title: D3 + Leaflet, only draw if visible (big data vis)
body: <p>In order to have a reasonable performance with a lot of svg paths, svg text and svg textpath elements on a leaflet map, I wonder how D3 handles elements which are currently not on screen.</p>
  
  <p>So for example when I zoom in to an area such as Washington State, 99.9% of the world is not shown - is D3 default behaviour to draw all the other elements regardless? </p>
  
  <p>I am basing my project on Mike Bostocks <a href="http://bost.ocks.org/mike/leaflet/">d3 + leaflet example</a>. There are no viewports/ viewbox attributes used - is it done somewhere else? Thanks for your input.</p>