createOperations(): deal with spherical planetocentric geodetic CRS

This also fixes conversion between geocentric latlong and geodetic latlong
with cs2cs. This was dealt with in PR 1093, but in the wrong direction
(the geocentric latitude must be <= in absolute value to the geodetic one)
The issue here was linked to the semantics of the +geoc specifier, which
affects the semantics of the input coordinates in the forward direction
(+geoc means that the input coordinate is is a geocentric latitude),
which defeats the logic of doing A to B by using the inverse path of A
and the forward path of B.

1 files changed, 26 insertions, 23 deletions

diff --git a/src/iso19111/operation/transformation.cpp b/src/iso19111/operation/transformation.cpp
index 273b636f..a30e1248 100644
--- a/src/iso19111/operation/transformation.cpp
+++ b/src/iso19111/operation/transformation.cpp
@@ -474,13 +474,16 @@ static void getTransformationType(const crs::CRSNNPtr &sourceCRSIn,
         dynamic_cast<const crs::GeographicCRS *>(sourceCRSIn.get());
     auto targetCRSGeog =
         dynamic_cast<const crs::GeographicCRS *>(targetCRSIn.get());
-    if (!sourceCRSGeog || !targetCRSGeog) {
+    if (!(sourceCRSGeog ||
+          (sourceCRSGeod && sourceCRSGeod->isSphericalPlanetocentric())) ||
+        !(targetCRSGeog ||
+          (targetCRSGeod && targetCRSGeod->isSphericalPlanetocentric()))) {
         throw InvalidOperation("Inconsistent CRS type");
     }
     const auto nSrcAxisCount =
-        sourceCRSGeog->coordinateSystem()->axisList().size();
+        sourceCRSGeod->coordinateSystem()->axisList().size();
     const auto nTargetAxisCount =
-        targetCRSGeog->coordinateSystem()->axisList().size();
+        targetCRSGeod->coordinateSystem()->axisList().size();
     isGeog2D = nSrcAxisCount == 2 && nTargetAxisCount == 2;
     isGeog3D = !isGeog2D && nSrcAxisCount >= 2 && nTargetAxisCount >= 2;
 }
@@ -1003,36 +1006,36 @@ TransformationNNPtr Transformation::createTOWGS84(
             "Invalid number of elements in TOWGS84Parameters");
     }
 
-    crs::CRSPtr transformSourceCRS = sourceCRSIn->extractGeodeticCRS();
-    if (!transformSourceCRS) {
+    auto transformSourceGeodCRS = sourceCRSIn->extractGeodeticCRS();
+    if (!transformSourceGeodCRS) {
         throw InvalidOperation(
             "Cannot find GeodeticCRS in sourceCRS of TOWGS84 transformation");
     }
 
     util::PropertyMap properties;
     properties.set(common::IdentifiedObject::NAME_KEY,
-                   concat("Transformation from ", transformSourceCRS->nameStr(),
-                          " to WGS84"));
-
-    auto targetCRS =
-        dynamic_cast<const crs::GeographicCRS *>(transformSourceCRS.get())
-            ? util::nn_static_pointer_cast<crs::CRS>(
-                  crs::GeographicCRS::EPSG_4326)
-            : util::nn_static_pointer_cast<crs::CRS>(
-                  crs::GeodeticCRS::EPSG_4978);
-
+                   concat("Transformation from ",
+                          transformSourceGeodCRS->nameStr(), " to WGS84"));
+
+    auto targetCRS = dynamic_cast<const crs::GeographicCRS *>(
+                         transformSourceGeodCRS.get()) ||
+                             transformSourceGeodCRS->isSphericalPlanetocentric()
+                         ? util::nn_static_pointer_cast<crs::CRS>(
+                               crs::GeographicCRS::EPSG_4326)
+                         : util::nn_static_pointer_cast<crs::CRS>(
+                               crs::GeodeticCRS::EPSG_4978);
+
+    crs::CRSNNPtr transformSourceCRS = NN_NO_CHECK(transformSourceGeodCRS);
     if (TOWGS84Parameters.size() == 3) {
         return createGeocentricTranslations(
-            properties, NN_NO_CHECK(transformSourceCRS), targetCRS,
-            TOWGS84Parameters[0], TOWGS84Parameters[1], TOWGS84Parameters[2],
-            {});
+            properties, transformSourceCRS, targetCRS, TOWGS84Parameters[0],
+            TOWGS84Parameters[1], TOWGS84Parameters[2], {});
     }
 
-    return createPositionVector(properties, NN_NO_CHECK(transformSourceCRS),
-                                targetCRS, TOWGS84Parameters[0],
-                                TOWGS84Parameters[1], TOWGS84Parameters[2],
-                                TOWGS84Parameters[3], TOWGS84Parameters[4],
-                                TOWGS84Parameters[5], TOWGS84Parameters[6], {});
+    return createPositionVector(
+        properties, transformSourceCRS, targetCRS, TOWGS84Parameters[0],
+        TOWGS84Parameters[1], TOWGS84Parameters[2], TOWGS84Parameters[3],
+        TOWGS84Parameters[4], TOWGS84Parameters[5], TOWGS84Parameters[6], {});
 }
 
 // ---------------------------------------------------------------------------