Render ref of minor roads more than once

[jeisenbe]

Changes proposed in this pull request:

• Modify the code for display of the ref on unclassified and residential highways:
• Add text-placement: line for ref of minor roads so that the ref will display more than once on a way
• Remove deprecated text-min-distance, replace with text-repeat-distance instead.

Explanation

• Currently the reference number of an unclassified or residential highway (aka "minor highway") is only displayed once at the center of the OSM way, because text-placement has not been set to line. This PR will allow ref numbers to display every 760 pixels approximately, as intended.
• Also, text-min-distance was used, but this has been deprecated in the CartoCSS documentation. This has been changed to use the new recommended option, text-repeat-distance, which is already used for name label rendering in most other parts of roads.mss

Test renderings:

Before

After

[jeisenbe]

test.osm.xml.zip
Updated file for testing

[kocio-pl]

Another thing worth updating should be probably moving rendering them from z13+ to z15+, since they can clutter space when residential details are still not really visible, especially when refs get longer for lower highway classes (as it is in Poland for example):

https://www.openstreetmap.org/#map=13/52.2739/21.0992

[jeisenbe]

Residential and Unclassified refs render at z15 and higher, but without a shield. I think the white roads with shields in that screenshot are tertiary. I plan to make more extensive improvements, later, but I tried to keep this PR simple.

…

On Thu, Jan 10, 2019 at 12:30 AM kocio-pl wrote: Another thing worth updating should be probably moving rendering them from z13+ to z15+, since they can clutter space when residential details are still not really visible, especially when refs get longer for lower highway classes (as it is in Poland for example): https://www.openstreetmap.org/#map=13/52.2739/21.0992

[kocio-pl]

Thanks, so it looks like another issue. However it would be good to make real tests of residential refs too, so we can see if it could be improved too.

[jeisenbe]

It's tricky to find places where the OSM way is long enough that the ref repeats due to these changes, rather than a new way being started, but there are quite a number of unclassified and even residential roads with a ref in Northern Ireland:

z16 Samsonagh Road (highway=unclassified)
https://www.openstreetmap.org/#map=16/54.3505/-7.7417
Current master

• Ref renders once, and does not orient to way
  

After changes

• Renders twice (in this 1000 x 500 pixel image), about half as often as the name
  

highway=unclassified B523, in Londonderry/Derry

• There are three different ways with different names
  https://www.openstreetmap.org/#map=15/54.9924/-7.3110
  z15 Current
• Only one of the 3 refs renders, due to collisions
  

z15 After

z19 Current

• at this zoom level we can see just one of the ways
  

After

[kocio-pl]

Does this code change rendering ref orientation from "landscape" to "along the road"? It's not clear for me from the description, but it looks like this in latest examples.

[Adamant36]

I take it its from adding text-placement: line; Its interesting that would cause it to also display multiple times.

[kocio-pl]

I guess it's better solution - refs are less visible that way and for such small roads it makes sense to not stand out too much.

[kocio-pl]

Example I have found:

https://www.openstreetmap.org/#map=17/52.25744/21.03584

Before

After

[jeisenbe]

I’ve noticed that refs are rendered before names (both now and with this PR). It might be better to change this for highway=residential and highway=classified, so that the name is rendered first and the ref is only added if there is room. For major highways it is probably correct to prefer the ref to the name if there is not space for both (and this is less likely to happen for long-distance roads), but for small residential highways, I would rather see the name of there is only room for one or the other. But that can be decided in another PR.

…

On Thu, Jan 17, 2019 at 11:38 AM kocio-pl ***@***.***> wrote: Example I have found: https://www.openstreetmap.org/#map=17/52.25744/21.03584 Before [image: o5y2rqix] <https://user-images.githubusercontent.com/5439713/51291732-69499000-1a08-11e9-8af4-9d49182d7c5c.png> After [image: _gnot3cc] <https://user-images.githubusercontent.com/5439713/51291736-6cdd1700-1a08-11e9-82a3-734fe0bed047.png> — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#3627 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AoxshLSkuvG4rJfDLgob1Qy_WQdr_PU-ks5vD-IggaJpZM4Z3WE2> .

[kocio-pl]

Thanks, I like that refs are less intrusive going along the line. However further tuning is also possible.

[jeisenbe]

Thanks! Now I can test adding refs for highway=track (eg US Forest service roads, which are often unnamed)