scripts/startup/bl_ui/node_add_menu_geometry.py

@@ -187,6 +187,7 @@ class NODE_MT_geometry_node_GEO_GEOMETRY_READ(Menu):
         node_add_menu.add_node_type(layout, "GeometryNodeInputRadius")
         if context.space_data.geometry_nodes_type == 'TOOL':
             node_add_menu.add_node_type(layout, "GeometryNodeToolSelection")
+            node_add_menu.add_node_type(layout, "GeometryNodeToolActiveElement")
         node_add_menu.draw_assets_for_catalog(layout, "Geometry/Read")
 
 

source/blender/blenkernel/BKE_node.hh

@@ -1327,6 +1327,7 @@ void BKE_nodetree_remove_layer_n(bNodeTree *ntree, Scene *scene, int layer_index
 #define GEO_NODE_TOOL_VIEWPORT_TRANSFORM 2132
 #define GEO_NODE_TOOL_MOUSE_POSITION 2133
 #define GEO_NODE_SAMPLE_GRID_INDEX 2134
+#define GEO_NODE_TOOL_ACTIVE_ELEMENT 2135
 
 /** \} */
 

source/blender/bmesh/intern/bmesh_marking.cc

@@ -838,6 +838,30 @@ void BM_mesh_active_face_set(BMesh *bm, BMFace *f)
   bm->act_face = f;
 }
 
+int BM_mesh_active_face_index_get(BMesh *bm, bool is_sloppy, bool is_selected)
+{
+  const BMFace *f = BM_mesh_active_face_get(bm, is_sloppy, is_selected);
+  return f ? BM_elem_index_get(f) : -1;
+}
+
+int BM_mesh_active_edge_index_get(BMesh *bm)
+{
+  const BMEdge *e = BM_mesh_active_edge_get(bm);
+  return e ? BM_elem_index_get(e) : -1;
+}
+
+int BM_mesh_active_vert_index_get(BMesh *bm)
+{
+  const BMVert *v = BM_mesh_active_vert_get(bm);
+  return v ? BM_elem_index_get(v) : -1;
+}
+
+int BM_mesh_active_elem_index_get(BMesh *bm)
+{
+  const BMElem *e = BM_mesh_active_elem_get(bm);
+  return e ? BM_elem_index_get(e) : -1;
+}
+
 BMFace *BM_mesh_active_face_get(BMesh *bm, const bool is_sloppy, const bool is_selected)
 {
   if (bm->act_face && (!is_selected || BM_elem_flag_test(bm->act_face, BM_ELEM_SELECT))) {

source/blender/bmesh/intern/bmesh_marking.hh

@@ -120,6 +120,10 @@ int BM_mesh_elem_hflag_count_disabled(BMesh *bm, char htype, char hflag, bool re
 /* Edit selection stuff. */
 
 void BM_mesh_active_face_set(BMesh *bm, BMFace *f);
+int BM_mesh_active_face_index_get(BMesh *bm, bool is_sloppy, bool is_selected);
+int BM_mesh_active_edge_index_get(BMesh *bm);
+int BM_mesh_active_vert_index_get(BMesh *bm);
+int BM_mesh_active_elem_index_get(BMesh *bm);
 BMFace *BM_mesh_active_face_get(BMesh *bm, bool is_sloppy, bool is_selected);
 BMEdge *BM_mesh_active_edge_get(BMesh *bm);
 BMVert *BM_mesh_active_vert_get(BMesh *bm);

source/blender/editors/geometry/node_group_operator.cc

@@ -170,7 +170,8 @@ static void find_socket_log_contexts(const Main &bmain,
  * we need to create evaluated copies of geometry before passing it to geometry nodes. Implicit
  * sharing lets us avoid copying attribute data though.
  */
-static bke::GeometrySet get_original_geometry_eval_copy(Object &object)
+static bke::GeometrySet get_original_geometry_eval_copy(Object &object,
+                                                        nodes::GeoNodesOperatorData &operator_data)
 {
   switch (object.type) {
     case OB_CURVES: {
@@ -185,6 +186,9 @@ static bke::GeometrySet get_original_geometry_eval_copy(Object &object)
     case OB_MESH: {
       const Mesh *mesh = static_cast<const Mesh *>(object.data);
       if (std::shared_ptr<BMEditMesh> &em = mesh->runtime->edit_mesh) {
+        operator_data.active_point_index = BM_mesh_active_vert_index_get(em->bm);
+        operator_data.active_edge_index = BM_mesh_active_edge_index_get(em->bm);
+        operator_data.active_face_index = BM_mesh_active_face_index_get(em->bm, false, true);
         Mesh *mesh_copy = BKE_mesh_wrapper_from_editmesh(em, nullptr, mesh);
         BKE_mesh_wrapper_ensure_mdata(mesh_copy);
         Mesh *final_copy = BKE_mesh_copy_for_eval(mesh_copy);
@@ -556,7 +560,7 @@ static int run_node_group_exec(bContext *C, wmOperator *op)
       call_data.socket_log_contexts = &socket_log_contexts;
     }
 
-    bke::GeometrySet geometry_orig = get_original_geometry_eval_copy(*object);
+    bke::GeometrySet geometry_orig = get_original_geometry_eval_copy(*object, operator_eval_data);
 
     bke::GeometrySet new_geometry = nodes::execute_geometry_nodes_on_geometry(
         *node_tree, properties, compute_context, call_data, std::move(geometry_orig));

source/blender/makesdna/DNA_node_types.h

@@ -1986,6 +1986,11 @@ typedef struct NodeGeometryBake {
   char _pad[4];
 } NodeGeometryBake;
 
+typedef struct NodeGeometryToolActiveElement {
+  /** #AttrDomain. */
+  int8_t domain;
+} NodeGeometryToolActiveElement;
+
 /* script node mode */
 enum {
   NODE_SCRIPT_INTERNAL = 0,

source/blender/makesrna/RNA_enum_items.hh

@@ -226,6 +226,7 @@ DEF_ENUM(rna_enum_attribute_domain_items)
 DEF_ENUM(rna_enum_attribute_domain_edge_face_items)
 DEF_ENUM(rna_enum_attribute_domain_only_mesh_items)
 DEF_ENUM(rna_enum_attribute_domain_only_mesh_no_edge_items)
+DEF_ENUM(rna_enum_attribute_domain_only_mesh_no_corner_items)
 DEF_ENUM(rna_enum_attribute_domain_point_face_curve_items)
 DEF_ENUM(rna_enum_attribute_domain_point_edge_face_curve_items)
 DEF_ENUM(rna_enum_attribute_curves_domain_items)

source/blender/makesrna/intern/rna_attribute.cc

@@ -111,6 +111,13 @@ const EnumPropertyItem rna_enum_attribute_domain_only_mesh_no_edge_items[] = {
     {0, nullptr, 0, nullptr, nullptr},
 };
 
+const EnumPropertyItem rna_enum_attribute_domain_only_mesh_no_corner_items[] = {
+    {int(AttrDomain::Point), "POINT", 0, "Point", "Attribute on point"},
+    {int(AttrDomain::Edge), "EDGE", 0, "Edge", "Attribute on mesh edge"},
+    {int(AttrDomain::Face), "FACE", 0, "Face", "Attribute on mesh faces"},
+    {0, nullptr, 0, nullptr, nullptr},
+};
+
 const EnumPropertyItem rna_enum_attribute_domain_point_face_curve_items[] = {
     {int(AttrDomain::Point), "POINT", 0, "Point", "Attribute on point"},
     {int(AttrDomain::Face), "FACE", 0, "Face", "Attribute on mesh faces"},

source/blender/nodes/NOD_geometry_nodes_lazy_function.hh

@@ -193,6 +193,9 @@ struct GeoNodesOperatorData {
   int2 mouse_position;
   int2 region_size;
   const RegionView3D *rv3d = nullptr;
+  int active_point_index = -1;
+  int active_edge_index = -1;
+  int active_face_index = -1;
 };
 
 struct GeoNodesCallData {

source/blender/nodes/NOD_static_types.h

@@ -475,6 +475,7 @@ DefNode(GeometryNode, GEO_NODE_TOOL_3D_CURSOR, 0, "TOOL_3D_CURSOR", Tool3DCursor
 DefNode(GeometryNode, GEO_NODE_TOOL_FACE_SET, 0, "TOOL_FACE_SET", ToolFaceSet, "Face Set", "Each face's sculpt face set value")
 DefNode(GeometryNode, GEO_NODE_TOOL_MOUSE_POSITION, 0, "TOOL_MOUSE_POSITION", ToolMousePosition, "Mouse Position", "Retrieve the position of the mouse cursor")
 DefNode(GeometryNode, GEO_NODE_TOOL_SELECTION, 0, "TOOL_SELECTION", ToolSelection, "Selection", "User selection of the edited geometry, for tool execution")
+DefNode(GeometryNode, GEO_NODE_TOOL_ACTIVE_ELEMENT, 0, "TOOL_ACTIVE_ELEMENT", ToolActiveElement, "Active Element", "Active element indices of the edited geometry, for tool execution")
 DefNode(GeometryNode, GEO_NODE_TOOL_SET_FACE_SET, 0, "TOOL_SET_FACE_SET", ToolSetFaceSet, "Set Face Set", "Set sculpt face set values for faces")
 DefNode(GeometryNode, GEO_NODE_TOOL_SET_SELECTION, 0, "TOOL_SELECTION_SET", ToolSetSelection, "Set Selection", "Set selection of the edited geometry, for tool execution")
 DefNode(GeometryNode, GEO_NODE_TOOL_VIEWPORT_TRANSFORM, 0, "VIEWPORT_TRANFORM", ViewportTransform, "Viewport Transform", "Retrieve the view direction and location of the 3D viewport")

source/blender/nodes/geometry/CMakeLists.txt

@@ -197,6 +197,7 @@ set(SRC
   nodes/node_geo_subdivision_surface.cc
   nodes/node_geo_switch.cc
   nodes/node_geo_tool_3d_cursor.cc
+  nodes/node_geo_tool_active_element.cc
   nodes/node_geo_tool_face_set.cc
   nodes/node_geo_tool_selection.cc
   nodes/node_geo_tool_set_face_set.cc

source/blender/nodes/geometry/nodes/node_geo_tool_active_element.cc

@@ -0,0 +1,107 @@
+/* SPDX-FileCopyrightText: 2024 Blender Authors
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "UI_interface.hh"
+
+#include "RNA_enum_types.hh"
+
+#include "BKE_mesh.hh"
+#include "BKE_node.hh"
+
+#include "DNA_meshdata_types.h"
+
+#include "NOD_rna_define.hh"
+
+#include "node_geometry_util.hh"
+
+namespace blender::nodes::node_geo_tool_active_element_cc {
+
+NODE_STORAGE_FUNCS(NodeGeometryToolActiveElement)
+
+static void node_declare(NodeDeclarationBuilder &b)
+{
+  b.add_output<decl::Int>("Index").description(
+      "Index of the active element in the specified domain");
+  b.add_output<decl::Bool>("Exists").description(
+      "True if an active element exists in the mesh, false otherwise");
+}
+
+static void node_init(bNodeTree * /*tree*/, bNode *node)
+{
+  NodeGeometryToolActiveElement *data = MEM_cnew<NodeGeometryToolActiveElement>(__func__);
+  data->domain = int16_t(AttrDomain::Point);
+  node->storage = data;
+}
+
+static void node_rna(StructRNA *srna)
+{
+  RNA_def_node_enum(srna,
+                    "domain",
+                    "Domain",
+                    "",
+                    rna_enum_attribute_domain_only_mesh_no_corner_items,
+                    NOD_storage_enum_accessors(domain),
+                    int(AttrDomain::Point));
+}
+
+static void node_layout(uiLayout *layout, bContext * /*C*/, PointerRNA *ptr)
+{
+  uiLayoutSetPropSep(layout, true);
+  uiLayoutSetPropDecorate(layout, false);
+  uiItemR(layout, ptr, "domain", UI_ITEM_NONE, "", ICON_NONE);
+}
+
+static void node_exec(GeoNodeExecParams params)
+{
+  if (!check_tool_context_and_error(params)) {
+    return;
+  }
+
+  if (params.user_data()->call_data->operator_data->mode != OB_MODE_EDIT) {
+    params.set_default_remaining_outputs();
+    return;
+  }
+
+  const GeoNodesOperatorData *operator_data = params.user_data()->call_data->operator_data;
+
+  switch (static_cast<AttrDomain>(node_storage(params.node()).domain)) {
+    case AttrDomain::Point:
+      params.set_output("Exists", operator_data->active_point_index >= 0);
+      params.set_output("Index", std::max(0, operator_data->active_point_index));
+      break;
+    case AttrDomain::Edge:
+      params.set_output("Exists", operator_data->active_edge_index >= 0);
+      params.set_output("Index", std::max(0, operator_data->active_edge_index));
+      break;
+    case AttrDomain::Face:
+      params.set_output("Exists", operator_data->active_face_index >= 0);
+      params.set_output("Index", std::max(0, operator_data->active_face_index));
+      break;
+    default:
+      params.set_default_remaining_outputs();
+      BLI_assert_unreachable();
+      break;
+  }
+}
+
+static void node_register()
+{
+  static blender::bke::bNodeType ntype;
+  geo_node_type_base(&ntype, GEO_NODE_TOOL_ACTIVE_ELEMENT, "Active Element", NODE_CLASS_INPUT);
+  node_type_storage(&ntype,
+                    "NodeGeometryToolActiveElement",
+                    node_free_standard_storage,
+                    node_copy_standard_storage);
+  ntype.initfunc = node_init;
+  ntype.geometry_node_execute = node_exec;
+  ntype.declare = node_declare;
+  ntype.gather_link_search_ops = search_link_ops_for_tool_node;
+  ntype.draw_buttons = node_layout;
+  blender::bke::nodeRegisterType(&ntype);
+
+  node_rna(ntype.rna_ext.srna);
+}
+NOD_REGISTER_NODE(node_register)
+
+}  // namespace blender::nodes::node_geo_tool_active_element_cc