An RTree index for levelup, usage
npm install --save level-tree
var level = ;var sublevel = ;var levelTree = ;var db = ;// load in some geojsondb;db;// nonstrict querydb;db;
adds a treeQuery method, which either takes a bbox and returns a stream, or a bbox and a callback.
you can also pass false as the second argument to treeQuery, this turns off checks to make sure that the bbox you query actually intersects the feature that is returned and not just it's bbox. These checks can be very expensive especially for polygons so turning them off when you have mostly rectangular features or when you just don't care will speed things up.