Merge pull request #5795 from JosJuice/gc-region-detection

Improve GameCube region detection

Source/Core/Core/ConfigManager.cpp

@@ -13,6 +13,7 @@
 
 #include "AudioCommon/AudioCommon.h"
 
+#include "Common/Assert.h"
 #include "Common/CDUtils.h"
 #include "Common/CommonPaths.h"
 #include "Common/CommonTypes.h"
@@ -869,6 +870,18 @@ bool SConfig::IsUSBDeviceWhitelisted(const std::pair<u16, u16> vid_pid) const
   return m_usb_passthrough_devices.find(vid_pid) != m_usb_passthrough_devices.end();
 }
 
+// The reason we need this function is because some memory card code
+// expects to get a non-NTSC-K region even if we're emulating an NTSC-K Wii.
+DiscIO::Region SConfig::ToGameCubeRegion(DiscIO::Region region)
+{
+  if (region != DiscIO::Region::NTSC_K)
+    return region;
+
+  // GameCube has no NTSC-K region. No choice of replacement value is completely
+  // non-arbitrary, but let's go with NTSC-J since Korean GameCubes are NTSC-J.
+  return DiscIO::Region::NTSC_J;
+}
+
 const char* SConfig::GetDirectoryForRegion(DiscIO::Region region)
 {
   switch (region)
@@ -883,13 +896,8 @@ const char* SConfig::GetDirectoryForRegion(DiscIO::Region region)
     return EUR_DIR;
 
   case DiscIO::Region::NTSC_K:
-    // This function can't return a Korean directory name, because this
+    _assert_msg_(BOOT, false, "NTSC-K is not a valid GameCube region");
-    // function is only used for GameCube things (memory cards, IPL), and
+    return nullptr;
-    // GameCube has no NTSC-K region. Since NTSC-K doesn't correspond to any
-    // GameCube region, let's return an arbitrary pick. Returning nullptr like
-    // with unknown regions would be inappropriate, because Dolphin expects
-    // to get valid memory card paths even when running an NTSC-K Wii game.
-    return JAP_DIR;
 
   default:
     return nullptr;
@@ -982,7 +990,7 @@ bool SConfig::SetPathsAndGameMetadata(const BootParameters& boot)
     return false;
 
   // Set up region
-  const char* retrieved_region_dir = GetDirectoryForRegion(region);
+  const char* retrieved_region_dir = GetDirectoryForRegion(ToGameCubeRegion(region));
   m_region = retrieved_region_dir ? region : DiscIO::Region::PAL;
   const std::string set_region_dir = retrieved_region_dir ? retrieved_region_dir : EUR_DIR;
   if (!retrieved_region_dir &&

Source/Core/Core/ConfigManager.h

@@ -217,6 +217,9 @@ struct SConfig : NonCopyable
   void SetRunningGameMetadata(const IOS::ES::TMDReader& tmd);
 
   void LoadDefaults();
+  // Replaces NTSC-K with some other region, and doesn't replace non-NTSC-K regions
+  static DiscIO::Region ToGameCubeRegion(DiscIO::Region region);
+  // The region argument must be valid for GameCube (i.e. must not be NTSC-K)
   static const char* GetDirectoryForRegion(DiscIO::Region region);
   std::string GetBootROMPath(const std::string& region_directory) const;
   bool SetPathsAndGameMetadata(const BootParameters& boot);

Source/Core/Core/HW/EXI/EXI_DeviceMemoryCard.cpp

@@ -157,7 +157,7 @@ CEXIMemoryCard::CEXIMemoryCard(const int index, bool gciFolder) : card_index(ind
 
 void CEXIMemoryCard::SetupGciFolder(u16 sizeMb)
 {
-  DiscIO::Region region = SConfig::GetInstance().m_region;
+  const DiscIO::Region region = SConfig::ToGameCubeRegion(SConfig::GetInstance().m_region);
 
   const std::string& game_id = SConfig::GetInstance().GetGameID();
   u32 CurrentGameId = 0;

Source/Core/Core/HW/GCMemcard/GCMemcardDirectory.cpp

@@ -44,6 +44,7 @@ int GCMemcardDirectory::LoadGCI(const std::string& file_name, DiscIO::Region car
       return NO_INDEX;
     }
 
+    // This isn't a reliable way to detect regions. TODO: Get rid of this?
     DiscIO::Region gci_region = DiscIO::RegionSwitchGC(gci.m_gci_header.Gamecode[3]);
     // Some special save files have game IDs that we parse as UNKNOWN_REGION. For instance:
     // - Datel Action Replay uses C as the fourth character. (Can be on any region's card.)

Source/Core/Core/IOS/ES/Formats.cpp

@@ -232,14 +232,6 @@ u64 TMDReader::GetIOSId() const
   return Common::swap64(m_bytes.data() + offsetof(TMDHeader, ios_id));
 }
 
-DiscIO::Region TMDReader::GetRegion() const
-{
-  if (GetTitleId() == Titles::SYSTEM_MENU)
-    return DiscIO::GetSysMenuRegion(GetTitleVersion());
-
-  return DiscIO::RegionSwitchWii(static_cast<u8>(GetTitleId() & 0xff));
-}
-
 u64 TMDReader::GetTitleId() const
 {
   return Common::swap64(m_bytes.data() + offsetof(TMDHeader, title_id));
@@ -260,6 +252,14 @@ u16 TMDReader::GetGroupId() const
   return Common::swap16(m_bytes.data() + offsetof(TMDHeader, group_id));
 }
 
+DiscIO::Region TMDReader::GetRegion() const
+{
+  if (GetTitleId() == Titles::SYSTEM_MENU)
+    return DiscIO::GetSysMenuRegion(GetTitleVersion());
+
+  return DiscIO::RegionSwitchWii(static_cast<u8>(GetTitleId() & 0xff));
+}
+
 std::string TMDReader::GetGameID() const
 {
   char game_id[6];

Source/Core/Core/IOS/ES/Formats.h

@@ -185,12 +185,14 @@ public:
 
   u16 GetBootIndex() const;
   u64 GetIOSId() const;
-  DiscIO::Region GetRegion() const;
   u64 GetTitleId() const;
   u32 GetTitleFlags() const;
   u16 GetTitleVersion() const;
   u16 GetGroupId() const;
 
+  // Provides a best guess for the region. Might be inaccurate or UNKNOWN_REGION.
+  DiscIO::Region GetRegion() const;
+
   // Constructs a 6-character game ID in the format typically used by Dolphin.
   // If the 6-character game ID would contain unprintable characters,
   // the title ID converted to hexadecimal is returned instead.

Source/Core/Core/TitleDatabase.cpp

@@ -94,12 +94,12 @@ static bool IsWiiTitle(const std::string& game_id)
 
 static bool IsJapaneseGCTitle(const std::string& game_id)
 {
-  return IsGCTitle(game_id) && DiscIO::RegionSwitchGC(game_id[3]) == DiscIO::Region::NTSC_J;
+  return IsGCTitle(game_id) && DiscIO::CountrySwitch(game_id[3]) == DiscIO::Country::COUNTRY_JAPAN;
 }
 
 static bool IsNonJapaneseGCTitle(const std::string& game_id)
 {
-  return IsGCTitle(game_id) && DiscIO::RegionSwitchGC(game_id[3]) != DiscIO::Region::NTSC_J;
+  return IsGCTitle(game_id) && DiscIO::CountrySwitch(game_id[3]) != DiscIO::Country::COUNTRY_JAPAN;
 }
 
 // Note that this function will not overwrite entries that already are in the maps

Source/Core/DiscIO/Enums.cpp

@@ -48,7 +48,7 @@ Country TypicalCountryForRegion(Region region)
 Region RegionSwitchGC(u8 country_code)
 {
   Region region = RegionSwitchWii(country_code);
-  return region == Region::NTSC_K ? Region::UNKNOWN_REGION : region;
+  return region == Region::NTSC_K ? Region::NTSC_J : region;
 }
 
 Region RegionSwitchWii(u8 country_code)

Source/Core/DiscIO/Enums.h

@@ -40,10 +40,10 @@ enum class Country
   NUMBER_OF_COUNTRIES
 };
 
-// Regions 0 - 2 and 4 match Nintendo's Wii region numbering.
+// Regions 0 - 2 and 4 match Nintendo's GameCube/Wii region numbering.
 enum class Region
 {
-  NTSC_J = 0,          // Japan and Taiwan
+  NTSC_J = 0,          // Japan and Taiwan (and South Korea for GameCube only)
   NTSC_U = 1,          // Mainly North America
   PAL = 2,             // Mainly Europe and Oceania
   UNKNOWN_REGION = 3,  // 3 seems to be unused? Anyway, we need an UNKNOWN_REGION. Let's put it here
@@ -71,11 +71,16 @@ enum class Language
 bool IsDisc(Platform volume_type);
 bool IsWii(Platform volume_type);
 bool IsNTSC(Region region);
+
 Country TypicalCountryForRegion(Region region);
+// Avoid using this function if you can. Country codes aren't always reliable region indicators.
 Region RegionSwitchGC(u8 country_code);
+// Avoid using this function if you can. Country codes aren't always reliable region indicators.
 Region RegionSwitchWii(u8 country_code);
 Country CountrySwitch(u8 country_code);
+
 Region GetSysMenuRegion(u16 title_version);
 std::string GetSysMenuVersionString(u16 title_version);
+
 std::string GetCompanyFromID(const std::string& company_id);
 }

Source/Core/DiscIO/Volume.h

@@ -83,6 +83,7 @@ public:
   virtual Platform GetVolumeType() const = 0;
   virtual bool SupportsIntegrityCheck() const { return false; }
   virtual bool CheckIntegrity(const Partition& partition) const { return false; }
+  // May be inaccurate for WADs
   virtual Region GetRegion() const = 0;
   Country GetCountry() const { return GetCountry(GetGamePartition()); }
   virtual Country GetCountry(const Partition& partition) const = 0;

Source/Core/DiscIO/VolumeGC.cpp

@@ -60,14 +60,31 @@ std::string VolumeGC::GetGameID(const Partition& partition) const
 
 Region VolumeGC::GetRegion() const
 {
-  const std::optional<u8> country_code = ReadSwapped<u8>(3, PARTITION_NONE);
+  const std::optional<u32> region_code = ReadSwapped<u32>(0x458, PARTITION_NONE);
-  return country_code ? RegionSwitchGC(*country_code) : Region::UNKNOWN_REGION;
+  if (!region_code)
+    return Region::UNKNOWN_REGION;
+  const Region region = static_cast<Region>(*region_code);
+  return region <= Region::PAL ? region : Region::UNKNOWN_REGION;
 }
 
 Country VolumeGC::GetCountry(const Partition& partition) const
 {
-  const std::optional<u8> country_code = ReadSwapped<u8>(3, partition);
+  // The 0 that we use as a default value is mapped to COUNTRY_UNKNOWN and UNKNOWN_REGION
-  return country_code ? CountrySwitch(*country_code) : Country::COUNTRY_UNKNOWN;
+  const u8 country = ReadSwapped<u8>(3, partition).value_or(0);
+  const Region region = GetRegion();
+
+  // Korean GC releases use NTSC-J.
+  // E is normally used for America, but it's also used for English-language Korean GC releases.
+  // K is used by games that are in the Korean language.
+  // W means Taiwan for Wii games, but on the GC, it's used for English-language Korean releases.
+  // (There doesn't seem to be any pattern to which of E and W is used for Korean GC releases.)
+  if (region == Region::NTSC_J && (country == 'E' || country == 'K' || country == 'W'))
+    return Country::COUNTRY_KOREA;
+
+  if (RegionSwitchGC(country) != region)
+    return TypicalCountryForRegion(region);
+
+  return CountrySwitch(country);
 }
 
 std::string VolumeGC::GetMakerID(const Partition& partition) const

Source/Core/DiscIO/VolumeWad.h

@@ -50,6 +50,7 @@ public:
     return "";
   }
   Platform GetVolumeType() const override;
+  // Provides a best guess for the region. Might be inaccurate or UNKNOWN_REGION.
   Region GetRegion() const override;
   Country GetCountry(const Partition& partition = PARTITION_NONE) const override;
 

Source/Core/DiscIO/VolumeWii.cpp

@@ -233,7 +233,10 @@ std::string VolumeWii::GetGameID(const Partition& partition) const
 Region VolumeWii::GetRegion() const
 {
   const std::optional<u32> region_code = m_pReader->ReadSwapped<u32>(0x4E000);
-  return region_code ? static_cast<Region>(*region_code) : Region::UNKNOWN_REGION;
+  if (!region_code)
+    return Region::UNKNOWN_REGION;
+  const Region region = static_cast<Region>(*region_code);
+  return region <= Region::NTSC_K ? region : Region::UNKNOWN_REGION;
 }
 
 Country VolumeWii::GetCountry(const Partition& partition) const