Highway shield (glyph?) text not centered.

[acalcutt]

Hi Everyone,

I have been trying to make a maplibre version of Tileserver-GL with the newly revived node version of maplibre-gl-native which is up on github here ( https://github.com/acalcutt/tileserver-gl )

For the most page it all seems to be working, however on the "raster" pages which rely on maplibre-gl-native in the background, I notice the text for highway shields is not getting centered. like this

With the mapbox-gl-native used before, it looks correct like this

I brought this up on slack and another user said they had the same issue with the shields and had to move to mapbox-gl-native to fix the issue. since someone else confirmed this issues, i figured I would make a post here.

I am using this with this style, which is based on OMT Bright style
https://github.com/acalcutt/wifidb-tileserver-gl/blob/master/tileserver-gl/styles/WDB_OSM/style.json#L4724-L4773

here is a live example
https://tiles.wifidb.net/styles/WDB_OSM/?raster#11/42.2143/-71.8190

[lseelenbinder]

Thanks for making this ticket @acalcutt. I'm that other user, and in fact I had issues with all label positioning. For example, city labels that should have been top-left aligned where bottom-left aligned.

[acalcutt]

Thanks @lseelenbinder for confirming here.

I spent a little bit of time testing and did confirm just changing back to mapbox-gl-native did make the labels appear normal again. I did some comparing between mapbox 5.0.2 and the current maplibre, but there are many changes since that release so nothing stuck out.

I was mainly looking around symbol layout based on these previous mapbox shield text issues
mapbox/mapbox-gl-native#5683
mapbox/mapbox-gl-native#9395

[acalcutt]

I've uploaded a test style and a mbtiles file of massachusetts which includes shields at ( https://github.com/acalcutt/tileserver-gl/releases/download/test_data/test_data_massachusetts.zip )

This is an example of using the test data in the docker version of acalcutt\tileserver-gl (Ubuntu,Debian,WSL)
1.) git clone https://github.com/acalcutt/tileserver-gl.git
2.) cd tileserver-gl
4.) wget https://github.com/acalcutt/tileserver-gl/releases/download/test_data/test_data_massachusetts.zip
5.) unzip test_data_massachusetts.zip
3.) docker build --no-cache -t test1 .
6.) docker run -v $(pwd):/data -p 8080:80 test1
7.) Browse to 127.0.0.1:8080 and click 'raster' under the WDB_OSM style and zoom in to massachusetts (eg. http://127.0.0.1:8080/styles/wdb-osm/?raster#10/42.2595/-71.9028 ) .
8.) see shields and text not looking correct
9.) Ctrl+C in the docker window to kill tileserver-gl

[rmyhal]

@acalcutt the issue was introduced in this PR
I was going through different commits and found that on this commit the issue appeared.

cc @ntadej , could you please help us?

[acalcutt]

I can confirm, I tested reverting #270 in @acalcutt/[email protected] and manually changed my local tileserver-gl to use that release and it seems like it worked

[acalcutt]

While reverting #270 does fix the shields, there is still a bit of something going on with the text, for example.

With
docker run --rm -it -v $(pwd):/data -p 8080:80 wifidb/tileserver-gl

With
docker run --rm -it -v $(pwd):/data -p 8080:80 maptiler/tileserver-gl

This should probably be a separate issue though.

[ntadej]

Is this node bindings only? As I see no issues with text in apps.

Will look into shields.

[rmyhal]

Is this node bindings only? As I see no issues with text in apps.

Will look into shields.

I found the problem. Here you made a typo during adding static_cast and misplaced brackets. The fix looks like this:
shiftY = (-verticalAlign * static_cast<float>(lineCount) + 0.5f) * lineHeight;

[lseelenbinder]

@acalcutt The cut text issue is likely unrelated; that looks like typical label clipping issues that are fairly common with the NodeJS bindings. They don’t always properly set the map mode settings for tiles (vs larger area rendering).

[acalcutt]

I had seen this when researching the shield issue mapbox/mapbox-gl-native#15880 which at least sounds similar to the label issue i am seeing. though when i looked at the maplibre code it looked like some of that fix made it over already.

Not sure if this is a node issue since it didnt happen (or at least didn't happen as much) with the mapbox version (as you can see from the screenshot of the maptiler version

[acalcutt]

I can confirm the line rmyhal mentioned seems to work. I put back #270 and applied that line fix and the shields look correct.

[acalcutt]

I could put in a PR with that fix, unless @rmyhal wants to put it in.

[rmyhal]

thanks @acalcutt !
I can fill a PR soon

[rmyhal]

@acalcutt

#285

[ntadej]

Closing this one. Please reopen if there are any further issues.