Use ObjectEntryIndex for surface object

src/openrct2/paint/tile_element/Paint.Surface.cpp

@@ -217,7 +217,7 @@ struct TileDescriptor
 {
     TileCoordsXY tile_coords;
     const TileElement* tile_element;
-    uint8_t terrain;
+    ObjectEntryIndex terrain;
     uint8_t slope;
     CornerHeight corner_heights;
 };
@@ -1038,7 +1038,7 @@ void PaintSurface(PaintSession& session, uint8_t direction, uint16_t height, con
     TileDescriptor selfDescriptor = {
         TileCoordsXY(base),
         elementPtr,
-        static_cast<uint8_t>(terrain_type),
+        terrain_type,
         surfaceShape,
         {
             static_cast<uint8_t>(height / 16 + cornerHeights.top),

src/openrct2/world/Surface.cpp

@@ -17,7 +17,7 @@
 #include "Location.hpp"
 #include "Map.h"
 
-uint32_t SurfaceElement::GetSurfaceStyle() const
+ObjectEntryIndex SurfaceElement::GetSurfaceStyle() const
 {
     return SurfaceStyle;
 }
@@ -39,9 +39,9 @@ TerrainEdgeObject* SurfaceElement::GetEdgeStyleObject() const
     return static_cast<TerrainEdgeObject*>(objManager.GetLoadedObject(ObjectType::TerrainEdge, GetEdgeStyle()));
 }
 
-void SurfaceElement::SetSurfaceStyle(uint32_t newStyle)
+void SurfaceElement::SetSurfaceStyle(ObjectEntryIndex newStyle)
 {
-    SurfaceStyle = newStyle;
+    SurfaceStyle = static_cast<ObjectEntryIndex>(newStyle);
 }
 
 void SurfaceElement::SetEdgeStyle(uint32_t newStyle)

src/openrct2/world/TileElement.h

@@ -205,9 +205,10 @@ public:
     uint8_t GetSlope() const;
     void SetSlope(uint8_t newSlope);
 
-    uint32_t GetSurfaceStyle() const;
+    ObjectEntryIndex GetSurfaceStyle() const;
     TerrainSurfaceObject* GetSurfaceStyleObject() const;
-    void SetSurfaceStyle(uint32_t newStyle);
+    void SetSurfaceStyle(ObjectEntryIndex newStyle);
+
     uint32_t GetEdgeStyle() const;
     TerrainEdgeObject* GetEdgeStyleObject() const;
     void SetEdgeStyle(uint32_t newStyle);