Tools/MMapsGenerator: Use system supported threads instead of hardcoded amount

- Use unsigned int for thread count

- Use std::thread::hardware_concurrency() to try estimate available threads instead of hardcoded 3 threads by default

- Print thread count always regardless of using --threads switch or not

src/tools/mmaps_generator/MapBuilder.cpp

@@ -205,9 +205,11 @@ namespace MMAP
         }
     }
 
-    void MapBuilder::buildAllMaps(int threads)
+    void MapBuilder::buildAllMaps(unsigned int threads)
     {
-        for (int i = 0; i < threads; ++i)
+        printf("Using %u threads to extract mmaps\n", threads);
+
+        for (unsigned int i = 0; i < threads; ++i)
         {
             _workerThreads.push_back(std::thread(&MapBuilder::WorkerThread, this));
         }

src/tools/mmaps_generator/MapBuilder.h

@@ -94,7 +94,7 @@ namespace MMAP
             void buildSingleTile(uint32 mapID, uint32 tileX, uint32 tileY);
 
             // builds list of maps, then builds all of mmap tiles (based on the skip settings)
-            void buildAllMaps(int threads);
+            void buildAllMaps(unsigned int threads);
 
             void WorkerThread();
 

src/tools/mmaps_generator/PathGenerator.cpp

@@ -72,7 +72,7 @@ bool handleArgs(int argc, char** argv,
                bool &bigBaseUnit,
                char* &offMeshInputPath,
                char* &file,
-               int& threads)
+               unsigned int& threads)
 {
     char* param = NULL;
     for (int i = 1; i < argc; ++i)
@@ -94,8 +94,7 @@ bool handleArgs(int argc, char** argv,
             param = argv[++i];
             if (!param)
                 return false;
-            threads = atoi(param);
-            printf("Using %i threads to extract mmaps\n", threads);
+            threads = static_cast<unsigned int>(std::max(0, atoi(param)));
         }
         else if (strcmp(argv[i], "--file") == 0)
         {
@@ -241,7 +240,8 @@ int finish(const char* message, int returnValue)
 
 int main(int argc, char** argv)
 {
-    int threads = 3, mapnum = -1;
+    unsigned int threads = std::thread::hardware_concurrency();
+    int mapnum = -1;
     float maxAngle = 70.0f;
     int tileX = -1, tileY = -1;
     bool skipLiquid = false,