Nodes: Generate multi-function network from node tree

This adds new callbacks to `bNodeSocketType` and `bNodeType`.
Those are used to generate a multi-function network from a node
tree. Later, this network is evaluated on e.g. particle data.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D8169

7 files changed, 136 insertions, 6 deletions

diff --git a/source/blender/nodes/function/node_function_util.cc b/source/blender/nodes/function/node_function_util.cc
index 0927ba335fe..342c330a8fa 100644
--- a/source/blender/nodes/function/node_function_util.cc
+++ b/source/blender/nodes/function/node_function_util.cc
@@ -14,7 +14,7 @@
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
-#include "node_function_util.h"
+#include "node_function_util.hh"
 #include "node_util.h"
 
 bool fn_node_poll_default(bNodeType *UNUSED(ntype), bNodeTree *ntree)
diff --git a/source/blender/nodes/function/node_function_util.h b/source/blender/nodes/function/node_function_util.hh
index 85e252f9bdd..938cb5dd593 100644
--- a/source/blender/nodes/function/node_function_util.h
+++ b/source/blender/nodes/function/node_function_util.hh
@@ -19,6 +19,7 @@
 
 #include <string.h>
 
+#include "BLI_float3.hh"
 #include "BLI_utildefines.h"
 
 #include "MEM_guardedalloc.h"
@@ -26,6 +27,7 @@
 #include "DNA_node_types.h"
 
 #include "BKE_node.h"
+#include "BKE_node_tree_multi_function.hh"
 
 #include "BLT_translation.h"
 
@@ -33,6 +35,8 @@
 
 #include "node_util.h"
 
+#include "FN_multi_function_builder.hh"
+
 void fn_node_type_base(
     struct bNodeType *ntype, int type, const char *name, short nclass, short flag);
 bool fn_node_poll_default(struct bNodeType *ntype, struct bNodeTree *ntree);
diff --git a/source/blender/nodes/function/nodes/node_fn_boolean_math.cc b/source/blender/nodes/function/nodes/node_fn_boolean_math.cc
index 615ad4c6733..3a145311a08 100644
--- a/source/blender/nodes/function/nodes/node_fn_boolean_math.cc
+++ b/source/blender/nodes/function/nodes/node_fn_boolean_math.cc
@@ -19,7 +19,7 @@
 
 #include "RNA_enum_types.h"
 
-#include "node_function_util.h"
+#include "node_function_util.hh"
 
 static bNodeSocketTemplate fn_node_boolean_math_in[] = {
     {SOCK_BOOLEAN, N_("Boolean")},
@@ -50,6 +50,33 @@ static void node_boolean_math_label(bNodeTree *UNUSED(ntree), bNode *node, char
   BLI_strncpy(label, IFACE_(name), maxlen);
 }
 
+static const blender::fn::MultiFunction &get_multi_function(bNode &bnode)
+{
+  static blender::fn::CustomMF_SI_SI_SO<bool, bool, bool> and_fn{
+      "And", [](bool a, bool b) { return a && b; }};
+  static blender::fn::CustomMF_SI_SI_SO<bool, bool, bool> or_fn{
+      "Or", [](bool a, bool b) { return a || b; }};
+  static blender::fn::CustomMF_SI_SO<bool, bool> not_fn{"Not", [](bool a) { return !a; }};
+
+  switch (bnode.custom1) {
+    case NODE_BOOLEAN_MATH_AND:
+      return and_fn;
+    case NODE_BOOLEAN_MATH_OR:
+      return or_fn;
+    case NODE_BOOLEAN_MATH_NOT:
+      return not_fn;
+  }
+
+  BLI_assert(false);
+  return blender::fn::dummy_multi_function;
+}
+
+static void node_boolean_expand_in_mf_network(blender::bke::NodeMFNetworkBuilder &builder)
+{
+  const blender::fn::MultiFunction &fn = get_multi_function(builder.bnode());
+  builder.set_matching_fn(fn);
+}
+
 void register_node_type_fn_boolean_math()
 {
   static bNodeType ntype;
@@ -58,5 +85,6 @@ void register_node_type_fn_boolean_math()
   node_type_socket_templates(&ntype, fn_node_boolean_math_in, fn_node_boolean_math_out);
   node_type_label(&ntype, node_boolean_math_label);
   node_type_update(&ntype, node_boolean_math_update);
+  ntype.expand_in_mf_network = node_boolean_expand_in_mf_network;
   nodeRegisterType(&ntype);
 }
diff --git a/source/blender/nodes/function/nodes/node_fn_combine_strings.cc b/source/blender/nodes/function/nodes/node_fn_combine_strings.cc
index 1b6091451d9..a880933bc12 100644
--- a/source/blender/nodes/function/nodes/node_fn_combine_strings.cc
+++ b/source/blender/nodes/function/nodes/node_fn_combine_strings.cc
@@ -1,4 +1,20 @@
-#include "node_function_util.h"
+/*
+ * 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 "node_function_util.hh"
 
 static bNodeSocketTemplate fn_node_combine_strings_in[] = {
     {SOCK_STRING, N_("A")},
@@ -11,11 +27,20 @@ static bNodeSocketTemplate fn_node_combine_strings_out[] = {
     {-1, ""},
 };
 
+static void fn_node_combine_strings_expand_in_mf_network(
+    blender::bke::NodeMFNetworkBuilder &builder)
+{
+  static blender::fn::CustomMF_SI_SI_SO<std::string, std::string, std::string> combine_fn{
+      "Combine Strings", [](const std::string &a, const std::string &b) { return a + b; }};
+  builder.set_matching_fn(combine_fn);
+}
+
 void register_node_type_fn_combine_strings()
 {
   static bNodeType ntype;
 
   fn_node_type_base(&ntype, FN_NODE_COMBINE_STRINGS, "Combine Strings", 0, 0);
   node_type_socket_templates(&ntype, fn_node_combine_strings_in, fn_node_combine_strings_out);
+  ntype.expand_in_mf_network = fn_node_combine_strings_expand_in_mf_network;
   nodeRegisterType(&ntype);
 }
diff --git a/source/blender/nodes/function/nodes/node_fn_float_compare.cc b/source/blender/nodes/function/nodes/node_fn_float_compare.cc
index 9788402850b..fb2c4d88caf 100644
--- a/source/blender/nodes/function/nodes/node_fn_float_compare.cc
+++ b/source/blender/nodes/function/nodes/node_fn_float_compare.cc
@@ -14,12 +14,14 @@
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
+#include <cmath>
+
 #include "BLI_listbase.h"
 #include "BLI_string.h"
 
 #include "RNA_enum_types.h"
 
-#include "node_function_util.h"
+#include "node_function_util.hh"
 
 static bNodeSocketTemplate fn_node_float_compare_in[] = {
     {SOCK_FLOAT, N_("A"), 0.0f, 0.0f, 0.0f, 0.0f, -10000.0f, 10000.0f},
@@ -54,6 +56,46 @@ static void node_float_compare_label(bNodeTree *UNUSED(ntree),
   BLI_strncpy(label, IFACE_(name), maxlen);
 }
 
+static const blender::fn::MultiFunction &get_multi_function(bNode &node)
+{
+  static blender::fn::CustomMF_SI_SI_SO<float, float, bool> less_than_fn{
+      "Less Than", [](float a, float b) { return a < b; }};
+  static blender::fn::CustomMF_SI_SI_SO<float, float, bool> less_equal_fn{
+      "Less Equal", [](float a, float b) { return a <= b; }};
+  static blender::fn::CustomMF_SI_SI_SO<float, float, bool> greater_than_fn{
+      "Greater Than", [](float a, float b) { return a > b; }};
+  static blender::fn::CustomMF_SI_SI_SO<float, float, bool> greater_equal_fn{
+      "Greater Equal", [](float a, float b) { return a >= b; }};
+  static blender::fn::CustomMF_SI_SI_SI_SO<float, float, float, bool> equal_fn{
+      "Equal", [](float a, float b, float epsilon) { return std::abs(a - b) <= epsilon; }};
+  static blender::fn::CustomMF_SI_SI_SI_SO<float, float, float, bool> not_equal_fn{
+      "Not Equal", [](float a, float b, float epsilon) { return std::abs(a - b) > epsilon; }};
+
+  switch (node.custom1) {
+    case NODE_FLOAT_COMPARE_LESS_THAN:
+      return less_than_fn;
+    case NODE_FLOAT_COMPARE_LESS_EQUAL:
+      return less_equal_fn;
+    case NODE_FLOAT_COMPARE_GREATER_THAN:
+      return greater_than_fn;
+    case NODE_FLOAT_COMPARE_GREATER_EQUAL:
+      return greater_equal_fn;
+    case NODE_FLOAT_COMPARE_EQUAL:
+      return equal_fn;
+    case NODE_FLOAT_COMPARE_NOT_EQUAL:
+      return not_equal_fn;
+  }
+
+  BLI_assert(false);
+  return blender::fn::dummy_multi_function;
+}
+
+static void node_float_compare_expand_in_mf_network(blender::bke::NodeMFNetworkBuilder &builder)
+{
+  const blender::fn::MultiFunction &fn = get_multi_function(builder.bnode());
+  builder.set_matching_fn(fn);
+}
+
 void register_node_type_fn_float_compare()
 {
   static bNodeType ntype;
@@ -62,5 +104,6 @@ void register_node_type_fn_float_compare()
   node_type_socket_templates(&ntype, fn_node_float_compare_in, fn_node_float_compare_out);
   node_type_label(&ntype, node_float_compare_label);
   node_type_update(&ntype, node_float_compare_update);
+  ntype.expand_in_mf_network = node_float_compare_expand_in_mf_network;
   nodeRegisterType(&ntype);
 }
diff --git a/source/blender/nodes/function/nodes/node_fn_group_instance_id.cc b/source/blender/nodes/function/nodes/node_fn_group_instance_id.cc
index 2ac86ee2407..c61c941ee0d 100644
--- a/source/blender/nodes/function/nodes/node_fn_group_instance_id.cc
+++ b/source/blender/nodes/function/nodes/node_fn_group_instance_id.cc
@@ -1,15 +1,45 @@
-#include "node_function_util.h"
+/*
+ * 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 "node_function_util.hh"
 
 static bNodeSocketTemplate fn_node_group_instance_id_out[] = {
     {SOCK_STRING, N_("Identifier")},
     {-1, ""},
 };
 
+static void fn_node_group_instance_id_expand_in_mf_network(
+    blender::bke::NodeMFNetworkBuilder &builder)
+{
+  const blender::bke::DNode &node = builder.dnode();
+  std::string id = "/";
+  for (const blender::bke::DParentNode *parent = node.parent(); parent;
+       parent = parent->parent()) {
+    id = "/" + parent->node_ref().name() + id;
+  }
+  builder.construct_and_set_matching_fn<blender::fn::CustomMF_Constant<std::string>>(
+      std::move(id));
+}
+
 void register_node_type_fn_group_instance_id()
 {
   static bNodeType ntype;
 
   fn_node_type_base(&ntype, FN_NODE_GROUP_INSTANCE_ID, "Group Instance ID", 0, 0);
   node_type_socket_templates(&ntype, nullptr, fn_node_group_instance_id_out);
+  ntype.expand_in_mf_network = fn_node_group_instance_id_expand_in_mf_network;
   nodeRegisterType(&ntype);
 }
diff --git a/source/blender/nodes/function/nodes/node_fn_switch.cc b/source/blender/nodes/function/nodes/node_fn_switch.cc
index cb721058875..281ddb05c76 100644
--- a/source/blender/nodes/function/nodes/node_fn_switch.cc
+++ b/source/blender/nodes/function/nodes/node_fn_switch.cc
@@ -15,7 +15,7 @@
  */
 
 #include "BLI_listbase.h"
-#include "node_function_util.h"
+#include "node_function_util.hh"
 
 static bNodeSocketTemplate fn_node_switch_in[] = {
     {SOCK_BOOLEAN, N_("Switch")},