��.

- I started to do a KML Reader [2] because besides GeoJSON that is a widely used format. And this can be used in Google Earth which is the best free Geo editor that I know.

<Slighty OT>, What do you think of Mapbox ? I try to de-google as much as I can :)

Just to contextualize:

my mid-term goal is to have a mean to build simple �� digital twin �� that are integrated in Mapbox/Leaflet/OSM, using a priori three.js.

Spatiality is a bit tricky as not default in three.js and the three.js plugin of Mapbox is a bit limited as far a I understand it right now (I��m trying stuff on that especially with the reytracing possibility so as to augment 3D models).

There is a lib called maptalks where I put the demo here.

http://o0o.io/three/maptalks/

https://maptalks.org => https://github.com/maptalks/maptalks.js

This is the building block for interactive geospatial 3D model I experiment with the help of students.

</sligthy OT>

The "digital twin �� might be OT from the GIS related effort that is discussed here but I find it very related.

If you want a digital twin, it has to be geolocalized. Tell me if other have such kind of interest.

- As KML and GeoJSON use a similar model for representing geo shapes and POIs I started to factor out that into the Geography package [3].

Cool :)

- At the moment in the Geography package there is only a 2D point class GGPoint to have something to hold geo coordinates (there is also a 3D variant). In the past I used Point as the class for these things but came to the conclusion that there is a distinction between a point and geo point when it comes to things like distance etc. So it is better to have them separate. Into this model I want to morph the classes for LineStrings, LinearRings, Polygons etc. from GeoJSON and KML to have a common foundation for the basic geo shapes lines, multi-lines, closed multi-lines (=polygons) etc.

- As GGPoint is distinct to Point this is just the context where you use it. The Geography package should be a companion to the Geometry package [4] which I forked from TelescopeSt to make it a community package which is good for this plan but also for roassal which uses the Geometry package. To me the geoX model should be switched between Geometry and Geography regarding to the context you want to work in being planar or spherical.

- In my tools that I build this model classes have also gt-inspector extension so the shapes can be viewed just by inspecting them. I'm fighting with the roassal team to make it possible for geo coordinates which conflicts at the moment with their defined thresholds. But with the factoring the shapes into Geography I will move those extension to the Geography package as well

- I also implemented a polygon intersection algorithm (Weiler and Atherton) which I will then incorporate in any of the GeoX packages

Great :)

So these are the pieces that are there. The plan in text is:

- Have a incarnation of a "point" and make that switch context from planar to spherical
- Use planar treatment with the Geometry package (intersections etc.)
- Use this "point" to generate shapes either geometric or geographic
- Be able to read and write in common formats like GeoJSON and KML
- Make shapes be composable and inspectable with the existing tools

I think GIS needs more but what we have is more than just a start. The projection system with the current code is WGS84 for sure. If there are other needs we need to think about this early.

I think the projection system is one of the hard difficulties with GIS but also important. It��s out of my knowledge but probably people like Etienne can give their impression on that ?

Cheers and thanks again for all the efforts,

C��drick

For everything else I'm open ears. Even for the idea of having a pharo-gis github project to collect those things to a common place. But I like to discuss GIS and not if it makes sense to have a all of these github repos.

Norbert

[1] https://github.com/zweidenker/GeoJSON
[2] https://github.com/zweidenker/KML
[3] https://github.com/zweidenker/Geography
[4] https://github.com/pharo-contributions/Geometry

Am 04.06.2020 um 05:31 schrieb Serge Stinckwich <serge.stinckwich@gmail.com>: