Specify font for cluster

[hyperknot]

@edent has a question regarding specifying the fonts for clustering
hyperknot/openfreemap#10 (comment)

I see it's trying to reach ["Open Sans Regular", "Arial Unicode MS Regular"] which 404s.

My questions:

• Can it be configured or is it hard coded?
• If it's hard-coded, can you change it? The problematic part is especially Arial Unicode MS Regular, which is a proprietary Microsoft font.

I see it's hosted on GitHub in various places, like in the MapLibre demotiles repo, but I'd prefer only to include open source fonts in my repos.

[HarelM]

Not sure I remember why this was closed, but it was discussed here I believe:
maplibre/maplibre-style-spec#311

Nevertheless, this is a style definition that can be overridden as far as I know.

[hyperknot]

Do you know where it might come from? The cluster example has this:

{
    "id": "cluster-count",
    "type": "symbol",
    "source": "earthquakes",
    "filter": ["has", "point_count"],
    "layout": {
        "text-field": "{point_count_abbreviated}",
        "text-font": ["DIN Offc Pro Medium", "Arial Unicode MS Bold"],
        "text-size": 12
    }
}

But nothing about Open Sans, so it must be from another layer.

[edent]

Looking through the source of https://unpkg.com/maplibre-gl/dist/maplibre-gl.js, it appears there's a hard-coded requirement for those fonts.

If you follow the tutorial for adding clusters to a map - https://maplibre.org/maplibre-gl-js/docs/examples/cluster/ - you'll see this:

        map.addLayer({
            id: 'cluster-count',
            type: 'symbol',
            source: 'earthquakes',
            filter: ['has', 'point_count'],
            layout: {
                'text-field': '{point_count_abbreviated}',
                'text-font': ['DIN Offc Pro Medium', 'Arial Unicode MS Bold'],
                'text-size': 12
            }
        });

If you remove 'text-font': ['DIN Offc Pro Medium', 'Arial Unicode MS Bold'], the browser will request the fonts listed in maplibre-gl.js

Does that make sense?

[HarelM]

Yes, there is an implicit default font defined, which is open sans, as can be read in the issue I linked to.

[edent]

But the other default font is the proprietary "Arial Unicode MS Regular". That cannot be freely distributed.

[HarelM]

I agree, but all fonts can be overwritten, or am I missing something?

[hyperknot]

I checked it and there was no bug or error. Simply the font had to be changed in the official example to Noto Sans and everything worked fine.

I'll open a ticket about the non-open source fonts.