Geometry Nodes: Add named attribute nodes behind experimental flag

This commit adds three nodes:
- `Remove Attribute`: Removes an attribute with the given name
- `Named Attribute`: A field input node
- `Store Named Attribute`: Puts results of a field in a named attribute

They are added behind a new experimental feature flag, because further
development of attribute search and name dependency visualization will
happen as separate steps.

Ref T91742

Differential Revision: https://developer.blender.org/D12685

1 files changed, 131 insertions, 0 deletions

diff --git a/source/blender/nodes/geometry/nodes/node_geo_input_named_attribute.cc b/source/blender/nodes/geometry/nodes/node_geo_input_named_attribute.cc
new file mode 100644
index 00000000000..f6e2be9119c
--- /dev/null
+++ b/source/blender/nodes/geometry/nodes/node_geo_input_named_attribute.cc
@@ -0,0 +1,131 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "NOD_socket_search_link.hh"
+
+#include "node_geometry_util.hh"
+
+namespace blender::nodes::node_geo_input_named_attribute_cc {
+
+NODE_STORAGE_FUNCS(NodeGeometryInputNamedAttribute)
+
+static void node_declare(NodeDeclarationBuilder &b)
+{
+  b.add_input<decl::String>(N_("Name")).is_attribute_name();
+
+  b.add_output<decl::Vector>(N_("Attribute"), "Attribute_Vector").field_source();
+  b.add_output<decl::Float>(N_("Attribute"), "Attribute_Float").field_source();
+  b.add_output<decl::Color>(N_("Attribute"), "Attribute_Color").field_source();
+  b.add_output<decl::Bool>(N_("Attribute"), "Attribute_Bool").field_source();
+  b.add_output<decl::Int>(N_("Attribute"), "Attribute_Int").field_source();
+}
+
+static void node_layout(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
+{
+  uiItemR(layout, ptr, "data_type", 0, "", ICON_NONE);
+}
+
+static void node_init(bNodeTree *UNUSED(tree), bNode *node)
+{
+  NodeGeometryInputNamedAttribute *data = MEM_cnew<NodeGeometryInputNamedAttribute>(__func__);
+  data->data_type = CD_PROP_FLOAT;
+  node->storage = data;
+}
+
+static void node_update(bNodeTree *ntree, bNode *node)
+{
+  const NodeGeometryInputNamedAttribute &storage = node_storage(*node);
+  const CustomDataType data_type = static_cast<CustomDataType>(storage.data_type);
+
+  bNodeSocket *socket_vector = (bNodeSocket *)node->outputs.first;
+  bNodeSocket *socket_float = socket_vector->next;
+  bNodeSocket *socket_color4f = socket_float->next;
+  bNodeSocket *socket_boolean = socket_color4f->next;
+  bNodeSocket *socket_int32 = socket_boolean->next;
+
+  nodeSetSocketAvailability(ntree, socket_vector, data_type == CD_PROP_FLOAT3);
+  nodeSetSocketAvailability(ntree, socket_float, data_type == CD_PROP_FLOAT);
+  nodeSetSocketAvailability(ntree, socket_color4f, data_type == CD_PROP_COLOR);
+  nodeSetSocketAvailability(ntree, socket_boolean, data_type == CD_PROP_BOOL);
+  nodeSetSocketAvailability(ntree, socket_int32, data_type == CD_PROP_INT32);
+}
+
+static void node_gather_link_searches(GatherLinkSearchOpParams &params)
+{
+  if (U.experimental.use_named_attribute_nodes == 0) {
+    return;
+  }
+  const NodeDeclaration &declaration = *params.node_type().fixed_declaration;
+  search_link_ops_for_declarations(params, declaration.inputs());
+
+  if (params.in_out() == SOCK_OUT) {
+    const std::optional<CustomDataType> type = node_data_type_to_custom_data_type(
+        static_cast<eNodeSocketDatatype>(params.other_socket().type));
+    if (type && *type != CD_PROP_STRING) {
+      /* The input and output sockets have the same name. */
+      params.add_item(IFACE_("Attribute"), [type](LinkSearchOpParams &params) {
+        bNode &node = params.add_node("GeometryNodeInputNamedAttribute");
+        node_storage(node).data_type = *type;
+        params.update_and_connect_available_socket(node, "Attribute");
+      });
+    }
+  }
+}
+
+static void node_geo_exec(GeoNodeExecParams params)
+{
+  const NodeGeometryInputNamedAttribute &storage = node_storage(params.node());
+  const CustomDataType data_type = static_cast<CustomDataType>(storage.data_type);
+
+  const std::string name = params.extract_input<std::string>("Name");
+
+  if (!U.experimental.use_named_attribute_nodes) {
+    params.set_default_remaining_outputs();
+    return;
+  }
+
+  switch (data_type) {
+    case CD_PROP_FLOAT:
+      params.set_output("Attribute_Float", AttributeFieldInput::Create<float>(std::move(name)));
+      break;
+    case CD_PROP_FLOAT3:
+      params.set_output("Attribute_Vector", AttributeFieldInput::Create<float3>(std::move(name)));
+      break;
+    case CD_PROP_COLOR:
+      params.set_output("Attribute_Color",
+                        AttributeFieldInput::Create<ColorGeometry4f>(std::move(name)));
+      break;
+    case CD_PROP_BOOL:
+      params.set_output("Attribute_Bool", AttributeFieldInput::Create<bool>(std::move(name)));
+      break;
+    case CD_PROP_INT32:
+      params.set_output("Attribute_Int", AttributeFieldInput::Create<int>(std::move(name)));
+      break;
+    default:
+      break;
+  }
+}
+
+}  // namespace blender::nodes::node_geo_input_named_attribute_cc
+
+void register_node_type_geo_input_named_attribute()
+{
+  namespace file_ns = blender::nodes::node_geo_input_named_attribute_cc;
+
+  static bNodeType ntype;
+
+  geo_node_type_base(&ntype, GEO_NODE_INPUT_NAMED_ATTRIBUTE, "Named Attribute", NODE_CLASS_INPUT);
+  ntype.geometry_node_execute = file_ns::node_geo_exec;
+  ntype.declare = file_ns::node_declare;
+  ntype.draw_buttons = file_ns::node_layout;
+  ntype.gather_link_search_ops = file_ns::node_gather_link_searches;
+  ntype.updatefunc = file_ns::node_update;
+  node_type_init(&ntype, file_ns::node_init);
+  node_type_storage(&ntype,
+                    "NodeGeometryInputNamedAttribute",
+                    node_free_standard_storage,
+                    node_copy_standard_storage);
+  nodeRegisterType(&ntype);
+}