simplify active object logic

src/serverenvironment.cpp

@@ -336,13 +336,12 @@ void ActiveBlockList::update(std::vector<PlayerSAO*> &active_players,
 	s16 active_object_range,
 	std::set<v3s16> &blocks_removed,
 	std::set<v3s16> &blocks_added,
-	std::set<v3s16> &extra_blocks_added)
+	std::set<v3s16> &extralist)
 {
 	/*
 		Create the new list
 	*/
 	std::set<v3s16> newlist = m_forceloaded_list;
-	std::set<v3s16> extralist;
 	m_abm_list = m_forceloaded_list;
 	for (const PlayerSAO *playersao : active_players) {
 		v3s16 pos = getNodeBlockPos(floatToInt(playersao->getBasePosition(), BS));
@@ -366,37 +365,21 @@ void ActiveBlockList::update(std::vector<PlayerSAO*> &active_players,
 		}
 	}
 
-	/*
-		Find out which blocks on the old list are not on the new list
-	*/
-	// Go through old list
-	for (v3s16 p : m_list) {
-		// If not on new list, it's been removed
-		if (newlist.find(p) == newlist.end() && extralist.find(p) == newlist.end())
-			blocks_removed.insert(p);
-	}
-
-	/*
-		Find out which blocks on the new list are not on the old list
-	*/
-	// Go through new list
+	// make sure extra list only contains extra blocks
 	for (v3s16 p : newlist) {
-		// remove duplicate blocks from the extra list
 		extralist.erase(p);
-		// If not on old list, it's been added
-		if (m_list.find(p) == m_list.end())
-			blocks_added.insert(p);
-	}
-	for (v3s16 p : extralist) {
-		newlist.insert(p);
-		// If not on old list, it's been added
-		if (m_list.find(p) == m_list.end())
-			extra_blocks_added.insert(p);
 	}
 
-	/*
-		Update m_list
-	*/
+	// newlist now contains all blocks
+	newlist.insert(extralist.begin(), extralist.end());
+
+	// Find out which blocks on the old list are not on the new list
+	std::set_difference(m_list.begin(), m_list.end(), newlist.begin(), newlist.end(), std::inserter(blocks_removed, blocks_removed.end()));
+
+	// Find out which blocks on the new list are not on the old list
+	std::set_difference(newlist.begin(), newlist.end(), m_list.begin(), m_list.end(), std::inserter(blocks_added, blocks_added.end()));
+
+	// Update m_list
 	m_list = std::move(newlist);
 }