Grid overlays using different projections, e.g. UTM

hholzgra / ocitysmap

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Grid overlays using different projections, e.g. UTM #23

Open hholzgra opened 5 years ago

hholzgra commented 5 years ago

Right now the rendered index grid is just using arbitrary lines that are parallel to, but not especially bound to, sperical mercator (EPSG:3857) coordinate lines.

It should also be possible to have grids aligned to other spatial reference systems, e.g. WSG 84 latitude / longitude lines, or the UTM zone kilometer line grid.

hholzgra commented 5 years ago

Experimental support for an extra UTM grid overlay is now available, with some minor issues needing fixing:

[ ] improve vertical label placement
[ ] UTM grid lines aren't really straight in spherical mercator projection (but at the small bounding box sizes we currently support that should be an acceptable apporximation for now)
[ ] find out why labels only show in vector formats (dpi conversion problem?)
[ ] add special treatment for the Sweden/Norway zones 31V / 32V
[ ] include polar region zones A,B,Y,Z (low priority as they are mostly outside the bounds of spherical mercator, which we use for rendering so far, anyway)

Also still a TODO as the current implementation deals with UTM only:

[ ] Support grid for other spatial reference systems than UTM; e.g. WSG84 and GDA94 lat/lon grids

openbankingproject-ch commented 5 years ago

If possible, there is a Swiss Coord Grid:

https://de.m.wikipedia.org/wiki/Schweizer_Landeskoordinaten

With an approximation WGS84 to CH1903 described in the article 😊

hholzgra commented 5 years ago

If possible, there is a Swiss Coord Grid:

that would be EPSG:21781?

chatelao commented 5 years ago

Das 600'000 / 200'000 Zentrum der Welt :-)

jasonblewis commented 4 years ago

The UTM feature works well now on Maposmatic however it doesn't seem to render the easting numbers on the map. see https://maposmatic.osm-baustelle.de/results//131025_2020-09-25_03-38_test-utm-grid.pdf for example

jasonblewis commented 2 years ago

The UTM feature works well now on Maposmatic however it doesn't seem to render the easting numbers on the map. see https://maposmatic.osm-baustelle.de/results//131025_2020-09-25_03-38_test-utm-grid.pdf for example

As far as i can tell, the code is there to render the Eastings, but it doesn't seem to work (at least not on the maposmatic website)

https://github.com/hholzgra/ocitysmap/blob/40e731fb2f8a6da2d0a13f5e32f6b13fbea355cf/ocitysmap/layoutlib/render_plugins/utm_grid/__init__.py#L171