Add support for worldview / point of view alt geoms

[nvkelso]

WOF sister issue to nvkelso/natural-earth-vector#301 and PR nvkelso/natural-earth-vector#446.

I've been editing Natural Earth the last year to add support for a wide range of "points of view" (sometimes called worldview). This issue tracks that work, and is related to nvkelso/natural-earth-vector#108 – this is issue is more general.

More info in the two related Tilezen release notes (summarized below in this issue description):

• https://github.com/tilezen/vector-datasource/releases/tag/v1.8.0
• https://github.com/tilezen/vector-datasource/releases/tag/v1.7.0

I've also been updating OpenStreetMap so it can be used in concert with Natural Earth to show disputed ares:

• https://www.openstreetmap.org/user/nvk/diary/47890
• https://www.openstreetmap.org/user/nvk/diary/390496

There's even a demo map, here showing Kashmir (use the “POV” point-of-view menu in the upper-right corner to toggle the different visual treatments):

• http://tangrams.github.io/bubble-wrap/#5/33.523/-282.281

From the Tilezen release notes:

v1.8:

• boundaries: Add more kind:* point-of-view (POV) from Natural Earth for low zooms for disputed boundary lines, expanding on the v1.7 effort to also include region boundary disputes. (Issue #1840)
  • 
  • To handle disagreements about the location of borders, the kind may be prefixed with unrecognized_, e.g: unrecognized_country (was unrecognized in v1.7), unrecognized_macroregion, unrecognized_region, unrecognized_county for differing viewpoints (see kind:xx below).
  • kind:xx: alternate kind according to the viewpoint of country code xx. If you want to show features according to a particular viewpoint, then use kind:xx if it exists and fall back to kind if not. The range of values is the same as for kind. Note that the viewpoints are either lower-case ISO 3166-1 alpha-2 codes or the pseudo-code iso.

v1.7:

• boundaries: Adds support for alternate points of view in boundaries layer with kind:* properties (like kind:iso). Currently this is only for zooms 5, 6 and 7 from Natural Earth. We plan to add more lower zoom data from Natural Earth, and high-zoom data from OpenStreetMap in the next release. (Issue #1552) The following country and international organizations worldviews are supported:
  • Argentina (ar), Bangladesh (bd), Brazil (br), China (cn), Egypt (eg), France (fr), Germany (de), Greece (gr), India (in), Indonesia (id), Israel (il), Italy (it), Japan (jp), Morocco (ma), Nepal (np), Netherlands (nl), Pakistan (pk), Palestine (ps), Poland (pl), Portugal (pt), Russia (ru), Saudi Arabia (sa), South Korea (ko), Spain (es), Sweden (se), Taiwan (tw), Turkey (tr), United Kingdom (gb), United States (us), Vietnam (vn), ISO (iso)
• boundaries: Add new disputed boundary lines with kind values of disputed_breakaway, disputed_claim, disputed_elusive, disputed_reference_line, from Natural Earth at low zooms, for alternate points of view (Issue #1552)

[nvkelso]

• Update disputed areas
• Add country alternate geometries for POV for the "home country" and the "opinion" countries.

[nvkelso]

Here's pre-release v5 Natural Earth:

• ne_disputed_v5-pre.zip

[thisisaaronland]

This smells like a blog post.

[stepps00]

@nvkelso I'm wrapping up the prep work for this issue and found nine disputed records in Who's On First that are not in the NaturalEarth files you linked to above.

Here's a shapefile of the diff (places in WOF, not in NE): disputed_diff.zip

[nvkelso]

Here's a shapefile from Natural Earth v5-pre showing the defacto country boundaries. Please review WOF to make sure the default geom reflects defacto in the same way so we can cookie-cutter the disputed in seamlessly for the different point-of-view geoms.

• ne_10m_admin_0_countries_v5-pre.zip

[stepps00]

As I review all of the disputed places in both Who's On First and NaturalEarth, I'm noticing a handful of discrepancies. I'm tracking a list of those issues in this comment, which will be helpful in updating the NaturalEarth files provided above.

[stepps00]

Work on the disputed placetype is nearly complete for this issue and country records are currently being updated in branches in all ~260 per-country repos. A quick summary of the work that has been done so far:

• WOF has gained a handful of new disputed records, along with new NE properties and concordances at this placetype
• country boundaries have been aligned to one another to fix large gaps/overlaps
• All disputed records have been aligned with/snapped to country boundaries to again fix large gaps/overlaps

Now that all records have been created and align, we can start creating the building blocks for these "point of view" geometries. To do this, we'll need to create "core" geometries for countries that are essentially the area of the country that all countries agree on (default country shape minus any disputed place that falls within it). The "core" of India, for example, would look something like this (doesn't include any disputed areas):

To import these, we'll need to figure out a naming convention for these alt files.. I'm thinking either:

• {id}-alt-{source}-core.geojson or
• {id}-alt-{source}-pointofview.geojsonor
• {id}-alt-{source}-interior.geojson

Thoughts @nvkelso @thisisaaronland ?

[stepps00]

I've added these new alt features with the {id}-alt-{source}-interior.geojson convention for now, but can update filenames/prop values before merge if needed.

[stepps00]

Update: Much of this work has been merged in various per-country repos. There is additional work needed to create new point-of-view geometries for each country, but the "building blocks" for this work are now available in Who's On First.

Taking India as an example, the "default" geometry now contains the area that all countries agree is "India" plus the disputed areas that are controlled by India. In addition, Who's On First now maintains an "interior" alt geometry of just the portion of "India" that all countries agree is India. And, in the admin-xx repo, all of the disputed records have been updated with new geometries.

I'd like to keep this issue open until all of the point-of-view geometries are complete.

tldr: We've merged improvements to disputed and country records and have the necessary "building blocks" for future point-of-view geometries.