Simulation: add depsgraph relations for ids referenced by node tree

I'll really have to refactor `ntreeUpdateTree` soon to avoid scanning
all node trees multiple times.

3 files changed, 138 insertions, 0 deletions

diff --git a/source/blender/nodes/CMakeLists.txt b/source/blender/nodes/CMakeLists.txt
index 80720f5206a..bb2aaf35e52 100644
--- a/source/blender/nodes/CMakeLists.txt
+++ b/source/blender/nodes/CMakeLists.txt
@@ -278,6 +278,7 @@ set(SRC
   intern/node_common.c
   intern/node_exec.c
   intern/node_socket.cc
+  intern/node_tree_dependencies.cc
   intern/node_tree_multi_function.cc
   intern/node_tree_ref.cc
   intern/node_util.c
@@ -292,6 +293,7 @@ set(SRC
   NOD_composite.h
   NOD_derived_node_tree.hh
   NOD_function.h
+  NOD_node_tree_dependencies.hh
   NOD_node_tree_multi_function.hh
   NOD_node_tree_ref.hh
   NOD_shader.h
diff --git a/source/blender/nodes/NOD_node_tree_dependencies.hh b/source/blender/nodes/NOD_node_tree_dependencies.hh
new file mode 100644
index 00000000000..ca7059caa5f
--- /dev/null
+++ b/source/blender/nodes/NOD_node_tree_dependencies.hh
@@ -0,0 +1,79 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __NOD_NODE_TREE_DEPENDENCIES_H__
+#define __NOD_NODE_TREE_DEPENDENCIES_H__
+
+#include "BLI_vector_set.hh"
+
+#include "DNA_ID.h"
+#include "DNA_object_types.h"
+
+struct bNodeTree;
+
+namespace blender::nodes {
+
+class NodeTreeDependencies {
+ private:
+  VectorSet<Object *> transform_deps_;
+  VectorSet<Object *> geometry_deps_;
+  VectorSet<ID *> id_deps_;
+
+ public:
+  void add_transform_dependency(Object *object)
+  {
+    if (object == nullptr) {
+      return;
+    }
+    transform_deps_.add(object);
+    id_deps_.add(&object->id);
+  }
+
+  void add_geometry_dependency(Object *object)
+  {
+    if (object == nullptr) {
+      return;
+    }
+    geometry_deps_.add(object);
+    id_deps_.add(&object->id);
+  }
+
+  bool depends_on(ID *id) const
+  {
+    return id_deps_.contains(id);
+  }
+
+  Span<Object *> transform_dependencies()
+  {
+    return transform_deps_;
+  }
+
+  Span<Object *> geometry_dependencies()
+  {
+    return geometry_deps_;
+  }
+
+  Span<ID *> id_dependencies()
+  {
+    return id_deps_;
+  }
+};
+
+NodeTreeDependencies find_node_tree_dependencies(bNodeTree &ntree);
+
+}  // namespace blender::nodes
+
+#endif /* __NOD_NODE_TREE_DEPENDENCIES_H__ */
diff --git a/source/blender/nodes/intern/node_tree_dependencies.cc b/source/blender/nodes/intern/node_tree_dependencies.cc
new file mode 100644
index 00000000000..efe75a10f7e
--- /dev/null
+++ b/source/blender/nodes/intern/node_tree_dependencies.cc
@@ -0,0 +1,57 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include "NOD_node_tree_dependencies.hh"
+
+#include "DNA_node_types.h"
+
+#include "BKE_node.h"
+
+namespace blender::nodes {
+
+static void add_dependencies_of_node_tree(bNodeTree &ntree, NodeTreeDependencies &r_dependencies)
+{
+  /* TODO: Do a bit more sophisticated parsing to see which dependencies are really required. */
+  LISTBASE_FOREACH (bNode *, node, &ntree.nodes) {
+    LISTBASE_FOREACH (bNodeSocket *, socket, &node->inputs) {
+      if (socket->type == SOCK_OBJECT) {
+        Object *object = ((bNodeSocketValueObject *)socket->default_value)->value;
+        if (object != nullptr) {
+          r_dependencies.add_transform_dependency(object);
+          if (object->type == OB_MESH) {
+            r_dependencies.add_geometry_dependency(object);
+          }
+        }
+      }
+    }
+
+    if (node->type == NODE_GROUP) {
+      bNodeTree *group = (bNodeTree *)node->id;
+      if (group != nullptr) {
+        add_dependencies_of_node_tree(*group, r_dependencies);
+      }
+    }
+  }
+}
+
+NodeTreeDependencies find_node_tree_dependencies(bNodeTree &ntree)
+{
+  NodeTreeDependencies dependencies;
+  add_dependencies_of_node_tree(ntree, dependencies);
+  return dependencies;
+}
+
+}  // namespace blender::nodes