Font issue when multiple fonts defined

[acalcutt]

I have started to notice in one of my styles at https://tiles.wifidb.net/styles/WDB_DARK_MATTER/#2/0/0 that there seems to be some kind of font issue that prevents the map from loading. It is especially noticeable zooming into the USA, since it does not zoom in

You can see in the network tab of chrome that the font is failing to load. for example, this link https://tiles.wifidb.net/fonts/Metropolis%20Regular,Noto%20Sans%20Regular/5120-5375.pbf

In my font directory I have these fonts and have both fonts/Metropolis Regular/5120-5375.pbf fonts/Noto Sans Regular/5120-5375.pbf (Though I will note both pbf files are 1kb have little in them)

I am still trying to pinpoint where this broke. it seems like it was recent, maybe something that started with https://github.com/maptiler/tileserver-gl/pull/1294

I have seen this error when loading the raster map

 mlgl: {
  class: 'Style',
   severity: 'ERROR',
   text: 'Failed to load glyph range 5120-5375 for font stack Metropolis Regular,Noto Sans Regular: start must be between 0 and 255; given Infinit>
 }

[acalcutt]

I did some more testing and it does seem like it broke in 4.12.0

I locally tested 4.11.1 at commit 68d2f7174e62b4746dbfa197c4887345aa95a658 and it gives me back this pbf file for the mentioned url 5120-5375.pbf.txt

But when I moved up to 4.12.0 at commit 416d78356e088478b5f1e65b262cfa40e179202e, it doesn't give me back a file, just and empty "{}"

@prashis do you have any suggestions for this? @akx I know you also touched fonts recently with https://github.com/maptiler/tileserver-gl/pull/1320 but from my testing this seemed to be broken before that PR.

Note that I used node 20.14.0 in my tests since that was the version that still worked with the old @mapbox/glyph-pbf-composite

[prashis]

@acalcutt It seems to be an issue at https://github.com/jessekrubin/pbfont/blob/main/src/index.ts#L80

After adding following changes, this issue appears to have been resolved

@jessekrubin Will be needing your help resolving this 😅

[akx]

So apparently fixed via https://github.com/maptiler/tileserver-gl/pull/1369?

[acalcutt]

There is a more complete fix in pbfont v0.2.2 that should be merged soon by dependbot, but v0.2.1 at least allows the page to load.

After working with jessekrubin on a test for this issue and comparing the previous pbf I noticed there was also a range issue. 0.2.1 gives back a pbf, but the range was wrong (0 - 255) instead of (5120-5375) for the example I gave. In 0.2.2 a fix was added for that issue.

It seems like it occurs when both files being combined have no glyphs. before the minimum id was based on the lowest glyph id, whcih wasn't working since there were none. The workaround fix from above was also setting this min id to 0 if it did not exist.

[jessekrubin]

Howdy team (who's map server I do not personally use). I did a bit of rejiggering of things within the library to fix this problem. As bro dude above said it happens with effectively empty bufs (no glyphs). Lmk if you all have any problems.

Grepping around different map libs it looks like some toss out font stacks ranges that have no glyphs while others do not (tho they should).

[acalcutt]

This should be fixed in v4.13.0

[acalcutt]

@jessekrubin Thank you for your help getting this working

@prashis thanks for troubleshooting this with me.