Fixes 180th meridian crossing for @turf/rhumb-destination #771
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…ion; added tests;
| @@ -51,5 +51,8 @@ module.exports = function (origin, distance, bearing, units) { | |||
| var pt = new GeodesyLatLon(coords[1], coords[0]); | |||
| var destination = pt.rhumbDestinationPoint(distanceInMeters, bearing); | |||
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| // compensate the crossing of the 180th meridian (https://macwright.org/2016/09/26/the-180th-meridian.html) | |||
| // solution from https://github.com/mapbox/mapbox-gl-js/issues/3250#issuecomment-294887678 | |||
| destination.lon += (destination.lon - coords[0] > 180) ? -360 : (coords[0] - destination.lon > 180) ? 360 : 0; | |||
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👍 patch, but what if the input is [-720, 65].
I wrote a full library for this type of fix, this is "simple" but really annoying to implement.
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Example Point at -539 longitude
{
"type": "Feature",
"properties": {
"bearing": -90,
"dist": 100
},
"geometry": {
"type": "Point",
"coordinates": [
-539.5,
-16.5
]
}
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Oh nevermind, it seems to work just fine.
No we should keep the input coordinates the same, there's merit to having coordinates with +180 longitude, it's really up to the GIS application to handle those coordinates, Leaflet & MapboxGL can handle it just fine.
Yep I think we should apply this to these modules as well, this isn't a breaking change since this only affects Fiji or calculations crossing the 180th Meridian. CC: @morganherlocker @mourner Feel free to jump in if you think otherwise. |
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This fix reflects @tmcw's excellent The 180th Meridian article/blog. |
Fixes #770, returning if necessary longitude greater than 180 degrees.
Please fill free to add more tests.
I'd see this as a bug fix rather than a breaking compatibility with previous version.
Modules depending on
@turf/rhumb-destination:@turf/transform-translate@turf/transform-rotate@turf/transform-scale(still under-construction)@DenisCarriere we might want to mention this behaviour to the README?
Also, I was wondering if we needed now to check if the input has longitude greater than 180 degrees, so that it's normalized between -180..180 before the computation.
Finally, do you think we should add the same correction to
@turf/destinationand other modules?cc: @dpmcmlxxvi