code: function onePointPartial(
    d, axis, visit, flip,
    redStart, redEnd, red, redIndex,
    blueOffset, blue, blueId) {
  
    var elemSize = 2 * d
    var bluePtr  = blueOffset * elemSize
    var blueX    = blue[bluePtr + axis]
  
  red_loop:
    for(var i=redStart, redPtr=redStart*elemSize; i<redEnd; ++i, redPtr+=elemSize) {
      var r0 = red[redPtr+axis]
      var r1 = red[redPtr+axis+d]
      if(blueX < r0 || r1 < blueX) {
        continue
      }
      if(flip && blueX === r0) {
        continue
      }
      var redId = redIndex[i]
      for(var j=axis+1; j<d; ++j) {
        var r0 = red[redPtr+j]
        var r1 = red[redPtr+j+d]
        var b0 = blue[bluePtr+j]
        var b1 = blue[bluePtr+j+d]
        if(r1 < b0 || b1 < r0) {
          continue red_loop
        }
      }
      var retval
      if(flip) {
        retval = visit(blueId, redId)
      } else {
        retval = visit(redId, blueId)
      }
      if(retval !== void 0) {
        return retval
      }
    }
  }
docs: Special case:  Intersect single point with list of intervals