title: How to trace a point in jsxgraph when renderer = canvas
body: <p>I am trying to donwload a video from a canvas containing a jsxgraph sketch.
  I need to set</p>
  <p>JXG.Options.board.renderer = 'canvas';</p>
  <p>I discovered that when the renderer is canvas, the trace of a point is not drawn, for some reason.</p>
  <p>Is there a way to draw the trace of a point with renderer = canvas?</p>
  <p>Thanks!</p>