1 files changed, 155 insertions, 0 deletions
diff --git a/source/blender/nodes/geometry/nodes/node_geo_input_mesh_vertex_neighbors.cc b/source/blender/nodes/geometry/nodes/node_geo_input_mesh_vertex_neighbors.cc
new file mode 100644
index 00000000000..05140c92205
--- /dev/null
+++ b/source/blender/nodes/geometry/nodes/node_geo_input_mesh_vertex_neighbors.cc
@@ -0,0 +1,155 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "DNA_mesh_types.h"
+#include "DNA_meshdata_types.h"
+
+#include "BKE_mesh.h"
+
+#include "node_geometry_util.hh"
+
+namespace blender::nodes::node_geo_input_mesh_vertex_neighbors_cc {
+
+static void node_declare(NodeDeclarationBuilder &b)
+{
+  b.add_output<decl::Int>(N_("Vertex Count"))
+      .field_source()
+      .description(N_("Vertex count and edge count are equal"));
+  b.add_output<decl::Int>(N_("Face Count"))
+      .field_source()
+      .description(N_("Number of faces that contain the vertex"));
+}
+
+static VArray<int> construct_vertex_count_gvarray(const MeshComponent &component,
+                                                  const AttributeDomain domain)
+{
+  const Mesh *mesh = component.get_for_read();
+  if (mesh == nullptr) {
+    return {};
+  }
+
+  if (domain == ATTR_DOMAIN_POINT) {
+    Array<int> vertices(mesh->totvert, 0);
+    for (const int i : IndexRange(mesh->totedge)) {
+      vertices[mesh->medge[i].v1]++;
+      vertices[mesh->medge[i].v2]++;
+    }
+    return VArray<int>::ForContainer(std::move(vertices));
+  }
+  return {};
+}
+
+class VertexCountFieldInput final : public GeometryFieldInput {
+ public:
+  VertexCountFieldInput() : GeometryFieldInput(CPPType::get<int>(), "Vertex Count Field")
+  {
+    category_ = Category::Generated;
+  }
+
+  GVArray get_varray_for_context(const GeometryComponent &component,
+                                 const AttributeDomain domain,
+                                 IndexMask UNUSED(mask)) const final
+  {
+    if (component.type() == GEO_COMPONENT_TYPE_MESH) {
+      const MeshComponent &mesh_component = static_cast<const MeshComponent &>(component);
+      return construct_vertex_count_gvarray(mesh_component, domain);
+    }
+    return {};
+  }
+
+  uint64_t hash() const override
+  {
+    /* Some random constant hash. */
+    return 23574528465;
+  }
+
+  bool is_equal_to(const fn::FieldNode &other) const override
+  {
+    return dynamic_cast<const VertexCountFieldInput *>(&other) != nullptr;
+  }
+};
+
+static VArray<int> construct_face_count_gvarray(const MeshComponent &component,
+                                                const AttributeDomain domain)
+{
+  const Mesh *mesh = component.get_for_read();
+  if (mesh == nullptr) {
+    return {};
+  }
+
+  if (domain == ATTR_DOMAIN_POINT) {
+    Array<int> vertices(mesh->totvert, 0);
+    for (const int i : IndexRange(mesh->totloop)) {
+      int vertex = mesh->mloop[i].v;
+      vertices[vertex]++;
+    }
+    return VArray<int>::ForContainer(std::move(vertices));
+  }
+  return {};
+}
+
+class VertexFaceCountFieldInput final : public GeometryFieldInput {
+ public:
+  VertexFaceCountFieldInput() : GeometryFieldInput(CPPType::get<int>(), "Vertex Face Count Field")
+  {
+    category_ = Category::Generated;
+  }
+
+  GVArray get_varray_for_context(const GeometryComponent &component,
+                                 const AttributeDomain domain,
+                                 IndexMask UNUSED(mask)) const final
+  {
+    if (component.type() == GEO_COMPONENT_TYPE_MESH) {
+      const MeshComponent &mesh_component = static_cast<const MeshComponent &>(component);
+      return construct_face_count_gvarray(mesh_component, domain);
+    }
+    return {};
+  }
+
+  uint64_t hash() const override
+  {
+    /* Some random constant hash. */
+    return 3462374322;
+  }
+
+  bool is_equal_to(const fn::FieldNode &other) const override
+  {
+    return dynamic_cast<const VertexFaceCountFieldInput *>(&other) != nullptr;
+  }
+};
+
+static void node_geo_exec(GeoNodeExecParams params)
+{
+  Field<int> vertex_field{std::make_shared<VertexCountFieldInput>()};
+  Field<int> face_field{std::make_shared<VertexFaceCountFieldInput>()};
+
+  params.set_output("Vertex Count", std::move(vertex_field));
+  params.set_output("Face Count", std::move(face_field));
+}
+
+}  // namespace blender::nodes::node_geo_input_mesh_vertex_neighbors_cc
+
+void register_node_type_geo_input_mesh_vertex_neighbors()
+{
+  namespace file_ns = blender::nodes::node_geo_input_mesh_vertex_neighbors_cc;
+
+  static bNodeType ntype;
+  geo_node_type_base(
+      &ntype, GEO_NODE_INPUT_MESH_VERTEX_NEIGHBORS, "Vertex Neighbors", NODE_CLASS_INPUT, 0);
+  ntype.declare = file_ns::node_declare;
+  ntype.geometry_node_execute = file_ns::node_geo_exec;
+  nodeRegisterType(&ntype);
+}