February 2018 - mkgmap-dev - The mkgmap lists

Garmin uses overlapping tiles
by Gerd Petermann 07 Feb '18

07 Feb '18

Hi all, so far I've never seen the crash in MapSource using the Garmin maps, although they also have tiles with "invalid heights" and therefore the tile headers have the "Extra flag". my idea: - use mkgmap to create DEM data for exactly the same two areas as in a Garmin map [1] - Try to reproduce the crash with those two areas - replace Garmin DEM by mkgmap DEM and see what happens in MapSource The interesting point: Garmin tiles overlap. I've created this areas.list from the information in two Garmin TRE files: 00000029: 2174824,745652 to 2190360,768956 # 46,6667,16,0000 47,0000,16,5000 00000030: 2174824,768952 to 2190360,792260 # 46,6667,16,4999 47,0000,17,0001 Note that the first tile has eastern border at 768956 while the 2nd uses 768952 for the western border. When I use exactly those values I cannot reproduce the crash. When I move the boundary of one of the two tiles so that they are equal I can reproduce the crash, but not always with the same routes. I tried 768952, 768954, 768956. So, I tried to change mkgmap so that it calculates DEM as if the tile boundaries are overlapping, but with TRE where tiles have same 768956 --> crash possible. The next interesting point is that the 0x4a polygons of these two tiles do NOT overlap. They seem to share 768896 (!). So, I used a new areas.list with this value and still see the crash. My conclusion: We have to modify mkgmap to write a different TRE file, probably it has to cover the DEM area as well. Does that make sense? Gerd [1] TopoGuide Hungary 2.12c

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Re: [mkgmap-dev] Garmin uses overlapping tiles
by Frank Stinner 06 Feb '18

06 Feb '18

Hi Gerd, i have only picked 1 IMG from the "Garmin TransAlpin v2" (Immenstadt im Allgau / 16596679.img). The TRE-borders are overlapping with 2 units with all the 4 neighbors. Perhaps a border-value is ever even (?). Frank

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MapSource crash with DEM: Maybe tdb file needs changes?
by Gerd Petermann 05 Feb '18

05 Feb '18

Hi, Ive discussed with Frank if there might be a field in the tdb file that has to be changed. Maybe there is a value that tells MapSource something about the alignment of DEM data? I don't have a single original Garmin tdb file :-( It seems that mkgmap writes some constants that might be important, e.g. MapDetailBlock.java contains //01 c3 00 ff os.write4(0xff00c301); os.write(0); os.write(0); os.write(0); The wiki [1] describes these 7 bytes as "byte:0 has copyright text,byte 1: has 0x53 text : byte 2:if 1 then bytes 3_7: an unknown total (density) " The display tool seems to expect something similar to the wiki: d.rawValue(2, "01 01"); d.byteValue("intro flag"); d.intValue("intro %d"); Any idea what this "intro" or "unknown total(density) could be ? And what is the 0x53 text? [1]https://wiki.openstreetmap.org/wiki/OSM_Map_On_Garmin/TDB_File_Format Gerd

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My findings about the crash in MapSource
by Gerd Petermann 05 Feb '18

05 Feb '18

Hi all, I found out that whenever mkgmap r4100 wrote a tile with DEM data that has the "extra flag" set to 2 (which means that the tile contains invalid height information which should be ignored) I was able to reproduce the crash in MapSource when clicking on "Show profile..." for a route which crosses the boundaries of this tile I found one error in the code for the --dem-poly option. This produced too many "invalid" values, even for tiles which are completely inside the bounding polygon. I fixed that with r4101. Still, the same problem occurs when a hgt file contains too many voids or the tile is in fact partly outside the polygon. It seems that Andrzejs patch dem-align-6.patch is part of the problem. When I disable parts of the code with the attached patch the problem seems to disappear. Gerd

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Commit r4103: improve description of DEM options
by svn commit 05 Feb '18

05 Feb '18

Version mkgmap-r4103 was committed by gerd on Sat, 03 Feb 2018 improve description of DEM options dem-options2.patch by Carlos Dávila, changes in options.txt should be similar http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4103

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Build instructions
by Jeremy Audet 04 Feb '18

04 Feb '18

Hi all, I maintain the mkgmap and splitter packages in the Arch Linux AUR. [1] [2] As far as I can tell, both of these applications require Java 8. For example, if splitter is executed with Java 7, it will throw a java.lang.UnsupportedClassVersionError. [3] Consequently, I've set both mkgmap and splitter to require Java 8. However, the mkgmap dev instructions indicate that Java 7 is supported. Is Java 7 supported? When responding, please cc me, as I'm not subscribed to mkgmap-dev. -Jeremy [1] https://aur.archlinux.org/packages/mkgmap/ [2] https://aur.archlinux.org/packages/splitter/ [3] https://pastebin.com/ZgceAK0w

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Commit r4105: improve description of options
by svn commit 04 Feb '18

04 Feb '18

Version mkgmap-r4105 was committed by gerd on Sun, 04 Feb 2018 improve description of options documentation-v4.patch by Mike Baggaley: -- Clarification that if you specify --route you do not also need to specify --net. -- Clarification that --net is for producing a map with full address search but no routing. -- Clarification that 25 is the default value for --draw-priority. -- Reversed the order of --transparent and --draw-priority so that the reader knows about transparency before reading about the drawing priority. -- Added a set of equivalents to --polygon-size (that I hope I have understood correctly). http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4105

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documentation improvements
by Mike Baggaley 03 Feb '18

03 Feb '18

Hi Gerd, I have attached a further patch for documentation improvements. This clarifies the syntax for several of the options and moves all the deprecated and obsolete options to the end. Please review and commit if happy. In further reading the documentation, I have the following questions that require clarification in the documentation: What are the units for --polygon-size-limits? Can we clarify --draw-priority=25. There is no explanation of what the 25 does. Is this only value that can be provided? What is different if this option is not provided? The operation of the --max-jobs option seems illogical. Why is the default not to use all the CPU cores and hence presumably minimise execution time? Cheers, Mike

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Commit r4104: Prevent crash when a typ text file contains an empty CodePage=
by svn commit 03 Feb '18

03 Feb '18

Version mkgmap-r4104 was committed by steve on Sat, 03 Feb 2018 Prevent crash when a typ text file contains an empty CodePage= http://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4104

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Please help with news about new DEM options
by Gerd Petermann 03 Feb '18

03 Feb '18

Hi all, with r4093 I've merged the dem-tdb branch into trunk. I think it would be good to mention this in the "Latest news" on [1] , maybe with one or two screen shots, but I have no idea how to write this "from a users view". Do we need a how-to that describes the sources for hgt files and maybe more about the new options? It would be great if somebody could help with that. Gerd [1] http://www.mkgmap.org.uk/

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