Cpp on Treadwell

Steam Leaderboard Grouping

Sat, 06 Sep 2025 00:00:00 +0000

So in Backseat Drivers we wanted to group players together (since the game is coop) on the leaderboard. Well this isn’t something that’s supported out of the box by Valve so I had to do some hacky stuff.

How?

So in the Steam API UploadLeaderboardScore it accepts a pScoreDetails (const int32*). Do you see where I’m going with this yet?

I take each player’s SteamID, split it into two int32 values (low/high), and store them in sequence: [0] = P1.low, [1] = P1.high, [2] = P2.low, [3] = P2.high

Some Simple Optimizations in Unreal Engine

Wed, 12 May 2021 00:00:00 +0000

When it boils down to it you should profile things before optimizing however, these things can be added without the need to profile.

TArray.Reserve(size)
- This will reserve memory for the array in advance. Do this before modifying an array to prevent allocations in a loop etc. When adding elements to a container in a loop, performances can be impacted because of multiple heap allocations to resize the container.
- Also, do this on temporary allocations. (if you allocate an array in a method and then return that array later or need to do something specific to the results)

 
 
 
// Adds N copies of a character to the end of an array.
void AppendCharacterCopies(char CharToCopy, int32 N, TArray<char>& Result)
{
 if (N > 0)
 {
 Result.Reserve(Result.Num() + N);
 for (int32 Index=0; Index < N; Index++)
 {
 Result.Add(CharToCopy);
 }
 }
}

void AppendCharacterCopies(char CharToCopy, int32 N)
{
 if (N > 0)
 {
 TArray<char> Result;
 Result.Reserve(N);
 for (int32 Index = 0; Index < N; Index++)
 {
 Result.Add(CharToCopy);
 }

 // do something with Result
 }
}

TArray.Emplace(type)

Steam Party and UE4

Sun, 25 Apr 2021 00:00:00 +0000

In my Discord someone was asking about Steam parties so I thought that it was a good topic to write a guide on so here we are. Quite frankly this is something that someone should’ve made a guide on a long time ago.

Prerequisites

Steam plugin (SteamBridge, UWorks, SteamCore, etc)
Some C++ or BP knowledge
A brain and patience 😀

In this guide, I’m using my SteamBridge plugin, but you’re more than welcome to use any other Steam plugin that you already have. (The Steam API is the same across the board, but each plugin may implement it differently.)

How to Fix VAX Suggestions

Mon, 11 Jan 2021 00:00:00 +0000

So your suggestions from VAX aren’t updated or are wrong? Look no further!

Navigate to Extensions -> VAssistX -> Visual Assist Options

Then go to Performance and click Rebuild and Clear. (then reset your Visual Studio)

until next time

UE4 and Steam Rich Presence

Tue, 01 Dec 2020 00:00:00 +0000

NOTE: If you’re wanting a Steam wrapper for UE4 then check out SteamBridge. If you use SteamBridge it already has the code below so you won’t need to do any code portion of this guide.

So you’re wanting some cool Rich Presence for your game right?

Cool so here’s a quick guide on doing this in C++ in UE4. (don’t worry, the methods are exposed to BP)

Go to your projects Build.cs and add Steamworks. PrivateDependencyModuleNames.AddRange(new string[] { "Steamworks" });
Regenerate your project and open your solution. Add the following code to whatever class you want. I chose to do this in the GameInstance as it exists for the lifetime of the game.

 
 
 
UFUNCTION(BlueprintCallable, Category = "GameInstance")
void SetSteamRichPresence(const FString& Key, const FString& Value);

UFUNCTION(BlueprintCallable, Category = "GameInstance")
void ClearSteamRichPresence();

// At the time of writing this sdk version 150 is released, but UE4 only has 147. This doesn't matter, but just a note.
#include "ThirdParty/Steamworks/Steamv147/sdk/public/steam/steam_api.h"

void UCGameInstance::SetSteamRichPresence(const FString& Key, const FString& Value)
{
 SteamFriends()->SetRichPresence(TCHAR_TO_UTF8(*Key), TCHAR_TO_UTF8(*Value));
}
void UCGameInstance::ClearSteamRichPresence()
{
 SteamFriends()->ClearRichPresence();
}

Before you can go off and do what I did above you should know that you have to make a json file with the strings that can be set. Yeah, the messages have to be uploaded to Steam. 🙁

Using Other Types in UE4 BP

Tue, 24 Nov 2020 00:00:00 +0000

While building out SteamBridge I needed a way to access SteamID in BP which happens to be a uint64 so I’m not able to directly. Here’s the solution I came up with and I must say it’s not the most ideal solution as I mainly needed typedefs, but this works.

 
 
 
USTRUCT(BlueprintType)
struct FUint64
{
 GENERATED_BODY()

 uint64 Value;

 operator uint64() const { return Value; }

 FUint64() : Value(0) {}
 FUint64(uint64 value) : Value(value) {}
};

USTRUCT(BlueprintType)
struct FMyCoolUint64Type : public FUint64 { GENERATED_BODY() using FUint64::FUint64; };

To avoid writing the same FUint64 struct for all of the types that just need to be a uint64 you can just derive your struct from it and add a using FUint64::FUint64; so we use it’s constructors.

UE4 and Vivox

Wed, 18 Nov 2020 00:00:00 +0000

So you want a cross-platform and scalable voice chat? Great, let’s begin.

Prerequisites

A Vivox developer account (you need a v5 account so ask for a v5 account via email)
A Vivox app
A C++ UE4 project (or ability to add C++)
Patience

NOTE: Make sure you check this or like I said above email the support for a v5 account.

BeginPlay()

Cool once you have your app and credentials then proceed to step 1.

Useful Snippets for UE4 using VAX

Mon, 16 Nov 2020 00:00:00 +0000

These require Visual Assist, but you might be able to set this up using the default stuff with Visual Studio.

Extensions -> VAssistX -> Code Generation and Refactoring -> Edit Refactoring Snippets…
Type: By Title then click thebutton.
Add the following options. Repeat the process for each of these.

 
 
 
Title: UFUNCTION Callable Macro
Shortcut: ufcall
UFUNCTION(BlueprintCallable, Category = "$PROJECT_NAME$|$ClassName$")

Title: UFUNCTION Const Callable Macro
Shortcut: ufcon
UFUNCTION(BlueprintCallable, BlueprintPure=false, Category = "$PROJECT_NAME$|$ClassName$")

Title: UFUNCTION Get Macro
Shortcut: ufget
UFUNCTION(BlueprintPure, Category = "$PROJECT_NAME$|$ClassName$")

Title: UPROPERTY BlueprintAssignable Macro
Shortcut: upass
UPROPERTY(BlueprintAssignable, Category = "$PROJECT_NAME$|$ClassName$", meta = (DisplayName = "$SymbolName$"))

Title: UPROPERTY BlueprintReadOnly Macro
Shortcut: upread
UPROPERTY(BlueprintReadOnly, Category = "$PROJECT_NAME$|$ClassName$", meta = (DisplayName = "$SymbolName$"))

Title: UPROPERTY EditAnywhere Macro
Shortcut: upedit
UPROPERTY(BlueprintReadWrite, EditAnywhere, Category = "$PROJECT_NAME$|$ClassName$", meta = (DisplayName = "$SymbolName$"))

Title: UPROPERTY EditDefaultsOnly Macro
Shortcut: updef
UPROPERTY(EditDefaultsOnly, Category = "$PROJECT_NAME$|$ClassName$", meta = (DisplayName = "$SymbolName$"))

Title: UPROPERTY Replicated Macro
Shortcut: uprep
UPROPERTY(Replicated)

Title: UENUM Macro
Shortcut: uenum
UENUM(BlueprintType)
enum class E$SymbolName$ : uint8
{
 None UMETA(DisplayName = "None"),
};

Title: USTRUCT Macro
Shortcut: ustruct
USTRUCT(BlueprintType)
struct F$SymbolName$
{
 GENERATED_BODY()

 F$SymbolName$() {}
}

To use these you just type the shortcut in the editor and it should popup.

Adding Text Chat to UE4 in C++

Tue, 10 Nov 2020 00:00:00 +0000

Note, this is a C++ based example. However, it’s easily converted to BP.

If you want to just check out the code or skip the guide then you can download the project here.

There are a few things wrong with this setup such as no deletion of messages so you’ll keep a copy of them until you exit the game so you’re probably going to want to set up a timer to destroy them after x time.

Feedback via Discord in UE4

Sat, 26 Sep 2020 00:00:00 +0000

You can just download the class here if you’re lazy. mbpfl.h and mbpfl.cpp

Create a BlueprintFunctionLibrary class in C++ and add these includes and defines.

 C++
 
 
#if PLATFORM_WINDOWS
#include "Windows/WindowsPlatformMisc.h"
#elif PLATFORM_LINUX
#include "Linux/LinuxPlatformMisc.h"
#elif PLATFORM_MAC
#include "Mac/MacPlatformMisc.h"
#endif

#include "GameFramework/GameUserSettings.h"

#define BUG_REPORT_WEBHOOK_URL "YOURWEBHOOKURLHERE"
#define MYGAME_VERSION "v1.0-pre-alpha"
#define DEFAULT_ICON_URL "https://www.google.com/images/branding/googlelogo/1x/googlelogo_color_272x92dp.png"

Add the following enums and structs to the header.

 C++
 
 
UENUM(BlueprintType)
enum class EBugReportCategory : uint8
{
 Map,
 Weapon,
 Other
};

UENUM(BlueprintType)
enum class EBugReportPriority : uint8
{
 Crash,
 High,
 Med,
 Low
};

USTRUCT()
struct FDiscordMessageField
{
 GENERATED_BODY()

 UPROPERTY()
 FString name;
 UPROPERTY()
 FString value;
 UPROPERTY()
 bool binline;
};

USTRUCT()
struct FDiscordMessageEmbedAuthor
{
 GENERATED_BODY()

 UPROPERTY()
 FString name;
 UPROPERTY()
 FString url;
 UPROPERTY()
 FString icon_url;

 FDiscordMessageEmbedAuthor() : url("https://trdwll.com"), icon_url(DEFAULT_ICON_URL) {}
};

USTRUCT()
struct FDiscordMessageEmbedFooter
{
 GENERATED_BODY()

 UPROPERTY()
 FString text;
 UPROPERTY()
 FString icon_url;

 FDiscordMessageEmbedFooter() : icon_url(DEFAULT_ICON_URL) {}
};

USTRUCT()
struct FDiscordMessageEmbed
{
 GENERATED_BODY()

 UPROPERTY()
 FString title;
 UPROPERTY()
 FString description;
 UPROPERTY()
 uint32 color;
 UPROPERTY()
 TArray<FDiscordMessageField> fields;
 UPROPERTY()
 FDiscordMessageEmbedAuthor author;
 UPROPERTY()
 FDiscordMessageEmbedFooter footer;
 UPROPERTY()
 FString timestamp;

 FDiscordMessageEmbed() : color(720640), timestamp(FDateTime::Now().ToIso8601()) {}

 uint32 GetColor(const EBugReportPriority Priority)
 {
 switch (Priority)
 {
 case EBugReportPriority::Crash: return 16711680;
 case EBugReportPriority::High: return 12389388;
 case EBugReportPriority::Med: return 16742912;
 default:
 case EBugReportPriority::Low: return 720640;
 }
 }
};

USTRUCT()
struct FDiscordMessage
{
 GENERATED_BODY()

 UPROPERTY()
 FString username;
 UPROPERTY()
 FString avatar_url;
 UPROPERTY()
 FString content;
 UPROPERTY()
 TArray<FDiscordMessageEmbed> embeds;

 FDiscordMessage() : avatar_url(DEFAULT_ICON_URL) {}
};

USTRUCT(BlueprintType)
struct FBugReportUserData
{
 GENERATED_BODY()

 UPROPERTY(BlueprintReadWrite)
 FString Author;
 UPROPERTY(BlueprintReadWrite)
 FVector Location;
 UPROPERTY(BlueprintReadWrite)
 FString MapName;
 UPROPERTY(BlueprintReadWrite)
 FString Message;
};

Add the following to your header file.

 C++
 
 
 // Thanks to Rama for this method
 // GetEnumValueAsString<EEnumType>("EEnumType", Value);
 template<typename TEnum>
 static FString GetEnumValueAsString(const FString& Name, TEnum Value)
 {
 const UEnum* enumPtr = FindObject<UEnum>(ANY_PACKAGE, *Name, true);
 if (!enumPtr)
 {
 return FString("Invalid");
 }
 return enumPtr->GetNameByValue((int64)Value).ToString();
 }

 UFUNCTION(BlueprintCallable, Category = "Discord")
 static void SubmitBugReport(const EBugReportCategory Category, const EBugReportPriority Priority, const FBugReportUserData& AuthorData, FString& ReportID, bool bIncludeSpecs = true);

 /**
 * Gets the number of RAM on the system
 */
 UFUNCTION(BlueprintPure)
 static FORCEINLINE int32 GetTotalRAM()
 {
 const FPlatformMemoryConstants& MemoryConstants = FPlatformMemory::GetConstants();
 return MemoryConstants.TotalPhysicalGB;
 }

 UFUNCTION(BlueprintPure)
 static FString GetGameResolution() { return *FString::Printf(TEXT("%dx%d"), UGameUserSettings::GetGameUserSettings()->GetScreenResolution().X, UGameUserSettings::GetGameUserSettings()->GetScreenResolution().Y); }

 /**
 * Gets the CPU Brand Name information.
 */
 UFUNCTION(BlueprintPure)
 static FString GetCPUBrandName()
 {
#if PLATFORM_WINDOWS
 return FWindowsPlatformMisc::GetCPUBrand();
#elif PLATFORM_LINUX
 return FLinuxPlatformMisc::GetCPUBrand();
#elif PLATFORM_MAC
 return FMacPlatformMisc::GetCPUBrand();
#endif
 }

 /**
 * Gets the CPU Vendor Name information.
 */
 UFUNCTION(BlueprintPure)
 static FString GetCPUVendorName()
 {
#if PLATFORM_WINDOWS
 return FWindowsPlatformMisc::GetCPUVendor();
#elif PLATFORM_LINUX
 return FLinuxPlatformMisc::GetCPUVendor();
#elif PLATFORM_MAC
 return FMacPlatformMisc::GetCPUVendor();
#endif
 }

 /**
 * Gets the GPU Brand Name information.
 */
 UFUNCTION(BlueprintPure)
 static FString GetGPUBrandName()
 {
#if PLATFORM_WINDOWS
 return FWindowsPlatformMisc::GetPrimaryGPUBrand();
#elif PLATFORM_LINUX
 return FLinuxPlatformMisc::GetPrimaryGPUBrand();
#elif PLATFORM_MAC
 return FMacPlatformMisc::GetPrimaryGPUBrand();
#endif
 }

 /**
 * Gets the GPU Driver information.
 */
 UFUNCTION(BlueprintPure)
 static FORCEINLINE FString GetGPUDriverInfo() { return GRHIAdapterUserDriverVersion; }

Why I use Hungarian Notation with C++

Wed, 15 Jul 2020 00:00:00 +0000

So Hungarian Notation is an old(er) formatting for code. I don’t fully use it, but I mainly use m_ for members so I know if they’re a member of said class and s_ so I know the member is static.

A lot of people disagree with this formatting, but I use it just for cleanliness. Honestly, I don’t really have another reason for this, it’s just what I like. I like being able to read code and know where a member is from.

Using const in C++

Thu, 02 Apr 2020 00:00:00 +0000

So what is const? Const means constant… Why should you use const? You should use const when you don’t need to edit the value etc.

I’m by no means an expert, but if I made a typo feel free to reach out.

 C++
 
 
class Example
{
public:

 Example() {}

 // const on the end means you "promise" that the method won't edit any values in the class Example (can get around this by marking a variable mutable)
 int GetA() const { return m_A; }

 // If you're going to return a pointer you can add const before and after the * just like below (ugly)
 const int* const GetB() const { return m_B; }

private:
 int m_A;
 int* m_B;
};

int main()
{
 // const before a * means you can't modify the contents of the pointer
 // const after a * means you can't modify the pointer
 // const before and after adds both above

 int VALUE = 1337;

 int* a = new int(1);
 const int* b = new int(50);
 int* const c = new int(100);
 const int* const d = new int(8000);

 // You can also do int const* instead of const int* which means the same thing as they're before the *

 std::cout << "A: " << *a << std::endl;
 std::cout << "B: " << *b << std::endl;
 std::cout << "C: " << *c << std::endl;
 std::cout << "D: " << *d << std::endl;

 *a = 2; // We can set the value
 // *b = 10; // We can't set the value of b since const is before the *
 b = &VALUE; // We can set the pointer
 *c = 25; // We can set the value
 // c = &a; // We can't set the pointer to something else

 // We can't do anything to d as we specify const before and after the * (there are ways around stuff like this though)
 // *d = 80;
 // d = &CONST_VALUE;

 std::cout << "A: " << *a << std::endl;
 std::cout << "B: " << *b << std::endl;
 std::cout << "C: " << *c << std::endl;
 std::cout << "D: " << *d << std::endl;

 std::cin.get();
}