[Bf-blender-cvs] [218d81a99b3] sybren-usd-experiments: Start of abstract hierarchy iterator for exporters

[Sybren A. Stüvel]

Commit: 218d81a99b3808a79a740a53421592080c5562fd
Author: Sybren A. Stüvel
Date:   Fri Jun 14 14:24:35 2019 +0200
Branches: sybren-usd-experiments
https://developer.blender.org/rB218d81a99b3808a79a740a53421592080c5562fd

Start of abstract hierarchy iterator for exporters

===================================================================

A	source/blender/usd/intern/usd_hierarchy_iterator.cc
A	source/blender/usd/intern/usd_hierarchy_iterator.h

===================================================================

diff --git a/source/blender/usd/intern/usd_hierarchy_iterator.cc b/source/blender/usd/intern/usd_hierarchy_iterator.cc
new file mode 100644
index 00000000000..2f3da814f85
--- /dev/null
+++ b/source/blender/usd/intern/usd_hierarchy_iterator.cc
@@ -0,0 +1,185 @@
+#include "usd_hierarchy_iterator.h"
+
+#include <string>
+
+#include <pxr/base/tf/stringUtils.h>
+
+extern "C" {
+#include "BKE_anim.h"
+#include "BLI_assert.h"
+
+#include "DEG_depsgraph_query.h"
+
+#include "DNA_ID.h"
+#include "DNA_layer_types.h"
+#include "DNA_object_types.h"
+}
+
+static std::string get_id_name(const Object *const ob)
+{
+  if (!ob) {
+    return "";
+  }
+
+  return get_id_name(&ob->id);
+}
+
+static std::string get_id_name(const ID *const id)
+{
+  if (!id)
+    return "";
+
+  std::string name(id->name + 2);
+  return pxr::TfMakeValidIdentifier(name);
+}
+
+/**
+ * \brief get_object_dag_path_name returns the name under which the object
+ *  will be exported in the Alembic file. It is of the form
+ *  "[../grandparent/]parent/object" if dupli_parent is NULL, or
+ *  "dupli_parent/[../grandparent/]parent/object" otherwise.
+ * \param ob:
+ * \param dupli_parent:
+ * \return
+ */
+static std::string get_object_dag_path_name(const Object *const ob, Object *dupli_parent)
+{
+  std::string name = get_id_name(ob);
+
+  Object *p = ob->parent;
+
+  while (p) {
+    name = get_id_name(p) + "/" + name;
+    p = p->parent;
+  }
+
+  if (dupli_parent && (ob != dupli_parent)) {
+    name = get_id_name(dupli_parent) + "/" + name;
+  }
+
+  return name;
+}
+
+void AbstractHierarchyIterator::iterate()
+{
+  ViewLayer *view_layer = DEG_get_input_view_layer(depsgraph);
+  for (Base *base = static_cast<Base *>(view_layer->object_bases.first); base; base = base->next) {
+    Object *ob = base->object;
+    visit_object(base, ob, ob->parent, NULL);
+  }
+}
+
+void AbstractHierarchyIterator::visit_object(Base *base,
+                                             Object *object,
+                                             Object *parent,
+                                             Object *dupliObParent)
+{
+  /* If an object isn't exported itself, its duplilist shouldn't be
+   * exported either. */
+  if (!should_visit_object(base, dupliObParent != NULL)) {
+    return;
+  }
+
+  Object *ob = DEG_get_evaluated_object(depsgraph, object);
+  export_object_and_parents(ob, parent, dupliObParent);
+
+  ListBase *lb = object_duplilist(depsgraph, DEG_get_input_scene(depsgraph), ob);
+
+  if (lb) {
+    DupliObject *link = static_cast<DupliObject *>(lb->first);
+    Object *dupli_ob = NULL;
+    Object *dupli_parent = NULL;
+
+    for (; link; link = link->next) {
+      //   /* This skips things like custom bone shapes. */
+      //   if (m_settings.renderable_only && link->no_draw) {
+      //     continue;
+      //   }
+
+      if (link->type == OB_DUPLICOLLECTION) {
+        dupli_ob = link->ob;
+        dupli_parent = (dupli_ob->parent) ? dupli_ob->parent : ob;
+
+        visit_object(base, dupli_ob, dupli_parent, ob);
+      }
+    }
+
+    free_object_duplilist(lb);
+  }
+}
+
+TEMP_WRITER_TYPE *AbstractHierarchyIterator::export_object_and_parents(Object *ob,
+                                                                       Object *parent,
+                                                                       Object *dupliObParent)
+{
+  /* An object should not be its own parent, or we'll get infinite loops. */
+  BLI_assert(ob != parent);
+  BLI_assert(ob != dupliObParent);
+
+  std::string name;
+  //   if (m_settings.flatten_hierarchy) {
+  //     name = get_id_name(ob);
+  //   }
+  //   else {
+  name = get_object_dag_path_name(ob, dupliObParent);
+  //   }
+
+  /* check if we have already created a transform writer for this object */
+  TEMP_WRITER_TYPE *my_writer = get_writer(name);
+  if (my_writer != NULL) {
+    return my_writer;
+  }
+
+  TEMP_WRITER_TYPE *parent_writer = NULL;
+
+  if (/* m_settings.flatten_hierarchy || */ parent == NULL) {
+  }
+  else {
+    /* Since there are so many different ways to find parents (as evident
+     * in the number of conditions below), we can't really look up the
+     * parent by name. We'll just call export_object_and_parents(), which will
+     * return the parent's writer pointer. */
+    if (parent->parent) {
+      if (parent == dupliObParent) {
+        parent_writer = export_object_and_parents(parent, parent->parent, NULL);
+      }
+      else {
+        parent_writer = export_object_and_parents(parent, parent->parent, dupliObParent);
+      }
+    }
+    else if (parent == dupliObParent) {
+      if (dupliObParent->parent == NULL) {
+        parent_writer = export_object_and_parents(parent, NULL, NULL);
+      }
+      else {
+        parent_writer = export_object_and_parents(
+            parent, dupliObParent->parent, dupliObParent->parent);
+      }
+    }
+    else {
+      parent_writer = export_object_and_parents(parent, dupliObParent, dupliObParent);
+    }
+
+    BLI_assert(parent_writer);
+  }
+
+  my_writer = create_object_writer(name, ob, parent_writer);
+
+  //   /* When flattening, the matrix of the dupliobject has to be added. */
+  //   if (m_settings.flatten_hierarchy && dupliObParent) {
+  //     my_writer->m_proxy_from = dupliObParent;
+  //   }
+
+  writers[name] = my_writer;
+  return my_writer;
+}
+
+TEMP_WRITER_TYPE *AbstractHierarchyIterator::get_writer(const std::string &name)
+{
+  WriterMap::iterator it = writers.find(name);
+
+  if (it == writers.end()) {
+    return NULL;
+  }
+  return it->second;
+}
\ No newline at end of file
diff --git a/source/blender/usd/intern/usd_hierarchy_iterator.h b/source/blender/usd/intern/usd_hierarchy_iterator.h
new file mode 100644
index 00000000000..6cf149e62cd
--- /dev/null
+++ b/source/blender/usd/intern/usd_hierarchy_iterator.h
@@ -0,0 +1,40 @@
+#ifndef __USD__USD_HIERARCHY_ITERATOR_H__
+#define __USD__USD_HIERARCHY_ITERATOR_H__
+
+#include <map>
+#include <string>
+
+struct Depsgraph;
+struct ViewLayer;
+
+typedef void TEMP_WRITER_TYPE;
+
+class AbstractHierarchyIterator {
+ protected:
+  Depsgraph *depsgraph;
+
+  typedef std::map<std::string, TEMP_WRITER_TYPE *> WriterMap;
+  WriterMap writers;
+
+ public:
+  AbstractHierarchyIterator(Dpesgraph *depsgraph);
+  ~AbstractHierarchyIterator();
+
+  void iterate();
+
+ private:
+  void visit_object(Base *base, Object *object, Object *parent, Object *dupliObParent);
+
+  TEMP_WRITER_TYPE *export_object_and_parents(Object *ob, Object *parent, Object *dupliObParent);
+  TEMP_WRITER_TYPE *get_writer(const std::string &name);
+
+ protected:
+  /* Not visiting means not exporting and also not expanding its duplis. */
+  virtual bool should_visit_object(const Base *const base, bool is_duplicated) = 0;
+
+  virtual TEMP_WRITER_TYPE *create_object_writer(const std::string &name,
+                                                 Object *object,
+                                                 void *parent_writer) = 0;
+};
+
+#endif /* __USD__USD_HIERARCHY_ITERATOR_H__ */