1 files changed, 118 insertions, 0 deletions
diff --git a/source/blender/nodes/geometry/nodes/node_geo_mesh_topology_offset_corner_in_face.cc b/source/blender/nodes/geometry/nodes/node_geo_mesh_topology_offset_corner_in_face.cc
new file mode 100644
index 00000000000..ef5c9a445f2
--- /dev/null
+++ b/source/blender/nodes/geometry/nodes/node_geo_mesh_topology_offset_corner_in_face.cc
@@ -0,0 +1,118 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "BKE_mesh.h"
+#include "BKE_mesh_mapping.h"
+
+#include "BLI_task.hh"
+
+#include "node_geometry_util.hh"
+
+namespace blender::nodes::node_geo_mesh_topology_offset_corner_in_face_cc {
+
+static void node_declare(NodeDeclarationBuilder &b)
+{
+  b.add_input<decl::Int>(N_("Corner Index"))
+      .implicit_field(implicit_field_inputs::index)
+      .description(
+          N_("The corner to retrieve data from. Defaults to the corner from the context"));
+  b.add_input<decl::Int>(N_("Offset"))
+      .supports_field()
+      .description(N_("The number of corners to move around the face before finding the result, "
+                      "circling around the start of the face if necessary"));
+  b.add_output<decl::Int>(N_("Corner Index"))
+      .dependent_field()
+      .description(N_("The index of the offset corner"));
+}
+
+class OffsetCornerInFaceFieldInput final : public bke::MeshFieldInput {
+  const Field<int> corner_index_;
+  const Field<int> offset_;
+
+ public:
+  OffsetCornerInFaceFieldInput(Field<int> corner_index, Field<int> offset)
+      : bke::MeshFieldInput(CPPType::get<int>(), "Offset Corner in Face"),
+        corner_index_(std::move(corner_index)),
+        offset_(std::move(offset))
+  {
+    category_ = Category::Generated;
+  }
+
+  GVArray get_varray_for_context(const Mesh &mesh,
+                                 const eAttrDomain domain,
+                                 const IndexMask mask) const final
+  {
+    const IndexRange corner_range(mesh.totloop);
+    const Span<MPoly> polys = mesh.polys();
+
+    const bke::MeshFieldContext context{mesh, domain};
+    fn::FieldEvaluator evaluator{context, &mask};
+    evaluator.add(corner_index_);
+    evaluator.add(offset_);
+    evaluator.evaluate();
+    const VArray<int> corner_indices = evaluator.get_evaluated<int>(0);
+    const VArray<int> offsets = evaluator.get_evaluated<int>(1);
+
+    Array<int> loop_to_poly_map = bke::mesh_topology::build_loop_to_poly_map(polys, mesh.totloop);
+
+    Array<int> offset_corners(mask.min_array_size());
+    threading::parallel_for(mask.index_range(), 2048, [&](const IndexRange range) {
+      for (const int selection_i : range) {
+        const int corner_i = corner_indices[selection_i];
+        const int offset = offsets[selection_i];
+        if (!corner_range.contains(corner_i)) {
+          offset_corners[selection_i] = 0;
+          continue;
+        }
+
+        const int poly_i = loop_to_poly_map[corner_i];
+        const IndexRange poly_range(polys[poly_i].loopstart, polys[poly_i].totloop);
+        offset_corners[selection_i] = apply_offset_in_cyclic_range(poly_range, corner_i, offset);
+      }
+    });
+
+    return VArray<int>::ForContainer(std::move(offset_corners));
+  }
+
+  uint64_t hash() const final
+  {
+    return get_default_hash(offset_);
+  }
+
+  bool is_equal_to(const fn::FieldNode &other) const final
+  {
+    if (const OffsetCornerInFaceFieldInput *other_field =
+            dynamic_cast<const OffsetCornerInFaceFieldInput *>(&other)) {
+      return other_field->corner_index_ == corner_index_ && other_field->offset_ == offset_;
+    }
+    return false;
+  }
+
+  std::optional<eAttrDomain> preferred_domain(const Mesh & /*mesh*/) const final
+  {
+    return ATTR_DOMAIN_CORNER;
+  }
+};
+
+static void node_geo_exec(GeoNodeExecParams params)
+{
+  params.set_output("Corner Index",
+                    Field<int>(std::make_shared<OffsetCornerInFaceFieldInput>(
+                        params.extract_input<Field<int>>("Corner Index"),
+                        params.extract_input<Field<int>>("Offset"))));
+}
+
+}  // namespace blender::nodes::node_geo_mesh_topology_offset_corner_in_face_cc
+
+void register_node_type_geo_mesh_topology_offset_corner_in_face()
+{
+  namespace file_ns = blender::nodes::node_geo_mesh_topology_offset_corner_in_face_cc;
+
+  static bNodeType ntype;
+  geo_node_type_base(&ntype,
+                     GEO_NODE_MESH_TOPOLOGY_OFFSET_CORNER_IN_FACE,
+                     "Offset Corner in Face",
+                     NODE_CLASS_INPUT);
+  ntype.geometry_node_execute = file_ns::node_geo_exec;
+  ntype.declare = file_ns::node_declare;
+  nodeRegisterType(&ntype);
+}