docs: function pnpoly (x,y,coords) {
      var vert = [ [0,0] ]
  
      for (var i = 0; i < coords.length; i++) {
        for (var j = 0; j < coords[i].length; j++) {
          vert.push(coords[i][j])
        }
        vert.push([0,0])
      }
  
      var inside = false
      for (var i = 0, j = vert.length - 1; i < vert.length; j = i++) {
        if (((vert[i][0] > y) != (vert[j][0] > y)) && (x < (vert[j][1] - vert[i][1]) * (y - vert[i][0]) / (vert[j][0] - vert[i][0]) + vert[i][1])) inside = !inside
      }
  
      return inside
    }