improve isEquivalentTo() when comparing Helmert transformations

3 files changed, 89 insertions, 1 deletions

diff --git a/src/coordinateoperation.cpp b/src/coordinateoperation.cpp
index ac2c4196..ef03edf8 100644
--- a/src/coordinateoperation.cpp
+++ b/src/coordinateoperation.cpp
@@ -1463,6 +1463,57 @@ bool SingleOperation::_isEquivalentTo(
             // Check it by using convertToOtherMethod()
 
             const int otherMethodEPSGCode = otherSO->d->method_->getEPSGCode();
+
+            if ((methodEPSGCode ==
+                     EPSG_CODE_METHOD_GEOCENTRIC_TRANSLATION_GEOCENTRIC &&
+                 (otherMethodEPSGCode ==
+                      EPSG_CODE_METHOD_POSITION_VECTOR_GEOCENTRIC ||
+                  otherMethodEPSGCode ==
+                      EPSG_CODE_METHOD_COORDINATE_FRAME_GEOCENTRIC)) ||
+                (methodEPSGCode ==
+                     EPSG_CODE_METHOD_GEOCENTRIC_TRANSLATION_GEOGRAPHIC_2D &&
+                 (otherMethodEPSGCode ==
+                      EPSG_CODE_METHOD_POSITION_VECTOR_GEOGRAPHIC_2D ||
+                  otherMethodEPSGCode ==
+                      EPSG_CODE_METHOD_COORDINATE_FRAME_GEOGRAPHIC_2D)) ||
+                (methodEPSGCode ==
+                     EPSG_CODE_METHOD_GEOCENTRIC_TRANSLATION_GEOGRAPHIC_3D &&
+                 (otherMethodEPSGCode ==
+                      EPSG_CODE_METHOD_POSITION_VECTOR_GEOGRAPHIC_3D ||
+                  otherMethodEPSGCode ==
+                      EPSG_CODE_METHOD_COORDINATE_FRAME_GEOGRAPHIC_3D))) {
+                auto transf = static_cast<const Transformation *>(this);
+                auto otherTransf = static_cast<const Transformation *>(otherSO);
+                auto params = transf->getTOWGS84Parameters();
+                auto otherParams = otherTransf->getTOWGS84Parameters();
+                return params == otherParams;
+            }
+
+            if ((otherMethodEPSGCode ==
+                     EPSG_CODE_METHOD_GEOCENTRIC_TRANSLATION_GEOCENTRIC &&
+                 (methodEPSGCode ==
+                      EPSG_CODE_METHOD_POSITION_VECTOR_GEOCENTRIC ||
+                  methodEPSGCode ==
+                      EPSG_CODE_METHOD_COORDINATE_FRAME_GEOCENTRIC)) ||
+                (otherMethodEPSGCode ==
+                     EPSG_CODE_METHOD_GEOCENTRIC_TRANSLATION_GEOGRAPHIC_2D &&
+                 (methodEPSGCode ==
+                      EPSG_CODE_METHOD_POSITION_VECTOR_GEOGRAPHIC_2D ||
+                  methodEPSGCode ==
+                      EPSG_CODE_METHOD_COORDINATE_FRAME_GEOGRAPHIC_2D)) ||
+                (otherMethodEPSGCode ==
+                     EPSG_CODE_METHOD_GEOCENTRIC_TRANSLATION_GEOGRAPHIC_3D &&
+                 (methodEPSGCode ==
+                      EPSG_CODE_METHOD_POSITION_VECTOR_GEOGRAPHIC_3D ||
+                  methodEPSGCode ==
+                      EPSG_CODE_METHOD_COORDINATE_FRAME_GEOGRAPHIC_3D))) {
+                auto transf = static_cast<const Transformation *>(this);
+                auto otherTransf = static_cast<const Transformation *>(otherSO);
+                auto params = transf->getTOWGS84Parameters();
+                auto otherParams = otherTransf->getTOWGS84Parameters();
+                return params == otherParams;
+            }
+
             if (methodEPSGCode ==
                     EPSG_CODE_METHOD_LAMBERT_CONIC_CONFORMAL_1SP &&
                 otherMethodEPSGCode ==
diff --git a/src/crs.cpp b/src/crs.cpp
index 40a8e2e1..10bec815 100644
--- a/src/crs.cpp
+++ b/src/crs.cpp
@@ -3806,12 +3806,13 @@ bool BoundCRS::_isEquivalentTo(const util::IComparable *other,
          !ObjectUsage::_isEquivalentTo(other, criterion))) {
         return false;
     }
+    const auto standardCriterion = getStandardCriterion(criterion);
     return d->baseCRS_->_isEquivalentTo(otherBoundCRS->d->baseCRS_.get(),
                                         criterion) &&
            d->hubCRS_->_isEquivalentTo(otherBoundCRS->d->hubCRS_.get(),
                                        criterion) &&
            d->transformation_->_isEquivalentTo(
-               otherBoundCRS->d->transformation_.get(), criterion);
+               otherBoundCRS->d->transformation_.get(), standardCriterion);
 }
 
 // ---------------------------------------------------------------------------
diff --git a/test/unit/test_operation.cpp b/test/unit/test_operation.cpp
index 3d1cfc42..b5bd188c 100644
--- a/test/unit/test_operation.cpp
+++ b/test/unit/test_operation.cpp
@@ -6654,3 +6654,39 @@ TEST(operation, lcc2sp_to_lcc1sp_invalid_eccentricity) {
         EPSG_CODE_METHOD_LAMBERT_CONIC_CONFORMAL_1SP);
     EXPECT_FALSE(targetConv != nullptr);
 }
+
+// ---------------------------------------------------------------------------
+
+TEST(operation, three_param_equivalent_to_seven_param) {
+
+    auto three_param = Transformation::createGeocentricTranslations(
+        PropertyMap(), GeographicCRS::EPSG_4269, GeographicCRS::EPSG_4326, 1.0,
+        2.0, 3.0, {});
+
+    auto seven_param_pv = Transformation::createPositionVector(
+        PropertyMap(), GeographicCRS::EPSG_4269, GeographicCRS::EPSG_4326, 1.0,
+        2.0, 3.0, 0.0, 0.0, 0.0, 0.0, {});
+
+    auto seven_param_cf = Transformation::createCoordinateFrameRotation(
+        PropertyMap(), GeographicCRS::EPSG_4269, GeographicCRS::EPSG_4326, 1.0,
+        2.0, 3.0, 0.0, 0.0, 0.0, 0.0, {});
+
+    auto seven_param_non_eq = Transformation::createPositionVector(
+        PropertyMap(), GeographicCRS::EPSG_4269, GeographicCRS::EPSG_4326, 1.0,
+        2.0, 3.0, 1.0, 0.0, 0.0, 0.0, {});
+
+    EXPECT_TRUE(three_param->isEquivalentTo(
+        seven_param_pv.get(), IComparable::Criterion::EQUIVALENT));
+
+    EXPECT_TRUE(three_param->isEquivalentTo(
+        seven_param_cf.get(), IComparable::Criterion::EQUIVALENT));
+
+    EXPECT_TRUE(seven_param_cf->isEquivalentTo(
+        three_param.get(), IComparable::Criterion::EQUIVALENT));
+
+    EXPECT_TRUE(seven_param_pv->isEquivalentTo(
+        three_param.get(), IComparable::Criterion::EQUIVALENT));
+
+    EXPECT_FALSE(three_param->isEquivalentTo(
+        seven_param_non_eq.get(), IComparable::Criterion::EQUIVALENT));
+}