[mkgmap-dev] r3678 and overview map problems

Fri Jul 15 06:34:51 BST 2016

Hi all,

I assume Thomas did not find any problems. I'd like to commit the patch.
Any complains?

Gerd

Thomas Morgenstern wrote
> Hi Gerd, thank's for the solution. I have testet the patched r-3678.jar  
> binary for two examples. It works  well.  But i must make a few more 
> test's. Till now, all is okay..
>   Thomas
> Am 09.07.2016 um 08:14 schrieb Gerd Petermann:
>>
>> Hi Thomas,
>>
>>
>> okay, I have now checked your test case as well.
>>
>> I think Steve has already explained why the change in r3674 introduced 
>> the problem,
>>
>> the newer versions read the input files in sorted order when creating 
>> the overview map,
>>
>> older releases used the order given in the command line.
>>
>>
>> A simple work-around would be to use higher numbers for the tiles 
>> which should be processed later,
>>
>> e.g. 9999 instead of 4000 for the contour tiles.
>>
>>
>> A better solution would be to detect the needed resolution. The 
>> problem here:
>>
>> mkgmap has to read all input tiles (completely) to find out which one 
>> uses the lowest resolution,
>>
>> current code doesn't allow to read only the levels info. So one has to 
>> accept a longer run time.
>>
>> I don't know if that is really needed, maybe an empty overview map can 
>> always use a low resoltion
>>
>> like 12?
>>
>>
>> Another solution would be to evaluate the overview-levels option as 
>> suggested by Steve.
>>
>>
>> In your case the overview map is empty, it contains only the 0x4a 
>> polygons, so it is quite simple.
>>
>>
>> I have no idea what mkgmap should do when a user tries to combine 
>> ovm*.img files which were
>>
>> created with different overview-level options, I leave that open.
>>
>>
>> I've impemented both alternatives in the attached patch, a binary 
>> based on r3678 is here:
>>
>> http://files.mkgmap.org.uk/download/299/mkgmap.jar
>>
>>
>> The patch solves your problem, but I'd prefer to avoid the additional 
>> reading of all input files
>>
>> before the overview map is produced.
>>
>> @all : What do you think about the alternative to use a fixed 
>> resolution of 12 for an overview map
>>
>> that contains only the tile boundary infos?
>>
>>
>> Gerd
>>
>>
>>
>> ------------------------------------------------------------------------
>> *Von:* mkgmap-dev <

> mkgmap-dev-bounces at .org

> > im Auftrag 
>> von Thomas Morgenstern <

> webmaster@

> >
>> *Gesendet:* Freitag, 8. Juli 2016 20:41:08
>> *An:* Development list for mkgmap
>> *Betreff:* Re: [mkgmap-dev] r3678 and overview map problems
>> Hi Gerd , Update:
>>
>> r-3778 create now 1 0x4a like expected. This is a good news. But in my 
>> testenvironment are 2 osm-tiles and 1 contourtile. One of the osmtile 
>> has a wrong position. it is shifted to east ~22 degrees. The tile 
>> itself has 25.4 degreees east-west .
>> thomas
>>
>> Am 08.07.2016 um 16:49 schrieb Thomas Morgenstern:

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