d3.geoFit{,Size,Extent}()

[mbostock]

It’d be nice to have a simple projection that only does scale and translate (and possibly inverts y), so that you can use path.fitExtent or path.fitSize in conjunction with pre-projected TopoJSON.

You can resize manually with d3.geoTransform, but it’s a pain to compute the scale yourself.

[mbostock]

Perhaps instead of:

var projection = d3.geoCartesian().fitSize([width, height], feature);

We could just say:

var projection = d3.geoFitSize([width, height], feature);

And similarly for d3.geoFitExtent.

[mbostock]

And maybe that would just be a convenience method for d3.geoFit:

var projection = d3.geoFit().scale(k).translate([x, y]);

[mbostock]

I think d3.geoIdentity is fine for now.

var projection = d3.geoIdentity().fitSize([width, height], feature);