projection.prepreclip?

[mbostock]

It’d be nice to be able to use d3.geoClipPolygon prior to rotation for clipping in geographic coordinates (as opposed to using rotated coordinates with projection.preclip, as is suitable for the outline of an interrupted projection).

[Fil]

If what we want is to clip a geojson with a polygon, this is a geometric operation that should happen on the sphere. It’s not clear to me why this would be tied to the projection.

Related:

• Easier usage with d3.geoProject? d3-geo-polygon#22 (almost a solution)
• https://observablehq.com/@d3/spherical-clipping (a use case)

[Fil]

Also that particular use case is arguably better served by planar post-clipping projection.clipExtent
https://observablehq.com/d/c613d80805786986

but of course this currently allows only rectangle extents. It would be cool to allow arbitrary geometry planar post-clipping.

[Fil]

See also d3/d3-polygon#4