feat(Core/Visibility): Visibility improvements part 1 (#22624)

src/server/game/Entities/Object/ObjectVisibilityContainer.h

@@ -0,0 +1,101 @@
+/*
+ * This file is part of the AzerothCore Project. See AUTHORS file for Copyright information
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Affero General Public License as published by the
+ * Free Software Foundation; either version 3 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 Affero General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _OBJECTVISIBILITYCONTAINER_H
+#define _OBJECTVISIBILITYCONTAINER_H
+
+#include "Common.h"
+#include "ObjectGuid.h"
+#include <memory>
+#include <unordered_map>
+
+class Player;
+class WorldObject;
+
+typedef std::unordered_map<ObjectGuid, WorldObject*> VisibleWorldObjectsMap;
+typedef std::unordered_map<ObjectGuid, Player*> VisiblePlayersMap;
+
+// Class that manages the visibility containers of a worldobject
+class ObjectVisibilityContainer
+{
+public:
+    ObjectVisibilityContainer(WorldObject* selfObject);
+    ~ObjectVisibilityContainer();
+
+    // Creates the _visibleWorldObjectsMap map if we are a player
+    void InitForPlayer();
+
+    // Cleans up all visibility references from other worldobjects,
+    // this is used before a worldobject is deleted to prevent any dangling references
+    void CleanVisibilityReferences();
+
+    void LinkWorldObjectVisibility(WorldObject* worldObject);
+    void UnlinkWorldObjectVisibility(WorldObject* worldObject);
+
+    // These helpers aren't ideal, but needed in a few spots for cleaning up references
+    VisibleWorldObjectsMap::iterator UnlinkVisibilityFromPlayer(WorldObject* worldObject, VisibleWorldObjectsMap::iterator itr);
+    VisiblePlayersMap::iterator UnlinkVisibilityFromWorldObject(Player* player, VisiblePlayersMap::iterator itr);
+
+    // Returns a list of all players who can see us
+    VisiblePlayersMap& GetVisiblePlayersMap() { return _visiblePlayersMap; }
+    VisiblePlayersMap const& GetVisiblePlayersMap() const { return _visiblePlayersMap; }
+
+    // Returns a list of all worldobjects who we can see
+    // Warning: This is for player objects only, all other objects will return a nullptr
+    VisibleWorldObjectsMap* GetVisibleWorldObjectsMap()
+    {
+        if (!_visibleWorldObjectsMap)
+            return nullptr;
+
+        return _visibleWorldObjectsMap.get();
+    }
+
+    VisibleWorldObjectsMap const* GetVisibleWorldObjectsMap() const
+    {
+        if (!_visibleWorldObjectsMap)
+            return nullptr;
+
+        return _visibleWorldObjectsMap.get();
+    }
+
+private:
+
+    // Directly removes visibility reference. This is to be ONLY used as
+    // a more efficient method for cleaning up visibility references.
+    // Warning: Improper use will leave dangling references and result in crashes.
+    void DirectRemoveVisibilityReference(ObjectGuid guid);
+
+    // Directly inserts player visibility reference.
+    // Warning: Improper use will leave dangling references and result in crashes.
+    void DirectInsertVisiblePlayerReference(Player* player);
+
+    // Directly removes player visibility reference.
+    // Warning: Improper use will leave dangling references and result in crashes.
+    void DirectRemoveVisiblePlayerReference(ObjectGuid guid);
+
+    WorldObject* _selfObject;
+
+    // List of all worldobjects that are visible to us (including other players)
+    // Only players contain this map, thus we will only allocate it as needed.
+    std::unique_ptr<VisibleWorldObjectsMap> _visibleWorldObjectsMap;
+
+    // List of players who are currently able to see this worldobject.
+    // All worldobjects will contain this map
+    VisiblePlayersMap _visiblePlayersMap;
+};
+
+#endif