[mkgmap-dev] [PATCH v1] Handling of boundary multipolygons

Mon Apr 19 20:08:02 BST 2010

>
> I don't really understand what this patch is trying to achieve. There is
> a patch by Thilo Hanneman (I'm attaching it for you) that makes it
> possible to directly render relations from the relations file, I think
> that is more useful - or don't I understand something here that you
> intend to achieve???
>

Felix,
I had a closer look at the patch and got some questions.

As far as I understand the patch it tries to connect all ways of a 
relation and tags these ways with a special mkgmap:gtype tag which is a 
summary of all attributes of the relation(?)

The convertRelation method tries to connect all ways of a relation. The 
responsible addWayToListAndChainIfPossible method seems to care about 
oneway tags if a way is classified as road.
I don't know if the handling of two connected ways in following order is 
correct:
Way 1: road, oneway=yes
Way 2: no road
You will get one way tagged with oneway=yes although the 2nd way is no 
road.

All new assembled ways are put to the waymap, but with a different id. 
The assembled way copies the original way id from the first way but for 
the way map a fake id is generated. Although it's working I think that's 
no good programming style.

I am a bit surprised because I think that the patch creates at least one 
new way for each relation. Doesn't that mean that you have n overlapping 
ways in case you have n relations on the same way? Probably I don't 
understand it so could you please explain what happens if one way is 
contained in multiple relations?

WanMil