GRIDEDIT-1566 Testing another, simpler mesh merging

Deltares · Dec 19, 2024 · 0bd19ce · 0bd19ce
1 parent 496d2dd
commit 0bd19ce
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Showing 3 changed files with 72 additions and 1 deletion.
diff --git a/libs/MeshKernel/include/MeshKernel/Mesh2D.hpp b/libs/MeshKernel/include/MeshKernel/Mesh2D.hpp
@@ -348,6 +348,13 @@ namespace meshkernel
         /// it may be required to call Administrate after merging
         static std::unique_ptr<Mesh2D> Merge(const Mesh2D& mesh1, const Mesh2D& mesh2);
 
+        /// @brief Merges mesh node and edge connectivity into a single mesh.
+        static std::unique_ptr<Mesh2D> Merge(const std::vector<Point>& mesh1Nodes,
+                                             const std::vector<Edge>& mesh1Edges,
+                                             const std::vector<Point>& mesh2Nodes,
+                                             const std::vector<Edge>& mesh2Edges,
+                                             const Projection projection);
+
         /// @brief Get the mesh bounding box
         ///
         /// @return The mesh bounding box

diff --git a/libs/MeshKernel/src/Mesh2D.cpp b/libs/MeshKernel/src/Mesh2D.cpp
@@ -2470,6 +2470,67 @@ std::unique_ptr<Mesh2D> Mesh2D::Merge(const Mesh2D& mesh1, const Mesh2D& mesh2)
                                     mergedMesh.m_projection);
 }
 
+std::unique_ptr<meshkernel::Mesh2D> Mesh2D::Merge(const std::vector<Point>& mesh1Nodes,
+                                                  const std::vector<Edge>& mesh1Edges,
+                                                  const std::vector<Point>& mesh2Nodes,
+                                                  const std::vector<Edge>& mesh2Edges,
+                                                  const Projection projection)
+{
+    std::vector<Point> mergedNodes(mesh1Nodes.size() + mesh2Nodes.size());
+    std::vector<Edge> mergedEdges(mesh1Edges.size() + mesh2Edges.size());
+
+    if (mesh1Nodes.size() > 0)
+    {
+        // Merge node array from mesh1 nodes
+        mergedNodes.insert(mergedNodes.begin(), mesh1Nodes.begin(), mesh1Nodes.end());
+
+        // Merge edge array from mesh1 edges
+        mergedEdges.insert(mergedEdges.begin(), mesh1Edges.begin(), mesh1Edges.end());
+    }
+
+    if (mesh2Nodes.size() > 0)
+    {
+        // Merge node array from mesh2 nodes
+        mergedNodes.insert(mergedNodes.begin() + mesh1Nodes.size(), mesh2Nodes.begin(), mesh2Nodes.end());
+
+        // A copy is needed so that the node connectivity ids can be reassigned
+        // The copy is needed only if mesh1Nodes.size() > 0 (most likelly to be true)
+        std::vector<Edge> mesh2EdgesCopy;
+        std::span<const Edge> mesh2EdgesSpan;
+
+        if (mesh1Nodes.size() > 0)
+        {
+            mesh2EdgesCopy = mesh2Edges;
+            const UInt numberOfMesh1Nodes = mesh1Nodes.size();
+
+            // Re-assign the node ids for the second mesh data set
+            for (size_t i = 0; i < mesh2Edges.size(); ++i)
+            {
+                if (mesh2EdgesCopy[i].first != constants::missing::uintValue)
+                {
+                    mesh2EdgesCopy[i].first += numberOfMesh1Nodes;
+                }
+
+                if (mesh2EdgesCopy[i].second != constants::missing::uintValue)
+                {
+                    mesh2EdgesCopy[i].second += numberOfMesh1Nodes;
+                }
+            }
+
+            mesh2EdgesSpan = std::span<const Edge>(mesh2EdgesCopy.data(), mesh2EdgesCopy.size());
+        }
+        else
+        {
+            mesh2EdgesSpan = std::span<const Edge>(mesh2Edges.data(), mesh2Edges.size());
+        }
+
+        // Merge edge array from mesh2 edges
+        mergedEdges.insert(mergedEdges.begin() + mesh1Edges.size(), mesh2EdgesSpan.begin(), mesh2EdgesSpan.end());
+    }
+
+    return std::make_unique<Mesh2D>(mergedEdges, mergedNodes, projection);
+}
+
 meshkernel::BoundingBox Mesh2D::GetBoundingBox() const
 {
     Point lowerLeft(std::numeric_limits<double>::max(), std::numeric_limits<double>::max());

diff --git a/libs/MeshKernel/tests/src/Mesh2DConnectDDTest.cpp b/libs/MeshKernel/tests/src/Mesh2DConnectDDTest.cpp
@@ -441,7 +441,10 @@ TEST(Mesh2DConnectDD, MergeTwoSameMeshesNoOffset)
 
     std::shared_ptr<meshkernel::Mesh2D> mesh2 = generateMesh(origin, delta, nx, ny);
 
-    const auto mergedMesh = meshkernel::Mesh2D::Merge(*mesh1, *mesh2);
+    const auto mergedMesh = meshkernel::Mesh2D::Merge(mesh1->Nodes(), mesh1->Edges(),
+                                                      mesh2->Nodes(), mesh2->Edges(),
+                                                      mesh1->m_projection);
+    // const auto mergedMesh = meshkernel::Mesh2D::Merge(*mesh1, *mesh2);
 
     const std::vector<meshkernel::Point> originalNodes(mergedMesh->Nodes());
     const std::vector<meshkernel::Edge> originalEdges(mergedMesh->Edges());