Simulations: Add simulation node tree type

This implements a new builtin node tree type called `SimulationNodeTree`.
It is not yet embedded in the `Simulation` data block.

The node tree will initially be used for the new particle nodes system.

When the cmake option `WITH_NEW_SIMULATION_TYPE` is enabled, a new
`Simulation Editor` is shown in the editors menu (which is just a node editor).

This patch does not add entries to the Add Node menu, so it is empty.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D7287

2 files changed, 65 insertions, 2 deletions

diff --git a/source/blender/makesrna/RNA_access.h b/source/blender/makesrna/RNA_access.h
index 673669d26f6..a77d07dfe17 100644
--- a/source/blender/makesrna/RNA_access.h
+++ b/source/blender/makesrna/RNA_access.h
@@ -549,6 +549,8 @@ extern StructRNA RNA_ShrinkwrapModifier;
 extern StructRNA RNA_SimpleDeformModifier;
 extern StructRNA RNA_SimplifyGpencilModifier;
 extern StructRNA RNA_Simulation;
+extern StructRNA RNA_SimulationNode;
+extern StructRNA RNA_SimulationNodeTree;
 extern StructRNA RNA_SkinModifier;
 extern StructRNA RNA_SmoothGpencilModifier;
 extern StructRNA RNA_SmoothModifier;
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index 31d6ff80f34..104423322e6 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -669,6 +669,20 @@ static const EnumPropertyItem *rna_node_static_type_itemf(bContext *UNUSED(C),
 #  undef DefNode
   }
 
+  if (RNA_struct_is_a(ptr->type, &RNA_SimulationNode)) {
+#  define DefNode(Category, ID, DefFunc, EnumName, StructName, UIName, UIDesc) \
+    if (STREQ(#Category, "SimulationNode")) { \
+      tmp.value = ID; \
+      tmp.identifier = EnumName; \
+      tmp.name = UIName; \
+      tmp.description = UIDesc; \
+      tmp.icon = ICON_NONE; \
+      RNA_enum_item_add(&item, &totitem, &tmp); \
+    }
+#  include "../../nodes/NOD_static_types.h"
+#  undef DefNode
+  }
+
   RNA_enum_item_end(&item, &totitem);
   *r_free = true;
 
@@ -1785,6 +1799,28 @@ static StructRNA *rna_TextureNode_register(Main *bmain,
   return nt->rna_ext.srna;
 }
 
+static StructRNA *rna_SimulationNode_register(Main *bmain,
+                                              ReportList *reports,
+                                              void *data,
+                                              const char *identifier,
+                                              StructValidateFunc validate,
+                                              StructCallbackFunc call,
+                                              StructFreeFunc free)
+{
+  bNodeType *nt = rna_Node_register_base(
+      bmain, reports, &RNA_SimulationNode, data, identifier, validate, call, free);
+  if (!nt) {
+    return NULL;
+  }
+
+  nodeRegisterType(nt);
+
+  /* update while blender is running */
+  WM_main_add_notifier(NC_NODE | NA_EDITED, NULL);
+
+  return nt->rna_ext.srna;
+}
+
 static IDProperty *rna_Node_idprops(PointerRNA *ptr, bool create)
 {
   bNode *node = ptr->data;
@@ -7936,6 +7972,16 @@ static void rna_def_texture_node(BlenderRNA *brna)
   RNA_def_struct_register_funcs(srna, "rna_TextureNode_register", "rna_Node_unregister", NULL);
 }
 
+static void rna_def_simulation_node(BlenderRNA *brna)
+{
+  StructRNA *srna;
+
+  srna = RNA_def_struct(brna, "SimulationNode", "NodeInternal");
+  RNA_def_struct_ui_text(srna, "Simulation Node", "");
+  RNA_def_struct_sdna(srna, "bNode");
+  RNA_def_struct_register_funcs(srna, "rna_SimulationNode_register", "rna_Node_unregister", NULL);
+}
+
 /* -------------------------------------------------------------------------- */
 
 static void rna_def_node_socket(BlenderRNA *brna)
@@ -9251,6 +9297,7 @@ static void rna_def_nodetree(BlenderRNA *brna)
       {NTREE_SHADER, "SHADER", ICON_MATERIAL, "Shader", "Shader nodes"},
       {NTREE_TEXTURE, "TEXTURE", ICON_TEXTURE, "Texture", "Texture nodes"},
       {NTREE_COMPOSIT, "COMPOSITING", ICON_RENDERLAYERS, "Compositing", "Compositing nodes"},
+      {NTREE_SIMULATION, "SIMULATION", ICON_PHYSICS, "Simulation", "Simulation nodes"},
       {0, NULL, 0, NULL, NULL},
   };
 
@@ -9474,6 +9521,17 @@ static void rna_def_texture_nodetree(BlenderRNA *brna)
   RNA_def_struct_ui_icon(srna, ICON_TEXTURE);
 }
 
+static void rna_def_simulation_nodetree(BlenderRNA *brna)
+{
+  StructRNA *srna;
+
+  srna = RNA_def_struct(brna, "SimulationNodeTree", "NodeTree");
+  RNA_def_struct_ui_text(
+      srna, "Simulation Node Tree", "Node tree consisting of linked nodes used for simulations");
+  RNA_def_struct_sdna(srna, "bNodeTree");
+  RNA_def_struct_ui_icon(srna, ICON_PHYSICS); /* TODO: Use correct icon. */
+}
+
 static StructRNA *define_specific_node(BlenderRNA *brna,
                                        const char *struct_name,
                                        const char *base_name,
@@ -9560,6 +9618,7 @@ void RNA_def_nodetree(BlenderRNA *brna)
   rna_def_shader_node(brna);
   rna_def_compositor_node(brna);
   rna_def_texture_node(brna);
+  rna_def_simulation_node(brna);
 
   rna_def_nodetree(brna);
 
@@ -9568,6 +9627,7 @@ void RNA_def_nodetree(BlenderRNA *brna)
   rna_def_composite_nodetree(brna);
   rna_def_shader_nodetree(brna);
   rna_def_texture_nodetree(brna);
+  rna_def_simulation_nodetree(brna);
 
 #  define DefNode(Category, ID, DefFunc, EnumName, StructName, UIName, UIDesc) \
     { \
@@ -9584,12 +9644,13 @@ void RNA_def_nodetree(BlenderRNA *brna)
    */
 #  include "../../nodes/NOD_static_types.h"
 
-  /* Node group types need to be defined for shader, compositor, texture nodes individually.
-   * Cannot use the static types header for this, since they share the same int id.
+  /* Node group types need to be defined for shader, compositor, texture, simulation nodes
+   * individually. Cannot use the static types header for this, since they share the same int id.
    */
   define_specific_node(brna, "ShaderNodeGroup", "ShaderNode", "Group", "", def_group);
   define_specific_node(brna, "CompositorNodeGroup", "CompositorNode", "Group", "", def_group);
   define_specific_node(brna, "TextureNodeGroup", "TextureNode", "Group", "", def_group);
+  define_specific_node(brna, "SimulationNodeGroup", "SimulationNode", "Group", "", def_group);
   def_custom_group(brna,
                    "ShaderNodeCustomGroup",
                    "ShaderNode",