source/blender/nodes/geometry/nodes/node_geo_mesh_subdivide.cc

@@ -2,8 +2,11 @@
  *
  * SPDX-License-Identifier: GPL-2.0-or-later */
 
+#include "BKE_mesh.hh"
+#include "BKE_editmesh.hh"
 #include "BKE_subdiv.hh"
 #include "BKE_subdiv_mesh.hh"
+#include "ED_mesh.hh"
 
 #include "UI_resources.hh"
 
@@ -17,12 +20,75 @@ static void node_declare(NodeDeclarationBuilder &b)
 {
   b.add_input<decl::Geometry>("Mesh").supported_type(GeometryComponent::Type::Mesh);
   b.add_input<decl::Int>("Level").default_value(1).min(0).max(6);
+  b.add_input<decl::Bool>("Selection").default_value(true).hide_value().field_on_all();
   b.add_output<decl::Geometry>("Mesh").propagate_all();
 }
 
 #ifdef WITH_OPENSUBDIV
-static Mesh *simple_subdivide_mesh(const Mesh &mesh, const int level)
+static Mesh *simple_subdivide_mesh(const Mesh &mesh, const int level, const Field<bool> &selection_field)
 {
+  const bke::MeshFieldContext context{mesh, AttrDomain::Edge};
+  FieldEvaluator evaluator{context, mesh.edges_num};
+  evaluator.set_selection(selection_field);
+  evaluator.evaluate();
+  const IndexMask selection = evaluator.get_evaluated_selection_as_mask();
+  if (selection.is_empty()) {
+//    return;
+  }
+
+  if(selection.size() != mesh.edges_num) {  
+    Mesh* copy = BKE_mesh_copy_for_eval(&mesh);
+    const BMAllocTemplate allocsize = BMALLOC_TEMPLATE_FROM_ME(copy);
+    BMeshCreateParams bm_create_params{};
+    bm_create_params.use_toolflags = true;
+    BMesh *bm = BM_mesh_create(&allocsize, &bm_create_params);
+    BMeshFromMeshParams mesh_to_bm_params{};
+    mesh_to_bm_params.calc_face_normal = true;
+    mesh_to_bm_params.calc_vert_normal = true;
+    BM_mesh_bm_from_me(bm, copy, &mesh_to_bm_params);
+
+    BMEditMesh *em = BKE_editmesh_create(bm);
+    copy->edit_mesh = em;
+
+    BM_mesh_elem_table_ensure(em->bm, BM_ALL);
+    BM_mesh_elem_toolflags_ensure(em->bm);
+    BMO_push(em->bm, nullptr);
+
+    BM_mesh_elem_hflag_disable_all(em->bm, BM_ALL, BM_ELEM_SELECT, false);
+    selection.foreach_index([&](int x) {
+      BLI_assert(x<em->bm->totedge);
+      BM_edge_select_set(em->bm, BM_edge_at_index(em->bm, x), true);
+    });
+    BM_mesh_esubdivide(em->bm,
+                         BM_ELEM_SELECT,
+                         1,
+                         SUBD_FALLOFF_LIN,
+                         false,
+                         0.0/*fractal*/,
+                         0.0/*along_normal*/,
+                         (1<<level)-1,
+                         SUBDIV_SELECT_ORIG,
+                         SUBD_CORNER_STRAIGHT_CUT,
+                         false,
+                         true,
+                         false,
+                         0);
+    EDBMUpdate_Params params{};
+    params.calc_looptris = true;
+    params.calc_normals = false;
+    params.is_destructive = true;
+    EDBM_update(copy, &params);
+
+    BMeshToMeshParams bm_to_mesh_params{};
+    bm_to_mesh_params.calc_object_remap = false;
+    copy = BKE_mesh_from_bmesh_nomain(bm, &bm_to_mesh_params, &mesh);
+    BMO_pop(em->bm);
+    BKE_editmesh_free_data(em);
+    MEM_freeN(em);
+
+    return copy;
+  }
+
   /* Initialize mesh settings. */
   SubdivToMeshSettings mesh_settings;
   mesh_settings.resolution = (1 << level) + 1;
@@ -56,6 +122,7 @@ static Mesh *simple_subdivide_mesh(const Mesh &mesh, const int level)
 static void node_geo_exec(GeoNodeExecParams params)
 {
   GeometrySet geometry_set = params.extract_input<GeometrySet>("Mesh");
+  const Field<bool> selection_field = params.extract_input<Field<bool>>("Selection");
 #ifdef WITH_OPENSUBDIV
   /* See CCGSUBSURF_LEVEL_MAX for max limit. */
   const int level = clamp_i(params.extract_input<int>("Level"), 0, 11);
@@ -66,7 +133,7 @@ static void node_geo_exec(GeoNodeExecParams params)
 
   geometry_set.modify_geometry_sets([&](GeometrySet &geometry_set) {
     if (const Mesh *mesh = geometry_set.get_mesh()) {
-      geometry_set.replace_mesh(simple_subdivide_mesh(*mesh, level));
+      geometry_set.replace_mesh(simple_subdivide_mesh(*mesh, level, selection_field));
     }
   });
 #else