Render some amenities linear ways as icons

[Tomasz-W]

There is almost 4k of artworks drew as lines:
https://taginfo.openstreetmap.org/tags/tourism=artwork#overview

Those are mostly graffities and murals painted on the walls. Some examples below:
https://www.openstreetmap.org/way/464155454
https://www.openstreetmap.org/way/504508965
https://www.openstreetmap.org/way/370396569

If we render artworks drew as nodes and areas, we should render tourism=artwork ways too, I think.
For me, the best option would be to render an artwork icon in the middle of these lines.

[imagico]

For info: of the ~4k ways with tourism=artwork more than 3k are polygons which are already rendered with an icon.

The question to ask is probably more general: in what cases should we also allow linear ways in amenity-points?

[Tomasz-W]

@imagico My lists of:

linear amenities which should be rendered as icons:

• tourism=artwork
• amenity=clock
• amenity=recycling

linear amenities, which should be rendered as icons or icons with lines:

• amenity=bicycle_parking (grey line with current icon in the middle)
• amenity=bicycle_rental (grey line with current icon in the middle)

linear amenities, which should be rendered as lines:

• amenity=bench (brown line, add line rendering for benches  #1890)

other:

• leisure=pitch + sport=soccer (there are often wild pitches without borders on the grass, mapped as a line between goal gates - it could be rendered as 2 goal gates on the ends of this line)

[imagico]

None of these has documentation on the wiki how to map as linear ways, for most of them the documentation says not to use on linear ways.

Rendering as lines is usually out of the questions because of possible confusion with other line features (highways, railways, barriers etc.).

[Tomasz-W]

for most of them the documentation says not to use on linear ways.

Due to OSM Wiki, it's true just for clocks , bicycle rentals and recycling, so it's not "most of them", but we can forget about these 3. All the rest (artworks, bicycle parkings, benches and pitches ) could be mapped as linear ways, so we should discuss them, at least as icons.

[HolgerJeromin]

If a polygon of an amenity has (also) an icon I propose to render only the icon on lines. Least possible confusion, most gain of shown data.

[Tomasz-W]

The question to ask is probably more general: in what cases should we also allow linear ways in amenity-points?

Due to @imagico comment, I propose to discuss icon-rendering of these elements (mapped as linear ways):

• tourism=artwork
• amenity=bicycle_parking
• amenity=bench
• leisure=pitch

[HolgerJeromin]

Ref for bench #1890
Ref for attraction / barrier #1824

[Tomasz-W]

Related #844

[kocio-pl]

I guess at least tourism=artwork could be added, because wiki treats such nodes, ways and areas the same. I haven't checked other tags.

[Tomasz-W]

• tourism=artwork may be a mural, mapped as a line attached to a building outline
  

• amenity=bicycle_parking/ rental are sometimes mapped as linear ways, because they are often a line of standing bikes
  
  

• amenity=bench - there are examples of long benches which is easier to map as lines than nodes
  
  

[matkoniecz]

For info: of the ~4k ways with tourism=artwork more than 3k are polygons which are already rendered with an icon.

Do you know how to get this kind of statistics? I see nothing on taginfo and hopefully somebody already shared tool to do that.

For tourism=artwork tagging on lines makes sense and rendering them makes sense. For others I have some doubts but for start I want to check how these are tagged.

[joshinils]

according to taginfo, currently these many ways are not shown in any way:
54 816 amenity=bicycle_parking
19 556 amenity=bench
9 427 tourism=artwork

these are potential tagging mistakes as ways, taginfo does not differentiate areas from lines:
21 933 amenity=recycling
1 540 amenity=bicycle_rental
351 amenity=clock

as for leisure=pitch:
50 629 leisure=pitch nodes are not rendered.
leisure=pitch may not be a way (but an area), but a node is not rendered, example.

[imagico]

Keep in mind taginfo lists the number of ways, not the number of linear ways. To find out the number of linear ways with a certain tag you need to interpret the geometries and the presence of the area=yes/no tag.

[matkoniecz]

In my opinion linear ways with amenity=bicycle_parking should remain not rendered, mapping them as area is always better and in case where mapping them as way could be done then mapping them as area was also feasible (except rare exceptions)

I partially implemented "Add rendering for amenity=bicycle_parking, change rendering for amenity=parking"
#1364 - and not rendering ways was deliberate

[AndrewKvalheim]

Example of a sculpture that I’ve mapped as a linear way:

[1ec5]

I’ve updated the documentation for artwork_type=mural to explicitly allow murals to be mapped as unclosed ways for consistency with several related tags. Currently, unclosed ways outnumber areas by more than 3 to 1.

[imagico]

Yes, tourism=artwork is probably relatively speaking the feature most widely mapped with linear ways that we render with a point symbol on nodes and polygons and that would therefore be good to extend to allow linear ways in amenity-points.

Note since many of these will be two node ways good design will call for using ST_LineInterpolatePoint(way, 0.5) rather than ST_PointOnSurface(way).

[richlv]

Given the general consensus on tourism=artwork, would it make sense to split it out from this issue?
Mapped a couple of murals as ways, considering to revert back to nodes to tag for the renderer ;)

[jidanni]

I added a note to https://wiki.openstreetmap.org/wiki/Tag:amenity%3Dbench#Rendering .

[okainov]

Any updates on this one? What is blocking to improve the render style here?

[imagico]

For tourism=artwork we have agreement that this would be desirable to render on linear ways. For some of the other suggestions there is no consensus so far.

The main obstacle is someone would need to go ahead implementing it - and that is difficult in light of #3880. There are essentially three options:

• actually solving Symbol and label prioritization is not in sync with the starting zoom levels #3880 with support for linear geometries next to nodes and polygons.
• integrating lines (currently separate in the amenity-line layer - essentially just ford and slipway, as well as other stuff that does not belong there anyway - see Linear features inappropriately rendered in amenity-line layer #4104, leisure=track gets rendered too late in the layer stack #4726) into the amenity-points layer - that does not solve Symbol and label prioritization is not in sync with the starting zoom levels #3880, but is a cleaner approach - would be wasted work though if Symbol and label prioritization is not in sync with the starting zoom levels #3880 is to be addressed at some point.
• lazily adding it to amenity-line - would just pile onto existing problems so not likely seen very favorably by anyone.

Bottom line: what is blocking this is our over-extension in technical debt, which makes it hard to find the legroom for meaningful design changes.