Opened 9 years ago

Closed 9 years ago

Last modified 9 years ago

#2995 closed defect (fixed)

Merkaartor TMS implementation is backwards

Reported by: HamishB Owned by: cbro@…
Priority: major Milestone:
Component: merkaartor Version:
Keywords: tms Cc: merkaartor@…

Description

Hi,

After a bit of frustration ... it appears that Merkaartor (well, Slippy tiles really) follows Google maps in making the TMS tile grid start from 0,0 in the top-left, not the bottom left as specified by the TMS spec.

Slippy tiles spec:

http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#X_and_Y

TMS spec:

http://wiki.osgeo.org/wiki/Tile_Map_Service_Specification#Tile_Resources

gdal2tiles.py code comments on the subject:

https://trac.osgeo.org/gdal/browser/trunk/gdal/swig/python/scripts/gdal2tiles.py?rev=19288#L146

I'm not asking that Slippy tiles, T@H, CycleMap?, etc all suddenly turn on their head and start following the official spec, but as Merkaartor calls it "TMS" it would be nice if there were at least a tickbox on the Merkaartor TMS server editor setup that let you choose the alternate convention for those times you would like to connect to a TMS which is following the spec.

(I'm not sure which spec came first, but at this point they are both established so it doesn't really matter)

Manifestation: TMS tilesets created with GDAL's gdal2tiles.py script don't show up where you expect them (they end up reversed in the wrong hemisphere).

thanks, Hamish

Change History (2)

comment:1 Changed 9 years ago by Chris Browet

Cc: merkaartor@… added
Resolution: fixed
Status: newclosed

This is already implemented in trunk/0.16. There is a new checkbox that allows to specify that (0,0) is bottom-left (osgeo way).

Furthermore, the full osgeo tms spec is now implemented, so giving a TMS generic url and clicking on the "get services" button will show you the same kind of list as in the WMS editor.

comment:2 Changed 9 years ago by HamishB

now that's what I call fast service. excellent, thanks!

regards, Hamish

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