Sounds good Wanmil, a separate style file for generating the overview map is also a good thing. I have succesfully updated the overview maps for my Europe maps with the patch, it is already an improvement to see no blank maps anymore when zooming out! Wanmil wrote:
What about the following ideas:
1. Retrieve the data from the highest instead of the lowest level. The lowest level often contains fragmentary data, e.g. have a look a the boundaries in your example image http://gis.19327.n5.nabble.com/file/n5754697/africa_overview.png The data could be merged so that long ways are created that do not fall through the filters (DouglasPeucker etc.). The MapReader.linesForLevel and other methods must have filters that returns only selected garmin id types.
2. Use a separate overview style file and fetch the Garmin ids out of it. Then use these Garmin ids to build the overview map. I think the overview map should be configurable (one likes to see motorways, others like to see rivers etc.) Maybe it would also be possible to add a special overview statement or use special overview levels in the normal style files to achieve the same.
3. In case --precomp-sea parameter is set the data from an additional file in the precompiled sea folder is used.
WanMil