Remove SPRITE_INDEX_NULL

src/openrct2/common.h

@@ -123,8 +123,6 @@ constexpr money16 ToMoney16(money64 value)
 using EMPTY_ARGS_VOID_POINTER = void();
 using rct_string_id = uint16_t;
 
-constexpr uint16_t SPRITE_INDEX_NULL = 0xFFFF;
-
 #define SafeFree(x)                                                                                                            \
     do                                                                                                                         \
     {                                                                                                                          \

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

@@ -1103,7 +1103,7 @@ void PaintSurface(paint_session& session, uint8_t direction, uint16_t height, co
 
     // Draw Staff Patrol Areas
     // loc_660D02
-    if (gStaffDrawPatrolAreas != SPRITE_INDEX_NULL)
+    if (gStaffDrawPatrolAreas != EntityId::GetNull().ToUnderlying())
     {
         // TODO: Split is_staff_list into a new variable.
         const int32_t staffIndex = gStaffDrawPatrolAreas;