[mkgmap-dev] Sea generation

Sun Nov 14 15:07:50 GMT 2010

On 14/11/2010 04:40, Adrian wrote:
> On 5/11/2010, Charlie Ferrero wrote:
>> One improvement would be for the --generate-sea:mp version to imitate
>> the non-mp version in that a land polygon is generated to overwrite
>> the ugly Garmin yellow base colour.
>>
>> This is the only issue stopping me from switching to --generate-sea:mp
>
> I have produced a modification for mkgmap. It creates a land polygon
> covering each tile, when you are using the option
> --generate-sea=multipolygon. The tag of the land polygon is set in the
> same way as for the no-mp option. Note: Felix has reported that doing
> this, slows down redrawing of the screen. For that reason, he recommends
> against this approach. I was not sure whether you wanted a land polygon
> over the whole tile, or only over the actual land area. The latter would
> be more difficult, and I'm not a Java programmer. Perhaps my
> modification will do as a temporary fix. If you do not specify a land
> polygon type in the style file, the modification should have no effect.
>
> I will go into more detail than you may need, in the hope that it will
> be helpful to less expert readers.
> Download the source, e.g. mkgmap-r1728.src.tar.gz
> Unpack the file, to produce the directory, e.g. mkgmap-r1728
> Use a text editor to open the file
> mkgmap-r1728/src/uk/me/parabola/mkgmap/reader/osm/SeaGenerator.java
> After line 148, [Coord se = new Coord(maxLat, maxLong);] insert
>
> if (generateSeaUsingMP) {
> /*
> * Add a land polygon covering the tile
> */
> long landId = FakeIdGenerator.makeFakeId();
> Way land = new Way(landId);
> land.addPoint(nw);
> land.addPoint(sw);
> land.addPoint(se);
> land.addPoint(ne);
> land.addPoint(nw);
> land.addTag(landTag[0], landTag[1]);
> saver.addWay(land);
> }
>
> I have seen strange things happen to text in e-mails, such as tabs being
> converted to spaces, and leading blanks being suppressed. Each of the
> lines above starts with either two tabs or three tabs. So I have also
> attached a file containing the same block of code. (But the last time I
> sent a text attachment, it appeared on the mailing list web site with a
> .pl extension and with all the line-endings removed!) If your text
> editor cannot handle Unix line-endings, you may need to use unix2dos and
> dos2unix.
>
> Having saved the file, change to the directory mkgmap-r1728, and compile
> mkgmap by entering
> ant dist
> at the command line.
> (Note for Mac OS 10.5 Leopard. You need 64-bit Intel hardware to run
> Apple's Java v1.6. To get ant to use Java v1.6, change the symbolic link
> CurrentJDK in /System/Library/Frameworks/JavaVM.framework/Versions to
> point to 1.6 instead of 1.5. Changing the preferred version of Java in
> the Java Preferences utility will not do the trick. You may need to redo
> the change to the symbolic link after a Java update.)
> If you need to rerun the compilation after fixing a problem, sometimes
> it will not succeed unless you first issue the command
> ant clean
> The directory mkgmap-r1728/dist will contain what you would normally
> download as mkgmap-r1728.zip or mkgmap-r1728.tar.gz. The jar file will
> be at mkgmap-r1728/dist/mkgmap.jar
>
> I discovered while testing, that the restriction on short option names
> in the configuration (.args) file, also applies to input files. If you
> just put a file name in the .args file, it will be silently ignored. You
> have to put e.g. input-file:white.TYP
>
> I would have liked to make this work also when you are not using
> --generate-sea, but I could not see how, because method end() of class
> SeaGenerator is not invoked when you are not using --generate-sea. If
> you try to insert similar code into method init(...), which *is* always
> invoked, you find that saver.getBoundingBox returns default values - it
> has not yet been set up to correspond to the map. As a workaround for a
> land-only map, you could use my modified version of mkgmap, with
> --generate-sea=multipolygon, and use a custom style with the line
> natural=sea [0x32 resolution 10]
> removed from the polygons file, in order to avoid any possible problems
> with flooding. For a map with a coastline, this workaround will not give
> you a coastline way drawn on a white background.
>
> To get a white background, you need to use a custom style and a custom
> .TYP file. The style needs to contain a line such as
> natural=land [0x010100 resolution 16]
> in the polygons file. The .TYP file needs to specify the colour of
> polygon type 0x010100 (or whatever you have chosen). There is a good
> description of how to construct a .TYP file in the cGPSmapper manual
> http://cgpsmapper.com/download/cGPSmapper-UsrMan-v02.5.pdf
> There is a good online .TYP file creator/editor at
> http://ati.land.cz/gps/typdecomp/editor.cgi
> You will not need this for making a white background, but details of the
> Garmin colour palette are here
> http://www.mkgmap.org.uk/pipermail/mkgmap-dev/2010q1/007419.html
> Details of what you need to do for certain, particularly recalcitrant
> GPS receivers, are here
> http://www.mkgmap.org.uk/pipermail/mkgmap-dev/2010q1/006929.html
> Pay attention to the drawing order, to placeholders; make sure that the
> family-id in your .TYP file matches the family-id of your map. The land
> should be at drawing order 1 and the sea at drawing order 2. To include
> the .TYP file in your map, add it to the list of input files to mkgmap.
>

Hi, thanks for your patch.  Unfortunately it doesn't work well for me.

1. Compiled with mkgmap r1724, using 
generate-sea:no-mp,no-sea-sectors,extend-sea-sectors,close-gaps=1000 (my 
normal compile)
http://cferrero.net/maps/img/1724_polygons.png
Sea correct, land polygon present

2. Compiled with mkgmap r1724, using: 
generate-sea:multipolygon,extend-sea-sectors,close-gaps=1000
http://cferrero.net/maps/img/1724_multipolygons.png
Sea correct, no land polygon

3. Compiled with mkgmap r1728 with your patch, using: 
generate-sea:multipolygon,extend-sea-sectors,close-gaps=1000
http://cferrero.net/maps/img/1728_createlandpatch.png
No sea, entire map is land

--
Charlie