Station rename command (#984)

This re-introduces the possibility of resetting/regenerating station names automatically
by using an empty station name. Previously, our re-implementation (C++ code) inadvertently
removed this option.

CHANGELOG.md

@@ -2,6 +2,7 @@
 ------------------------------------------------------------------------
 - Feature: [#856] Allow filtering the vehicle list by station or cargo type.
 - Fix: [#982] Incorrect rating calculation for cargo causing penalty for fast vehicles.
+- Fix: [#984] Unable to reset/regenerate station names by using an empty name.
 - Fix: [#1008] Inability to decrease max altitude for trees in landscape editor.
 - Fix: [#1016] Incorrect detection of station causing incorrect smoke sounds.
 - Technical: [#986] Stack misalignment in GCC builds caused unexplained crashes on Linux and Mac during interop hooks with loco.exe.

src/OpenLoco/GameCommands/GameCommands.cpp

@@ -57,7 +57,7 @@ namespace OpenLoco::GameCommands
         { GameCommand::gc_unk_8,                     nullptr,                   0x0049C7F2, true  },
         { GameCommand::changeLoan,                   nullptr,                   0x0046DE88, false },
         { GameCommand::vehicleRename,                Vehicles::rename,          0x004B6572, false },
-        { GameCommand::changeStationName,            nullptr,                   0x00490756, false },
+        { GameCommand::changeStationName,            renameStation,             0x00490756, false },
         { GameCommand::vehicleLocalExpress,          nullptr,                   0x004B694B, true  },
         { GameCommand::gc_unk_13,                    nullptr,                   0x00488BDB, true  },
         { GameCommand::gc_unk_14,                    nullptr,                   0x004891E4, true  },

src/OpenLoco/GameCommands/GameCommands.h

@@ -675,6 +675,9 @@ namespace OpenLoco::GameCommands
     // Defined in GameCommands/RenameIndustry.cpp
     void renameIndustry(registers& regs);
 
+    // Defined in GameCommands/RenameStation.cpp
+    void renameStation(registers& regs);
+
     // Defined in GameCommands/RenameTown.cpp
     void renameTown(registers& regs);
 

src/OpenLoco/GameCommands/RenameStation.cpp

@@ -0,0 +1,109 @@
+#include "../Economy/Expenditures.h"
+#include "../Industry.h"
+#include "../Interop/Interop.hpp"
+#include "../Localisation/FormatArguments.hpp"
+#include "../Localisation/StringIds.h"
+#include "../Localisation/StringManager.h"
+#include "../StationManager.h"
+#include "../TownManager.h"
+#include "../Types.hpp"
+#include "GameCommands.h"
+
+using namespace OpenLoco::Interop;
+
+namespace OpenLoco::GameCommands
+{
+    /**
+     * 0x00490756
+     * Renames a particular station.
+     *
+     * This command is called 3 times before the buffer is applied. Each time, 12 chars of the 36 char buffer are provided.
+     * The resulting station name has a maximum length of 31 chars; the last bytes are not used.
+     *
+     * @param flags @<bl> - game command flags
+     * @param stationId @<cx> - station id
+     * @param index @<ax> - update index (in order of: 1, 2, 0)
+     * @param buffer0 @<edx> - First part (4 chars) of the 12 update buffer
+     * @param buffer1 @<dx> - Second part (4 chars) of the 12 update buffer
+     * @param buffer2 @<bp> - Third part (4 chars) of the 12 update buffer
+     * @return @<ebx> - returns 0 if rename is successful; otherwise GameCommands::FAILURE
+     */
+    static uint32_t renameStation(const uint8_t flags, StationId_t stationId, int16_t index, uint32_t buffer0, uint32_t buffer1, uint32_t buffer2)
+    {
+        GameCommands::setExpenditureType(ExpenditureType::Miscellaneous);
+
+        // Keep track of the station id over several calls.
+        static StationId_t _stationId{};
+        if (index == 1)
+            _stationId = stationId;
+
+        static uint32_t renameBuffer[9];
+
+        // Fill buffer over calls into the renameBuffer
+        if ((flags & GameCommands::Flags::apply) != 0)
+        {
+            static const std::array<int, 3> transformTable = { 2, 0, 1 };
+            int arrayIndex = transformTable.at(index);
+            renameBuffer[arrayIndex * 3] = buffer0;
+            renameBuffer[arrayIndex * 3 + 1] = buffer1;
+            renameBuffer[arrayIndex * 3 + 2] = buffer2;
+        }
+
+        // Applying the buffer?
+        if (index != 0)
+            return 0;
+
+        char renameStringBuffer[37] = "";
+        memcpy(renameStringBuffer, renameBuffer, sizeof(renameBuffer));
+        renameStringBuffer[36] = '\0';
+
+        // Figure out the current name for this station.
+        char currentStationName[256] = "";
+        auto station = StationManager::get(_stationId);
+        auto args = FormatArguments::common(station->town);
+        StringManager::formatString(currentStationName, station->name, &args);
+
+        // Verify the new name actually differs from the old one.
+        if (strcmp(currentStationName, renameStringBuffer) == 0)
+            return 0;
+
+        string_id oldStringId = station->name;
+
+        // If an empty string is given, generate one instead.
+        if (strlen(renameStringBuffer) == 0)
+        {
+            // Are we bailing out early?
+            if ((flags & GameCommands::Flags::apply) == 0)
+                return 0;
+
+            station->name = StationManager::generateNewStationName(_stationId, station->town, Map::Pos3(station->x, station->y, station->z), 0);
+        }
+        else
+        {
+            // Allocate a string id for the new name.
+            string_id allocatedStringId = StringManager::userStringAllocate(renameStringBuffer, 0);
+            if (allocatedStringId == StringIds::empty)
+                return GameCommands::FAILURE;
+
+            // Are we bailing out early?
+            if ((flags & GameCommands::Flags::apply) == 0)
+            {
+                StringManager::emptyUserString(allocatedStringId);
+                return 0;
+            }
+
+            // Apply the new name to the station.
+            station->name = allocatedStringId;
+        }
+
+        StringManager::emptyUserString(oldStringId);
+        station->updateLabel();
+        Gfx::invalidateScreen();
+        return 0;
+    }
+
+    void renameStation(registers& regs)
+    {
+        regs.ebx = renameStation(regs.bl, regs.cx, regs.ax, regs.edx, regs.ebp, regs.edi);
+    }
+}

src/OpenLoco/Localisation/StringIds.h

@@ -249,6 +249,7 @@ namespace OpenLoco::StringIds
     constexpr string_id tooltip_signal_single_direction = 277;
     constexpr string_id tooltip_bridge_stats = 278;
     constexpr string_id tooltip_select_station_type = 279;
+    constexpr string_id station_name_ordinal = 280;
 
     constexpr string_id vehicle_details_weight = 328;
     constexpr string_id vehicle_details_total_power_and_weight = 329;

src/OpenLoco/StationManager.cpp

@@ -1,6 +1,7 @@
 #include "StationManager.h"
 #include "CompanyManager.h"
 #include "Interop/Interop.hpp"
+#include "Localisation/FormatArguments.hpp"
 #include "OpenLoco.h"
 #include "TownManager.h"
 #include "Ui/WindowManager.h"
@@ -120,6 +121,27 @@ namespace OpenLoco::StationManager
         }
     }
 
+    // 0x048F988
+    string_id generateNewStationName(StationId_t stationId, TownId_t townId, Map::Pos3 position, uint8_t mode)
+    {
+        auto* station = get(stationId);
+        if (station == nullptr)
+            return StringIds::null;
+
+        station->name = StringIds::null;
+
+        registers regs;
+        regs.esi = reinterpret_cast<int32_t>(station);
+        regs.ebx = townId;
+        regs.dh = static_cast<uint8_t>(position.z / 4);
+        regs.dl = mode;
+        regs.ax = position.x & 0xFFE0;
+        regs.cx = position.y & 0xFFE0;
+
+        call(0x048F988, regs);
+        return regs.bx;
+    }
+
     // 0x0049088B
     void zeroUnused()
     {

src/OpenLoco/StationManager.h

@@ -15,5 +15,6 @@ namespace OpenLoco::StationManager
     void update();
     void updateLabels();
     void updateDaily();
+    string_id generateNewStationName(StationId_t stationId, TownId_t townId, Map::Pos3 position, uint8_t mode);
     void zeroUnused();
 }

src/OpenLoco/Windows/StationWindow.cpp

@@ -846,9 +846,6 @@ namespace OpenLoco::Ui::Windows::Station
             if (callingWidget != Common::widx::caption)
                 return;
 
-            if (strlen(input) == 0)
-                return;
-
             GameCommands::setErrorTitle(StringIds::error_cant_rename_station);
 
             uint32_t* buffer = (uint32_t*)input;

src/OpenLoco/openloco.vcxproj

@@ -38,6 +38,7 @@
     <ClCompile Include="GameCommands\GameCommands.cpp" />
     <ClCompile Include="GameCommands\LoadSaveQuit.cpp" />
     <ClCompile Include="GameCommands\RenameIndustry.cpp" />
+    <ClCompile Include="GameCommands\RenameStation.cpp" />
     <ClCompile Include="GameCommands\RenameTown.cpp" />
     <ClCompile Include="GameCommands\TogglePause.cpp" />
     <ClCompile Include="GameCommands\VehiclePickup.cpp" />