Distinct college/university icon

[wmisener]

Fixes #694. Changes the rendering for amenity=college and amenity=university (in OMT, class=college + subclass=college/university) to a mortarboard cap-style icon: . Previously, these were rendered as a generic school icon ; this schoolhouse icon is now reserved for amenity=school and amenity=kindergarten.

I think the "higher ed"/"schools for adults" vs "schools for children" is a useful distinction for the map to make. Meanwhile, the distinction between an OSM college and university is a bit fuzzy in practice IMO, so this PR renders both tags the same. In #694, while there were multiple potential icons in various US map samples, the consensus was that a mortarboard cap was the most recognizable symbol of institutions of higher education. The new legend entry is "College or university", whereas the schoolhouse icon retains "School". I think this is not too confusing, but I'm open to suggestions.

The icon itself is a modified version of the maki symbol. I'm open to modifying the dimensions/length ratios/style/etc.

I've added rendering to begin at z14, one zoom level out compared to most other POIs, since colleges and universities can be quite important local destinations (I think that eventually starting zoom levels for POIs might need to be reconsidered more holistically, but that's out of scope for this PR). Rendering at z<14 is not currently possible, as non-transport POIs only appear in the tiles at z14 (openmaptiles/openmaptiles#387). In the future, it might also be good to render these objects as areas as well, but I also leave that out for now.

Samples:
UCLA z14 (localhost link):

Note that the Anderson School of Management is tagged as amenity=university, which may or may not be a tagging error.

UCLA z15 (localhost link):

Indiana University Bloomington (localhost link):

The icon renders near the center of the university polygon. This may or may not be equivalent to the main activity center of the campus. This problem could be helped, though not really entirely solved, by rendering the area as a boundary.

City College of San Francisco (localhost link):

This is a two-year community college, the predominant use of amenity=college I anecdotally observe in the US. I see these institutions are more close to a university than they are to e.g. a high school, so I think it makes more sense to render them together with universities.

Boston/Cambridge, MA (localhost link):

Cambridge, UK (localhost link):

Again, these seem like tagging errors to me, though the UK university/college system is incredibly convoluted so I wouldn't go in and change the tags myself. But this seems at least an improvement over rendering them the same as elementary schools.

[Pengor]

Nice, I think this looks great! I'd at least fix the paths in taginfo_template.json and the stroke color in the SVG file, but otherwise could be merged 👍

[ZeLonewolf]

I think the original filename of poi_mortarboard is better. As the number of icons grow, they'll be easier to understand in the code if they're closer in description to what's in the icon rather than what the icon represents.

[github-actions]

PR Preview:

• Map
• Shield Test
• style.json
• shields.json
• taginfo.json

Sprite Sheets:

[Pengor]

Sorry for the slowness on getting back to this. After the discussions on here and slack I don't think there's anything holding this design up from being merged

[ZeLonewolf]

Looks great, thanks!