[mkgmap-dev] Drive-on-left

Sun Aug 18 19:13:47 BST 2013

>> Hi
>>
>>> Btw.: If it's necessary to set --drive-on-left to get everything you
>>> need for such a map, then we can remove also the automatism, because
>>> everyone will set the param ;)
>>
>> I'm in favour of removing the guessing. In addition to the problem that
>> it might be wrong because of bad data or two countries in the same tile
>> (the UK/France is particularly likely), the code is not thread safe and
>> so could cause extra tiles to have the wrong flag when used with
>> --max-jobs.
>>
>> I realise that it probably works 99 times out of a 100 or even more, but
>> when it does fail there is no possible warning or clue as to what
>> might have happened.
>>
>> ..Steve
>>
>
> Hi Steve,
>
> attached patch forwards the "guessed" drive-on-left value in a thread
> safe way to the NOD header by using a ThreadLocal variable. This is a
> small code change.
> Anyhow this makes only sense if you think that the guess algorithm is ok.
>
> WanMil
>

I have commited the patch although it does not solve all problems.

I found out that the driveOnLeft flag is always set to false if 
precompiled sea is used and there are mixed sea/land areas in the tile. 
The reason is that loading of precompiled sea tiles uses a MapDataSource 
that instantiates a StyledConverter without any config parameters. 
Therefore the driveOnLeft flag is always set to false.

I will fix that soon.

WanMil