Geometry Nodes: add socket value logging capability

The node tree evaluator now calls a callback for every used socket with
its corresponding value(s). Right now the callback does nothing.
However, we can use it to collect attribute name hints, socket values
for debugging or data that will be displayed in the spreadsheet.

The main difficulty here was to also call the callback for sockets in
nodes that are not directly executed (such as group nodes, muted
nodes and reroutes).

No functional changes are expected.

1 files changed, 18 insertions, 2 deletions

diff --git a/source/blender/nodes/NOD_derived_node_tree.hh b/source/blender/nodes/NOD_derived_node_tree.hh
index c29de611e18..e294bef2ea8 100644
--- a/source/blender/nodes/NOD_derived_node_tree.hh
+++ b/source/blender/nodes/NOD_derived_node_tree.hh
@@ -59,6 +59,7 @@ class DTreeContext {
   const NodeTreeRef *tree_;
   /* All the children contexts of this context. */
   Map<const NodeRef *, DTreeContext *> children_;
+  DerivedNodeTree *derived_tree_;
 
   friend DerivedNodeTree;
 
@@ -67,6 +68,7 @@ class DTreeContext {
   const DTreeContext *parent_context() const;
   const NodeRef *parent_node() const;
   const DTreeContext *child_context(const NodeRef &node) const;
+  const DerivedNodeTree &derived_tree() const;
   bool is_root() const;
 };
 
@@ -117,6 +119,8 @@ class DSocket {
   operator bool() const;
 
   uint64_t hash() const;
+
+  DNode node() const;
 };
 
 /* A (nullable) reference to an input socket and the context it is in. */
@@ -132,7 +136,7 @@ class DInputSocket : public DSocket {
   DOutputSocket get_corresponding_group_node_output() const;
   Vector<DOutputSocket, 4> get_corresponding_group_input_sockets() const;
 
-  void foreach_origin_socket(FunctionRef<void(DSocket)> callback) const;
+  void foreach_origin_socket(FunctionRef<void(DSocket)> origin_fn) const;
 };
 
 /* A (nullable) reference to an output socket and the context it is in. */
@@ -148,7 +152,8 @@ class DOutputSocket : public DSocket {
   DInputSocket get_corresponding_group_node_input() const;
   DInputSocket get_active_corresponding_group_output_socket() const;
 
-  void foreach_target_socket(FunctionRef<void(DInputSocket)> callback) const;
+  void foreach_target_socket(FunctionRef<void(DInputSocket)> target_fn,
+                             FunctionRef<void(DSocket)> skipped_fn) const;
 };
 
 class DerivedNodeTree {
@@ -214,6 +219,11 @@ inline const DTreeContext *DTreeContext::child_context(const NodeRef &node) cons
   return children_.lookup_default(&node, nullptr);
 }
 
+inline const DerivedNodeTree &DTreeContext::derived_tree() const
+{
+  return *derived_tree_;
+}
+
 inline bool DTreeContext::is_root() const
 {
   return parent_context_ == nullptr;
@@ -319,6 +329,12 @@ inline uint64_t DSocket::hash() const
   return get_default_hash_2(context_, socket_ref_);
 }
 
+inline DNode DSocket::node() const
+{
+  BLI_assert(socket_ref_ != nullptr);
+  return {context_, &socket_ref_->node()};
+}
+
 /* --------------------------------------------------------------------
  * DInputSocket inline methods.
  */