a12a8a71bb
The goal is to solve confusion of the "All rights reserved" for licensing
code under an open-source license.
The phrase "All rights reserved" comes from a historical convention that
required this phrase for the copyright protection to apply. This convention
is no longer relevant.
However, even though the phrase has no meaning in establishing the copyright
it has not lost meaning in terms of licensing.
This change makes it so code under the Blender Foundation copyright does
not use "all rights reserved". This is also how the GPL license itself
states how to apply it to the source code:
<one line to give the program's name and a brief idea of what it does.>
Copyright (C) <year> <name of author>
This program is free software ...
This change does not change copyright notice in cases when the copyright
is dual (BF and an author), or just an author of the code. It also does
mot change copyright which is inherited from NaN Holding BV as it needs
some further investigation about what is the proper way to handle it.
97 lines
2.8 KiB
C++
97 lines
2.8 KiB
C++
/* SPDX-License-Identifier: GPL-2.0-or-later
|
|
* Copyright 2015 Blender Foundation */
|
|
|
|
/** \file
|
|
* \ingroup depsgraph
|
|
*/
|
|
|
|
#include "intern/builder/deg_builder_transitive.h"
|
|
|
|
#include "MEM_guardedalloc.h"
|
|
|
|
#include "intern/node/deg_node.h"
|
|
#include "intern/node/deg_node_component.h"
|
|
#include "intern/node/deg_node_operation.h"
|
|
|
|
#include "intern/debug/deg_debug.h"
|
|
#include "intern/depsgraph.h"
|
|
#include "intern/depsgraph_relation.h"
|
|
|
|
namespace blender::deg {
|
|
|
|
/* -------------------------------------------------- */
|
|
|
|
/* Performs a transitive reduction to remove redundant relations.
|
|
* https://en.wikipedia.org/wiki/Transitive_reduction
|
|
*
|
|
* XXX The current implementation is somewhat naive and has O(V*E) worst case
|
|
* runtime.
|
|
* A more optimized algorithm can be implemented later, e.g.
|
|
*
|
|
* http://www.sciencedirect.com/science/article/pii/0304397588900321/pdf?md5=3391e309b708b6f9cdedcd08f84f4afc&pid=1-s2.0-0304397588900321-main.pdf
|
|
*
|
|
* Care has to be taken to make sure the algorithm can handle the cyclic case
|
|
* too! (unless we can to prevent this case early on).
|
|
*/
|
|
|
|
enum {
|
|
OP_VISITED = 1,
|
|
OP_REACHABLE = 2,
|
|
};
|
|
|
|
static void deg_graph_tag_paths_recursive(Node *node)
|
|
{
|
|
if (node->custom_flags & OP_VISITED) {
|
|
return;
|
|
}
|
|
node->custom_flags |= OP_VISITED;
|
|
for (Relation *rel : node->inlinks) {
|
|
deg_graph_tag_paths_recursive(rel->from);
|
|
/* Do this only in inlinks loop, so the target node does not get
|
|
* flagged. */
|
|
rel->from->custom_flags |= OP_REACHABLE;
|
|
}
|
|
}
|
|
|
|
void deg_graph_transitive_reduction(Depsgraph *graph)
|
|
{
|
|
int num_removed_relations = 0;
|
|
Vector<Relation *> relations_to_remove;
|
|
|
|
for (OperationNode *target : graph->operations) {
|
|
/* Clear tags. */
|
|
for (OperationNode *node : graph->operations) {
|
|
node->custom_flags = 0;
|
|
}
|
|
/* Mark nodes from which we can reach the target
|
|
* start with children, so the target node and direct children are not
|
|
* flagged. */
|
|
target->custom_flags |= OP_VISITED;
|
|
for (Relation *rel : target->inlinks) {
|
|
deg_graph_tag_paths_recursive(rel->from);
|
|
}
|
|
/* Remove redundant paths to the target. */
|
|
for (Relation *rel : target->inlinks) {
|
|
if (rel->from->type == NodeType::TIMESOURCE) {
|
|
/* HACK: time source nodes don't get "custom_flags" flag
|
|
* set/cleared. */
|
|
/* TODO: there will be other types in future, so iterators above
|
|
* need modifying. */
|
|
continue;
|
|
}
|
|
if (rel->from->custom_flags & OP_REACHABLE) {
|
|
relations_to_remove.append(rel);
|
|
}
|
|
}
|
|
for (Relation *rel : relations_to_remove) {
|
|
rel->unlink();
|
|
delete rel;
|
|
}
|
|
num_removed_relations += relations_to_remove.size();
|
|
relations_to_remove.clear();
|
|
}
|
|
DEG_DEBUG_PRINTF((::Depsgraph *)graph, BUILD, "Removed %d relations\n", num_removed_relations);
|
|
}
|
|
|
|
} // namespace blender::deg
|