[mkgmap-dev] Polygon draw order, and routing across tiles

Sun Jun 23 12:04:59 BST 2013

Hi,

This is not a bug report, but something I found interesting.

I recently noticed a problem with polygon draw order in Mapsource; and on my Dakota 20. Sometimes a polygon was drawn correctly above another (according with the draw order specified in the TYP file), and at other times not. I don’t believe mkgmap actually processes the TYP file so I did not report it here. This morning I was playing with drawing dark lines around polygons to “fix” this, but found mkgmap created a 28000+ Kb file that was too large for Mapsource to show. When I reduced the –max-nodes option to produce smaller tiles I noticed it fixed some, but not all of the polygon draw order problems. So I reduced it further (from the original 1500000, to 750000) and found it fixed all the draw order problems I had noticed.

>From previous posts and experience, I knew there was a problem routing across tile boundaries (which is why I had been using 1500000 to reduce the number of tiles produced, and thus the boundaries). So I found an area where 4 tiles met close to each other, and tried auto-routing across the boundaries in Mapsource. To my surprise reducing the max-nodes had now fixed this problem as well, and I could route anyway I liked E->W, W->E, N->S, S->N across the four boundaries. Auto-routing also worked fine on my device as well 

So if anyone is experiencing similar problems; I suggest trying to reduce the max-nodes and seeing if that helps.

Geoff. 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.mkgmap.org.uk/pipermail/mkgmap-dev/attachments/20130623/f0ae2918/attachment.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/png
Size: 1046 bytes
Desc: not available
Url : http://lists.mkgmap.org.uk/pipermail/mkgmap-dev/attachments/20130623/f0ae2918/attachment.png 