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gbif / maps

GBIF mapping service built on HBase and ElasticSearch, supporting Mapbox Vector Tiles and PNGs
Apache License 2.0
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map demo13 shows wrong tile value for y #72

Open jhnwllr opened 1 year ago

jhnwllr commented 1 year ago

I find this demo useful for navigating map tiles, as users sometimes request a static map.

https://api.gbif.org/v2/map/demo13.html#map=4.721949986524806/-230.5/37.74/0

I believe both y values should be zero in this image:

image

MattBlissett commented 1 year ago

There are/were two ways of addressing map tiles, either with the origin at the top left, or the bottom left.

The version of OpenLayers used here has a different internal addressing scheme than the most common way, used by our tiles, so the Y values are negative. It is indeed confusing.

https://api.gbif-uat.org/v1/geocode/debug/map.html uses a newer version of OpenLayers, so the solution will be to upgrade OpenLayers on these demos.