fitBounds not working correctly for large bounds

[oliverheilig]

I'm experiencing issues with setting the map viewport with fitBounds when bounds is a large rectangle. I've looked into the code and it seems the fitBounds uses setView with L.latLngBounds(bounds).getCenter() as center. But this is not correct if the map uses a Mercator projection. If i want to set the map to a latitude range of (0, 85) your calculation uses 42.5 as center latitude. But in a mercator world the correct latitude is 66.5!

The correct calcuation would be:

• project the LatLng bounds on the map projection bounds
• calculate the center on the projected bounds
• re-project the center on LatLng
• use this point for setView

Don't know if this also affects other methods on the map.

[mourner]

You're absolutely right, I never thought about it this way! Thanks for the report!

[MaZderMind]

it would look like this:

    geoFitBounds: function(bbox) {
        var b = L.latLngBounds(bbox);
            pb = L.bounds(this.project(b.getSouthWest()), this.project(b.getNorthEast())),
            z = this.getBoundsZoom(b),
            c = b.getCenter(),
            pc = this.unproject(pb.getCenter());

        this.setView(pc, z);
        return this;
    },