[mapserver-users] Label text always clipped by tiles

Jean-François Gigand jean-francois at gigand.fr
Wed Jan 26 11:46:33 PST 2011


Hi,

2011/1/26 Gregor at HostGIS <gregor at hostgis.com>:
>> My problem is that I need ALL labels to be complete and visible.
>
> I don't think that's possible if you're using tiles. Somewhere, some label
> will be close to a tile boundary and be truncated or omitted.

I think it is possible! Because setting a "big enough" metaBuffer will
make all labels "far enough" from tile boundaries (since the
metaBuffer artificially extends tile boundaries).

What about the "labelcache_map_edge_buffer" metadata option of
MapServer the TileCache doc talks about ?
(http://tilecache.org/docs/README.html)
I could not find good doc about it.

However, it should not be needed. Try setting the metaBuffer quite big
(more than 20, say 100 as a test).
Disable metaTile to keep things simple for the test.

Enable MapServer logging and check the GetMap dimensions requested by TileCache.
Requesting TileCache for 256px with metaBuffer=100 should generate
MapServer GetMap requests with width and height of 456px.
Also, make sure PIL has no problem cropping the image back to 256px.
Check the interlaced PNG issue
(http://tilecache.org/docs/README.html).



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