Close #6326: Add support for RCTC SV6 files with 15000 entities

distribution/changelog.txt

@@ -1,5 +1,6 @@
 0.4.2 (in development)
 ------------------------------------------------------------------------
+- Feature: [#6326] Ability to load .SV6 files from RCT Classic that have more than 9601 guests.
 - Feature: [#13634] Add ability to sell merchandise in random colours.
 - Feature: [#16164] Add new track elements for Flying Coaster and Lay-Down Coaster and add paint code for more elements.
 - Feature: [#16283] Added parkinfo command line tool to list objects in a save file.

src/openrct2/rct2/Limits.h

@@ -18,6 +18,7 @@ namespace RCT2::Limits
     constexpr const uint8_t MaxTrainsPerRide = 32;
     constexpr const uint8_t DowntimeHistorySize = 8;
     constexpr const uint16_t MaxEntities = 10000;
+    constexpr const uint16_t MaxEntitiesFlag15 = 15000;
     constexpr const uint32_t MaxTileElements = 0x30000;
     constexpr const uint16_t MaxAnimatedObjects = 2000;
     constexpr const uint8_t MaxResearchedRideTypeQuads = 8;  // With 32 bits per uint32_t, this means there is room for

src/openrct2/rct2/RCT2.h

@@ -834,7 +834,7 @@ namespace RCT2
 
         // SC6[6]
         uint32_t next_free_tile_element_pointer_index;
-        Entity sprites[Limits::MaxEntities];
+        Entity sprites[Limits::MaxEntitiesFlag15];
         uint16_t sprite_lists_head[static_cast<uint8_t>(EntityListId::Count)];
         uint16_t sprite_lists_count[static_cast<uint8_t>(EntityListId::Count)];
         StringId park_name;
@@ -1019,7 +1019,7 @@ namespace RCT2
         uint16_t wide_path_tile_loop_y;
         uint8_t pad_13CE778[434];
     };
-    assert_struct_size(S6Data, 0x46b44a);
+    assert_struct_size(S6Data, 0x5a3c4a);
 
     struct StexEntry
     {

src/openrct2/rct2/S6Importer.cpp

@@ -18,6 +18,7 @@
 #include "../core/Console.hpp"
 #include "../core/FileStream.h"
 #include "../core/IStream.hpp"
+#include "../core/MemoryStream.h"
 #include "../core/Numerics.hpp"
 #include "../core/Path.hpp"
 #include "../core/Random.hpp"
@@ -166,11 +167,6 @@ namespace RCT2
                 }
             }
 
-            if (_s6.header.classic_flag == 0xf)
-            {
-                throw UnsupportedRCTCFlagException(_s6.header.classic_flag);
-            }
-
             // Read packed objects
             // TODO try to contain this more and not store objects until later
             for (uint16_t i = 0; i < _s6.header.num_packed_objects; i++)
@@ -190,7 +186,7 @@ namespace RCT2
             {
                 chunkReader.ReadChunk(&_s6.elapsed_months, 16);
                 chunkReader.ReadChunk(&_s6.tile_elements, sizeof(_s6.tile_elements));
-                chunkReader.ReadChunk(&_s6.next_free_tile_element_pointer_index, 2560076);
+                ReadChunk6(chunkReader, 76);
                 chunkReader.ReadChunk(&_s6.guests_in_park, 4);
                 chunkReader.ReadChunk(&_s6.last_guests_in_park, 8);
                 chunkReader.ReadChunk(&_s6.park_rating, 2);
@@ -203,7 +199,7 @@ namespace RCT2
             {
                 chunkReader.ReadChunk(&_s6.elapsed_months, 16);
                 chunkReader.ReadChunk(&_s6.tile_elements, sizeof(_s6.tile_elements));
-                chunkReader.ReadChunk(&_s6.next_free_tile_element_pointer_index, 3048816);
+                ReadChunk6(chunkReader, 488816);
             }
 
             _isScenario = isScenario;
@@ -212,6 +208,22 @@ namespace RCT2
             return ParkLoadResult(GetRequiredObjects());
         }
 
+        void ReadChunk6(SawyerChunkReader& chunkReader, uint32_t sizeWithoutEntities)
+        {
+            uint32_t entitiesSize = GetMaxEntities() * sizeof(Entity);
+            auto bufferSize = sizeWithoutEntities + entitiesSize;
+            uint8_t buffer[bufferSize];
+            chunkReader.ReadChunk(&buffer, bufferSize);
+            auto stream = OpenRCT2::MemoryStream(&buffer, bufferSize);
+
+            uint32_t preEntitiesSize = sizeof(_s6.next_free_tile_element_pointer_index);
+            uint32_t postEntitiesSize = sizeWithoutEntities - preEntitiesSize;
+
+            stream.Read(&_s6.next_free_tile_element_pointer_index, preEntitiesSize);
+            stream.Read(&_s6.sprites, entitiesSize);
+            stream.Read(&_s6.sprite_lists_head, postEntitiesSize);
+        }
+
         bool GetDetails(scenario_index_entry* dst) override
         {
             *dst = {};
@@ -1168,8 +1180,9 @@ namespace RCT2
         {
             // The number of riders might have overflown or underflown. Re-calculate the value.
             uint16_t numRiders = 0;
-            for (const auto& sprite : _s6.sprites)
+            for (int32_t i = 0; i < GetMaxEntities(); i++)
             {
+                const auto& sprite = _s6.sprites[i];
                 if (sprite.unknown.sprite_identifier == RCT12SpriteIdentifier::Peep)
                 {
                     if (sprite.peep.current_ride == static_cast<RCT12RideId>(rideIndex.ToUnderlying())
@@ -1592,12 +1605,17 @@ namespace RCT2
 
         void ImportEntities()
         {
-            for (int32_t i = 0; i < Limits::MaxEntities; i++)
+            for (int32_t i = 0; i < GetMaxEntities(); i++)
             {
                 ImportEntity(_s6.sprites[i].unknown);
             }
         }
 
+        uint16_t GetMaxEntities()
+        {
+            return (_s6.header.classic_flag == 0xf) ? Limits::MaxEntitiesFlag15 : Limits::MaxEntities;
+        }
+
         template<typename OpenRCT2_T> void ImportEntity(const RCT12SpriteBase& src);
 
         void ImportEntityPeep(::Peep* dst, const Peep* src)