Merge pull request #1631 from rouault/fix_1623

Document the autopromotion to 3D when mix of 2D/3D CRS in createOperations(), and test it (fixes #1623)

3 files changed, 11 insertions, 41 deletions

diff --git a/src/apps/projinfo.cpp b/src/apps/projinfo.cpp
index 1760ae29..fd9b2f46 100644
--- a/src/apps/projinfo.cpp
+++ b/src/apps/projinfo.cpp
@@ -601,37 +601,6 @@ static void outputOperationSummary(const CoordinateOperationNNPtr &op,
 
 // ---------------------------------------------------------------------------
 
-static size_t getAxisCount(const CRSNNPtr &crs) {
-    const auto singleCRS = dynamic_cast<const SingleCRS *>(crs.get());
-    if (singleCRS) {
-        return singleCRS->coordinateSystem()->axisList().size();
-    }
-    const auto compoundCRS = dynamic_cast<const CompoundCRS *>(crs.get());
-    if (compoundCRS) {
-        size_t axisCount = 0;
-        const auto &components = compoundCRS->componentReferenceSystems();
-        for (const auto &subCRS : components) {
-            axisCount += getAxisCount(subCRS);
-        }
-        return axisCount;
-    }
-    const auto boundCRS = dynamic_cast<const BoundCRS *>(crs.get());
-    if (boundCRS) {
-        return getAxisCount(boundCRS->baseCRS());
-    }
-    return 0;
-}
-
-// ---------------------------------------------------------------------------
-
-static bool is2D(const CRSNNPtr &crs) { return getAxisCount(crs) == 2; }
-
-// ---------------------------------------------------------------------------
-
-static bool is3D(const CRSNNPtr &crs) { return getAxisCount(crs) == 3; }
-
-// ---------------------------------------------------------------------------
-
 static void outputOperations(
     DatabaseContextPtr dbContext, const std::string &sourceCRSStr,
     const std::string &targetCRSStr, const ExtentPtr &bboxFilter,
@@ -666,15 +635,6 @@ static void outputOperations(
     }
     auto nnTargetCRS = NN_NO_CHECK(targetCRS);
 
-    if (!promoteTo3D && !outputOpt.quiet &&
-        ((is2D(nnSourceCRS) && is3D(nnTargetCRS)) ||
-         (is3D(nnSourceCRS) && is2D(nnTargetCRS)))) {
-        std::cerr << "Warning: mix of 2D and 3D CRS. Vertical transformations, "
-                     "if available, will not be applied. Consider using 3D "
-                     "version of the CRS, or the --3d switch"
-                  << std::endl;
-    }
-
     std::vector<CoordinateOperationNNPtr> list;
     size_t spatialCriterionPartialIntersectionResultCount = 0;
     try {
diff --git a/src/iso19111/c_api.cpp b/src/iso19111/c_api.cpp
index fd4090b2..090d59a1 100644
--- a/src/iso19111/c_api.cpp
+++ b/src/iso19111/c_api.cpp
@@ -7080,6 +7080,11 @@ void PROJ_DLL proj_operation_factory_context_set_discard_superseded(
  * by increasing accuracy. Operations with unknown accuracy are sorted last,
  * whatever their area.
  *
+ * When one of the source or target CRS has a vertical component but not the
+ * other one, the one that has no vertical component is automatically promoted
+ * to a 3D version, where its vertical axis is the ellipsoidal height in metres,
+ * using the ellipsoid of the base geodetic CRS.
+ *
  * @param ctx PROJ context, or NULL for default context
  * @param source_crs source CRS. Must not be NULL.
  * @param target_crs source CRS. Must not be NULL.
diff --git a/src/iso19111/coordinateoperation.cpp b/src/iso19111/coordinateoperation.cpp
index aea8400c..56a3b38c 100644
--- a/src/iso19111/coordinateoperation.cpp
+++ b/src/iso19111/coordinateoperation.cpp
@@ -13445,8 +13445,13 @@ getResolvedCRS(const crs::CRSNNPtr &crs,
  * by increasing accuracy. Operations with unknown accuracy are sorted last,
  * whatever their area.
  *
+ * When one of the source or target CRS has a vertical component but not the
+ * other one, the one that has no vertical component is automatically promoted
+ * to a 3D version, where its vertical axis is the ellipsoidal height in metres,
+ * using the ellipsoid of the base geodetic CRS.
+ *
  * @param sourceCRS source CRS.
- * @param targetCRS source CRS.
+ * @param targetCRS target CRS.
  * @param context Search context.
  * @return a list
  */