Determine Point Type from CRS

[bethanywallace]

Hi, first of all thanks so much for help on the other issue I opened!

I was wondering if there was a way to create a point using a CRS without having to define the Geometry type? For example, instead of
GeographicPoint::create we could do Point::create and instead pass in the CRS that the point is in. So if it was a Projected CRS it would automatically define it using Metres?

[dvdoug]

Hi

Unfortunately not all projected CRSs are in metres - e.g particularly in the US, some are metres, some are international feet, some are US survey feet. In some cases there are even multiple CRS definitions for what is fundamentally the same projection, just using different units of measurement e.g. EPSG 3678/3679/3680 which are NAD83(NSRS2007) / Utah North, NAD83(NSRS2007) / Utah North (ft) and NAD83(NSRS2007) / Utah North (ftUS) respectively.

It's for this sort of reason the library is quite insistent on making specify the units involved the hard way.

However if you want to implement an auto-unit implementation yourself that should be doable - you can do something like this

$crs = Projected::fromSRID(Projected::EPSG_WHATEVER);
$axes = $crs->getCoordinateSystem->getAxes();
$eastingUnitOfMeasureId = $axes->getAxisByName(Axis::EASTING)->getUnitOfMeasureId();
$easting = UnitOfMeasureFactory::makeUnit(12.345, $eastingUnitOfMeasureId );
$northingUnitOfMeasureId = $axes->getAxisByName(Axis::NORTHING)->getUnitOfMeasureId();
$northing = UnitOfMeasureFactory::makeUnit(12.345, $northingUnitOfMeasureId );


$point = ProjectedPoint::createFromEastingNorthing($crs, $easting, $northing);