circle to hexagon

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>

<body>
  <script>
    var width = 960;
    var height = 500;
    var svg = d3.select("body").append("svg")
      .attr("width", 960)
      .attr("height", 500)

var startX = radius * Math.cos(radians(startAngle));
      var startY = radius * Math.sin(radians(startAngle));
      var endX = radius * Math.cos(radians(endAngle));
      var endY = radius * Math.sin(radians(endAngle));

var centerX = 0;
      var centerY = 0;
      var posX = radius * Math.cos(angle);
      var posY = radius * Math.sin(angle);

var intersection = line_intersects(startX, startY, endX, endY, centerX, centerY, posX, posY)

var t = intersection[0];
      var hX = posX * t;
      var hY = posY * t;

return [
        hX + width/2,
        hY + height/2
      ]
    }
    
    svg.selectAll("circle.circle")
      .data(data)
    .enter().append("circle").classed("circle", true)
    .attr("cx", function(d) { return project(d.angle, d.radius)[0]})
    .attr("cy", function(d) { return project(d.angle, d.radius)[1]})
    .attr("r", 5)
    .attr("stroke", function(d) { return color(d.index)})
    .attr("fill", "none")
    
    svg.selectAll("circle.hex")
      .data(data)
    .enter().append("circle").classed("circle", true)
    .attr("cx", function(d) { return hexProject(d.angle, d.radius)[0]})
    .attr("cy", function(d) { return hexProject(d.angle, d.radius)[1]})
    .attr("r", 3)
    .attr("fill", function(d) { return color(d.index)})
    
    
    
		function line_intersects(p0_x, p0_y, p1_x, p1_y, p2_x, p2_y, p3_x, p3_y) {
     //https://gist.github.com/Joncom/e8e8d18ebe7fe55c3894

var s1_x, s1_y, s2_x, s2_y;
      s1_x = p1_x - p0_x;
      s1_y = p1_y - p0_y;
      s2_x = p3_x - p2_x;
      s2_y = p3_y - p2_y;

var s, t;
      s = (-s1_y * (p0_x - p2_x) + s1_x * (p0_y - p2_y)) / (-s2_x * s1_y + s1_x * s2_y);
      t = ( s2_x * (p0_y - p2_y) - s2_y * (p0_x - p2_x)) / (-s2_x * s1_y + s1_x * s2_y);

if (s >= 0 && s <= 1 && t >= 0 && t <= 1)
      {
          // Collision detected
          return [s,t];
      }

return []; // No collision
    }
  </script>
</body>

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