Core/Maps: Use the same logic to calculate grid coords to avoid mismatches

Use the same logic of (CENTER_GRID_ID - x / SIZE_OF_GRIDS) in GridMap::getMinHeight() as Map::GetGrid() to avoid coord grid mismatches caused by floating point precision, i.e. getting the wrong grid.
Replace defines with constexpr in grids to make debugging easier.

Closes #25652

2 files changed, 25 insertions, 18 deletions

diff --git a/src/server/game/Grids/GridDefines.h b/src/server/game/Grids/GridDefines.h
index 96dc3cd2b54..98077742773 100644
--- a/src/server/game/Grids/GridDefines.h
+++ b/src/server/game/Grids/GridDefines.h
@@ -31,29 +31,29 @@ class GameObject;
 class Pet;
 class Player;
 
-#define MAX_NUMBER_OF_CELLS     8
+constexpr uint32 MAX_NUMBER_OF_CELLS           = 8;
 
-#define MAX_NUMBER_OF_GRIDS      64
+constexpr uint32 MAX_NUMBER_OF_GRIDS           = 64;
 
-#define SIZE_OF_GRIDS            533.3333f
-#define CENTER_GRID_ID           (MAX_NUMBER_OF_GRIDS/2)
+constexpr float SIZE_OF_GRIDS                  = 533.3333f;
+constexpr uint32 CENTER_GRID_ID                = (MAX_NUMBER_OF_GRIDS / 2);
 
-#define CENTER_GRID_OFFSET      (SIZE_OF_GRIDS/2)
+constexpr float CENTER_GRID_OFFSET             = (SIZE_OF_GRIDS / 2);
 
-#define MIN_GRID_DELAY          (MINUTE*IN_MILLISECONDS)
-#define MIN_MAP_UPDATE_DELAY    50
+#define MIN_GRID_DELAY                           (MINUTE*IN_MILLISECONDS)
+#define MIN_MAP_UPDATE_DELAY                     50
 
-#define SIZE_OF_GRID_CELL       (SIZE_OF_GRIDS/MAX_NUMBER_OF_CELLS)
+constexpr float SIZE_OF_GRID_CELL              = (SIZE_OF_GRIDS / MAX_NUMBER_OF_CELLS);
+                                               
+constexpr uint32 CENTER_GRID_CELL_ID           = (MAX_NUMBER_OF_CELLS * MAX_NUMBER_OF_GRIDS / 2);
+constexpr float CENTER_GRID_CELL_OFFSET        = (SIZE_OF_GRID_CELL / 2);
 
-#define CENTER_GRID_CELL_ID     (MAX_NUMBER_OF_CELLS*MAX_NUMBER_OF_GRIDS/2)
-#define CENTER_GRID_CELL_OFFSET (SIZE_OF_GRID_CELL/2)
+constexpr uint32 TOTAL_NUMBER_OF_CELLS_PER_MAP = (MAX_NUMBER_OF_GRIDS * MAX_NUMBER_OF_CELLS);
 
-#define TOTAL_NUMBER_OF_CELLS_PER_MAP    (MAX_NUMBER_OF_GRIDS*MAX_NUMBER_OF_CELLS)
+constexpr uint32 MAP_RESOLUTION                = 128;
 
-#define MAP_RESOLUTION 128
-
-#define MAP_SIZE                (SIZE_OF_GRIDS*MAX_NUMBER_OF_GRIDS)
-#define MAP_HALFSIZE            (MAP_SIZE/2)
+constexpr float MAP_SIZE                       = (SIZE_OF_GRIDS * MAX_NUMBER_OF_GRIDS);
+constexpr float MAP_HALFSIZE                   = (MAP_SIZE / 2);
 
 // Creature used instead pet to simplify *::Visit templates (not required duplicate code for Creature->Pet case)
 typedef TYPELIST_4(Player, Creature/*pets*/, Corpse/*resurrectable*/, DynamicObject/*farsight target*/) AllWorldObjectTypes;
@@ -178,8 +178,8 @@ namespace Trinity
         double x_offset = (double(x) - center_offset)/size;
         double y_offset = (double(y) - center_offset)/size;
 
-        int x_val = int(x_offset + CENTER_VAL + 0.5f);
-        int y_val = int(y_offset + CENTER_VAL + 0.5f);
+        int x_val = int(x_offset + CENTER_VAL + 0.5);
+        int y_val = int(y_offset + CENTER_VAL + 0.5);
         return RET_TYPE(x_val, y_val);
     }
 
@@ -188,6 +188,13 @@ namespace Trinity
         return Compute<GridCoord, CENTER_GRID_ID>(x, y, CENTER_GRID_OFFSET, SIZE_OF_GRIDS);
     }
 
+    inline GridCoord ComputeGridCoordSimple(float x, float y)
+    {
+        int gx = (int)(CENTER_GRID_ID - x / SIZE_OF_GRIDS);
+        int gy = (int)(CENTER_GRID_ID - y / SIZE_OF_GRIDS);
+        return GridCoord((MAX_NUMBER_OF_GRIDS - 1) - gx, (MAX_NUMBER_OF_GRIDS - 1) - gy);
+    }
+
     inline CellCoord ComputeCellCoord(float x, float y)
     {
         return Compute<CellCoord, CENTER_GRID_CELL_ID>(x, y, CENTER_GRID_CELL_OFFSET, SIZE_OF_GRID_CELL);
diff --git a/src/server/game/Maps/Map.cpp b/src/server/game/Maps/Map.cpp
index 1e0af8d8d6f..1908f2efe2a 100644
--- a/src/server/game/Maps/Map.cpp
+++ b/src/server/game/Maps/Map.cpp
@@ -2305,7 +2305,7 @@ float GridMap::getMinHeight(float x, float y) const
     if (!_minHeightPlanes)
         return -500.0f;
 
-    GridCoord gridCoord = Trinity::ComputeGridCoord(x, y);
+    GridCoord gridCoord = Trinity::ComputeGridCoordSimple(x, y);
 
     int32 doubleGridX = int32(std::floor(-(x - MAP_HALFSIZE) / CENTER_GRID_OFFSET));
     int32 doubleGridY = int32(std::floor(-(y - MAP_HALFSIZE) / CENTER_GRID_OFFSET));