Rendering weird (offline map)

[PhungVanHoa]

it happen on both Android and Desktop

• inconsistent: Desktop, Android
• run around: Desktop, Android

Offline Map: v5/asia/vietnam.map
Coordinates: 16.475115, 107.575097

[devemux86]

GitHub can host images, so please include them in the report, instead of external sources.

[PhungVanHoa]

Sorry, i post video for demonstration

[devemux86]

It is strange, we've been using VTM with Mapsforge maps for years on Android and Desktop and never seen such issues.

In reports please always post the device specifications, operating system, graphics card, drivers, etc.

[devemux86]

Also report with small offline maps, like Andorra or Berlin.
(with default themes)

Then it will be easier for other users to check the reports.

[devemux86]

Sorry, i post video for demonstration

GitHub can also host videos.

[PhungVanHoa]

I tested on samsung note 20 ultra android 11 (pure android) and Macbook pro radeon pro 555x. I will try with map which you suggest. But can you test on area which has some Attraction. This issues only happen on that

[devemux86]

Symbols on polygons are automatically placed, enabled with Parameters.POLY_SYMBOL.

• Maybe the centroid algorithm in LabelTileLoaderHook needs improvement
• Or maybe there is a side effect on polygon symbols from Tile / Line clippers

Alternatively (or better):

• Enable the Parameters.POLY_LABEL for optimal placement of labels / symbols on polygons
  (more expensive operation)

[PhungVanHoa]

should we precompute Poly_Label and Poly_Symbol then add them as normal point label when build map ?

[devemux86]

The flags in Parameters are for the VTM map library / reader.

For offline maps creation, you can see the Mapsforge map-writer documentation.

There is the Parameters.POLY_CENTROID for centroid pre-calculation when reading the Mapsforge maps.
(more expensive operation)

For more details, it is easier to check where each parameter is used inside the code to understand its use.
(for most users the default values are sufficient)

[PhungVanHoa]

Thank you

[PhungVanHoa]

i disable POLY_SYMBOL (POLY_LABEL is false default) but symbol still display inconsistent. Enable POLY_CENTROID not working

5756545377124945119.mp4

[devemux86]

Parameters.POLY_SYMBOL enables the auto-generated symbols on polygons.
The symbols on nodes are always present.

Try with the Parameters.POLY_LABEL (to change the centroid calculation).
One (attraction) symbol near Berlin label was "fixed" with that parameter.

(all tests with Mapsforge offline maps)

[PhungVanHoa]

I did, but result is the same :(. why attraction symbol still display when i disable Parameters.POLY_SYMBOL

[devemux86]

result is the same

Someone with free time can check the symbols' origin (nodes | polygons),
why the "attraction" behave like that, what happens on other platforms, etc.

why attraction symbol still display when i disable Parameters.POLY_SYMBOL

It is already explained above: symbols exist on nodes and auto-generated on polygon centroids.
Parameters.POLY_SYMBOL disables the polygon symbols.
For more details you have to study the library and render themes.

Parameters.POLY_SYMBOL enables the auto-generated symbols on polygons.
The symbols on nodes are always present.

Better to find an example on berlin.map so the community can check it easier.
I can test it on Desktop (Linux) or Android emulator when time permits.

[PhungVanHoa]

i did test on Berlin map (lat: 52.519597, lng: 13.360688). Arrow on road display inconsistently

berlin.mp4

[devemux86]

i did test on Berlin map (lat: 52.519597, lng: 13.360688). Arrow on road display inconsistently

Thanks, it can be reproduced on Desktop (Linux),
but cannot know what happens there without proper check.

[PhungVanHoa]

another issue with building in Berlin

Coordinates: 52.525918, 13.395091

berlin_building.mp4

[PhungVanHoa]

Symbol run around in offline map Berlin

9205556505971707072.mp4

[devemux86]

Symbol run around in offline map Berlin

As mentioned above:

Try with the Parameters.POLY_LABEL (to change the centroid calculation).
One (attraction) symbol near Berlin label was "fixed" with that parameter.

[PhungVanHoa]

Oh sorry. Thanks!