fill-extrude layer is drawn above the next-above symbol layer

[westnordost]

Describe the bug
The icons shown in a symbol layer are drawn behind the geometries in a fill-extrude layer if the latter is immediately below the former in the layer list.

To Reproduce
Steps to reproduce the behavior:

1. Put a symbol layer directly above (i.e. after, in the layer list) a fill-extrude layer in a style json
2. Notice that the symbols are drawn behind the geometry in the fill-extrude layer

Expected behavior
fill-extrude should respect the layer order or the documentation should be updated to explain this.

Screenshots

Platform information (please complete the following information):

• OS: Android 13
• Version 11-pre04

(Only tested with v11-pre04)

[westnordost]

It looks like this is fixed with org.maplibre.gl:android-sdk:11.3.0-vulkan-pre0.

[louwers]

#2894 contains a reproduction

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From @Zverik:

Sometimes extruded buildings cover symbols and labels. Which never happens with MapLibre GL JS (on web) — and that made debugging this quite hard.

I was testing with Flutter package, which uses MapLibre Native for Android. We have also encountered this bug on a native Android application using the SDK.

After some experimenting, I narrowed styles to replicate this to those two:

• style2.json — between zooms 15 and 15.5, poi_r1 layer is covered by building-3d layer. There is no mention of zoom 15.5 in the style, so the reason buildings cover POI on on zoom and don't on others is unknown.
• style2_old.json — same style without building and poi_r7 layers. While it should not have affected the outcome, instead extruded buildings cover POI on all zooms 15+.

When you remove any layers from the label group, suddenly extruded buildings stop covering POI symbols. That is the most baffling: why labels affect this, and why not "all labels".

Versions:

• maplibre_gl flutter package: ^0.20.0
• maplibre-native for android: v11.0.0
• android 14 on sony xperia 10 vi

A screenshot:

[Zverik]

We have been testing, and the bug does not seem to completely go away with the Vulcan build. For POI — yes, it is fixed. But instead, landuse labels (e.g. park and pond names) get obscured by extruded buldings. Even on non-adjusted styles: osm-liberty shows this between zooms 14 and 15.

I'm doing more tests (using modified flutter library, so not sure it does use vulkan), but our Android developer reports this.

[alexcristici]

From what I tested so far it seems that this issue is happening only on OpenGL, not on Vulkan or Metal.
I'm looking into it.