[mkgmap-dev] Getting rid of the 'Node in too many areas' warning.

Mon Aug 16 12:46:59 BST 2010

Is there something wrong with this patch that kept it from going in?

Scott

On Thu, Jun 10, 2010 at 2:17 PM, Scott Crosby <scrosby06 at gmail.com> wrote:
> This patch to the splitter makes
> this warning MUCH more rare. With this patch, I can split the entire
> planet into 17219 areas with max-nodes=50000 resolution=14 without a
> single 'too many areas' warning among the the first 25 of 68
> passes. Without this patch, a max-nodes=500000 split has dozens of
> such warnings.
>
> This patch can also allow larger overlaps at a cost of more
> passes.
>
> The fix works by reordering the list of generated tiles. The trick is
> that the real limit in the splitter is that a node cannot be in more
> than 4 distinct areas PER PASS (A limit that remains unchanged with
> this patch.) If a node occurs in 10 tiles, but no single pass contains
> more than 4 of those tiles, everything works.   If there are still 'too many
> areas' warnings, they can be handled by reducing --max-areas.
>
> Note that my patch depends on some other bug fixes; there are several
> infinite recursion bugs in the current code that trigger when having
> the splitter generate such small tiles. Some of these were fixed in
> the trunk, but not all are. In addition, my fixes/cleanups try harder
> at getting a good split.
>
> Scott
>
>