covered tagging/rendering for railway=platform

[sun-geo]

Expected behavior

Not sure yet
a) change the rendering colour of objects with tag combination covered=yes + railway=platform to a average colour between current colour of railway=platform and current colour of covered=yes + railway=platform

b) give an idea how to tag a platform which is partly covered. Maybe assumed from building and building:part tagging scheme (even I don't like this scheme) like railway:part and so on, or using a relation?

c) ...?

Actual behavior

Using covered=yes for an partly covered platform shows no rendering at all

Links and screenshots illustrating the problem

Partly uncovered but not rendered at all:
https://www.openstreetmap.org/#map=18/51.42328/12.22250
https://www.openstreetmap.org/way/103695160#map=18/51.42328/12.22344
As contrast a example of a not covered and rendered platform:
https://www.openstreetmap.org/relation/5755375

[jeisenbe]

Welcome, @sun-geo!

The current rendering hides platforms which are tagged with "covered=yes", because this normally means that the platform is underneath a roof, and the roof will be rendered instead.

Generally the tag covered=yes is only used for platforms which are completely covered, though it could be used only on the section of the platform which is under the roof, if the platform has an uncovered section.

In these cases it might be confusing to show the platform, because it then appears to be rendered above the building or roof. Using transparence or mixing the colors would also cause similar problems, as well as being more difficult to distinguish from the large number of other features which are rendered in this style.

(For detailed questions about how something should or could be tagged, please discuss at https://help.openstreetmap.org or the Tagging mailing list or another forum, if the Openstreetmap wiki pages are not clear. We try not to getting into discussions of how things ought to be tagged here.)

[jeisenbe]

The current rendering, which does not show platforms with tunnel=yes, location=underground or covered=yes, began with PR #3162 - this PR was merged without a review or comments by other maintainers, so it's not clear if there was consensus in favor of this change or not.

See also the discussion in the previous issues #2037 and #2504, and related issues #3336 and #3421 - the last requests rendering platforms with covered=yes again.

[jeisenbe]

Anyone have comments about this issue or about #3162 and #3421 in general?

[jragusa]

Covered platform should be rendered regarding #2475

A very pale colour could be considered for underground platform as in the new version of Apple Map. See these screenshots for example (pink pale stuff): https://twitter.com/SongPKM/status/1229768596617908225?s=20

[sun-geo]

@jeisenbe Thanks for your comments. In # 3421 message i found a temporary solution by using covered=partial.

But maybe it could be interesting to use a mixed colour for railway=platform which are fully covered (covered=yes)

Btw, randomly i saw it seems that highway=platform +covered=yes is currently rendered, see example object:
https://www.openstreetmap.org/way/671588469/history (v5)
So what is the difference to not render railway=platform + covered=yes but render highway=platform + covered=yes ?

[jeisenbe]

So what is the difference to not render railway=platform + covered=yes but render highway=platform + covered=yes ?

I agree this does not make sense. It would be easiest to fix by restoring the rendering of railway=platform + covered=yes.

Would you be interested in submitting a PR to make that change?

[sun-geo]

Would you be interested in submitting a PR to make that change?

I would, but I never did a change of any Github project source code. Seems I'm still good for reporting so far. I would have to fork the entire project first before editing code lines?

[jeisenbe]

Forking the project is easy. The download is only a couple dozen megabytes. However, setting up Docker to do test renderings is a little more work, and nearly 1 gigabyte of downloads, mainly shapefiles which are needed to render the oceans and seas.

But if you are interested in become a contributor here (and perhaps at other open source projects in the future), the steps are described here:

#3869 (comment)

And a more detailed explanation is here, which will be helpful if you have not used git or docker or anything like that before: #3782 (comment)