1 files changed, 134 insertions, 0 deletions
diff --git a/source/blender/nodes/geometry/nodes/node_geo_edge_paths_to_selection.cc b/source/blender/nodes/geometry/nodes/node_geo_edge_paths_to_selection.cc
new file mode 100644
index 00000000000..9ef9ee8ad6e
--- /dev/null
+++ b/source/blender/nodes/geometry/nodes/node_geo_edge_paths_to_selection.cc
@@ -0,0 +1,134 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "BKE_attribute_math.hh"
+#include "BKE_mesh.h"
+
+#include "BLI_map.hh"
+#include "BLI_set.hh"
+#include "BLI_task.hh"
+
+#include "node_geometry_util.hh"
+
+#include <set>
+
+namespace blender::nodes::node_geo_edge_paths_to_selection_cc {
+
+static void node_declare(NodeDeclarationBuilder &b)
+{
+  b.add_input<decl::Bool>(N_("Start Vertices")).default_value(true).hide_value().supports_field();
+  b.add_input<decl::Int>(N_("Next Vertex Index")).default_value(-1).hide_value().supports_field();
+  b.add_output<decl::Bool>(N_("Selection")).field_source();
+}
+
+static void edge_paths_to_selection(const Mesh &src_mesh,
+                                    const IndexMask start_selection,
+                                    const Span<int> next_indices,
+                                    MutableSpan<bool> r_selection)
+{
+  const Span<MEdge> edges = src_mesh.edges();
+
+  Array<bool> selection(src_mesh.totvert, false);
+
+  for (const int start_vert : start_selection) {
+    selection[start_vert] = true;
+  }
+
+  for (const int start_i : start_selection) {
+    int iter = start_i;
+    while (iter != next_indices[iter] && !selection[next_indices[iter]]) {
+      if (next_indices[iter] < 0 || next_indices[iter] >= src_mesh.totvert) {
+        break;
+      }
+      selection[next_indices[iter]] = true;
+      iter = next_indices[iter];
+    }
+  }
+
+  for (const int i : edges.index_range()) {
+    const MEdge &edge = edges[i];
+    if ((selection[edge.v1] && selection[edge.v2]) &&
+        (edge.v1 == next_indices[edge.v2] || edge.v2 == next_indices[edge.v1])) {
+      r_selection[i] = true;
+    }
+  }
+}
+
+class PathToEdgeSelectionFieldInput final : public bke::MeshFieldInput {
+ private:
+  Field<bool> start_vertices_;
+  Field<int> next_vertex_;
+
+ public:
+  PathToEdgeSelectionFieldInput(Field<bool> start_verts, Field<int> next_vertex)
+      : bke::MeshFieldInput(CPPType::get<bool>(), "Edge Selection"),
+        start_vertices_(start_verts),
+        next_vertex_(next_vertex)
+  {
+    category_ = Category::Generated;
+  }
+
+  GVArray get_varray_for_context(const Mesh &mesh,
+                                 const eAttrDomain domain,
+                                 const IndexMask /*mask*/) const final
+  {
+    bke::MeshFieldContext context{mesh, ATTR_DOMAIN_POINT};
+    fn::FieldEvaluator evaluator{context, mesh.totvert};
+    evaluator.add(next_vertex_);
+    evaluator.add(start_vertices_);
+    evaluator.evaluate();
+    const VArraySpan<int> next_vert = evaluator.get_evaluated<int>(0);
+    const IndexMask start_verts = evaluator.get_evaluated_as_mask(1);
+
+    if (start_verts.is_empty()) {
+      return {};
+    }
+
+    Array<bool> selection(mesh.totedge, false);
+    MutableSpan<bool> selection_span = selection.as_mutable_span();
+
+    edge_paths_to_selection(mesh, start_verts, next_vert, selection_span);
+
+    return mesh.attributes().adapt_domain<bool>(
+        VArray<bool>::ForContainer(std::move(selection)), ATTR_DOMAIN_EDGE, domain);
+  }
+
+  uint64_t hash() const override
+  {
+    return get_default_hash_2(start_vertices_, next_vertex_);
+  }
+
+  bool is_equal_to(const fn::FieldNode &other) const override
+  {
+    if (const PathToEdgeSelectionFieldInput *other_field =
+            dynamic_cast<const PathToEdgeSelectionFieldInput *>(&other)) {
+      return other_field->start_vertices_ == start_vertices_ &&
+             other_field->next_vertex_ == next_vertex_;
+    }
+    return false;
+  }
+};
+
+static void node_geo_exec(GeoNodeExecParams params)
+{
+  Field<bool> start_verts = params.extract_input<Field<bool>>("Start Vertices");
+  Field<int> next_vertex = params.extract_input<Field<int>>("Next Vertex Index");
+  Field<bool> selection_field{
+      std::make_shared<PathToEdgeSelectionFieldInput>(start_verts, next_vertex)};
+  params.set_output("Selection", std::move(selection_field));
+}
+
+}  // namespace blender::nodes::node_geo_edge_paths_to_selection_cc
+
+void register_node_type_geo_edge_paths_to_selection()
+{
+  namespace file_ns = blender::nodes::node_geo_edge_paths_to_selection_cc;
+
+  static bNodeType ntype;
+
+  geo_node_type_base(
+      &ntype, GEO_NODE_EDGE_PATHS_TO_SELECTION, "Edge Paths to Selection", NODE_CLASS_INPUT);
+  ntype.declare = file_ns::node_declare;
+  node_type_size(&ntype, 150, 100, 300);
+  ntype.geometry_node_execute = file_ns::node_geo_exec;
+  nodeRegisterType(&ntype);
+}