[WIP] Borders rework

[kocio-pl]

This is a technical replacement for #3553, it should also make easier to catch up with the current state of proposed changes and includes changes from #3652.

Fixes #3489.
Closes #3526.
Related to #621 and #3102.
Related to #3563

Changes proposed in this pull request:

• use color palette from much darker for level 2 (#ac46ac +75% of grey = #6b516b) to the current #ac46ac for levels 9+10 (using @vholten patches)
• render country names in bold
• render admin names along the lines with medium color from the palette (level 5 - #8c4c8c)

I believe this is minimal set of changes to make sense. Further ideas for border improvements dropped from this PR:

• moving state labels into medium font to make them more distinct
• inserting level 5 pattern (-...-...), which in turn gives us possibility to use dots (maybe for example with some spacing, like: ... ... ...) to render admin levels 11 and 12

Names rendering

Countries and states - basically the same as in previous PR

All labels on lines (z16+) - this shade of violet is less magenta, but still is recognizable and different from other violet and blue objects:

Before/After https://www.openstreetmap.org/#map=17/52.32949/20.92530

Borders rendering

level 2, 4 and 6 - https://www.openstreetmap.org/#map=11/54.3842/19.7208

level 8 and 9 - https://www.openstreetmap.org/#map=19/51.63551/20.94475

[imagico]

This is not a convincing idea in my opinion.

The low admin level colors are not good to distinguish from various gray features, in particular railway lines. The high admin level colors obviously maintain all of the problems we currently have with the boundary color, in particular the disadvantageous color mixing on various backgrounds and the elephant in the room problem w.r.t. other color choices.

Using several different colors for different types of boundaries would be highly confusing for map users because they cannot intuitively recognize different boundary types as the same class of feature and it blocks a huge area of real estate in color space.

I will not block this change because of this but i want to make clear that this would not be destined to re-establish consensus on design questions here.

[jeisenbe]

Perhaps it would be better if all of the admin levels had the same color at each zoom level, but the color could transition from gray at z1-z4 to the current color at z10.

it blocks a huge area of real estate in color space.

This would be less of a problem if the color changes were limited to z5 to z10, where we should be simplifying the number of colors used for landcover, and fewer linear features are shown, and no icons. But it would still interfere with changing the motorway color, I’m afraid.

…

On Sun, Feb 3, 2019 at 8:48 PM Christoph Hormann ***@***.***> wrote: This is not a convincing idea in my opinion. The low admin level colors are not good to distinguish from various gray features, in particular railway lines. The high admin level colors obviously maintain all of the problems we currently have with the boundary color, in particular the disadvantageous color mixing on various backgrounds and the *elephant in the room* problem w.r.t. other color choices. Using several different colors for different types of boundaries would be highly confusing for mappers because they cannot intuitively recognize different boundary types as the same class of feature and it blocks a huge area of real estate in color space. I will not block this change because of this but i want to make clear that this would not be destined to re-establish consensus on design questions here. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#3666 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AoxshFufEd8hCKPUBcnBn6QH_B3bpTwgks5vJsyUgaJpZM4af9St> .

[kocio-pl]

Perhaps it would be better if all of the admin levels had the same color at each zoom level, but the color could transition from gray at z1-z4 to the current color at z10.

That sounds sane for me. Could you prepare your independent proof of concept code for it? I would like to test it then.

This would be less of a problem if the color changes were limited to z5 to z10, where we should be simplifying the number of colors used for landcover, and fewer linear features are shown, and no icons.

👍

Yes, I also think the biggest problem is low zoom. On the high zoom the bright magenta labels are the only thing that really troubles me, but that could be easily fixed without touching anything else.

The high admin level colors obviously maintain all of the problems we currently have with the boundary color, in particular the disadvantageous color mixing on various backgrounds and the elephant in the room problem w.r.t. other color choices.

Could we just switch off color mixing for borders? I don''t see where it hurts on the map (1-3 examples please?), but if that could help without creating other problems, maybe it would be sufficient solution.

If you have some other problems that should be solved immediately, please enlist them - with possible solutions, if possible.

I will not block this change because of this but i want to make clear that this would not be destined to re-establish consensus on design questions here.

I don't understand what do you mean here and the literal meaning makes little sense (it was not destined nor against many goals, also consensus was just persons agreeing with each other and the developers are now more diverse), but if this is not necessary here, I would be happy to discuss it in a separate ticket, please.

[imagico]

Could we just switch off color mixing for borders?

Color mixing is the result of using transparency for borders. Some other map styles use opaque boundary line signatures but that is not necessarily easier to work with overall.

If you have some other problems that should be solved immediately, please enlist them

That the line simplification on boundary polygons does not work has already been mentioned back when @nebulon42 first tried this (#907). Apart from the color that is the most serious issue at the moment.

I don't understand what do you mean here and the literal meaning makes little sense

I meant you can consider this a non-review as per #2436 (comment) - meaning if other maintainers find this beneficial i will not object. But i don't see the vision behind this, i don't see a path design wise where to go from there so i think it does not really help regarding building consensus in terms of #2436 (comment).

[kocio-pl]

Color mixing is the result of using transparency for borders. Some other map styles use opaque boundary line signatures but that is not necessarily easier to work with overall.

What solution would you suggest?

But i don't see the vision behind this

I don't agree that such general plan is needed or useful, but I guess vision belongs to #1975 anyway, even if you see it related to many individual issues.

[jeisenbe]

i don't see the vision behind this

I think the plan was to change the border color, so that we could consider using a different hue for motorways and shift the other road colors one level lower, so that highway=tertiary would be yellow instead of white.

The main problem would be with the admin level 2 and 4 borders, which might look similar to motorways if the motorway color was changed to purple.

Also, some people dislike the appearance of violet borders at low zoom levels where there are few or no other linear features on the map. Changing to a weaker color would make the map more pleasant at z1 to z7.

I had hoped that we could try the green border color from the German style and alt-colors style, but I think this was considered too similar to the protected_area boundary color. Perhaps if transparence were removed this could be reconsidered?

[kocio-pl]

Green is generally related to natural things, so I doubt that it fits the border rendering, it does not make sense for me as an idea, but the most important is to test different solutions to know for sure.

[jeisenbe]

I've created a new branch jeisenbe:borders-rework at https://github.com/jeisenbe/openstreetmap-carto/tree/borders-rework

This adds the different color borders lines for z6-10, with the grayest colors for z5 and below, and full color at z11 and above. A few of the widths are also adjusted, since we are adding details for those zoom levels, as suggested in the alt-colors style.

Rendering examples from Shikoku, Japan (sorry, mainly maritime borders):
z5

z6

z7

z8

z9

z10

z11

[imagico]

i don't see the vision behind this

I think the plan was to change the border color, so that we could consider using a different hue for motorways and shift the other road colors one level lower, so that highway=tertiary would be yellow instead of white.

I understand that - but in my eyes changing selectively some boundaries in color to remove what seems to be the obstacle to make a specific road color change does not appear to be something that brings this style forwards.

This is a tricky subject. I have made by choice in the ac-style based on my specific ideas and priorities (so i am not neutral in the discussion here) and based on a different cartographic context as well. It took a long time of contemplating and testing to come to this and i am still not really satisfied with it.

I would love to see other ideas here - in particular also ones that go beyond just varying the color.

[jeisenbe]

Here's some more tests in Libya with the gradual transition from gray at z5 to full color violet at z11. I'll show z4 to z9:

z4

z5

z6

z7

z8

z9

Another alternative would be to do the transition a little faster; here I've skipped 3 of the intermediate steps, so there are only 4 colors:

z5 (same as above)

z6 less gray

z7 less gray

z8 same as current rendering

I've pushed another commit to jeisenbe:borders-rework to allow testing this option as well.

[jeisenbe]

Here are z5 to z8 in Shikoku, Japan with the earlier transition to violet borders (commit 98c4075):

z5 Shikoku gray borders (same as earlier, #6b516b

z6 Shikoku less gray - Borders in #814d81

z7 Shikoku less gray - Borders in #964a96

z8 Same as current rendering (#ac46ac)

[jeisenbe]

Jakarta, Indonesia - comparing the current commit from kocio-pl:borders-rework with the current rendering (which is the same as my branch with commit 98c4075).

z11 current

z11 kocio-pl:borders-rework

z13 current

z13 kocio-pl:borders-rework

z15 current

z15 kocio-pl:borders-rework

[kocio-pl]

@jeisenbe Your proposition seems interesting to me, so maybe you could open your own PR?

[kocio-pl]

@jeisenbe ping?

[kocio-pl]

#3716 took over.