unreal-engine-cpp

C++ Code Conventions - Unreal Engine 5.7

Naming (CRITICAL)

• Classes: PascalCase with appropriate prefix:
  • A for Actors (ex: AMyProject2Character, APlayerController)
  • U for UObjects (ex: UMyGameInstance, UMyComponent)
  • F for Structs (ex: FPlayerStats, FWeaponData)
  • E for Enums (ex: EPlayerState, EWeaponType)
  • I for Interfaces (ex: IInteractable, IDamageable)
  • T for Templates (ex: TArray, TMap, TSet)
• Functions: PascalCase (ex: BeginPlay(), Tick(), OnHit())
• Variables: PascalCase with prefixes:
  • Booleans: b (ex: bIsRunning, bIsActive, bHasWeapon)
  • Floats: no prefix (ex: Health, MaxHealth, Speed)
  • Integers: no prefix (ex: AmmoCount, Level)
  • Enums: E (ex: EPlayerState CurrentState)
  • Interfaces: I (ex: IInteractable* InteractableObject)
• Constants: const with PascalCase (ex: const float MaxSpeed = 1000.0f;)

Macros and Annotations (ESSENTIAL)

• ALWAYS use Unreal macros for classes:
  • UCLASS() for classes that inherit from UObject
  • USTRUCT() for structs
  • UENUM() for enums
  • UINTERFACE() for interfaces
• UPROPERTY() - Use for:
  • UPROPERTY(BlueprintReadWrite) - Read/write in Blueprint
  • UPROPERTY(BlueprintReadOnly) - Read-only in Blueprint
  • UPROPERTY(VisibleAnywhere) - Visible in editor, not editable
  • UPROPERTY(EditAnywhere) - Editable in editor
  • UPROPERTY(EditDefaultsOnly) - Editable only in defaults
  • UPROPERTY(EditInstanceOnly) - Editable only in instances
  • UPROPERTY(Replicated) - Network replication
• UFUNCTION() - Use for:
  • UFUNCTION(BlueprintCallable) - Callable from Blueprint
  • UFUNCTION(BlueprintImplementableEvent) - Implemented in Blueprint
  • UFUNCTION(BlueprintNativeEvent) - Default implementation in C++, can be overridden in Blueprint
  • UFUNCTION(Server, Reliable) - Server RPC
  • UFUNCTION(Client, Reliable) - Client RPC

Headers and Includes

• ALWAYS use #include "CoreMinimal.h" at the top of .cpp files
• Use #pragma once in all headers (don't use include guards)
• Use forward declarations in headers when possible:

  // In header (.h)
  class APlayerController;
  class UWidget;
  
  // In cpp
  #include "PlayerController.h"
  #include "Components/Widget.h"
  

• Organize includes in this order:
  1. Corresponding header (ex: #include "MyClass.h")
  2. Engine headers (ex: #include "Engine/Engine.h")
  3. Project headers
  4. Plugin headers
  5. STL (avoid when possible)