polybius.fyi/js/bootstrap-386.js

self._386 = self._386 || {};

$(function(){
  var character = { height: 20, width: 12.4 };

  function scrollLock() {
    var last = 0;
    $(window).bind('scroll', function(e) {
      var func, off = $(window).scrollTop();

      console.log(off, last, off < last ? "up" : "down");

      // this determines whether the user is intending to go up or down.
      func = off < last ? "floor" : "ceil";

      // make sure we don't run this from ourselves
      if(off % character.height === 0) {
        return;
      }
      last = off;

      window.scrollTo(
        0,
        Math[func](off / character.height) * character.height
      );

    }); 
  }  

  function loading() {

    if(_386.fastLoad) {
      document.body.style.visibility='visible';
      return;
    }

    var
      onePass = _386.onePass,
      speedFactor = 1 / (_386.speedFactor || 1) * 165000;
      wrap = document.createElement('div'),
      bar = wrap.appendChild(document.createElement('div')),

      cursor = document.createElement('div'),
      // If the user specified that the visibility is hidden, then we
      // start at the first pass ... otherwise we just do the 
      // cursor fly-by
      pass = ($(document.body).css('visibility') == 'visible') ? 1 : 0,
      height = $(window).height(),
      width = $(window).width(),

      // this makes the loading of the screen proportional to the real-estate of the window.
      // it helps keep the cool sequence there while not making it waste too much time.
      rounds = (height * width / speedFactor),
      column = width, row = height - character.height;
      
    wrap.id = "wrap386";
    bar.id = "bar386";
    cursor.id = "cursor386";

    cursor.innerHTML = bar.innerHTML = '&#9604;';

    // only inject the wrap if the pass is 0
    if(pass === 0) {
      document.body.appendChild(wrap);
      document.body.style.visibility='visible';
    } else {
      document.body.appendChild(cursor);
      rounds /= 2;
      character.height *= 4;
    }

    var ival = setInterval(function(){
      for(var m = 0; m < rounds; m++) {
        column -= character.width;

        if(column <= 0) {
          column = width;
          row -= character.height;
        }
        if(row <= 0) {
          pass++;
          row = height - character.height;

          if(pass == 2) {
            document.body.removeChild(cursor);
            clearInterval(ival);
          } else {
            wrap.parentNode.removeChild(wrap);
            if(onePass) {
              clearInterval(ival);
            } else {
              document.body.appendChild(cursor);
              rounds /= 2;
              character.height *= 4;
            }
          }
        }

        if(pass === 0) {
          bar.style.width = column + "px";
          wrap.style.height = row + "px";
        } else {
          cursor.style.right = column + "px";
          cursor.style.bottom = row + "px";
        }
      }
    }, 1);
  }
  loading();
});