examples/vr_crop/quickhull.js
function(vertex) {
      if (this.head === null) {
        this.head = vertex;
      } else {
        this.tail.next = vertex;
      }

      vertex.prev = this.tail;
      vertex.next = null; // the tail has no subsequent vertex

      this.tail = vertex;

      return this;
    }
function(vertex) {
      if (this.head === null) {
        this.head = vertex;
      } else {
        this.tail.next = vertex;
      }

      vertex.prev = this.tail;
      vertex.next = null; // the tail has no subsequent vertex

      this.tail = vertex;

      return this;
    }
Appends a vertex to the end of the linked list