[PATCH] overflow with near-pole data and mercator

[openstreetmap-trac]

Reporter: Kompa
[Submitted to the original trac issue database at 3.03pm, Tuesday, 11th January 2011]

Here's a patch to (hopefully) fix "South Pole Near Africa" problem with osm2pgsql.

Demonstration of that:

• OSM mapnik: http://www.openstreetmap.org/?lat=0&lon=0&zoom=15&layers=M
• Custom mapnik: http://latlon.org/~komzpa/screenshots/osm2pgsql.jpg

What this patch does:

1. Checks for Sphrical Mercator;
2. Checks whether node is a lot outside tile 0/0/0. Snaps it to boundary that does not lead to overflow;
3. Replaces proj4 calculation with direct Spherical Mercator formula, which is less strict about overflows and gave me ~5% speedup on test dataset.

[openstreetmap-trac]

Author: jburgess777[at]googlemail.com
[Added to the original trac issue at 5.54pm, Sunday, 16th January 2011]

Patch applied with some minor tweaks in r25075.

[openstreetmap-trac]

Author: chris66
[Added to the original trac issue at 6.35pm, Sunday, 13th February 2011]

Still South Pole data can be seen at Africa:

http://www.openstreetmap.org/?lat=-0.111&lon=0.154&zoom=10&layers=M

[openstreetmap-trac]

Author: Ldp
[Added to the original trac issue at 7.06pm, Sunday, 13th February 2011]

It is fixed, in the tools.

Now, it takes time to work that out of the data and the map. It'll be gone after the next full import, which hopefully will not take that long anymore to start.