title: Google Maps API V3: Snapping to nodes of another polygon
body: <p>I am drawing polygons that are adjacent and whose borders are shared. Looking at the example image below, if I were to draw a polygon for Montana, I'd like to be able to click on the nodes of the Idaho polygon for the part of the border that is the same to ensure the borders don't overlap or have holes. However, the nodes don't allow clicks directly on them, and if I make the nodes invisible then the accuracy is worsened and I'll probably end up with holes or overlaps between the two polygons.</p>
  
  <p>Is there a way to snap a drawing to a node of an existing polygon? If not, is there at least a way to make it so that I can click directly where the nodes are? I've set the polygon's properties to editable: false and clickable: false, but the boundary of the polygon (and the nodes) still disallows clicks.</p>
  
  <p>I haven't seen any documentation in the API for snapping.</p>
  
  <p><img src="https://i.stack.imgur.com/MTsme.png" alt="polygon on google maps"></p>