selectPt (pt, ctrlNum) {
    this.clearSelection()
    if (!pt) {
      this.eachSeg(function (i) {
        // 'this' is the segment here.
        if (this.prev) {
          pt = i
        }
      })
    }
    this.addPtsToSelection(pt)
    if (ctrlNum) {
      this.dragctrl = ctrlNum

      if (svgCanvas.getLinkControlPts()) {
        this.segs[pt].setLinked(ctrlNum)
      }
    }
  }
@param {Integer} pt
@param {Integer} ctrlNum
@returns {void}