Depsgraph: Introduce depsgraph registry

Allows to access dependency graphs created for render engines
to inform them about changes in .blend file structure from the
Python handlers.

Reviewers: brecht

Differential Revision: https://developer.blender.org/D5724

1 files changed, 74 insertions, 0 deletions

diff --git a/source/blender/depsgraph/intern/depsgraph_registry.cc b/source/blender/depsgraph/intern/depsgraph_registry.cc
new file mode 100644
index 00000000000..ad60b1bc4cf
--- /dev/null
+++ b/source/blender/depsgraph/intern/depsgraph_registry.cc
@@ -0,0 +1,74 @@
+/*
+ * 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.
+ *
+ * The Original Code is Copyright (C) 2019 Blender Foundation.
+ * All rights reserved.
+ */
+
+/** \file
+ * \ingroup depsgraph
+ */
+
+#include "intern/depsgraph_registry.h"
+
+#include "BLI_utildefines.h"
+
+#include "intern/depsgraph.h"
+
+namespace DEG {
+
+typedef set<Depsgraph *> DepsgraphStorage;
+typedef map<Main *, DepsgraphStorage> MainDepsgraphMap;
+
+static MainDepsgraphMap g_graph_registry;
+
+void register_graph(Depsgraph *depsgraph)
+{
+  Main *bmain = depsgraph->bmain;
+  MainDepsgraphMap::iterator it = g_graph_registry.find(bmain);
+  if (it == g_graph_registry.end()) {
+    it = g_graph_registry.insert(make_pair(bmain, DepsgraphStorage())).first;
+  }
+  DepsgraphStorage &storage = it->second;
+  storage.insert(depsgraph);
+}
+
+void unregister_graph(Depsgraph *depsgraph)
+{
+  Main *bmain = depsgraph->bmain;
+  MainDepsgraphMap::iterator it = g_graph_registry.find(bmain);
+  BLI_assert(it != g_graph_registry.end());
+
+  // Remove dependency graph from storage.
+  DepsgraphStorage &storage = it->second;
+  storage.erase(depsgraph);
+
+  // If this was the last depsgraph associated with the main, remove the main entry as well.
+  if (storage.empty()) {
+    g_graph_registry.erase(bmain);
+  }
+}
+
+const set<Depsgraph *> &get_all_registered_graphs(Main *bmain)
+{
+  MainDepsgraphMap::iterator it = g_graph_registry.find(bmain);
+  if (it == g_graph_registry.end()) {
+    static DepsgraphStorage empty_storage;
+    return empty_storage;
+  }
+  return it->second;
+}
+
+}  // namespace DEG