Geometry Nodes: decouple Delete Geometry node from Mask modifier

This dependency was a bit ugly and the functions from the mask modifier
did a few things that we don't need in the Delete Geometry node:
* The mask modifier uses `CustomData_copy_data` which the node doesn't need.
* The mask modifier checks for `-2` in some values, but this special value is
  not used by the node.

Differential Revision: https://developer.blender.org/D13335

1 files changed, 91 insertions, 15 deletions

diff --git a/source/blender/nodes/geometry/nodes/node_geo_delete_geometry.cc b/source/blender/nodes/geometry/nodes/node_geo_delete_geometry.cc
index 055e44998cb..8e3429fa909 100644
--- a/source/blender/nodes/geometry/nodes/node_geo_delete_geometry.cc
+++ b/source/blender/nodes/geometry/nodes/node_geo_delete_geometry.cc
@@ -29,21 +29,6 @@
 
 #include "node_geometry_util.hh"
 
-/* Code from the mask modifier in MOD_mask.cc. */
-void copy_masked_vertices_to_new_mesh(const Mesh &src_mesh,
-                                      Mesh &dst_mesh,
-                                      blender::Span<int> vertex_map);
-void copy_masked_edges_to_new_mesh(const Mesh &src_mesh,
-                                   Mesh &dst_mesh,
-                                   blender::Span<int> vertex_map,
-                                   blender::Span<int> edge_map);
-void copy_masked_polys_to_new_mesh(const Mesh &src_mesh,
-                                   Mesh &dst_mesh,
-                                   blender::Span<int> vertex_map,
-                                   blender::Span<int> edge_map,
-                                   blender::Span<int> masked_poly_indices,
-                                   blender::Span<int> new_loop_starts);
-
 namespace blender::nodes {
 
 using blender::bke::CustomDataAttributes;
@@ -184,6 +169,24 @@ static void copy_face_corner_attributes(const Map<AttributeIDRef, AttributeKind>
       attributes, in_component, out_component, ATTR_DOMAIN_CORNER, IndexMask(indices));
 }
 
+static void copy_masked_vertices_to_new_mesh(const Mesh &src_mesh,
+                                             Mesh &dst_mesh,
+                                             Span<int> vertex_map)
+{
+  BLI_assert(src_mesh.totvert == vertex_map.size());
+  for (const int i_src : vertex_map.index_range()) {
+    const int i_dst = vertex_map[i_src];
+    if (i_dst == -1) {
+      continue;
+    }
+
+    const MVert &v_src = src_mesh.mvert[i_src];
+    MVert &v_dst = dst_mesh.mvert[i_dst];
+
+    v_dst = v_src;
+  }
+}
+
 static void copy_masked_edges_to_new_mesh(const Mesh &src_mesh, Mesh &dst_mesh, Span<int> edge_map)
 {
   BLI_assert(src_mesh.totedge == edge_map.size());
@@ -202,6 +205,28 @@ static void copy_masked_edges_to_new_mesh(const Mesh &src_mesh, Mesh &dst_mesh,
   }
 }
 
+static void copy_masked_edges_to_new_mesh(const Mesh &src_mesh,
+                                          Mesh &dst_mesh,
+                                          Span<int> vertex_map,
+                                          Span<int> edge_map)
+{
+  BLI_assert(src_mesh.totvert == vertex_map.size());
+  BLI_assert(src_mesh.totedge == edge_map.size());
+  for (const int i_src : IndexRange(src_mesh.totedge)) {
+    const int i_dst = edge_map[i_src];
+    if (i_dst == -1) {
+      continue;
+    }
+
+    const MEdge &e_src = src_mesh.medge[i_src];
+    MEdge &e_dst = dst_mesh.medge[i_dst];
+
+    e_dst = e_src;
+    e_dst.v1 = vertex_map[e_src.v1];
+    e_dst.v2 = vertex_map[e_src.v2];
+  }
+}
+
 /* Faces and edges changed but vertices are the same. */
 static void copy_masked_polys_to_new_mesh(const Mesh &src_mesh,
                                           Mesh &dst_mesh,
@@ -255,6 +280,33 @@ static void copy_masked_polys_to_new_mesh(const Mesh &src_mesh,
   }
 }
 
+static void copy_masked_polys_to_new_mesh(const Mesh &src_mesh,
+                                          Mesh &dst_mesh,
+                                          Span<int> vertex_map,
+                                          Span<int> edge_map,
+                                          Span<int> masked_poly_indices,
+                                          Span<int> new_loop_starts)
+{
+  for (const int i_dst : masked_poly_indices.index_range()) {
+    const int i_src = masked_poly_indices[i_dst];
+
+    const MPoly &mp_src = src_mesh.mpoly[i_src];
+    MPoly &mp_dst = dst_mesh.mpoly[i_dst];
+    const int i_ml_src = mp_src.loopstart;
+    const int i_ml_dst = new_loop_starts[i_dst];
+
+    const MLoop *ml_src = src_mesh.mloop + i_ml_src;
+    MLoop *ml_dst = dst_mesh.mloop + i_ml_dst;
+
+    mp_dst = mp_src;
+    mp_dst.loopstart = i_ml_dst;
+    for (int i : IndexRange(mp_src.totloop)) {
+      ml_dst[i].v = vertex_map[ml_src[i].v];
+      ml_dst[i].e = edge_map[ml_src[i].e];
+    }
+  }
+}
+
 static void spline_copy_builtin_attributes(const Spline &spline,
                                            Spline &r_spline,
                                            const IndexMask mask)
@@ -973,6 +1025,30 @@ static void do_mesh_separation(GeometrySet &geometry_set,
       copy_masked_edges_to_new_mesh(mesh_in, *mesh_out, vertex_map, edge_map);
       copy_masked_polys_to_new_mesh(
           mesh_in, *mesh_out, vertex_map, edge_map, selected_poly_indices, new_loop_starts);
+
+      Vector<int64_t> indices;
+      copy_attributes_based_on_mask(
+          attributes,
+          in_component,
+          out_component,
+          ATTR_DOMAIN_POINT,
+          index_mask_indices(vertex_map, num_selected_vertices, indices));
+      copy_attributes_based_on_mask(attributes,
+                                    in_component,
+                                    out_component,
+                                    ATTR_DOMAIN_EDGE,
+                                    index_mask_indices(edge_map, num_selected_edges, indices));
+      copy_attributes_based_on_mask(attributes,
+                                    in_component,
+                                    out_component,
+                                    ATTR_DOMAIN_FACE,
+                                    IndexMask(Vector<int64_t>(selected_poly_indices.as_span())));
+      copy_face_corner_attributes(attributes,
+                                  in_component,
+                                  out_component,
+                                  num_selected_loops,
+                                  selected_poly_indices,
+                                  mesh_in);
       break;
     }
     case GEO_NODE_DELETE_GEOMETRY_MODE_EDGE_FACE: {