Spiral Circle [UNLISTED]

Inspired by an untitled GIF by PATAKK and Hypnos by Hakim El Hattab.

forked from mbostock's block: Spiral Circle

<!DOCTYPE html>
<meta charset="utf-8">
<style>

rect {
  fill: #fff;
  stroke: #000;
  stroke-width: .7px;
}

</style>
<svg width="960" height="500">
  <defs>
    <clippath id="clip-upper">
      <rect width="960" height="250" x="-480" y="-250"></rect>
    </clippath>
    <clippath id="clip-lower">
      <rect width="960" height="250" x="-480" y="0"></rect>
    </clippath>
  </defs>
  <g clip-path="url(#clip-upper)" transform="translate(480,250)"></g>
  <g clip-path="url(#clip-lower)" transform="translate(480,250)"></g>
</svg>
<script src="//d3js.org/d3.v4.min.js"></script>
<script>

var width = 960,
    height = 500,
    circleRadius = 180,
    squareCount = 200,
    squareSize = 78,
    speed = .08;

var square = d3.selectAll("g")
  .append("g")
    .attr("transform", function(d, i) { return i ? "rotate(180)" : null; })
  .selectAll("rect")
    .data(d3.range(squareCount))
  .enter().append("rect")
    .datum(function(i) { return i / squareCount; })
    .attr('width', squareSize)
    .attr('height', squareSize)
    .attr('x', -squareSize / 2)
    .attr('y', -squareSize / 2);

d3.timer(function(elapsed) {
  square
      .attr("transform", function(t) { return "rotate(" + (t * 360) + ")translate(0," + circleRadius + ")rotate(" + (t * 360 + elapsed * speed) + ")"; });
});

</script>

https://d3js.org/d3.v4.min.js