[Core] Open mmtiles with the axes the baker named them by (#311)

Recast X is world Y, so the navmesh baker writes a tile at grid (gx, gy)
as navTileX = gy, navTileY = gx. NavMeshBuilder.hpp states the contract
outright: "the runtime opens mmaps/%04u%02i%02i.mmtile with (mapId, y,
x); see MMapManager::loadMap". loadMap passes (x, y) straight through,
so every off-diagonal tile is looked up transposed and fails to open --
only the gx == gy diagonal loads.

Stormwind is ADT Azeroth_30_48: the baker emits 00003048.mmtile and
loadMap asks for 00004830.mmtile.

mangoszero, mangosone and mangostwo all carry this swap in loadMap;
mangosthree and mangosfour are the two that do not. This adds it here,
matching mangostwo's naming and its convention of using the swapped
pair only for messages that name the file -- the already-loaded warning
keeps the grid position, which is what it is reporting.

Also of note: the .mmap GM command in this tree already prints the
swapped order, so the loader was the only place still disagreeing.

Author: r-log

src/game/WorldHandlers/MoveMap.cpp

@@ -323,8 +323,13 @@ namespace MMAP
             return false;
         }
 
+        /// Recast X is world Y, so the baker names a tile with the axes swapped
+        /// relative to the grid position. See NavMeshBuilder.hpp.
+        const int32 filenameTileX = y;
+        const int32 filenameTileY = x;
+
         // load this tile :: mmaps/MMMMXXYY.mmtile
-        const std::string fileName = MMapTileFileName(mapId, x, y);
+        const std::string fileName = MMapTileFileName(mapId, filenameTileX, filenameTileY);
 
         FILE* file = fopen(fileName.c_str(), "rb");
         if (!file)
@@ -339,15 +344,15 @@ namespace MMAP
 
         if (fileHeader.mmapMagic != MMAP_MAGIC)
         {
-            sLog.outError("MMAP:loadMap: Bad header in mmap %04u%02i%02i.mmtile", mapId, x, y);
+            sLog.outError("MMAP:loadMap: Bad header in mmap %04u%02i%02i.mmtile", mapId, filenameTileX, filenameTileY);
             fclose(file);
             return false;
         }
 
         if (fileHeader.mmapVersion != MMAP_VERSION)
         {
             sLog.outError("MMAP:loadMap: %04u%02i%02i.mmtile was built with generator v%i, expected v%i",
-                          mapId, x, y, fileHeader.mmapVersion, MMAP_VERSION);
+                          mapId, filenameTileX, filenameTileY, fileHeader.mmapVersion, MMAP_VERSION);
             fclose(file);
             return false;
         }
@@ -358,7 +363,7 @@ namespace MMAP
         size_t result = fread(data, fileHeader.size, 1, file);
         if (!result)
         {
-            sLog.outError("MMAP:loadMap: Bad header or data in mmap %04u%02i%02i.mmtile", mapId, x, y);
+            sLog.outError("MMAP:loadMap: Bad header or data in mmap %04u%02i%02i.mmtile", mapId, filenameTileX, filenameTileY);
             fclose(file);
             return false;
         }
@@ -371,7 +376,7 @@ namespace MMAP
         // memory allocated for data is now managed by detour, and will be deallocated when the tile is removed
         if (mmap->navMesh->addTile(data, fileHeader.size, DT_TILE_FREE_DATA, 0, &tileRef) != DT_SUCCESS)
         {
-            sLog.outError("MMAP:loadMap: Could not load %04u%02i%02i.mmtile into navmesh", mapId, x, y);
+            sLog.outError("MMAP:loadMap: Could not load %04u%02i%02i.mmtile into navmesh", mapId, filenameTileX, filenameTileY);
             dtFree(data);
             return false;
         }