This function returns a bounding box for a given feature.
````javascript
var METERS_PER_LEVEL = 3;
var DEFAULT_HEIGHT = 10;
function getBoundingBox(osmb, feature) {
var bounds = {
left: Infinity,
top: Infinity,
right: -Infinity,
bottom: -Infinity
};
var pos;
var height = feature.properties.height ||
(feature.properties.levels ? feature.properties.levels*METERS_PER_LEVEL : DEFAULT_HEIGHT);
for (var coord of feature.geometry.coordinates[0]) {
for (var lat=0; lat <= height; lat += height) {
pos = osmb.project(coord[1], coord[0], lat);
if (pos.x < bounds.left) {
bounds.left = pos.x;
} else if (pos.x > bounds.right) {
bounds.right = pos.x;
}
if (pos.y < bounds.top) {
bounds.top = pos.y;
} else if (pos.y > bounds.bottom) {
bounds.bottom = pos.y;
}
}
}
return bounds;
}
````