createOperations(): fine tune for 'GDA94 + AHD height' to 'GDA2020 to AVWS height'

src/iso19111/operation/coordinateoperationfactory.cpp

@@ -6452,17 +6452,23 @@ void CoordinateOperationFactory::Private::createOperationsCompoundToCompound(
     if (srcGeog == nullptr || dstGeog == nullptr) {
         return;
     }
-
-    // Use PointMotionOperations if appropriate and available
+    const bool srcGeogIsSameAsDstGeog = srcGeog->_isEquivalentTo(
+        dstGeog.get(), util::IComparable::Criterion::EQUIVALENT);
     const auto &authFactory = context.context->getAuthorityFactory();
     auto dbContext =
         authFactory ? authFactory->databaseContext().as_nullable() : nullptr;
+    const auto intermGeogSrc = srcGeog->promoteTo3D(std::string(), dbContext);
+    const auto intermGeogDst =
+        srcGeogIsSameAsDstGeog ? intermGeogSrc
+                               : dstGeog->promoteTo3D(std::string(), dbContext);
+    const auto opsGeogSrcToGeogDst = createOperations(
+        intermGeogSrc, sourceEpoch, intermGeogDst, targetEpoch, context);
 
+    // Use PointMotionOperations if appropriate and available
     if (authFactory && sourceEpoch.has_value() && targetEpoch.has_value() &&
         !sourceEpoch->coordinateEpoch()._isEquivalentTo(
             targetEpoch->coordinateEpoch()) &&
-        srcGeog->_isEquivalentTo(dstGeog.get(),
-                                 util::IComparable::Criterion::EQUIVALENT)) {
+        srcGeogIsSameAsDstGeog) {
         const auto pmoSrc = authFactory->getPointMotionOperationsFor(
             NN_NO_CHECK(srcGeog), true);
         if (!pmoSrc.empty()) {
@@ -6588,9 +6594,20 @@ void CoordinateOperationFactory::Private::createOperationsCompoundToCompound(
                 // If we didn't find a non-ballpark transformation between
                 // the 2 vertical CRS, then try through intermediate geographic
                 // CRS
+                // Do that although when the geographic CRS of the source and
+                // target CRS are not the same, but only if they have a 3D
+                // known version, and there is a non-ballpark transformation
+                // between them.
+                // This helps for "GDA94 + AHD height" to "GDA2020 + AVWS
+                // height" going through GDA94 3D and GDA2020 3D
                 bTryThroughIntermediateGeogCRS =
                     (verticalTransforms.size() == 1 &&
-                     verticalTransforms.front()->hasBallparkTransformation());
+                     verticalTransforms.front()->hasBallparkTransformation()) ||
+                    (!srcGeogIsSameAsDstGeog &&
+                     !intermGeogSrc->identifiers().empty() &&
+                     !intermGeogDst->identifiers().empty() &&
+                     !opsGeogSrcToGeogDst.empty() &&
+                     !opsGeogSrcToGeogDst.front()->hasBallparkTransformation());
             }
         }
     }
@@ -6648,14 +6665,6 @@ void CoordinateOperationFactory::Private::createOperationsCompoundToCompound(
         // WGS 84 + EGM96 --> ETRS89 + Belfast height where
         // there is a geoid model for EGM96 referenced to WGS 84
         // and a geoid model for Belfast height referenced to ETRS89
-        const auto intermGeogSrc =
-            srcGeog->promoteTo3D(std::string(), dbContext);
-        const bool intermGeogSrcIsSameAsIntermGeogDst =
-            srcGeog->_isEquivalentTo(dstGeog.get());
-        const auto intermGeogDst =
-            intermGeogSrcIsSameAsIntermGeogDst
-                ? intermGeogSrc
-                : dstGeog->promoteTo3D(std::string(), dbContext);
         const auto opsSrcToGeog = createOperations(
             sourceCRS, sourceEpoch, intermGeogSrc, sourceEpoch, context);
         const auto opsGeogToTarget = createOperations(
@@ -6695,9 +6704,6 @@ void CoordinateOperationFactory::Private::createOperationsCompoundToCompound(
         double bestAccuracy = -1;
         size_t bestStepCount = 0;
         if (hasNonTrivialSrcTransf && hasNonTrivialTargetTransf) {
-            const auto opsGeogSrcToGeogDst =
-                createOperations(intermGeogSrc, sourceEpoch, intermGeogDst,
-                                 targetEpoch, context);
             // In first pass, exclude (horizontal) ballpark operations, but
             // accept them in second pass.
             for (int pass = 0; pass <= 1 && res.empty(); pass++) {
@@ -6726,7 +6732,7 @@ void CoordinateOperationFactory::Private::createOperationsCompoundToCompound(
                             try {
                                 res.emplace_back(
                                     ConcatenatedOperation::createComputeMetadata(
-                                        intermGeogSrcIsSameAsIntermGeogDst
+                                        srcGeogIsSameAsDstGeog
                                             ? std::vector<
                                                   CoordinateOperationNNPtr>{op1,
                                                                             op3}

test/unit/test_operationfactory.cpp

@@ -5992,6 +5992,44 @@ TEST(operation, compoundCRS_to_compoundCRS_context_helmert) {
 
 // ---------------------------------------------------------------------------
 
+TEST(operation, compoundCRS_to_compoundCRS_GDA94_AHD_to_GDA2020_AVWS) {
+    auto dbContext = DatabaseContext::create();
+    auto authFactory = AuthorityFactory::create(dbContext, "EPSG");
+    auto ctxt = CoordinateOperationContext::create(authFactory, nullptr, 0.0);
+    ctxt->setGridAvailabilityUse(
+        CoordinateOperationContext::GridAvailabilityUse::
+            IGNORE_GRID_AVAILABILITY);
+    ctxt->setSpatialCriterion(
+        CoordinateOperationContext::SpatialCriterion::PARTIAL_INTERSECTION);
+    auto list = CoordinateOperationFactory::create()->createOperations(
+        // GDA94 + AHD height
+        authFactory->createCoordinateReferenceSystem("9464"),
+        // GDA2020 + AVWS height
+        authFactory->createCoordinateReferenceSystem("9462"), ctxt);
+    ASSERT_GE(list.size(), 1U);
+    EXPECT_EQ(list[0]->nameStr(),
+              "Inverse of 'GDA94 to GDA94 + AHD height (1)' + "
+              "GDA94 to GDA2020 (1) + "
+              "GDA2020 to AVWS height (2)");
+    EXPECT_EQ(list[0]->exportToPROJString(PROJStringFormatter::create().get()),
+              "+proj=pipeline "
+              "+step +proj=axisswap +order=2,1 "
+              "+step +proj=unitconvert +xy_in=deg +xy_out=rad "
+              "+step +proj=vgridshift +grids=au_ga_AUSGeoid09_V1.01.tif "
+              "+multiplier=1 "
+              "+step +proj=cart +ellps=GRS80 "
+              "+step +proj=helmert +x=0.06155 +y=-0.01087 +z=-0.04019 "
+              "+rx=-0.0394924 +ry=-0.0327221 +rz=-0.0328979 +s=-0.009994 "
+              "+convention=coordinate_frame "
+              "+step +inv +proj=cart +ellps=GRS80 "
+              "+step +inv +proj=vgridshift +grids=au_ga_AGQG_20201120.tif "
+              "+multiplier=1 "
+              "+step +proj=unitconvert +xy_in=rad +xy_out=deg "
+              "+step +proj=axisswap +order=2,1");
+}
+
+// ---------------------------------------------------------------------------
+
 TEST(
     operation,
     compoundCRS_to_compoundCRS_concatenated_operation_with_two_vert_transformation) {