Military Symbols in narratives

[MiklerGM]

Expand narratives by adding new layer of data with additional information about troops and their movements.

Initial proposal:

• Expeditions and paths
• Arrows for armies movements
• Front lines

Additional wish list (feel free to add more in comments)

• Units icons
• HQ position
• ...

[MiklerGM]

For army movements we could do the GeoJSON features in shape of arrow with filled with color

For expeditions in can be the line or multiline with dashed-stroke. Probably with text along the path.

I would propose to add field to store GeoJSON with styled elements,

[quorth0n]

So, for this ticket we should add blank/null columns in the narration table for:

• army movements
• expeditions
• HQ/units

and anything else?

[MiklerGM]

I think everything can be stored in a single GeoJSON field with multiple classes inside.

[quorth0n]

Okay, let's go with a GeometryCollection field then

[MiklerGM]

Are you sure we can add any parameters to GeometryCollection?
Probably not, because it's PostGis, and to form proper GeoJSON you are usually using all columns from the table, not only the geometry one.
https://postgis.net/workshops/postgis-intro/geometries.html

[MiklerGM]

Or we can add a table for One to Many relations. From Narration to Symbols.

In this case, columns that needed are like
narration_id*, geometry_collection*, sprite, type*, label*, fill_color, stroke_color, ..., options

If you want to do in RDB way we need to describe a style for every feature layer before we got further.

[quorth0n]

I was thinking about an o2m relation, that might be a cleaner option. Or, maybe we could consider storing the collections in a JSONField, and validate it through a DRF serializer.

The simplestyle spec outlines these parameters for geojson styles:

"stroke": "#555555",
"stroke-opacity": 1.0,
"stroke-width": 2,
"fill": "#555555",
"fill-opacity": 0.5

[MiklerGM]

We also need type* and sprite options.

• type or class is needed for me to determine which style to apply. I can use one MVT or GeoJSON as a source for multiple layers with different decorations.
• Sprite-name for special icons in our sprite files. (optional)
  As Abraxis mentioned on discord, we probably need some fancy lines and it can be done by using paint-line-pattern and sprite images
  

[quorth0n]

We have agreed on Slack to store all extra geometries in a JSONField containing a FeatureCollection. This is to ensure geometries' properties are preserved. Serialization in the API should confirm geometries are stored in this new field.

[quorth0n]

Maybe it would make sense to store some symbols in the global narrative? For example front lines, I can imagine this being of use to multiple narratives. Then we can have a Narration > Symbol m2m relationship in the db.

[MiklerGM]

adsfgsadgWDEWGGWGw.zip
Example shapefile for testing testing additional borders in narratives