1 files changed, 56 insertions, 20 deletions

diff --git a/source/blender/functions/intern/field.cc b/source/blender/functions/intern/field.cc
index f55b9cd92ff..3274af4a7be 100644
--- a/source/blender/functions/intern/field.cc
+++ b/source/blender/functions/intern/field.cc
@@ -540,28 +540,65 @@ FieldOperation::FieldOperation(std::shared_ptr<const MultiFunction> function,
   owned_function_ = std::move(function);
 }
 
-static bool any_field_depends_on_input(Span<GField> fields)
+/**
+ * Returns the field inputs used by all the provided fields.
+ * This tries to reuse an existing #FieldInputs whenever possible to avoid copying it.
+ */
+static std::shared_ptr<const FieldInputs> combine_field_inputs(Span<GField> fields)
 {
+  /* The #FieldInputs that we try to reuse if possible. */
+  const std::shared_ptr<const FieldInputs> *field_inputs_candidate = nullptr;
   for (const GField &field : fields) {
-    if (field.node().depends_on_input()) {
-      return true;
+    const std::shared_ptr<const FieldInputs> &field_inputs = field.node().field_inputs();
+    /* Only try to reuse non-empty #FieldInputs. */
+    if (field_inputs && !field_inputs->nodes.is_empty()) {
+      if (field_inputs_candidate == nullptr) {
+        field_inputs_candidate = &field_inputs;
+      }
+      else if ((*field_inputs_candidate)->nodes.size() < field_inputs->nodes.size()) {
+        /* Always try to reuse the #FieldInputs that has the most nodes already. */
+        field_inputs_candidate = &field_inputs;
+      }
+    }
+  }
+  if (field_inputs_candidate == nullptr) {
+    /* None of the field depends on an input. */
+    return {};
+  }
+  /* Check if all inputs are in the */
+  Vector<const FieldInput *> inputs_not_in_candidate;
+  for (const GField &field : fields) {
+    const std::shared_ptr<const FieldInputs> &field_inputs = field.node().field_inputs();
+    if (!field_inputs) {
+      continue;
+    }
+    if (&field_inputs == field_inputs_candidate) {
+      continue;
     }
+    for (const FieldInput *field_input : field_inputs->nodes) {
+      if (!(*field_inputs_candidate)->nodes.contains(field_input)) {
+        inputs_not_in_candidate.append(field_input);
+      }
+    }
+  }
+  if (inputs_not_in_candidate.is_empty()) {
+    /* The existing #FieldInputs can be reused, because no other field has additional inputs. */
+    return *field_inputs_candidate;
   }
-  return false;
+  /* Create new #FieldInputs that contains all of the inputs that the fields depend on. */
+  std::shared_ptr<FieldInputs> new_field_inputs = std::make_shared<FieldInputs>(
+      **field_inputs_candidate);
+  for (const FieldInput *field_input : inputs_not_in_candidate) {
+    new_field_inputs->nodes.add(field_input);
+    new_field_inputs->deduplicated_nodes.add(*field_input);
+  }
+  return new_field_inputs;
 }
 
 FieldOperation::FieldOperation(const MultiFunction &function, Vector<GField> inputs)
-    : FieldNode(false, any_field_depends_on_input(inputs)),
-      function_(&function),
-      inputs_(std::move(inputs))
+    : FieldNode(false), function_(&function), inputs_(std::move(inputs))
 {
-}
-
-void FieldOperation::foreach_field_input(FunctionRef<void(const FieldInput &)> foreach_fn) const
-{
-  for (const GField &field : inputs_) {
-    field.node().foreach_field_input(foreach_fn);
-  }
+  field_inputs_ = combine_field_inputs(inputs);
 }
 
 /* --------------------------------------------------------------------
@@ -569,13 +606,12 @@ void FieldOperation::foreach_field_input(FunctionRef<void(const FieldInput &)> f
  */
 
 FieldInput::FieldInput(const CPPType &type, std::string debug_name)
-    : FieldNode(true, true), type_(&type), debug_name_(std::move(debug_name))
-{
-}
-
-void FieldInput::foreach_field_input(FunctionRef<void(const FieldInput &)> foreach_fn) const
+    : FieldNode(true), type_(&type), debug_name_(std::move(debug_name))
 {
-  foreach_fn(*this);
+  std::shared_ptr<FieldInputs> field_inputs = std::make_shared<FieldInputs>();
+  field_inputs->nodes.add_new(this);
+  field_inputs->deduplicated_nodes.add_new(*this);
+  field_inputs_ = std::move(field_inputs);
 }
 
 /* --------------------------------------------------------------------