[mkgmap-dev] [PATCH v1] make DP filter avoid removing points located at nodes

Mon Nov 23 09:39:03 GMT 2009

> If I understand the problem correctly, if someone (Felix, for example)
> generates multiple lines from the same OSM way and one of the lines is
> routable and the other(s) are not, then the original DP code would
> generate different shaped lines for the routable and non-routable ways
> because only the routable version of the line had CoordNodes in it. 
OK, I understand the problem so far.
> So,
> my patch just marks those points that are going to be nodes but that's
> done before the way is duplicated so those marked points will be seen
> in the DP code for both the routable and non-routable lines that are
> based on the same set of points. That's the theory, hopefully someone
> (Felix, for example) will test the patch and let us know if it works as
> expected.
>
>   
Isn't the only difference between routable and non routable lines the 
occurence of CoordNodes? Is I understand the structure of the classes, a 
Coord has only a location info, and a CoordNode is nearly the same, but 
means, that this coord has connections to multiple ways. This means not 
neccessarily that the way is routable, but that there are 
interconnections of lines.
(I have not looked into the code up to now, this is my understanding 
from remembering)

Your patch has moved the information 'this is a connecting node' from 
the class level to a member level. I would not say it is wrong, but this 
increases memory consumption, as this adds a new member (4 bytes?) to 
every instance of coord!

So in my opinion the error is in the copy function of the line. If a 
line contains CoordNodes, than also the copy should contain CoordNodes. 
Can you point me to the code, where the lines gets duplicated?

This all was some unfinished work of the dp filter. I would need some 
time to understand the classes structure in full and prepare a solution.

Regards,
Johann

> Cheers,
>
> Mark
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