put(coord[1], value) }
};

~coord = ~grid.shape.rand;
~next = { |p|
   var possible = [p] + [[0, 1], [1, 0], [-1, 0], [0, -1]];
   possible = possible.select { |x|
      var c = ~at.(x);
      c.notNil and: { c == 0 }
   };
   possible.choose
};
~walkN = { |p, scale|
   var next = ~next.(p);
   if(next.notNil) {
      ~put.(next, 1);
      Pen.lineTo(~topoint.(next, scale));
      ~walkN.(next, scale);
      ~walkN.(next, scale);
      Pen.moveTo(~topoint.(p, scale));
   };
};

~topoint = { |c, scale| (c + [1, 1] * scale).asPoint };

)

// do the drawing
(
var b, w;

b = Rect(100, 100, 700, 700);
w = Window("so-a-mazing", b);
w.view.background_(Color.black);

w.drawFunc = {
   var p = ~grid.shape.rand;
   var scale = b.width / ~grid.size * 0.98;
   Pen.moveTo(~topoint.(p, scale));
   ~walkN.(p, scale);
   Pen.width = scale / 4;
   Pen.color = Color.white;
   Pen.stroke;
};
w.front.refresh;
)