Geometry Nodes: Move normal field input to be usable elsewhere

This commit moves the normal field input to `BKE_geometry_set.hh`
from the node file so that normals can be used as an implicit input to
other nodes.

Differential Revision: https://developer.blender.org/D13779

1 files changed, 1 insertions, 239 deletions

diff --git a/source/blender/nodes/geometry/nodes/node_geo_input_normal.cc b/source/blender/nodes/geometry/nodes/node_geo_input_normal.cc
index db5f30fb6c9..120ae0e9bd1 100644
--- a/source/blender/nodes/geometry/nodes/node_geo_input_normal.cc
+++ b/source/blender/nodes/geometry/nodes/node_geo_input_normal.cc
@@ -31,247 +31,9 @@ static void node_declare(NodeDeclarationBuilder &b)
   b.add_output<decl::Vector>(N_("Normal")).field_source();
 }
 
-static VArray<float3> mesh_face_normals(const Mesh &mesh,
-                                        const Span<MVert> verts,
-                                        const Span<MPoly> polys,
-                                        const Span<MLoop> loops,
-                                        const IndexMask mask)
-{
-  /* Use existing normals to avoid unnecessarily recalculating them, if possible. */
-  if (!(mesh.runtime.cd_dirty_poly & CD_MASK_NORMAL) &&
-      CustomData_has_layer(&mesh.pdata, CD_NORMAL)) {
-    const void *data = CustomData_get_layer(&mesh.pdata, CD_NORMAL);
-
-    return VArray<float3>::ForSpan({(const float3 *)data, polys.size()});
-  }
-
-  auto normal_fn = [verts, polys, loops](const int i) -> float3 {
-    float3 normal;
-    const MPoly &poly = polys[i];
-    BKE_mesh_calc_poly_normal(&poly, &loops[poly.loopstart], verts.data(), normal);
-    return normal;
-  };
-
-  return VArray<float3>::ForFunc(mask.min_array_size(), normal_fn);
-}
-
-static VArray<float3> mesh_vertex_normals(const Mesh &mesh,
-                                          const Span<MVert> verts,
-                                          const Span<MPoly> polys,
-                                          const Span<MLoop> loops,
-                                          const IndexMask mask)
-{
-  /* Use existing normals to avoid unnecessarily recalculating them, if possible. */
-  if (!(mesh.runtime.cd_dirty_vert & CD_MASK_NORMAL) &&
-      CustomData_has_layer(&mesh.vdata, CD_NORMAL)) {
-    const void *data = CustomData_get_layer(&mesh.pdata, CD_NORMAL);
-
-    return VArray<float3>::ForSpan({(const float3 *)data, mesh.totvert});
-  }
-
-  /* If the normals are dirty, they must be recalculated for the output of this node's field
-   * source. Ideally vertex normals could be calculated lazily on a const mesh, but that's not
-   * possible at the moment, so we take ownership of the results. Sadly we must also create a copy
-   * of MVert to use the mesh normals API. This can be improved by adding mutex-protected lazy
-   * calculation of normals on meshes.
-   *
-   * Use mask.min_array_size() to avoid calculating a final chunk of data if possible. */
-  Array<MVert> temp_verts(verts);
-  Array<float3> normals(verts.size()); /* Use full size for accumulation from faces. */
-  BKE_mesh_calc_normals_poly_and_vertex(temp_verts.data(),
-                                        mask.min_array_size(),
-                                        loops.data(),
-                                        loops.size(),
-                                        polys.data(),
-                                        polys.size(),
-                                        nullptr,
-                                        (float(*)[3])normals.data());
-
-  return VArray<float3>::ForContainer(std::move(normals));
-}
-
-static VArray<float3> construct_mesh_normals_gvarray(const MeshComponent &mesh_component,
-                                                     const Mesh &mesh,
-                                                     const IndexMask mask,
-                                                     const AttributeDomain domain)
-{
-  Span<MVert> verts{mesh.mvert, mesh.totvert};
-  Span<MEdge> edges{mesh.medge, mesh.totedge};
-  Span<MPoly> polys{mesh.mpoly, mesh.totpoly};
-  Span<MLoop> loops{mesh.mloop, mesh.totloop};
-
-  switch (domain) {
-    case ATTR_DOMAIN_FACE: {
-      return mesh_face_normals(mesh, verts, polys, loops, mask);
-    }
-    case ATTR_DOMAIN_POINT: {
-      return mesh_vertex_normals(mesh, verts, polys, loops, mask);
-    }
-    case ATTR_DOMAIN_EDGE: {
-      /* In this case, start with vertex normals and convert to the edge domain, since the
-       * conversion from edges to vertices is very simple. Use the full mask since the edges
-       * might use the vertex normal from any index. */
-      GVArray vert_normals = mesh_vertex_normals(
-          mesh, verts, polys, loops, IndexRange(verts.size()));
-      Span<float3> vert_normals_span = vert_normals.get_internal_span().typed<float3>();
-      Array<float3> edge_normals(mask.min_array_size());
-
-      /* Use "manual" domain interpolation instead of the GeometryComponent API to avoid
-       * calculating unnecessary values and to allow normalizing the result much more simply. */
-      for (const int i : mask) {
-        const MEdge &edge = edges[i];
-        edge_normals[i] = float3::interpolate(
-                              vert_normals_span[edge.v1], vert_normals_span[edge.v2], 0.5f)
-                              .normalized();
-      }
-
-      return VArray<float3>::ForContainer(std::move(edge_normals));
-    }
-    case ATTR_DOMAIN_CORNER: {
-      /* The normals on corners are just the mesh's face normals, so start with the face normal
-       * array and copy the face normal for each of its corners. */
-      VArray<float3> face_normals = mesh_face_normals(
-          mesh, verts, polys, loops, IndexRange(polys.size()));
-
-      /* In this case using the mesh component's generic domain interpolation is fine, the data
-       * will still be normalized, since the face normal is just copied to every corner. */
-      return mesh_component.attribute_try_adapt_domain<float3>(
-          std::move(face_normals), ATTR_DOMAIN_FACE, ATTR_DOMAIN_CORNER);
-    }
-    default:
-      return {};
-  }
-}
-
-static void calculate_bezier_normals(const BezierSpline &spline, MutableSpan<float3> normals)
-{
-  Span<int> offsets = spline.control_point_offsets();
-  Span<float3> evaluated_normals = spline.evaluated_normals();
-  for (const int i : IndexRange(spline.size())) {
-    normals[i] = evaluated_normals[offsets[i]];
-  }
-}
-
-static void calculate_poly_normals(const PolySpline &spline, MutableSpan<float3> normals)
-{
-  normals.copy_from(spline.evaluated_normals());
-}
-
-/**
- * Because NURBS control points are not necessarily on the path, the normal at the control points
- * is not well defined, so create a temporary poly spline to find the normals. This requires extra
- * copying currently, but may be more efficient in the future if attributes have some form of CoW.
- */
-static void calculate_nurbs_normals(const NURBSpline &spline, MutableSpan<float3> normals)
-{
-  PolySpline poly_spline;
-  poly_spline.resize(spline.size());
-  poly_spline.positions().copy_from(spline.positions());
-  poly_spline.tilts().copy_from(spline.tilts());
-  normals.copy_from(poly_spline.evaluated_normals());
-}
-
-static Array<float3> curve_normal_point_domain(const CurveEval &curve)
-{
-  Span<SplinePtr> splines = curve.splines();
-  Array<int> offsets = curve.control_point_offsets();
-  const int total_size = offsets.last();
-  Array<float3> normals(total_size);
-
-  threading::parallel_for(splines.index_range(), 128, [&](IndexRange range) {
-    for (const int i : range) {
-      const Spline &spline = *splines[i];
-      MutableSpan spline_normals{normals.as_mutable_span().slice(offsets[i], spline.size())};
-      switch (splines[i]->type()) {
-        case Spline::Type::Bezier:
-          calculate_bezier_normals(static_cast<const BezierSpline &>(spline), spline_normals);
-          break;
-        case Spline::Type::Poly:
-          calculate_poly_normals(static_cast<const PolySpline &>(spline), spline_normals);
-          break;
-        case Spline::Type::NURBS:
-          calculate_nurbs_normals(static_cast<const NURBSpline &>(spline), spline_normals);
-          break;
-      }
-    }
-  });
-  return normals;
-}
-
-static VArray<float3> construct_curve_normal_gvarray(const CurveComponent &component,
-                                                     const AttributeDomain domain)
-{
-  const CurveEval *curve = component.get_for_read();
-  if (curve == nullptr) {
-    return nullptr;
-  }
-
-  if (domain == ATTR_DOMAIN_POINT) {
-    const Span<SplinePtr> splines = curve->splines();
-
-    /* Use a reference to evaluated normals if possible to avoid an allocation and a copy.
-     * This is only possible when there is only one poly spline. */
-    if (splines.size() == 1 && splines.first()->type() == Spline::Type::Poly) {
-      const PolySpline &spline = static_cast<PolySpline &>(*splines.first());
-      return VArray<float3>::ForSpan(spline.evaluated_normals());
-    }
-
-    Array<float3> normals = curve_normal_point_domain(*curve);
-    return VArray<float3>::ForContainer(std::move(normals));
-  }
-
-  if (domain == ATTR_DOMAIN_CURVE) {
-    Array<float3> point_normals = curve_normal_point_domain(*curve);
-    VArray<float3> varray = VArray<float3>::ForContainer(std::move(point_normals));
-    return component.attribute_try_adapt_domain<float3>(
-        std::move(varray), ATTR_DOMAIN_POINT, ATTR_DOMAIN_CURVE);
-  }
-
-  return nullptr;
-}
-
-class NormalFieldInput final : public GeometryFieldInput {
- public:
-  NormalFieldInput() : GeometryFieldInput(CPPType::get<float3>(), "Normal node")
-  {
-    category_ = Category::Generated;
-  }
-
-  GVArray get_varray_for_context(const GeometryComponent &component,
-                                 const AttributeDomain domain,
-                                 IndexMask mask) const final
-  {
-    if (component.type() == GEO_COMPONENT_TYPE_MESH) {
-      const MeshComponent &mesh_component = static_cast<const MeshComponent &>(component);
-      const Mesh *mesh = mesh_component.get_for_read();
-      if (mesh == nullptr) {
-        return {};
-      }
-
-      return construct_mesh_normals_gvarray(mesh_component, *mesh, mask, domain);
-    }
-    if (component.type() == GEO_COMPONENT_TYPE_CURVE) {
-      const CurveComponent &curve_component = static_cast<const CurveComponent &>(component);
-      return construct_curve_normal_gvarray(curve_component, domain);
-    }
-    return {};
-  }
-
-  uint64_t hash() const override
-  {
-    /* Some random constant hash. */
-    return 669605641;
-  }
-
-  bool is_equal_to(const fn::FieldNode &other) const override
-  {
-    return dynamic_cast<const NormalFieldInput *>(&other) != nullptr;
-  }
-};
-
 static void node_geo_exec(GeoNodeExecParams params)
 {
-  Field<float3> normal_field{std::make_shared<NormalFieldInput>()};
+  Field<float3> normal_field{std::make_shared<bke::NormalFieldInput>()};
   params.set_output("Normal", std::move(normal_field));
 }