[Bf-blender-cvs] [c0cb036] alembic_basic_io: Use a hash map to store object reader / object path pair to be able to reconstruct the object hierarchy more easily.

[Kévin Dietrich]

Commit: c0cb036a5aa8909f7f2df10e786d53c950d53830
Author: Kévin Dietrich
Date:   Mon Jun 6 10:30:13 2016 +0200
Branches: alembic_basic_io
https://developer.blender.org/rBc0cb036a5aa8909f7f2df10e786d53c950d53830

Use a hash map to store object reader / object path pair to be able to
reconstruct the object hierarchy more easily.

The previous approach was brute forcing by iterating over all the
objects in the scene for each object creating to find the object
(parent) that has the same name as its parent in the abc archive.

This was both inefficient and prone to errors since multiple objects in
the abc archive can have the same name, as long as their path are
different, but Blender only allows for unique object name, so the wrong
object could have been choosen as the parent of a given object.

Now all of the tests file import correctly.

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

M	source/blender/alembic/intern/alembic_capi.cc

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

diff --git a/source/blender/alembic/intern/alembic_capi.cc b/source/blender/alembic/intern/alembic_capi.cc
index 8cfe54f..8fa1f26 100644
--- a/source/blender/alembic/intern/alembic_capi.cc
+++ b/source/blender/alembic/intern/alembic_capi.cc
@@ -51,6 +51,7 @@ extern "C" {
 #include "BKE_screen.h"
 #undef new
 
+#include "BLI_ghash.h"
 #include "BLI_math.h"
 #include "BLI_string.h"
 
@@ -343,6 +344,7 @@ int ABC_export(Scene *scene, bContext *C, const char *filepath,
 
 static void visit_object(const IObject &object,
                          std::vector<AbcObjectReader *> &readers,
+                         GHash *parent_map,
                          ImportSettings &settings)
 {
 	if (!object.valid()) {
@@ -421,51 +423,14 @@ static void visit_object(const IObject &object,
 
 		if (reader) {
 			readers.push_back(reader);
-		}
-
-		visit_object(child, readers, settings);
-	}
-}
 
-static Object *find_object(Scene *scene, const std::string &name)
-{
-	Base *base;
-
-	for (base = static_cast<Base *>(scene->base.first); base; base = base->next) {
-		Object *ob = base->object;
-
-		if (ob->id.name + 2 == name) {
-			return ob;
+			/* Cast to `void *` explicitly to avoid compiler errors because it
+			 * is a `const char *` which the compiler cast to `const void *`
+			 * instead of the expected `void *`. */
+			BLI_ghash_insert(parent_map, (void *)child.getFullName().c_str(), reader);
 		}
-	}
-
-	return NULL;
-}
-
-static void create_hierarchy(Main *bmain, Scene *scene, AbcObjectReader *root)
-{
-	const IObject &iobjet = root->iobject();
-	const std::string &full_name = iobjet.getFullName();
-
-	std::vector<std::string> parts;
-	split(full_name, '/', parts);
-
-	Object *parent = NULL;
 
-	std::vector<std::string>::reverse_iterator iter;
-	for (iter = parts.rbegin() + 1; iter != parts.rend(); ++iter) {
-		parent = find_object(scene, *iter);
-
-		if (parent != NULL && root->object() != parent) {
-			Object *ob = root->object();
-			ob->parent = parent;
-
-			DAG_id_tag_update(&ob->id, OB_RECALC_OB);
-			DAG_relations_tag_update(bmain);
-			WM_main_add_notifier(NC_OBJECT | ND_PARENT, ob);
-
-			return;
-		}
+		visit_object(child, readers, parent_map, settings);
 	}
 }
 
@@ -499,7 +464,8 @@ static void import_startjob(void *cjv, short *stop, short *do_update, float *pro
 	*data->progress = 0.05f;
 
 	std::vector<AbcObjectReader *> readers;
-	visit_object(archive.getTop(), readers, data->settings);
+	GHash *parent_map = BLI_ghash_ptr_new("alembic parent ghash");
+	visit_object(archive.getTop(), readers, parent_map, data->settings);
 
 	*data->do_update = true;
 	*data->progress = 0.1f;
@@ -522,7 +488,36 @@ static void import_startjob(void *cjv, short *stop, short *do_update, float *pro
 
 	i = 0;
 	for (iter = readers.begin(); iter != readers.end(); ++iter) {
-		create_hierarchy(data->bmain, data->scene, *iter);
+		const AbcObjectReader *reader = *iter;
+		const AbcObjectReader *parent_reader = NULL;
+		const IObject &iobject = reader->iobject();
+
+		if (IXform::matches(iobject.getHeader())) {
+			parent_reader = reinterpret_cast<AbcObjectReader *>(
+			                    BLI_ghash_lookup(parent_map,
+			                                     iobject.getParent().getFullName().c_str()));
+		}
+		else {
+			/* In the case of an non XForm node, the parent is the transform
+			 * matrix of the data itself, so skip it. */
+			parent_reader = reinterpret_cast<AbcObjectReader *>(
+			                    BLI_ghash_lookup(parent_map,
+			                                     iobject.getParent().getParent().getFullName().c_str()));
+		}
+
+		if (parent_reader) {
+			Object *parent = parent_reader->object();
+
+			if (parent != NULL && reader->object() != parent) {
+				Object *ob = reader->object();
+				ob->parent = parent;
+
+				DAG_id_tag_update(&ob->id, OB_RECALC_OB);
+				DAG_relations_tag_update(data->bmain);
+				WM_main_add_notifier(NC_OBJECT | ND_PARENT, ob);
+			}
+		}
+
 		*data->progress = 0.7f + 0.3f * (++i / size);
 	}
 
@@ -530,6 +525,8 @@ static void import_startjob(void *cjv, short *stop, short *do_update, float *pro
 		delete *iter;
 	}
 
+	BLI_ghash_free(parent_map, NULL, NULL);
+
 	WM_main_add_notifier(NC_SCENE | ND_FRAME, data->scene);
 }