【UnLua】在 Lua 中定义 UE 反射类型

用法

• 启动编辑器时遍历 Defines 目录下 lua 脚本来加载 UE 反射类型（开个临时的 Lua VM 即可）
• 直接像

-- define a uenum in lua
UEnum.EEnumGuestSomethingElse {
    Value1 = 1;
    Value2 = 2;
}

-- use it like a native uenum
UnLua.Log(UE.EEnumGuestSomethingElse.Value2)

====== UEnum ======

C++

UENUM(BlueprintType)
enum class ETest : uint8
{
   Walking,
   Running,
   Sprinting,
   ALS_MAX UMETA(DisplayName="ALS MAX")
};

Test.generated.h

#include "UObject/ObjectMacros.h"
#include "UObject/ScriptMacros.h"

#define FOREACH_ENUM_ETEST(op) \
   op(ETest::Walking) \
   op(ETest::Running) \
   op(ETest::Sprinting) \
   op(ETest::ALS_MAX)


enum class ETest : uint8;
template<> struct TIsUEnumClass<ETest> { enum { Value = true }; };
template<> LYRAGAME_API UEnum* StaticEnum<ETest>();

Test.gen.cpp

• 生成代码入口 FNativeClassHeaderGenerator::ExportGeneratedEnumInitCode
• 构造 UEnum 入口 UECodeGen_Private::ConstructUEnum
• 构造时机：static 注册，所以 C++ 启动时

void EmptyLinkFunctionForGeneratedCodeTest() {}
// Cross Module References
    LYRAGAME_API UEnum* Z_Construct_UEnum_LyraGame_ETest();
    UPackage* Z_Construct_UPackage__Script_LyraGame();
// End Cross Module References
    static FEnumRegistrationInfo Z_Registration_Info_UEnum_ETest;
    static UEnum* ETest_StaticEnum()
    {
        if (!Z_Registration_Info_UEnum_ETest.OuterSingleton)
        {
            Z_Registration_Info_UEnum_ETest.OuterSingleton = GetStaticEnum(Z_Construct_UEnum_LyraGame_ETest, Z_Construct_UPackage__Script_LyraGame(), TEXT("ETest"));
        }
        return Z_Registration_Info_UEnum_ETest.OuterSingleton;
    }
    template<> LYRAGAME_API UEnum* StaticEnum<ETest>()
    {
        return ETest_StaticEnum();
    }
    struct Z_Construct_UEnum_LyraGame_ETest_Statics
    {
        static const UECodeGen_Private::FEnumeratorParam Enumerators[];
#if WITH_METADATA
        static const UECodeGen_Private::FMetaDataPairParam Enum_MetaDataParams[];
#endif
        static const UECodeGen_Private::FEnumParams EnumParams;
    };
    const UECodeGen_Private::FEnumeratorParam Z_Construct_UEnum_LyraGame_ETest_Statics::Enumerators[] = {
        { "ETest::Walking", (int64)ETest::Walking },
        { "ETest::Running", (int64)ETest::Running },
        { "ETest::Sprinting", (int64)ETest::Sprinting },
        { "ETest::ALS_MAX", (int64)ETest::ALS_MAX },
    };
#if WITH_METADATA
    const UECodeGen_Private::FMetaDataPairParam Z_Construct_UEnum_LyraGame_ETest_Statics::Enum_MetaDataParams[] = {
        { "ALS_MAX.DisplayName", "ALS MAX" },
        { "ALS_MAX.Name", "ETest::ALS_MAX" },
        { "BlueprintType", "true" },
        { "ModuleRelativePath", "Common/Defines/Test.h" },
        { "Running.Name", "ETest::Running" },
        { "Sprinting.Name", "ETest::Sprinting" },
        { "Walking.Name", "ETest::Walking" },
    };
#endif
    const UECodeGen_Private::FEnumParams Z_Construct_UEnum_LyraGame_ETest_Statics::EnumParams = {
        (UObject*(*)())Z_Construct_UPackage__Script_LyraGame,
        nullptr,
        "ETest",
        "ETest",
        Z_Construct_UEnum_LyraGame_ETest_Statics::Enumerators,
        UE_ARRAY_COUNT(Z_Construct_UEnum_LyraGame_ETest_Statics::Enumerators),
        RF_Public|RF_Transient|RF_MarkAsNative,
        EEnumFlags::None,
        (uint8)UEnum::ECppForm::EnumClass,
        METADATA_PARAMS(Z_Construct_UEnum_LyraGame_ETest_Statics::Enum_MetaDataParams, UE_ARRAY_COUNT(Z_Construct_UEnum_LyraGame_ETest_Statics::Enum_MetaDataParams))
    };
    UEnum* Z_Construct_UEnum_LyraGame_ETest()
    {
        if (!Z_Registration_Info_UEnum_ETest.InnerSingleton)
        {
            UECodeGen_Private::ConstructUEnum(Z_Registration_Info_UEnum_ETest.InnerSingleton, Z_Construct_UEnum_LyraGame_ETest_Statics::EnumParams);
        }
        return Z_Registration_Info_UEnum_ETest.InnerSingleton;
    }
    struct Z_CompiledInDeferFile_FID_Lyra_Source_LyraGame_Common_Defines_Test_h_Statics
    {
        static const FEnumRegisterCompiledInInfo EnumInfo[];
    };
    const FEnumRegisterCompiledInInfo Z_CompiledInDeferFile_FID_Lyra_Source_LyraGame_Common_Defines_Test_h_Statics::EnumInfo[] = {
        { ETest_StaticEnum, TEXT("ETest"), &Z_Registration_Info_UEnum_ETest, CONSTRUCT_RELOAD_VERSION_INFO(FEnumReloadVersionInfo, 2142314138U) },
    };
    static FRegisterCompiledInInfo Z_CompiledInDeferFile_FID_Lyra_Source_LyraGame_Common_Defines_Test_h_3878057739(TEXT("/Script/LyraGame"),
        nullptr, 0,
        nullptr, 0,
        Z_CompiledInDeferFile_FID_Lyra_Source_LyraGame_Common_Defines_Test_h_Statics::EnumInfo, UE_ARRAY_COUNT(Z_CompiledInDeferFile_FID_Lyra_Source_LyraGame_Common_Defines_Test_h_Statics::EnumInfo));

Python

• 创建入口 FPythonGeneratedEnumBuilder::RegisterDescriptors
• 创建时机 uenum -> GenerateEnum

@unreal.uenum()
class PyTestColor(unreal.EnumBase):
    RED = unreal.uvalue(1, meta={"DisplayName": "Red (255, 0, 0)"})
    GREEN = unreal.uvalue(2)
    BLUE = unreal.uvalue(3)

====== UStruct ======

====== UClass ======