(function() {
  var A, GOSPER_GEN, HEX_DIRS, TRI_LINES, fractalize, fractalize_step;

  HEX_DIRS = 'abcdef';

  GOSPER_GEN = 'AfdEAAb';

  fractalize_step = function(seq, gen) {
    var delta, el, gen_el, i, new_el, res_seq, tmp_seq, _i, _j, _len, _len2, _ref;
    res_seq = '';
    for (_i = 0, _len = seq.length; _i < _len; _i++) {
      el = seq[_i];
      tmp_seq = '';
      delta = HEX_DIRS.indexOf(el.toLowerCase());
      for (_j = 0, _len2 = gen.length; _j < _len2; _j++) {
        gen_el = gen[_j];
        new_el = HEX_DIRS[(HEX_DIRS.indexOf(gen_el.toLowerCase()) + delta) % 6];
        if (gen_el.toUpperCase() === gen_el) new_el = new_el.toUpperCase();
        tmp_seq += new_el;
      }
      if (el.toLowerCase() === el) {
        tmp_seq = tmp_seq.split('').reverse();
        for (i = 0, _ref = tmp_seq.length; 0 <= _ref ? i < _ref : i > _ref; 0 <= _ref ? i++ : i--) {
          if (tmp_seq[i].toLowerCase() === tmp_seq[i]) {
            tmp_seq[i] = tmp_seq[i].toUpperCase();
          } else {
            tmp_seq[i] = tmp_seq[i].toLowerCase();
          }
        }
        tmp_seq = tmp_seq.join('');
      }
      res_seq += tmp_seq;
    }
    return res_seq;
  };

  fractalize = function(gen, stage) {
    var i, seq, _ref;
    seq = gen;
    for (i = 0, _ref = stage - 1; 0 <= _ref ? i < _ref : i > _ref; 0 <= _ref ? i++ : i--) {
      seq = fractalize_step(seq, gen);
    }
    return seq;
  };

  A = 3;

  TRI_LINES = {
    'a': "l" + (2 * A) + " 0",
    'b': "l" + A + " " + (A * Math.sqrt(3)),
    'c': "l" + (-A) + " " + (A * Math.sqrt(3)),
    'd': "l" + (-2 * A) + " 0",
    'e': "l" + (-A) + " " + (-A * Math.sqrt(3)),
    'f': "l" + A + " " + (-A * Math.sqrt(3))
  };

  window.main = function() {
    var d, el, height, seq, svg, width, _i, _len;
    seq = fractalize(GOSPER_GEN, 4);
    d = 'M0 0';
    for (_i = 0, _len = seq.length; _i < _len; _i++) {
      el = seq[_i];
      d += TRI_LINES[el.toLowerCase()];
    }
    width = 960;
    height = 500;
    svg = d3.select('body').append('svg').attr('width', width).attr('height', height);
    return svg.append('path').attr('class', 'gosper').attr('d', d).attr('transform', 'translate(500,390)');
  };

}).call(this);