1 files changed, 158 insertions, 0 deletions
diff --git a/source/blender/nodes/geometry/nodes/node_geo_input_mesh_face_neighbors.cc b/source/blender/nodes/geometry/nodes/node_geo_input_mesh_face_neighbors.cc
new file mode 100644
index 00000000000..80bb25dc7ca
--- /dev/null
+++ b/source/blender/nodes/geometry/nodes/node_geo_input_mesh_face_neighbors.cc
@@ -0,0 +1,158 @@
+/*
+ * 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_face_neighbors_cc {
+
+static void node_declare(NodeDeclarationBuilder &b)
+{
+  b.add_output<decl::Int>(N_("Vertex Count"))
+      .field_source()
+      .description(N_("Number of edges or points in the face"));
+  b.add_output<decl::Int>(N_("Face Count"))
+      .field_source()
+      .description(N_("Number of faces which share an edge with the face"));
+}
+
+static VArray<int> construct_neighbor_count_gvarray(const MeshComponent &component,
+                                                    const AttributeDomain domain)
+{
+  const Mesh *mesh = component.get_for_read();
+  if (mesh == nullptr) {
+    return {};
+  }
+
+  Array<int> edge_count(mesh->totedge, 0);
+  for (const int i : IndexRange(mesh->totloop)) {
+    edge_count[mesh->mloop[i].e]++;
+  }
+
+  Array<int> poly_count(mesh->totpoly, 0);
+  for (const int poly_num : IndexRange(mesh->totpoly)) {
+    MPoly &poly = mesh->mpoly[poly_num];
+    for (const int loop_num : IndexRange(poly.loopstart, poly.totloop)) {
+      poly_count[poly_num] += edge_count[mesh->mloop[loop_num].e] - 1;
+    }
+  }
+
+  return component.attribute_try_adapt_domain<int>(
+      VArray<int>::ForContainer(std::move(poly_count)), ATTR_DOMAIN_FACE, domain);
+}
+
+class FaceNeighborCountFieldInput final : public GeometryFieldInput {
+ public:
+  FaceNeighborCountFieldInput()
+      : GeometryFieldInput(CPPType::get<int>(), "Face Neighbor 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_neighbor_count_gvarray(mesh_component, domain);
+    }
+    return {};
+  }
+
+  uint64_t hash() const override
+  {
+    /* Some random constant hash. */
+    return 823543774;
+  }
+
+  bool is_equal_to(const fn::FieldNode &other) const override
+  {
+    return dynamic_cast<const FaceNeighborCountFieldInput *>(&other) != nullptr;
+  }
+};
+
+static VArray<int> construct_vertex_count_gvarray(const MeshComponent &component,
+                                                  const AttributeDomain domain)
+{
+  const Mesh *mesh = component.get_for_read();
+  if (mesh == nullptr) {
+    return {};
+  }
+
+  return component.attribute_try_adapt_domain<int>(
+      VArray<int>::ForFunc(mesh->totpoly,
+                           [mesh](const int i) -> float { return mesh->mpoly[i].totloop; }),
+      ATTR_DOMAIN_FACE,
+      domain);
+}
+
+class FaceVertexCountFieldInput final : public GeometryFieldInput {
+ public:
+  FaceVertexCountFieldInput() : 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 236235463634;
+  }
+
+  bool is_equal_to(const fn::FieldNode &other) const override
+  {
+    return dynamic_cast<const FaceVertexCountFieldInput *>(&other) != nullptr;
+  }
+};
+
+static void node_geo_exec(GeoNodeExecParams params)
+{
+  Field<int> vertex_count_field{std::make_shared<FaceVertexCountFieldInput>()};
+  Field<int> neighbor_count_field{std::make_shared<FaceNeighborCountFieldInput>()};
+  params.set_output("Vertex Count", std::move(vertex_count_field));
+  params.set_output("Face Count", std::move(neighbor_count_field));
+}
+
+}  // namespace blender::nodes::node_geo_input_mesh_face_neighbors_cc
+
+void register_node_type_geo_input_mesh_face_neighbors()
+{
+  namespace file_ns = blender::nodes::node_geo_input_mesh_face_neighbors_cc;
+
+  static bNodeType ntype;
+  geo_node_type_base(
+      &ntype, GEO_NODE_INPUT_MESH_FACE_NEIGHBORS, "Face Neighbors", NODE_CLASS_INPUT, 0);
+  node_type_size_preset(&ntype, NODE_SIZE_MIDDLE);
+  ntype.declare = file_ns::node_declare;
+  ntype.geometry_node_execute = file_ns::node_geo_exec;
+  nodeRegisterType(&ntype);
+}