[mkgmap-dev] Really Serious bug when not using --route

Thu May 27 12:34:14 BST 2010


Felix Hartmann schrieb:
> On 27.05.2010 13:12, Johann Gail wrote:
>   
>>> Setting the fourth via gmaptool breaks the routing for routable maps 
>>> even though it should be there for setting maps tranparent/opaque is 
>>> some obscure way different from the general transparent/opaque flag
>>>
>>>       
>> Could this be the exactly the NOD flag?
>> If modifying this flag breaks routing then this IS a strong hint for 
>> influencing routing. Could it be that in this byte one bit is the flag 
>> for the presence (or absence) of the NOD table? If this bit is 
>> set/cleared then it tells the device that there is no NOD table and 
>> therefore no routing is possible.
>>
>>
>>     
> Well I don't know how to clear it. Setting it to 0 doesn't help. It 
> seems to only matter whether it is even or uneven. 
This is exactly what I meant by clearing the bit. With uneven values it 
is not set, i.e. cleared.
> Setting it even 
> breaks routing, while all uneven values work. Therefore I'm more or less 
> sure, this is not the NOD flag.
>   
Could you tell please, what happens with broken routing? Does it mean, 
there is no routing at all, or happens wrong routing?
> Also this byte is set for non routable garmin maps to even and uneven 
> values, so no, I don't think this has anything to do with it.
>
>   
This is the point which confuses me at the moment. This bit does 
influence routing in some way. But you say that there are nonroutable 
maps with this bit set/unset. So what could the meaning of this bit be?