Simulations: Embed simulation node tree in simulation data block

This adds an embedded node tree to the simulation data block dna.
The UI in the `Simulation Editor` has been updated to show a list
of simulation data blocks, instead of individual node trees.

The new `SpaceNodeEditor.simulation` property wraps the existing
`SpaceNodeEditor.id` property. It allows scripts to get and set
the simulation data block that is being edited.

Reviewers: brecht, mont29

Differential Revision: https://developer.blender.org/D7301

release/scripts/startup/bl_operators/__init__.py

@@ -42,6 +42,7 @@ _modules = [
     "rigidbody",
     "screen_play_rendered_anim",
     "sequencer",
+    "simulation",
     "userpref",
     "uvcalc_follow_active",
     "uvcalc_lightmap",

release/scripts/startup/bl_operators/simulation.py

@@ -0,0 +1,39 @@
+# ##### BEGIN GPL LICENSE BLOCK #####
+#
+#  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.
+#
+# ##### END GPL LICENSE BLOCK #####
+
+import bpy
+
+class NewSimulation(bpy.types.Operator):
+    """Create a new simulation data block and edit it in the opened simulation editor"""
+
+    bl_idname = "simulation.new"
+    bl_label = "New Simulation"
+    bl_options = {'REGISTER', 'UNDO'}
+
+    @classmethod
+    def poll(cls, context):
+        return context.area.type == 'NODE_EDITOR' and context.space_data.tree_type == 'SimulationNodeTree'
+
+    def execute(self, context):
+        simulation = bpy.data.simulations.new("Simulation")
+        context.space_data.simulation = simulation
+        return {'FINISHED'}
+
+classes = (
+    NewSimulation,
+)

release/scripts/startup/bl_ui/space_node.py

@@ -151,6 +151,14 @@ class NODE_HT_header(Header):
             if snode_id:
                 layout.prop(snode_id, "use_nodes")
 
+        elif snode.tree_type == 'SimulationNodeTree':
+            row = layout.row(align=True)
+            row.prop(snode, "simulation", text="")
+            row.operator("simulation.new", text="", icon='ADD')
+            simulation = snode.simulation
+            if simulation:
+                row.prop(snode.simulation, "use_fake_user", text="")
+
         else:
             # Custom node tree is edited as independent ID block
             NODE_MT_editor_menus.draw_collapsible(context, layout)

release/scripts/startup/nodeitems_builtins.py

@@ -58,6 +58,13 @@ class TextureNodeCategory(SortedNodeCategory):
                 context.space_data.tree_type == 'TextureNodeTree')
 
 
+class SimulationNodeCategory(SortedNodeCategory):
+    @classmethod
+    def poll(cls, context):
+        return (context.space_data.type == 'NODE_EDITOR' and
+                context.space_data.tree_type == 'SimulationNodeTree')
+
+
 # menu entry for node group tools
 def group_tools_draw(self, layout, context):
     layout.operator("node.group_make")
@@ -70,6 +77,7 @@ node_tree_group_type = {
     'CompositorNodeTree': 'CompositorNodeGroup',
     'ShaderNodeTree': 'ShaderNodeGroup',
     'TextureNodeTree': 'TextureNodeGroup',
+    'SimulationNodeTree': 'SimulationNodeGroup',
 }
 
 
@@ -467,17 +475,28 @@ texture_node_categories = [
     ]),
 ]
 
+simulation_node_categories = [
+    # Simulation Nodes
+    SimulationNodeCategory("SIM_GROUP", "Group", items=node_group_items),
+    SimulationNodeCategory("SIM_LAYOUT", "Layout", items=[
+        NodeItem("NodeFrame"),
+        NodeItem("NodeReroute"),
+    ]),
+]
+
 
 def register():
     nodeitems_utils.register_node_categories('SHADER', shader_node_categories)
     nodeitems_utils.register_node_categories('COMPOSITING', compositor_node_categories)
     nodeitems_utils.register_node_categories('TEXTURE', texture_node_categories)
+    nodeitems_utils.register_node_categories('SIMULATION', simulation_node_categories)
 
 
 def unregister():
     nodeitems_utils.unregister_node_categories('SHADER')
     nodeitems_utils.unregister_node_categories('COMPOSITING')
     nodeitems_utils.unregister_node_categories('TEXTURE')
+    nodeitems_utils.unregister_node_categories('SIMULATION')
 
 
 if __name__ == "__main__":

source/blender/blenkernel/BKE_node.h

@@ -852,6 +852,7 @@ struct NodeTreeIterStore {
   struct Light *light;
   struct World *world;
   struct FreestyleLineStyle *linestyle;
+  struct Simulation *simulation;
 };
 
 void BKE_node_tree_iter_init(struct NodeTreeIterStore *ntreeiter, struct Main *bmain);

source/blender/blenkernel/intern/lib_query.c

@@ -1286,6 +1286,15 @@ static void library_foreach_ID_link(Main *bmain,
         }
         break;
       }
+      case ID_SIM: {
+        Simulation *simulation = (Simulation *)id;
+        if (simulation->nodetree) {
+          /* nodetree **are owned by IDs**, treat them as mere sub-data and not real ID! */
+          library_foreach_ID_as_subdata_link(
+              (ID **)&simulation->nodetree, callback, user_data, flag, &data);
+        }
+        break;
+      }
 
       /* Nothing needed for those... */
       case ID_IM:
@@ -1295,7 +1304,6 @@ static void library_foreach_ID_link(Main *bmain,
       case ID_PAL:
       case ID_PC:
       case ID_CF:
-      case ID_SIM:
         break;
 
       /* Deprecated. */

source/blender/blenkernel/intern/node.c

@@ -37,6 +37,7 @@
 #include "DNA_material_types.h"
 #include "DNA_node_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_simulation_types.h"
 #include "DNA_texture_types.h"
 #include "DNA_world_types.h"
 
@@ -2267,6 +2268,8 @@ bNodeTree **BKE_ntree_ptr_from_id(ID *id)
       return &((Scene *)id)->nodetree;
     case ID_LS:
       return &((FreestyleLineStyle *)id)->nodetree;
+    case ID_SIM:
+      return &((Simulation *)id)->nodetree;
     default:
       return NULL;
   }
@@ -4200,6 +4203,7 @@ void BKE_node_tree_iter_init(struct NodeTreeIterStore *ntreeiter, struct Main *b
   ntreeiter->light = bmain->lights.first;
   ntreeiter->world = bmain->worlds.first;
   ntreeiter->linestyle = bmain->linestyles.first;
+  ntreeiter->simulation = bmain->simulations.first;
 }
 bool BKE_node_tree_iter_step(struct NodeTreeIterStore *ntreeiter,
                              bNodeTree **r_nodetree,
@@ -4240,6 +4244,11 @@ bool BKE_node_tree_iter_step(struct NodeTreeIterStore *ntreeiter,
     *r_id = (ID *)ntreeiter->linestyle;
     ntreeiter->linestyle = ntreeiter->linestyle->id.next;
   }
+  else if (ntreeiter->simulation) {
+    *r_nodetree = ntreeiter->simulation->nodetree;
+    *r_id = (ID *)ntreeiter->simulation;
+    ntreeiter->simulation = ntreeiter->simulation->id.next;
+  }
   else {
     return false;
   }

source/blender/blenkernel/intern/simulation.cc

@@ -37,8 +37,11 @@
 #include "BKE_lib_query.h"
 #include "BKE_lib_remap.h"
 #include "BKE_main.h"
+#include "BKE_node.h"
 #include "BKE_simulation.h"
 
+#include "NOD_simulation.h"
+
 #include "BLT_translation.h"
 
 static void simulation_init_data(ID *id)
@@ -47,13 +50,38 @@ static void simulation_init_data(ID *id)
   BLI_assert(MEMCMP_STRUCT_AFTER_IS_ZERO(simulation, id));
 
   MEMCPY_STRUCT_AFTER(simulation, DNA_struct_default_get(Simulation), id);
+
+  bNodeTree *ntree = ntreeAddTree(nullptr, "Simulation Nodetree", ntreeType_Simulation->idname);
+  simulation->nodetree = ntree;
 }
 
-static void simulation_copy_data(Main *UNUSED(bmain),
-                                 ID *UNUSED(id_dst),
-                                 const ID *UNUSED(id_src),
-                                 const int UNUSED(flag))
+static void simulation_copy_data(Main *bmain, ID *id_dst, const ID *id_src, const int flag)
 {
+  Simulation *simulation_dst = (Simulation *)id_dst;
+  Simulation *simulation_src = (Simulation *)id_src;
+
+  /* We always need allocation of our private ID data. */
+  const int flag_private_id_data = flag & ~LIB_ID_CREATE_NO_ALLOCATE;
+
+  if (simulation_src->nodetree) {
+    BKE_id_copy_ex(bmain,
+                   (ID *)simulation_src->nodetree,
+                   (ID **)&simulation_dst->nodetree,
+                   flag_private_id_data);
+  }
+}
+
+static void simulation_free_data(ID *id)
+{
+  Simulation *simulation = (Simulation *)id;
+
+  BKE_animdata_free(&simulation->id, false);
+
+  if (simulation->nodetree) {
+    ntreeFreeNestedTree(simulation->nodetree);
+    MEM_freeN(simulation->nodetree);
+    simulation->nodetree = nullptr;
+  }
 }
 
 void *BKE_simulation_add(Main *bmain, const char *name)
@@ -77,6 +105,6 @@ IDTypeInfo IDType_ID_SIM = {
 
     /* init_data */ simulation_init_data,
     /* copy_data */ simulation_copy_data,
-    /* free_data */ nullptr,
+    /* free_data */ simulation_free_data,
     /* make_local */ nullptr,
 };

source/blender/blenloader/intern/writefile.c

@@ -3858,6 +3858,12 @@ static void write_simulation(WriteData *wd, Simulation *simulation)
     if (simulation->adt) {
       write_animdata(wd, simulation->adt);
     }
+
+    /* nodetree is integral part of simulation, no libdata */
+    if (simulation->nodetree) {
+      writestruct(wd, DATA, bNodeTree, 1, simulation->nodetree);
+      write_nodetree_nolib(wd, simulation->nodetree);
+    }
   }
 }
 

source/blender/makesdna/DNA_simulation_types.h

@@ -27,6 +27,8 @@ typedef struct Simulation {
   ID id;
   struct AnimData *adt; /* animation data (must be immediately after id) */
 
+  struct bNodeTree *nodetree;
+
   int flag;
   int _pad1[1];
 } Simulation;

source/blender/makesrna/intern/rna_simulation.c

@@ -34,11 +34,16 @@
 static void rna_def_simulation(BlenderRNA *brna)
 {
   StructRNA *srna;
+  PropertyRNA *prop;
 
   srna = RNA_def_struct(brna, "Simulation", "ID");
   RNA_def_struct_ui_text(srna, "Simulation", "Simulation data-block");
   RNA_def_struct_ui_icon(srna, ICON_PHYSICS); /* TODO: Use correct icon. */
 
+  prop = RNA_def_property(srna, "node_tree", PROP_POINTER, PROP_NONE);
+  RNA_def_property_pointer_sdna(prop, NULL, "nodetree");
+  RNA_def_property_ui_text(prop, "Node Tree", "Node tree defining the simulation");
+
   /* common */
   rna_def_animdata_common(srna);
 }

source/blender/makesrna/intern/rna_space.c

@@ -45,6 +45,7 @@
 #include "DNA_node_types.h"
 #include "DNA_object_types.h"
 #include "DNA_sequence_types.h"
+#include "DNA_simulation_types.h"
 #include "DNA_space_types.h"
 #include "DNA_view3d_types.h"
 #include "DNA_workspace_types.h"
@@ -2166,6 +2167,40 @@ static void rna_SpaceNodeEditor_node_tree_update(const bContext *C, PointerRNA *
   ED_node_tree_update(C);
 }
 
+#  ifdef WITH_NEW_SIMULATION_TYPE
+static PointerRNA rna_SpaceNodeEditor_simulation_get(PointerRNA *ptr)
+{
+  SpaceNode *snode = (SpaceNode *)ptr->data;
+  ID *id = snode->id;
+  if (id && GS(id->name) == ID_SIM) {
+    return rna_pointer_inherit_refine(ptr, &RNA_Simulation, snode->id);
+  }
+  else {
+    return PointerRNA_NULL;
+  }
+}
+
+static void rna_SpaceNodeEditor_simulation_set(PointerRNA *ptr,
+                                               const PointerRNA value,
+                                               struct ReportList *UNUSED(reports))
+{
+  SpaceNode *snode = (SpaceNode *)ptr->data;
+  if (!STREQ(snode->tree_idname, "SimulationNodeTree")) {
+    return;
+  }
+
+  Simulation *sim = (Simulation *)value.data;
+  if (sim != NULL) {
+    bNodeTree *ntree = sim->nodetree;
+    ED_node_tree_start(snode, ntree, NULL, NULL);
+  }
+  else {
+    ED_node_tree_start(snode, NULL, NULL, NULL);
+  }
+  snode->id = &sim->id;
+}
+#  endif
+
 static int rna_SpaceNodeEditor_tree_type_get(PointerRNA *ptr)
 {
   SpaceNode *snode = (SpaceNode *)ptr->data;
@@ -6215,6 +6250,19 @@ static void rna_def_space_node(BlenderRNA *brna)
   RNA_def_property_ui_text(
       prop, "ID From", "Data-block from which the edited data-block is linked");
 
+#  ifdef WITH_NEW_SIMULATION_TYPE
+  prop = RNA_def_property(srna, "simulation", PROP_POINTER, PROP_NONE);
+  RNA_def_property_flag(prop, PROP_EDITABLE);
+  RNA_def_property_struct_type(prop, "Simulation");
+  RNA_def_property_ui_text(prop, "Simulation", "Simulation that is being edited");
+  RNA_def_property_pointer_funcs(prop,
+                                 "rna_SpaceNodeEditor_simulation_get",
+                                 "rna_SpaceNodeEditor_simulation_set",
+                                 NULL,
+                                 NULL);
+  RNA_def_property_update(prop, NC_SPACE | ND_SPACE_NODE, NULL);
+#  endif
+
   prop = RNA_def_property(srna, "path", PROP_COLLECTION, PROP_NONE);
   RNA_def_property_collection_sdna(prop, NULL, "treepath", NULL);
   RNA_def_property_struct_type(prop, "NodeTreePath");