Hi Henning, I don't think that we should apply a bounding polygon only to the overview map. If you compile tiles for whole Germany and produce a map for Bremen using some of these tiles and an overview map that was created with a proper polygon I would assume that this looks strange when you zoom in/out. I don't understand what you mean with maximizing/minimizing the polygon. Please explain. Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Henning Scholland <osm@hscholland.de> Gesendet: Freitag, 12. Januar 2018 12:35:04 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: Re: [mkgmap-dev] The 0x4b background polygon in the overview map Hi Gerd, I think this would be best and additionally I would suggest to make the polygon defined by user (as suggested in DEM-poly and precomp-sea thread). As default I would limit overview map to the map tiles. Maybe then we should name the parameter --overview-map-polygon=filename I'm not sure, if the actual rectangle should be maximizing the polygon and the map tile area minimizing it or if Garmin doesn't care at all about it. If no external sea-data is given I would keep map tile area as background polygon. Otherwise it will look strange. Henning On 12.01.2018 19:19, Gerd Petermann wrote:

Hi all,

up to now mkgmap always creates a rectangular 0x4b polygon for the overview map. I wonder if I should change that so that the 0x4b polygons of the sub tiles are used. This seems to be the better way if we start using non-rectangular 0x4b polygons?

Gerd _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev

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Hi Henning, reg. Bremen: I thought the other way around. Say you split and compile Niedersachsen as 15 rectangular tiles. Next you compile Bremen using some of these tiles and an polygon for Bremen that is only used for the overview map. I guess that would look very strange. I also don't know yet if Garmin software complains when an overview map doesn't fully cover the tiles. Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Henning Scholland <osm@hscholland.de> Gesendet: Freitag, 12. Januar 2018 13:16:19 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: Re: [mkgmap-dev] The 0x4b background polygon in the overview map Hi Gerd, I probably didn't got your issue. So far I understand I gave mkgmap a list of data tiles or already compiled map tiles. based on this mkgmap creates a complete map. At the moment the overview map is rectangle of maxlat,maxlon,minlat,minlon. Based on my suggestion user in future would be able to gave a different polygon for overview map. If I let mkgmap use the tiles of Bremen, I should use a matching bounding polygon. Of course if overview map is larger than detailed map, the exceeding area will only have rough sea/land area and DEM. In your example, if I use Germany.poly for Bremen map, I will see rough DEM of Germany and North Sea and Baltic Sea cost line (based on polygon). I wouldn't see an issue unless it's fine for Garmin. Are you talking about generating a partial map with BaseCamp/MapSource? I haven't checked how Garmin handle overview map in that case. I'm not sure, if Garmin supports smaller/larger overview maps then detailed map area is available. That's why I was thinking about if we need to gave some limits, like overview map shouldn't be larger than actual rectangle or not covering all the detailed map area. Henning On 12.01.2018 19:43, Gerd Petermann wrote:

Hi Henning,

I don't think that we should apply a bounding polygon only to the overview map. If you compile tiles for whole Germany and produce a map for Bremen using some of these tiles and an overview map that was created with a proper polygon I would assume that this looks strange when you zoom in/out.

I don't understand what you mean with maximizing/minimizing the polygon. Please explain.

Gerd

________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Henning Scholland <osm@hscholland.de> Gesendet: Freitag, 12. Januar 2018 12:35:04 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: Re: [mkgmap-dev] The 0x4b background polygon in the overview map

Hi Gerd,

I think this would be best and additionally I would suggest to make the polygon defined by user (as suggested in DEM-poly and precomp-sea thread). As default I would limit overview map to the map tiles. Maybe then we should name the parameter --overview-map-polygon=filename

I'm not sure, if the actual rectangle should be maximizing the polygon and the map tile area minimizing it or if Garmin doesn't care at all about it. If no external sea-data is given I would keep map tile area as background polygon. Otherwise it will look strange.

Henning

On 12.01.2018 19:19, Gerd Petermann wrote:

...

Hi all,

up to now mkgmap always creates a rectangular 0x4b polygon for the overview map. I wonder if I should change that so that the 0x4b polygons of the sub tiles are used. This seems to be the better way if we start using non-rectangular 0x4b polygons?

Gerd _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev

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Hi Henning, sorry, can't follow. All I tried to point out was that it is not a good idea to use an option --overview-map-polygon. My understanding is that a bounding polygon has to be used for all tiles that build a map and that the 0x4b polygon of the overview map should be the combination of the 0x4b polygons of those tiles. The option name --overview-map-polygon implies that it is only used to cut the overview map without cutting the tiles. Gerd ________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Henning Scholland <osm@hscholland.de> Gesendet: Freitag, 12. Januar 2018 14:31:59 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: Re: [mkgmap-dev] The 0x4b background polygon in the overview map So your idea was basically: User has splitted a data file covering city A in the upper part and city B in the lower part. Now user wants to ask mkgmap creating a map with that data file for city A only by giving mkgmap a polygon only covering upper part of that data tile. Ok, I haven't thought about it. So I would agree with you, that both maps should follow that given poly-file. That would also make handling of overlapping map areas, which are splitted in one step more easy. But will require some changes in splitter too. Following the above example, if I give splitter an osm-file with rectangle of city A and another rectangle of city B, splitter will create 2 data tiles. In case A and B are overlapping, 3 tiles will be created. But finally the tiles will be much better with that additional polygon, as splitter just can use one big tile instead of 2 or 3 smaller ones. At the moment some tiles of my maps are pretty small, because of that overlapping areas. Henning. On 12.01.2018 20:23, Gerd Petermann wrote:

Hi Henning,

reg. Bremen: I thought the other way around. Say you split and compile Niedersachsen as 15 rectangular tiles. Next you compile Bremen using some of these tiles and an polygon for Bremen that is only used for the overview map. I guess that would look very strange. I also don't know yet if Garmin software complains when an overview map doesn't fully cover the tiles.

Gerd

________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Henning Scholland <osm@hscholland.de> Gesendet: Freitag, 12. Januar 2018 13:16:19 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: Re: [mkgmap-dev] The 0x4b background polygon in the overview map

Hi Gerd,

I probably didn't got your issue.

So far I understand I gave mkgmap a list of data tiles or already compiled map tiles. based on this mkgmap creates a complete map. At the moment the overview map is rectangle of maxlat,maxlon,minlat,minlon. Based on my suggestion user in future would be able to gave a different polygon for overview map. If I let mkgmap use the tiles of Bremen, I should use a matching bounding polygon. Of course if overview map is larger than detailed map, the exceeding area will only have rough sea/land area and DEM. In your example, if I use Germany.poly for Bremen map, I will see rough DEM of Germany and North Sea and Baltic Sea cost line (based on polygon). I wouldn't see an issue unless it's fine for Garmin. Are you talking about generating a partial map with BaseCamp/MapSource? I haven't checked how Garmin handle overview map in that case.

I'm not sure, if Garmin supports smaller/larger overview maps then detailed map area is available. That's why I was thinking about if we need to gave some limits, like overview map shouldn't be larger than actual rectangle or not covering all the detailed map area.

Henning

On 12.01.2018 19:43, Gerd Petermann wrote:

...

Hi Henning,

I don't think that we should apply a bounding polygon only to the overview map. If you compile tiles for whole Germany and produce a map for Bremen using some of these tiles and an overview map that was created with a proper polygon I would assume that this looks strange when you zoom in/out.

I don't understand what you mean with maximizing/minimizing the polygon. Please explain.

Gerd

________________________________________ Von: mkgmap-dev <mkgmap-dev-bounces@lists.mkgmap.org.uk> im Auftrag von Henning Scholland <osm@hscholland.de> Gesendet: Freitag, 12. Januar 2018 12:35:04 An: mkgmap-dev@lists.mkgmap.org.uk Betreff: Re: [mkgmap-dev] The 0x4b background polygon in the overview map

Hi Gerd,

I think this would be best and additionally I would suggest to make the polygon defined by user (as suggested in DEM-poly and precomp-sea thread). As default I would limit overview map to the map tiles. Maybe then we should name the parameter --overview-map-polygon=filename

I'm not sure, if the actual rectangle should be maximizing the polygon and the map tile area minimizing it or if Garmin doesn't care at all about it. If no external sea-data is given I would keep map tile area as background polygon. Otherwise it will look strange.

Henning

On 12.01.2018 19:19, Gerd Petermann wrote:

...

Hi all,

up to now mkgmap always creates a rectangular 0x4b polygon for the overview map. I wonder if I should change that so that the 0x4b polygons of the sub tiles are used. This seems to be the better way if we start using non-rectangular 0x4b polygons?

Gerd _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev

_______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev

_______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev _______________________________________________ mkgmap-dev mailing list mkgmap-dev@lists.mkgmap.org.uk http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev

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Hi Henning,

you should be able to split Europe once and then just let mkgmap calculate all the country maps based on the boundary polygons

I'm doing something similar for my maps. I create a map of a continent, for example Africa and then I execute mkgmap with list of img to create regional map. So what I would need is an easy way to create a list. I think mkgmap could support a polygon, which selects, which input files should be processed. Something like this: mkgmap ... --input-area=country.poly *.img mkgmap ... --input-area=country.poly -c areas.list I like that tiles aren't clipped, so for me would be good enough to select all tiles that are inside poly or intersect poly. My current procedure involve some awk scripts and manual processing of areas.list in Qgis. -- Best regards, Andrzej

Oh, forgotten to mention: --polygon-desc-file=filename.osm you need to use for splitter. Henning

Hi Andrzej For Africa it can be useful, as areas with drive on left /right are at least roughly horizontal and vertical. Also you don't need overlapping for this use case. In general I also think, as soon as mkgmap can support non-rectangle tiles, it will be better obsolete. Using non-rectangle map-area would be a first step on that long way. Anyway we will need either splitter generating all the necessary args-files as for polygon-desc-file or mkgmap picking only tiles within or touching the giving poly file. I estimate using splitter would be faster. Henning On 13.01.2018 00:11, Andrzej Popowski wrote:

Hi Henning,

...

--polygon-desc-file=filename.osm

Thanks for info. That's very interesting. Actually I would like similar processing for mkgmap, since I'm satisfied with standard splitting.

But I see a good uses for this feature. I can create polygons for drive on left and drive on right countries. Then I hope splitter would create small tiles on borders of these areas, which would minimize size of area with wrong settings.

Small tiles are mainly caused by not well aligned polygons. I attached you kmz with my splitter result. You can compare them for example in josm. I just have realized the small tiles while testing in beginning of DEM-support. While checking for broken img-files with 0kb I found several others with only 200kb. During searching for a reason, I found out, some tiles are a little strange. But as written before it's my fault, as some overlapping areas are terrible by design.  Henning On 13.01.2018 00:43, Andrzej Popowski wrote:

Hi Henning,

you are right, using splitter is a valid alternative to my process.

Is it this right-angled shape of polys required? And where are created small tiles, around any border or only on overlapping areas?

Hi Henning, looking at your files, I see that small rectangles are forced by overlapping areas. I think restriction for poly are the same as for option --polygon-file, quote from doc: "If the polygon area(s) describe(s) a rectilinear area with no more than 40 vertices, splitter will try to create output files that fit exactly into the area, otherwise it will approximate the polygon area with rectangles. " -- Best regards, Andrzej

Hi Gerd, using poly to clip background could be a way to create irregular maps. There are some caveats. Background doesn't clip map data, they will be still visible. The proper way would be to clip data too. Detailed tiles and overview map have different resolution and usually their edges don't match. It is visible in BaseCamp and Mapsource. Mapsource (maybe BaseCamp to) calculate routes only inside background area. I think overview background is used for estimating this area at some zooms. If overview doesn't cover full map or there are holes, then some area can be excluded as destination of calculated route, program will use direct routes instead. All this said, I like clipping DEM in overview map, but I don't think that clipping background will improve maps unless you clip data in detailed tiles. -- Best regards, Andrzej