Advance a point-in-circle simulation one step

next.ts

public next(): void
{
  let circ: TSMT$Circle;
  let g: PIXI.Graphics;

  // first, redraw any circles previously marked as containing the point with the default stroke color
  while (this._identifiedDO.length > 0)
  {
    g    = this._identifiedDO.pop();
    circ = this._identified.pop();

    canvasRenderCircle(g, circ, this.strokeWidth, this.strokeColor.toString());
  }

  /*
    random walk the point (realize that it could eventually 'walk' off the visible area; whether or not
    that is something that should be tested and compensated for is up to you
   */
  [this._px, this._py] = pointRandomWalk(this._px, this._py, CircleService.LOW_RADIUS, CircleService.HIGH_RADIUS);

  // draw the point and update the quadrant
  this.__drawPoint();

  this._curQuad = TSMT$getQuadrant(this._px, this._py, 0, 0, this._width, this._height);
  this.__drawQuadrants();

  // Only check circles in the quad in which the point is located
  if (this._curQuad > 0 && this._curQuad < 5)
  {
    // only update the id list if the quadrant changed
    if (this._curQuad != this._prevQuad)
    {
      this._prevQuad = this._curQuad;
      this._check    = Object.keys(this[`_quad${this._curQuad}`]);
    }

    this._check.forEach( (id: string): void =>
    {
      circ = this._circleRefs[+id];
      g    = this._circleDO[+id];
      if (TSMT$PointInCircle(this._px, this._py, circ.x, circ.y, circ.radius))
      {
        this._identified.push(circ);
        this._identifiedDO.push(g);

        g.clear();
        g.lineStyle(this.strokeWidth, '0xff0000');
        g.drawCircle(circ.x, circ.y, circ.radius);

        this.onIntersect.emit(id);
      }
    });
  }
}