Tweak rendering of light buildings.

[vincentdephily]

• Add a border
• Make them more transparent
• Require a higher zoom to render them

The main change is adding the border, to prevent joined buildings looking like one big blob. Then I also made the rendering lighter and start at higer zoom, because those buildings are usually smaller, and by definition less important.

This should close the last item on issue #68, since the other items have been fixed by other PRs.

[matkoniecz]

Can you provide examples of how this will change rendering?

[vincentdephily]

Here's the main before/after :

Small difference due to light buildings not rendered at this zoom :

Those examples were taken from http://osm.org/go/esz2DgLc-- and rendered using tilemill.

[vincentdephily]

Any 👍 / 👎 on this ? I feel that even if we eventually merge pnorman's #565 rewrite, it'll take a while to reach consensus, while this PR is small and AFAIK from previous discussions, uncontroversial.

[matthijsmelissen]

I have a slight preference for reaching consensus about all changes concerning buildings before changing anythibg, rather than making incremental changes.

[talllguy]

I see, theres a border on the light buildings now. Those are things like garages and sheds?

[gravitystorm]

I'm generally in favour of this, with only two caveats:

• I don't like opacity as a way of controlling colour - buildings should avoid opacity and just have a solid fill.
• I don't know how this conflicts/complements with Rewrite buildings code #565 . Can anyone comment?

If the consensus is to merge this in the interim, I'll do that.

[matthijsmelissen]

With the risk of making enemies: I propose to close this one, and implement #565 first. After that, we can reconsider if a special styling of light buildings is still necessary/desirable.

[vincentdephily]

No hard feelings math1985 :) Let's see how #565 pans out first, I can try to resurect light buildings afterwards.

One thing that might make it harder is that #565 is already styling buildings very light. Coming up with an even lighter styling for some buildings might turn them near-invisible.

I have to admit I wasn't too happy with using opacity either. Except for some cases such as building=canopy where it kinda makes sense. Will try opaque styling next time.