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Yes, should be. Because I see no other clear suggestion here. Except the suggestion from Tobias here

So only the proposal above (using a renderer according to theme version, when V3 maps are used) would work properly.

which is too complicated to create (as I wrote before).
Themes optimized for V3 maps does not work correctly in new system when tiles are scaled in new MapsForge renderer and oposite.

I'm fine with that, at least there's finally full V4-theme compatibility that is correctly rendered (with V4-maps), this is way more important than full backwards compatibility, which would be just the icing on the cake.

As I wrote above backward compatibilty of the render engine is great, so you can throw any theme or map version at 0.11 (except locus extended), old V1 themes will also be scaled according to dpi etc.

But there's no "forward" compatibilty, so it makes no sense using a render engine 0.3 (locus ext.) with maps higher than V3 and themes higher than V1 (whatever happened to V2 and V3?).

So only the proposal above (using a renderer according to theme version, when V3 maps are used) would work properly.

I also just checked the new version, the rendering of V3 maps with V4 themes is wrong.
What renderer is used for V3 maps with V4+ themes? If it's the forked 0.3 version (locus-extended) it makes not a lot of sense, as at least mapsforge 0.5+ is needed.
I would propose checking the theme version in the xml-file, if it's version="1" and/or locus-extended="1", use the Locus-Fork, if it's version="4" or higher, use the standard engine.

I don't fully agree with Tobias and really don't understand the zooming idea.
For example, when I change from LoMap (or OAM V3) ZL 20 @ 75% to OAM Mapsforge V4 the zoom changes to ZL 18 @ 100% with the map showing the same area.

I meant that the rendering is finally how it's meant to be for mapsforge maps, so no rendering differences anymore for the major apps. I think it depends on user preferences if switching maps should show the same area or the same zoom level (although most without deeper understanding will prefer probably the former).

That obviously seriously affects what items are displayed at what map size. Will I need to change all the zoom-min settings in the V4 theme or what?

Until now with fixed tile size in order to have the map look the same on any device one would need a different theme for every major ppi step. You adjusted your theme to look fine with the ppi of your device, but it looked different on one with a different ppi screen.
You may have to adjust the V4 theme now, but it will look alright and show the same things in the same area no matter if you use it on a 160ppi tablet or 480ppi smartphone.

PS - @John: I also had my issues with this when it was introduced in standard mapsforge, but after a while I realized this is a pretty genius idea. Once set it works flawless.

"zoom level/magnificaction can't be switched on when touching the map scale" - may you describe it little?

In the map view the map scale (e.g. 200 m) in the lower left corner can't be switched to show the zoom level/magnification in brackets by touching it (V4 OAM) any more.

"scale of V4 maps" - not same, hmm it's possible, but the difference should be really small

My mistake, as I didn't have the magnification in the map scale, I didn't realize that the map was slightly zoomed. Now I switched the top bar to show map info, and with 100% in all apps the view is the same - perfect!

Are you using an OpenAndroMap V4?

http://download.mapsforge.org/maps/v4/
Italy.map
And
Slovenja.map

Those maps don't contain contour lines. Only OpenAndroMaps contain all the data Elevate needs to work properly.

No way, Elevate Hiking or City, flagged and unflagged contour lines no results.
I also used your suggested procedure using top left back button.
It's the same with elements theme.
I tried to switch from italian to english language to test if it was something related to, but nothing

Are you using an OpenAndroMap V4?

contour lines not present on a map v4 elevate theme 4 but the shadows are correctly represented

Are you using city mapstyle? Check if contour lines are set.

Some observations:
- when using mapstyle menu and I'm changing mapstyle with Elevate and don't press the arrow top left/back button, but only touch the map, the mapstyle changes aren't applied (as it was before).
- probably known: zoom level/magnificaction can't be switched on when touching the map scale
- Edit: very much improved rendering of mapsforge maps at higher ppis, thanks to larger tile sizes; theme renders pretty much as intended, although not the same scale as in Cruiser or OruxMaps

Thanks, looks good at first glance, but no real test.

2. V4 theme for V3 maps? I'm no expert, but does it make sense?

That's the confusing thing with mapsforge: there are three version numbers (program, map and theme), but the only important one for compatibility is the program version, as it determines which highest map or theme version it supports. Until now there is a very good backward compatibility, so mixing theme and map version is no issue. The version numbers of themes is not connected to the one of maps at all, they where introduced at different points of time (e.g. Rendertheme V4 was end of 2014, Maps V4 end of 2015). As long as there are apps that only support V3 maps, it makes sense to have them on your device if you use several apps. But you can still have the (huge) advantage of V4 themes with them.

"P" Icon shows at ZL15, not at ZL16, but again at ZL17. This is the joys I try to prevent

As I wrote above - tile borders are with V4+ maps the only problem. The more you zoom in, the more map tiles are used, the more borders you get with the possibility of missing icons. As long as there are the tiny 256px map tiles in Locus there are a lot tile borders. When map tiles are scaled according to display pixel density, you will have e.g. 768px map tiles (for e.g. 480ppi displays), but this is work in progress (and works already fine in other apps).

My current tests with mf4 (I use Voluntary Mapsforge for this) and Locus were rather bad. E.g., I increased a bench size, want to see it from ZL14 onwards and stay on top no matter what, so I added priority. It does not display often. Quite a few ZL>14 where benches will not display at all. Not sure if it is a tile size problem.

No, benches are in the map from ZL17 on (see https://www.openandromaps.org/map-basics-2/tag-mapping), so changing this via theme doesn't work (exceptions may occur when a different tag with an lower zoom appear is on the same node).

Or, on new mapsforge maps, does Locus not know about priority yet?

With current mapsforge engine (at the moment hard coded to V4+ maps) it does, but not with Locus own engine (hard coded to V3 maps).

The only remedy is when Menion not only takes the mapsforge library as such as a base for the Locus core, but in addtion applies the concept of its "Label Layer" (like Cruiser does).
MF alone, w/o LL, is crappy, too, when it comes to labels.

Current mapsforge (not the Locus fork, so in Locus with V4 maps) is quite fine with labels (and priorities), except on tile borders. Only this last issue is solved with the label layer. It's not very likely that the label layer will be included in Locus soon, but at least larger tile sizes will come very soon, and therefore a lot less of those problematic tile borders:
https://forum.locusmap.eu/index.php?topic=6434.msg53911

A solution for me that I can see can only be a massively stripped down theme. Where I can turn off display of almost anything except the stuff I mentioned. But oh, the xml is not easy to handle.

This is already implemented in Elevate, just switch of every other overlay than "Car"; it will work better with V4 maps though.

[@Tobias]

@Tobias
excellent description I needed, thanks .

About themes: Currently, all V3 maps use Locus-MapsForge rendering system, V4+ maps use than MapsForge 0.10.0. So what I may do: allow all V3 and higher themes for V4+ maps oki? I'll look at it.

Allowing all V3 themes might make problems with V4+ maps when locus extended tags are used. V3 maps on the other hand won't make problems with mapsforge 0.10. So checking for locus-extended might make sense.

Another issue: on tile borders labels and symbols aren't rendered reliably. Using larger tiles with device depedent scaling helps a bit, but the only solution which completely solves this that I know of is the label layer of mapsforge. But I think the mapsforge maps viewer is necessary for this. More here: https://github.com/mapsforge/mapsforge/blob/master/docs/LabelLayer.md

"Device screen scaling": I already read the post from Tobias, but I'm not too clever from this. What is the main issue he tries to describe except lack of interest in compatibility?

That post was more my tiredness of only limited support of new mapsforge features in various apps (not just Locus, but this was the app John came up with) which limit app-independent development as we do at OpenAndroMaps. In an older discussion I got the impression that LoMaps have a bigger priority than compatibility, but this new thread let's me hope for a change :-)

But as far as device screen scaling is concerned - as a cross-app-theme-developer this is the most important issue. It was introduced with mapsforge 0.4 in 2014, at first I was a bit sceptical but with very high ppi nowadays it's a must for good rendering, as far as I'm concerned.

Here's a description of the problem I posted in a different forum:

Mapsforge maps are meant to be scaled to screen density of the device, so that a map at 160ppi looks exactly the same as with 480ppi. To do that, not only symbols and line width are scaled, but also map tile size. So if you have a map tile size of 256px at 160ppi, you get 768px at 480ppi.
Locus uses a mod of a very old mapsforge version with no scaled tiles. So with modern devices with very high pixel density, you still get 256px like for devices years ago. The only thing that is scaled is line width and symbols. But as these grow larger (3x as large at 480ppi), the space on a 256px map tile gets more crowded, and less can be displayed. So when looking at the same zoom level, less and coarse information is shown.

Here are some comparison of a densely mapped are at zoom level 17:


At first, it looks as if Locus shows more - but this isn't the case, as the area is only larger as the tile sizes are smaller. The same area can achieved by OruxMaps by using the zoom button.

Now here you can see what details are available if tile size is adjusted:

In Locus, streets are rendered much too fat, so they overlap and swallow too much space. Only a few symbols are displayed, as most are eliminated because of too little space.

So the scaling policy of OruxMaps is true to how the maps are meant to be displayed and can be scaled to every pixel density without loss of details. The only disadvantage is that with larger tile size direct comparison to online maps with old 256px tile size is not possible (although there are more HD maps coming with larger tile size as it's necessary to keep the legible on high density devices).

On my to-do-list for the Locus version right now is the idea of moving all zoom-appears 1-2 levels as this is the only possibility right now to get it a bit better, but with other disadvantages.

Other issues:
- Folder structure for themes: only one theme xml per folder is allowed, and folder are also needed. Any other app with theme support allows xml files in base folder and graphics whereever the xml points to. So a special Locus format is always necessary. I get the one folder, one theme policy, but why not two or more xml files?
- Forced connection of V4 maps with V4 themes - it should be possible to use V3 maps with V4/V5 themes, or V3 maps and V3 standard mapsforge themes etc. Maybe use standard-mapsforge for all themes, whatever version, and locus-mapsforge-fork for those themes with locus-extended="1" in the rendertheme tag? That would solve the issues of the two posts above.

Best regards,
Tobias

And now Tobias announced that "OpenAndroMaps will switch to Multilanguage "V4" Maps mid of 2019.".

That was Christian, not me. But of course I support this :-)

The theme used is a pretty current version of Elevate, not Andromaps, and the map is also one of OpenAndroMaps, as surface is rendered.
But the symbols/text size shouldn't be reduced by zooming, and also aren't in all but one example - that's just an optical illusion. As everything around is enlarged it seems that they are smaller, but they aren't. In the first example it seems like the text size is reduced via a Locus setting (or some bug), because in the theme code the size is constant.