Geometry Nodes: reduce overhead when processing single values

Currently the geometry nodes evaluator always stores a field for every
type that supports it, even if it is just a single value. This results in a lot
of overhead when there are many sockets that just contain a single
value, which is often the case.

This introduces a new `ValueOrField<T>` type that is used by the geometry
nodes evaluator. Now a field will only be created when it is actually
necessary. See D13307 for more details. In extrem cases this can speed
up the evaluation 2-3x (those cases are probably never hit in practice
though, but it's good to get rid of unnecessary overhead nevertheless).

Differential Revision: https://developer.blender.org/D13307

2 files changed, 43 insertions, 31 deletions

diff --git a/source/blender/nodes/intern/geometry_nodes_eval_log.cc b/source/blender/nodes/intern/geometry_nodes_eval_log.cc
index ddd3c991518..782ab43336c 100644
--- a/source/blender/nodes/intern/geometry_nodes_eval_log.cc
+++ b/source/blender/nodes/intern/geometry_nodes_eval_log.cc
@@ -31,6 +31,7 @@ using fn::CPPType;
 using fn::FieldCPPType;
 using fn::FieldInput;
 using fn::GField;
+using fn::ValueOrFieldCPPType;
 
 ModifierLog::ModifierLog(GeoLogger &logger)
     : input_geometry_log_(std::move(logger.input_geometry_log_)),
@@ -417,25 +418,38 @@ void LocalGeoLogger::log_value_for_sockets(Span<DSocket> sockets, GPointer value
         geometry_set, log_full_geometry);
     values_.append({copied_sockets, std::move(value_log)});
   }
-  else if (const FieldCPPType *field_type = dynamic_cast<const FieldCPPType *>(&type)) {
-    GField field = field_type->get_gfield(value.get());
-    bool log_full_field = false;
-    if (!field.node().depends_on_input()) {
-      /* Always log constant fields so that their value can be shown in socket inspection.
-       * In the future we can also evaluate the field here and only store the value. */
-      log_full_field = true;
-    }
-    if (!log_full_field) {
-      for (const DSocket &socket : sockets) {
-        if (main_logger_->log_full_sockets_.contains(socket)) {
-          log_full_field = true;
-          break;
+  else if (const ValueOrFieldCPPType *value_or_field_type =
+               dynamic_cast<const ValueOrFieldCPPType *>(&type)) {
+    const void *value_or_field = value.get();
+    if (value_or_field_type->is_field(value_or_field)) {
+      GField field = *value_or_field_type->get_field_ptr(value_or_field);
+      bool log_full_field = false;
+      if (!field.node().depends_on_input()) {
+        /* Always log constant fields so that their value can be shown in socket inspection.
+         * In the future we can also evaluate the field here and only store the value. */
+        log_full_field = true;
+      }
+      if (!log_full_field) {
+        for (const DSocket &socket : sockets) {
+          if (main_logger_->log_full_sockets_.contains(socket)) {
+            log_full_field = true;
+            break;
+          }
         }
       }
+      destruct_ptr<GFieldValueLog> value_log = allocator_->construct<GFieldValueLog>(
+          std::move(field), log_full_field);
+      values_.append({copied_sockets, std::move(value_log)});
+    }
+    else {
+      const CPPType &base_type = value_or_field_type->base_type();
+      const void *value = value_or_field_type->get_value_ptr(value_or_field);
+      void *buffer = allocator_->allocate(base_type.size(), base_type.alignment());
+      base_type.copy_construct(value, buffer);
+      destruct_ptr<GenericValueLog> value_log = allocator_->construct<GenericValueLog>(
+          GMutablePointer{base_type, buffer});
+      values_.append({copied_sockets, std::move(value_log)});
     }
-    destruct_ptr<GFieldValueLog> value_log = allocator_->construct<GFieldValueLog>(
-        std::move(field), log_full_field);
-    values_.append({copied_sockets, std::move(value_log)});
   }
   else {
     void *buffer = allocator_->allocate(type.size(), type.alignment());
diff --git a/source/blender/nodes/intern/node_socket.cc b/source/blender/nodes/intern/node_socket.cc
index 200e4120346..68e8f6421bd 100644
--- a/source/blender/nodes/intern/node_socket.cc
+++ b/source/blender/nodes/intern/node_socket.cc
@@ -51,6 +51,7 @@
 #include "FN_field.hh"
 
 using namespace blender;
+using blender::fn::ValueOrField;
 using blender::nodes::SocketDeclarationPtr;
 
 struct bNodeSocket *node_add_socket_from_template(struct bNodeTree *ntree,
@@ -701,11 +702,11 @@ static bNodeSocketType *make_socket_type_bool()
   socktype->get_base_cpp_value = [](const bNodeSocket &socket, void *r_value) {
     *(bool *)r_value = ((bNodeSocketValueBoolean *)socket.default_value)->value;
   };
-  socktype->geometry_nodes_cpp_type = &blender::fn::CPPType::get<blender::fn::Field<bool>>();
+  socktype->geometry_nodes_cpp_type = &blender::fn::CPPType::get<ValueOrField<bool>>();
   socktype->get_geometry_nodes_cpp_value = [](const bNodeSocket &socket, void *r_value) {
     bool value;
     socket.typeinfo->get_base_cpp_value(socket, &value);
-    new (r_value) blender::fn::Field<bool>(blender::fn::make_constant_field(value));
+    new (r_value) ValueOrField<bool>(value);
   };
   return socktype;
 }
@@ -717,11 +718,11 @@ static bNodeSocketType *make_socket_type_float(PropertySubType subtype)
   socktype->get_base_cpp_value = [](const bNodeSocket &socket, void *r_value) {
     *(float *)r_value = ((bNodeSocketValueFloat *)socket.default_value)->value;
   };
-  socktype->geometry_nodes_cpp_type = &blender::fn::CPPType::get<blender::fn::Field<float>>();
+  socktype->geometry_nodes_cpp_type = &blender::fn::CPPType::get<ValueOrField<float>>();
   socktype->get_geometry_nodes_cpp_value = [](const bNodeSocket &socket, void *r_value) {
     float value;
     socket.typeinfo->get_base_cpp_value(socket, &value);
-    new (r_value) blender::fn::Field<float>(blender::fn::make_constant_field(value));
+    new (r_value) ValueOrField<float>(value);
   };
   return socktype;
 }
@@ -733,11 +734,11 @@ static bNodeSocketType *make_socket_type_int(PropertySubType subtype)
   socktype->get_base_cpp_value = [](const bNodeSocket &socket, void *r_value) {
     *(int *)r_value = ((bNodeSocketValueInt *)socket.default_value)->value;
   };
-  socktype->geometry_nodes_cpp_type = &blender::fn::CPPType::get<blender::fn::Field<int>>();
+  socktype->geometry_nodes_cpp_type = &blender::fn::CPPType::get<ValueOrField<int>>();
   socktype->get_geometry_nodes_cpp_value = [](const bNodeSocket &socket, void *r_value) {
     int value;
     socket.typeinfo->get_base_cpp_value(socket, &value);
-    new (r_value) blender::fn::Field<int>(blender::fn::make_constant_field(value));
+    new (r_value) ValueOrField<int>(value);
   };
   return socktype;
 }
@@ -749,12 +750,11 @@ static bNodeSocketType *make_socket_type_vector(PropertySubType subtype)
   socktype->get_base_cpp_value = [](const bNodeSocket &socket, void *r_value) {
     *(blender::float3 *)r_value = ((bNodeSocketValueVector *)socket.default_value)->value;
   };
-  socktype->geometry_nodes_cpp_type =
-      &blender::fn::CPPType::get<blender::fn::Field<blender::float3>>();
+  socktype->geometry_nodes_cpp_type = &blender::fn::CPPType::get<ValueOrField<blender::float3>>();
   socktype->get_geometry_nodes_cpp_value = [](const bNodeSocket &socket, void *r_value) {
     blender::float3 value;
     socket.typeinfo->get_base_cpp_value(socket, &value);
-    new (r_value) blender::fn::Field<blender::float3>(blender::fn::make_constant_field(value));
+    new (r_value) ValueOrField<blender::float3>(value);
   };
   return socktype;
 }
@@ -767,12 +767,11 @@ static bNodeSocketType *make_socket_type_rgba()
     *(blender::ColorGeometry4f *)r_value = ((bNodeSocketValueRGBA *)socket.default_value)->value;
   };
   socktype->geometry_nodes_cpp_type =
-      &blender::fn::CPPType::get<blender::fn::Field<blender::ColorGeometry4f>>();
+      &blender::fn::CPPType::get<ValueOrField<blender::ColorGeometry4f>>();
   socktype->get_geometry_nodes_cpp_value = [](const bNodeSocket &socket, void *r_value) {
     blender::ColorGeometry4f value;
     socket.typeinfo->get_base_cpp_value(socket, &value);
-    new (r_value)
-        blender::fn::Field<blender::ColorGeometry4f>(blender::fn::make_constant_field(value));
+    new (r_value) ValueOrField<blender::ColorGeometry4f>(value);
   };
   return socktype;
 }
@@ -784,13 +783,12 @@ static bNodeSocketType *make_socket_type_string()
   socktype->get_base_cpp_value = [](const bNodeSocket &socket, void *r_value) {
     new (r_value) std::string(((bNodeSocketValueString *)socket.default_value)->value);
   };
-  socktype->geometry_nodes_cpp_type =
-      &blender::fn::CPPType::get<blender::fn::Field<std::string>>();
+  socktype->geometry_nodes_cpp_type = &blender::fn::CPPType::get<ValueOrField<std::string>>();
   socktype->get_geometry_nodes_cpp_value = [](const bNodeSocket &socket, void *r_value) {
     std::string value;
     value.~basic_string();
     socket.typeinfo->get_base_cpp_value(socket, &value);
-    new (r_value) blender::fn::Field<std::string>(blender::fn::make_constant_field(value));
+    new (r_value) ValueOrField<std::string>(value);
   };
   return socktype;
 }