I'm using mapsforge 0.5.1. My App rendering the map displays certain highways at particular zoom levels. For example, it displays k="highway" v="primary" at zoom=13 and above. However it refuses to display the names of the highways until zoom=15. My rendertheme-v4.xml is the same as github ...\mapsforge-0.5.1\Applications\Android\Samples\assets\renderthemes\rendertheme-v4.xml with a small change that should allow the names to display at zooms 13 and 14. I replaced this rule in the original mapsforge-0.5.1 version of rendertheme-v4.xml:
<rule e="way" k="highway" v="secondary_link|primary_link|trunk_link|motorway_link|secondary|primary" zoom-min="15">
<pathText k="name" display="always" priority="-6" font-style="bold" font-size="12" fill="#000000" stroke="#FFFFFF" stroke-width="2.0"/>
</rule>
With this rule in my rendertheme-v4.xml:
<rule e="way" k="highway" v="secondary_link|primary_link|trunk_link|motorway_link|secondary|primary" zoom-min="13">
<pathText k="name" display="always" priority="-6" font-style="bold" font-size="12" fill="#000000" stroke="#FF0000" stroke-width="2.0"/>
</rule>
The name highway labels do not appear at zoom 13 or 14 (the stroke colour does change to red at zoom 15, proving my rendertheme-v4.xml is being used).
I also notice that if I reduce the font-size from 12 to 8 the label does appear at zoom 14 but not zoom 13.
Something is going on here that is unexpected and undocumented as far as I can tell. Can someone explain this behaviour? I'd like to be able to set up rules where I can display some highway labels at zooms 12 to 14 and use bigger fonts. Can someone describe rules that allow this?
When I received no answer to this question I submitted an issue report to the mapsforge developers. The response is that this is expected behaviour and that highway labels cannot be made visible at zoom levels 13 and 14. See https://github.com/mapsforge/mapsforge/issues/644. Hopefully this can be changed in future.