Support multiple threads for async nav mesh updater

apps/openmw/mwworld/worldimp.cpp

@@ -215,6 +215,7 @@ namespace MWWorld
         navigatorSettings.mRegionMergeSize = Settings::Manager::getInt("region merge size", "Navigator");
         navigatorSettings.mRegionMinSize = Settings::Manager::getInt("region min size", "Navigator");
         navigatorSettings.mTileSize = Settings::Manager::getInt("tile size", "Navigator");
+        navigatorSettings.mAsyncNavMeshUpdaterThreads = static_cast<std::size_t>(Settings::Manager::getInt("async nav mesh updater threads", "Navigator"));
         navigatorSettings.mMaxPolygonPathSize = static_cast<std::size_t>(Settings::Manager::getInt("max polygon path size", "Navigator"));
         navigatorSettings.mMaxSmoothPathSize = static_cast<std::size_t>(Settings::Manager::getInt("max smooth path size", "Navigator"));
         navigatorSettings.mTrianglesPerChunk = static_cast<std::size_t>(Settings::Manager::getInt("triangles per chunk", "Navigator"));

apps/openmw_test_suite/detournavigator/navigator.cpp

@@ -55,6 +55,7 @@ namespace
             mSettings.mRegionMergeSize = 20;
             mSettings.mRegionMinSize = 8;
             mSettings.mTileSize = 64;
+            mSettings.mAsyncNavMeshUpdaterThreads = 1;
             mSettings.mMaxPolygonPathSize = 1024;
             mSettings.mMaxSmoothPathSize = 1024;
             mSettings.mTrianglesPerChunk = 256;

components/detournavigator/asyncnavmeshupdater.cpp

@@ -52,8 +52,9 @@ namespace DetourNavigator
         , mRecastMeshManager(recastMeshManager)
         , mOffMeshConnectionsManager(offMeshConnectionsManager)
         , mShouldStop()
-        , mThread([&] { process(); })
     {
+        for (std::size_t i = 0; i < mSettings.get().mAsyncNavMeshUpdaterThreads; ++i)
+            mThreads.emplace_back([&] { process(); });
     }
 
     AsyncNavMeshUpdater::~AsyncNavMeshUpdater()
@@ -63,7 +64,8 @@ namespace DetourNavigator
         mJobs = decltype(mJobs)();
         mHasJob.notify_all();
         lock.unlock();
-        mThread.join();
+        for (auto& thread : mThreads)
+            thread.join();
     }
 
     void AsyncNavMeshUpdater::post(const osg::Vec3f& agentHalfExtents,

components/detournavigator/asyncnavmeshupdater.hpp

@@ -71,7 +71,7 @@ namespace DetourNavigator
         TilePosition mPlayerTile;
         std::mutex mFirstStartMutex;
         boost::optional<std::chrono::steady_clock::time_point> mFirstStart;
-        std::thread mThread;
+        std::vector<std::thread> mThreads;
 
         void process() throw();
 

components/detournavigator/settings.hpp

@@ -27,6 +27,7 @@ namespace DetourNavigator
         int mRegionMergeSize;
         int mRegionMinSize;
         int mTileSize;
+        std::size_t mAsyncNavMeshUpdaterThreads;
         std::size_t mMaxPolygonPathSize;
         std::size_t mMaxSmoothPathSize;
         std::size_t mTrianglesPerChunk;

files/settings-default.cfg

@@ -585,6 +585,9 @@ region merge size = 20
 # The minimum number of cells allowed to form isolated island areas. (value >= 0)
 region min size = 8
 
+# Number of background threads to update nav mesh (value >= 1)
+async nav mesh updater threads = 1
+
 # Maximum size of path over polygons (value > 0)
 max polygon path size = 1024