Cycles: Support rendering objects from dupli-list

This commit extends the work from Dalai made around scene iterators to
support iterating into objects from dupli-lists.

Changes can be summarized as:

- Depsgraph iterator will hold pointer to an object which created current
  duplilist. It is available via `dupli_parent` field of the iterator.
  It is only set when duplilist is not NULL and guaranteed to be NULL
  for all other cases.

- Introduced new depsgraph.duplis collection which gives a more extended
  information about depsgraph iterator.  It is basically a collection on top
  of DEGObjectsIteratorData.

  It is used to provide access to such data as persistent ID, generated space
  and so on.

Things which still needs to be done/finished/clarified:

- Need to introduce some sort of `is_instance` boolean property which will
  indicate Python and C++ RNA that we are inside of dupli-list.

- Introduce a way to skip dupli-list for particular objects.

  So, for example, if we are culling object due to distance we can skip all
  objects it was duplicating.

- Introduce a way to skip particular duplicators.

  So we can skip iterating into particle system.

- Introduce some cleaner API for C side of operators to access all data such as
  persistent ID and friends.

  This way we wouldn't need de-reference iterator and could keep access to such
  data really abstract. Who knows how we'll be storing internal state of the
  operator in the future.

While there is still stuff to do, current state works and moves us in the proper
direction.

1 files changed, 157 insertions, 2 deletions

diff --git a/source/blender/makesrna/intern/rna_depsgraph.c b/source/blender/makesrna/intern/rna_depsgraph.c
index 82f8c454b53..c1f84b44447 100644
--- a/source/blender/makesrna/intern/rna_depsgraph.c
+++ b/source/blender/makesrna/intern/rna_depsgraph.c
@@ -38,6 +38,8 @@
 
 #include "BKE_depsgraph.h"
 
+#include "DNA_object_types.h"
+
 #ifdef RNA_RUNTIME
 
 #include "BLI_iterator.h"
@@ -49,6 +51,58 @@
 
 #include "MEM_guardedalloc.h"
 
+/* **************** Depsgraph **************** */
+
+static PointerRNA rna_DepsgraphIter_object_get(PointerRNA *ptr)
+{
+	BLI_Iterator *iterator = ptr->data;
+	return rna_pointer_inherit_refine(ptr, &RNA_Object, iterator->current);
+}
+
+static PointerRNA rna_DepsgraphIter_parent_get(PointerRNA *ptr)
+{
+	BLI_Iterator *iterator = ptr->data;
+	DEGObjectsIteratorData *deg_iter = (DEGObjectsIteratorData *)iterator->data;
+	Object *dupli_parent = NULL;
+	if (deg_iter->dupli_object_current != NULL) {
+		dupli_parent = deg_iter->dupli_parent;
+	}
+	return rna_pointer_inherit_refine(ptr, &RNA_Object, dupli_parent);
+}
+
+static void rna_DepsgraphIter_persistent_id_get(PointerRNA *ptr, int *persistent_id)
+{
+	BLI_Iterator *iterator = ptr->data;
+	DEGObjectsIteratorData *deg_iter = (DEGObjectsIteratorData *)iterator->data;
+	memcpy(persistent_id, deg_iter->dupli_object_current->persistent_id,
+	       sizeof(deg_iter->dupli_object_current->persistent_id));
+}
+
+static void rna_DepsgraphIter_orco_get(PointerRNA *ptr, float *orco)
+{
+	BLI_Iterator *iterator = ptr->data;
+	DEGObjectsIteratorData *deg_iter = (DEGObjectsIteratorData *)iterator->data;
+	memcpy(orco, deg_iter->dupli_object_current->orco,
+	       sizeof(deg_iter->dupli_object_current->orco));
+}
+
+static unsigned int rna_DepsgraphIter_random_id_get(PointerRNA *ptr)
+{
+	BLI_Iterator *iterator = ptr->data;
+	DEGObjectsIteratorData *deg_iter = (DEGObjectsIteratorData *)iterator->data;
+	return deg_iter->dupli_object_current->random_id;
+}
+
+static void rna_DepsgraphIter_uv_get(PointerRNA *ptr, float *uv)
+{
+	BLI_Iterator *iterator = ptr->data;
+	DEGObjectsIteratorData *deg_iter = (DEGObjectsIteratorData *)iterator->data;
+	memcpy(uv, deg_iter->dupli_object_current->uv,
+	       sizeof(deg_iter->dupli_object_current->uv));
+}
+
+/* **************** Depsgraph **************** */
+
 static void rna_Depsgraph_debug_graphviz(Depsgraph *graph, const char *filename)
 {
 	FILE *f = fopen(filename, "w");
@@ -84,6 +138,8 @@ static void rna_Depsgraph_debug_stats(Depsgraph *graph, ReportList *reports)
 	            ops, rels, outer);
 }
 
+/* Iteration over objects, simple version */
+
 static void rna_Depsgraph_objects_begin(CollectionPropertyIterator *iter, PointerRNA *ptr)
 {
 	iter->internal.custom = MEM_callocN(sizeof(BLI_Iterator), __func__);
@@ -115,8 +171,93 @@ static PointerRNA rna_Depsgraph_objects_get(CollectionPropertyIterator *iter)
 	return rna_pointer_inherit_refine(&iter->parent, &RNA_Object, ob);
 }
 
+/* Iteration over objects, extended version
+ *
+ * Contains extra information about duplicator and persistent ID.
+ */
+
+static void rna_Depsgraph_duplis_begin(CollectionPropertyIterator *iter, PointerRNA *ptr)
+{
+	iter->internal.custom = MEM_callocN(sizeof(BLI_Iterator), __func__);
+	DEGObjectsIteratorData *data = MEM_callocN(sizeof(DEGObjectsIteratorData), __func__);
+
+	data->graph = (Depsgraph *)ptr->data;
+	data->flag = DEG_OBJECT_ITER_FLAG_ALL;
+
+	DEG_objects_iterator_begin(iter->internal.custom, data);
+	iter->valid = ((BLI_Iterator *)iter->internal.custom)->valid;
+}
+
+static void rna_Depsgraph_duplis_next(CollectionPropertyIterator *iter)
+{
+	DEG_objects_iterator_next(iter->internal.custom);
+	iter->valid = ((BLI_Iterator *)iter->internal.custom)->valid;
+}
+
+static void rna_Depsgraph_duplis_end(CollectionPropertyIterator *iter)
+{
+	DEG_objects_iterator_end(iter->internal.custom);
+	MEM_freeN(((BLI_Iterator *)iter->internal.custom)->data);
+	MEM_freeN(iter->internal.custom);
+}
+
+static PointerRNA rna_Depsgraph_duplis_get(CollectionPropertyIterator *iter)
+{
+	BLI_Iterator *iterator = (BLI_Iterator *)iter->internal.custom;
+	return rna_pointer_inherit_refine(&iter->parent, &RNA_DepsgraphIter, iterator);
+}
+
 #else
 
+static void rna_def_depsgraph_iter(BlenderRNA *brna)
+{
+	StructRNA *srna;
+	PropertyRNA *prop;
+
+	srna = RNA_def_struct(brna, "DepsgraphIter", NULL);
+	RNA_def_struct_ui_text(srna, "Dependency Graph Iterator",
+	                       "Extended information about dependency graph object iterator");
+
+	prop = RNA_def_property(srna, "object", PROP_POINTER, PROP_NONE);
+	RNA_def_property_struct_type(prop, "Object");
+	RNA_def_property_ui_text(prop, "Object", "Object the iterator points to");
+	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE | PROP_EDITABLE);
+	RNA_def_property_pointer_funcs(prop, "rna_DepsgraphIter_object_get", NULL, NULL, NULL);
+
+	prop = RNA_def_property(srna, "parent", PROP_POINTER, PROP_NONE);
+	RNA_def_property_struct_type(prop, "Object");
+	RNA_def_property_ui_text(prop, "Parent", "Parent of the duplication list");
+	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE | PROP_EDITABLE);
+	RNA_def_property_pointer_funcs(prop, "rna_DepsgraphIter_parent_get", NULL, NULL, NULL);
+
+	prop = RNA_def_property(srna, "persistent_id", PROP_INT, PROP_NONE);
+	RNA_def_property_ui_text(prop, "Persistent ID",
+	                         "Persistent identifier for inter-frame matching of objects with motion blur");
+	RNA_def_property_array(prop, 2*MAX_DUPLI_RECUR);
+	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE | PROP_EDITABLE);
+	RNA_def_property_int_funcs(prop, "rna_DepsgraphIter_persistent_id_get", NULL, NULL);
+
+	prop = RNA_def_property(srna, "orco", PROP_FLOAT, PROP_TRANSLATION);
+	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE | PROP_EDITABLE);
+	/* Seems system is not smart enough to figure that getter function should return
+	 * array for PROP_TRANSLATION.
+	 */
+	RNA_def_property_array(prop, 3);
+	RNA_def_property_ui_text(prop, "Generated Coordinates", "Generated coordinates in parent object space");
+	RNA_def_property_float_funcs(prop, "rna_DepsgraphIter_orco_get", NULL, NULL);
+
+	prop = RNA_def_property(srna, "random_id", PROP_INT, PROP_UNSIGNED);
+	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE | PROP_EDITABLE);
+	RNA_def_property_ui_text(prop, "Dupli random id", "Random id for this dupli object");
+	RNA_def_property_int_funcs(prop, "rna_DepsgraphIter_random_id_get", NULL, NULL);
+
+	prop = RNA_def_property(srna, "uv", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_ui_text(prop, "UV Coordinates", "UV coordinates in parent object space");
+	RNA_def_property_array(prop, 2);
+	RNA_def_property_clear_flag(prop, PROP_ANIMATABLE | PROP_EDITABLE);
+	RNA_def_property_float_funcs(prop, "rna_DepsgraphIter_uv_get", NULL, NULL);
+}
+
 static void rna_def_depsgraph(BlenderRNA *brna)
 {
 	StructRNA *srna;
@@ -141,13 +282,27 @@ static void rna_def_depsgraph(BlenderRNA *brna)
 
 	prop = RNA_def_property(srna, "objects", PROP_COLLECTION, PROP_NONE);
 	RNA_def_property_struct_type(prop, "Object");
-	RNA_def_property_collection_funcs(prop, "rna_Depsgraph_objects_begin", "rna_Depsgraph_objects_next",
-	                                  "rna_Depsgraph_objects_end", "rna_Depsgraph_objects_get",
+	RNA_def_property_collection_funcs(prop,
+	                                  "rna_Depsgraph_objects_begin",
+	                                  "rna_Depsgraph_objects_next",
+	                                  "rna_Depsgraph_objects_end",
+	                                  "rna_Depsgraph_objects_get",
+	                                  NULL, NULL, NULL, NULL);
+
+	/* TODO(sergey): Find a better name. */
+	prop = RNA_def_property(srna, "duplis", PROP_COLLECTION, PROP_NONE);
+	RNA_def_property_struct_type(prop, "DepsgraphIter");
+	RNA_def_property_collection_funcs(prop,
+	                                  "rna_Depsgraph_duplis_begin",
+	                                  "rna_Depsgraph_duplis_next",
+	                                  "rna_Depsgraph_duplis_end",
+	                                  "rna_Depsgraph_duplis_get",
 	                                  NULL, NULL, NULL, NULL);
 }
 
 void RNA_def_depsgraph(BlenderRNA *brna)
 {
+	rna_def_depsgraph_iter(brna);
 	rna_def_depsgraph(brna);
 }