3 months in 3 days (game engine dev)

3 months in 3 days (game engine dev)

the intro

Some weeks ago I found myself having a migraine. On that same day, I found out that migraine medicine is composed of basically two things. First, your average pain relief medicine. Second, *caffeine*. So, is that the secret? Is that the deal? That’s how you deal with migraines! Pain Relief Medicine with a side of coffee. I will keep that in mind.

Anyway, turns out that having a side of coffee at 9PM will keep you awake for some time. So I decided to, on a Friday night, do what every normal person does on a Friday night, write some game engine code.

Here are a few tasks that were cooking in my head.

I wanted to remove a bunch of things of my game library. The concept of layers, a debug memory tracker, precompiled headers, and dear imgui.

Having DearImGui on your C++ graphical project is pretty much a must in our Holy Year of Twenty Twenty Three. But it goes against my design philosophy that gueepo2D should only contain the bare bones to make a game. It can always be added into the game, or in a separate project alongside the game using the SDL2 and glad as dependencies, as those two are already included in the library.

DearImGui is very useful when creating tools, but I believe that tools should exist alongside games, not engines (Take that Unity Users!).

Oh well.

game jams, wintermute, and ECS

wntrmt by gueepo

On February 26th, 2023 the world has changed. I participated in a game jam and the experience and the result were so terrible that it made me reconsider my game library, the tactics game engine that I wanted to make with it, and the games I wanted to make.

A big win I had during this game jam was adding an entire API to my json file wrapper that was able to handle arrays, this was a big step towards being able to make games that are more data-oriented. But making a game on this piece of tech was a nightmare!

Human issues aside, there were a bunch of problems in the game engine that made it harder for me to able to do something with it. The first one is that gueepo2D is, by design, a bare-bones game library. It provides you with an application interface, it is capable of handling input and drawing textured squares to the screen, sure, but making a game requires a lot more abstraction, it requires a lot more tools.

In a sense, gueepo2D is something you use to make game engines, it is not something that you use to make games, although it can be used to make games.

The biggest thing that it lacks is some sort of Entity Component System. I have probably written a dozen times that “I don’t *need* an entity-component-system”, and it’s true, when making an engine that is tailored for tactics games I am confident I can come up with my own data structures that will work better for what I want to make, but what happens when I’m not really certain of what I want to make, and I need to make it fast?

Because that’s what a game jam is!

When you want more general-purpose functionality, ECS is a pretty good solution to go to, and not having it on the engine hurt my productivity and ability to partake in a game jam.

So here’s the question: If I need ECS to make simple games quicker, but ECS is against gueepo2D’s very own core philosophy, what is the answer? What is the solution? What should I do?

the goblin game engine

the goblin game engine

The Goblin Game Engine is the answer!

If “gueepo2D” is a piece of technology that you should use to build game engines, then why not build a general-purpose game engine on top of it? The Goblin Game Engine is born.

But what does this game engine have that gueepo2D doesn’t?

  1. A Resource Manager – A central way to store references to all types of resources that you would need in the game, and they all can be retrieved with a function call that asks for an ID. Not only that, the Resource Manager is data-oriented, so all the resources can be loaded from a json file, so no need to create pointers to create dozens of textures in the game.
  2. ECS and a Game World. You create entities, and the entities have components, all this is added to the Game World, a centralized place where you can see and consult all entities. The GameWorld, the entities, and the components will also take care of updating and rendering. And, of course, entities can be loaded from a file so you don’t have to spend hundreds of lines of code creating components.
  3. LUA scripting. Finally. Typing C++ is too much work, we need an easier way to add functionality to our entities without typing *too* much and without having to recompile the game, LUA is the perfect solution for that.
  4. Finally, an editor. If we can load configurations, resources, and entities from files, how do we create those files? Creating them by hand would be less work than creating it on code already, but the ideal workflow is to have an editor capable of creating, editing, and saving those files. Hence, The Goblin Editor! (currently under development)

Obviously, the final goal is to be able to create an entire game without having to touch C++ – That is a very ambitious goal, and I’m not even sure if I want to achieve that. Having Lua as auxiliary scripting is one thing, having it do the heavy lift on systems work is a whole other thing. But who knows! There’s a long road ahead for the game engine, and soon I plan on putting it to the test by making a small game and maybe partaking in another game jam.

But that is not all.

I forgot to mention that The Goblin Game Engine has a twin brother.

the machinist game engine

joder, esto si es motor de videojuegos

I talk a lot about making a “game engine really good at making the types of games that I want to make (tactics games)”, and I finally kicked that off. Well, this actually has existed for a while under the temporary name of gpg-1. But the goblin game engine and the whole experience with the game jam made me have a breakthrough and realize how this game engine should be done, and what it should look like.

So as I started making the goblin game engine, I also started “sketching” the machinist game engine.

This engine is called “machinist” because I desperately wanted a name that was related to Final Fantasy Tactics, and after looking at all characters’ names and jobs, I stumbled upon Mustadio’s special job, a Machinist. And I think it is a suitable name for the engine.

There’s a lot of work to be done on machinist.

Just like the goblin game engine, its focus is to be data-oriented, but this game engine can make way more assumptions about the final product than goblin.

And just like goblin, machinist will also have an editor tailored for creating the adventure maps of RPGs, and creating battle maps for tactical turn-based battles.

Whatever come out of this is still months away.

emscripten builds

Lastly, the final game engine adventure that happened on the last week or two after months of not doing game engine work was the one of adding the ability to export the games made with gueepo2D to the web.

This is very important for me because unless you are on Steam you don’t really want to download a game and click on a .exe file. Specially if we are talking about gamejams. Let’s be real, you are going to play a game jam game for 5 minutes at most, so being able to run all this on the web is very important.

Running emscripten through the engine took some work, but it is surprisingly easy considering the end result. You would imagine compiling a graphical application written in C++ into web assembly would be something extremely difficult. But it actually only took me a day. Well, whoever is behind emscripten is probably doing tons of work, and I appreciate that.

Changes to the engine include:

  1. Initializing OpenGL ES 3.0 instead of the default OpenGL Core 3.3 when building through emscripten
  2. Compiling an entirely different fragment shader and changing the OpenGL version on the header of the vertex shader
  3. Setting everything up on CMake so it can generate the proper makefiles to build the code where it outputs a playable version on HTML5
  4. An annoying thing that took me a while longer to notice and fix was that on OpenGL ES GL_RED is not a valid internal format, instead I have to use GL_R8, but when changing that my fonts worked just fine on the web, hooray!

So with all that, I’m looking to put my next little game on the web and not having people need to download it!

You can check the Goblin Game Engine HTML Demo Here:

goblin game engine by gueepo

why no one ever told me boy genius was a thing?

banger movie

the year of the gamer

I’ve decided to dust out this blog and start using it again.

The long story is that I’m always in an eternal state of either blogging or thinking “I should blog” – and every time that I think about it I ask myself: “But should I use WordPress? Medium? My own Website? or Cohost?”

The reason I like WordPress and why I am here is that this WordPress blog already has some stories. I used to write monthly here since January 24th, 2017. Wow! That’s a long time ago!

This website saw me going from my first weird game idea called “Zelda Souls”, trying pixel art, game music composition, making a weird tic-tac-toe-like thing prototype, making a weird puzzle-platformer prototype called simply “ghost game”, prototyping a bunch of other weird things, migrating from Unity to GameMaker, making my first few game jams, releasing two mobile games, migrating from GameMaker to Unity, making more weird prototypes, going to GDC for the first (and only!) time, moving to the United States, starting Peanut Butter Engine, realiti2D, visions2D, and killing all of them!

And it all pretty much ended when I got a job in the games industry, that’s it, right? That’s what it was all for! Grinding until I get a job and can sustain myself by working on video games!

Anyway, the TL;DR is that there was a lot of chaotic weirdness and experimentation going on here, and I want to add more to that pile! When I look back at all those things I think: “Wow! I used to do things!” – I remember when I used to be excited about doing things and experimenting with game development, good times! Now I am just an old guy burned out who wants to spend all of his free time writing and playing the piano. And watching movies. Watching movies is great!

Yesterday I rewatched this movie called “RRR”, right. It stands for “Rise, Roar, Revolt” and it’s an Indian movie made in Telugu language, right.

This is one of those movies that make you go: “Joder, Esto es cine!” while holding your cigarette.

The short is that it is a movie about two Indian revolutionaries – And what they supposedly did in times when there isn’t a lot of historical information about them.

It’s just a great movie and – Wait a minute. This is *not* what this is all about.

Oh boy, I wanted this to be a short post but turns out it’s going to be a long post.

The gist is that I want to use this WordPress blog again for time-based stuff that might not be relevant in a month or two, I used to do that on my website gueepo.me – but the reason I don’t want to do it there anymore is that when I post a link to the website on Twitter or on CoHost it looks weird. Yep. That’s the whole reason. Looks weird when linking to the post. So I’m here.

but what is this about, mate?

2023 RESOLUTIONS, what else would *this* be about?

When I first landed Home I had two things with me. A CyberPunk 2020 RPG book, and the thought that this book would be the key to an amazing year of game development.

The idea was really simple, yet very ambitious and very hard to execute: Create 12 Turn-Based Tactical RPGs based on the Cyberpunk universe using my game engine temporarily named GPG-1 that is built on top of my game library, temporarily named gueepo2D.

It can be done. I even flashed out the entire narrative for the first little game (in a single day!), it has 1,000 words and it’s about two Corporates being ambushed in a random alleyway. The flow would be simple, the game would start with some cutscenes, you would be thrown into a turn-based tactical battle and then there would be a cutscene to end it all. I would do that 12 times. The goal at the end was not only to have 12 small games but to have a robust game engine tailored to create games in that style so that I could use it to create an *actual* video game.

It sounds good in theory, but when I think about it, you know what’s better than creating 12 little games and building a game engine at the same time? Not doing that. I felt better by deciding to not do that.

I want to do *LESS* projects over a *BIGGER* period of time, with more *quality*, less *stress*, and more *passion* (the secret ingredient!) – And I want to make YouTube videos about them. I feel like 3 videos is a good amount to strive for.

The Tactics Project

The first project is the logical conclusion of the whole “1 game per month” thing I have designed and given up on – Just make one little game instead of making twelve. And make the engine at the same time.

The goal here is to have an engine capable of creating Tactics games, the goal is not the Tactics game itself. And I will be doing everything on the game, writing, programming, music, and pixel art. Fun Times Ahead!

It will probably still be based on the CyberPunk 2020 RPG and universe because I like it. I want to write stories about real life, I mean, ha, ha-ha. I want to write stories about dystopic capitalistic societies.

look at that dumb kid playing Nh3 lmao

The Chess Project

The other project that I want to tackle is making an AI for chess. That would mean making a simple chess implementation (obviously using my own game library temporarily named gueepo2D), making a headless version of the game, and then working on writing an AI for it.

Do I know how to play chess? No.

Do I know how to write a chess AI? Nah.

Do I know how to write AIs? Well, I’ve done that a few times in the past. You see, when I was more optimistic about computer science (and life) I used to be very passionate about AI and even worked on some AI-related research projects for 3 years or so on my bachelor’s degree. That’s almost the entire degree!

Is this project just an excuse for me to spend a huge amount of time learning how to play chess, get decent at it, and experiment with AI algorithms which were something that I was really passionate about when I had perspectives in life? Yes!

That’s *two* programming projects in a year! That’s enough already. That’s *more* than enough already.

Something that I want to explore and make a video about is DevOps, Automated Builds, etc., etc. – Especially in the context of game development, I feel like this is a weird thing to be *passionate* about, but I enjoy it and I think there’s a severe lack of knowledge about these things on game development, and it’s so important for running smooth processes. We will see!

me after watching Bullet Train for the third time

now what?

Now I hope I don’t give these projects up, which is a real possibility since I’m not really scheduling a consistent day or time to work on them. If you’ve read a few productivity books, first of all, read some actual books, and second of all, you know that’s the first mistake! But I am a burned-out dude after all, and I’m trying to figure out how to *enjoy* something that I have been doing *almost daily* for about ten years now (programming, I’ve been programming *almost daily* for about ten years now *sighs*)

But then we come to the bread-and-butter of my existence, my game library, gueepo2D!


My goal for gueepo2D in the holy year of twenty twenty-two was very simple and ambitious: Don’t deprecate it and start working on another engine, and I achieved it! Success!

The goal for this year is to Don’t deprecate it and start working on another engine. And change its name. I *hate* the name “gueepo2D” – It’s not even a “game engine” anymore! It’s a “game library” now! (What even is the difference?!) – That’s also something that happened in 2022.

But I’m here to talk about renderer backends.

Windows has DirectX, MacOS has Metal, and they both, together with Linux, have OpenGL and Vulkan – That’s a lot of different ways to create windows, something that is abstracted with SDL2, which is a good thing. But that means that individual graphics implementations are still in my hand. And I’m fine with that, I don’t *hate* doing graphics programming until suddenly I do start *hating* graphics programming.

It’s too much work, there are a lot of things going on, and it is very difficult to do graphics programming correctly and efficiently while also doing a whole engine around the graphics, even if the graphics are simple 2D pixel art graphics. So it comes a time when I just have to decide if I want to really have the graphics APIs on my hands or if I should use something like SDL2 Renderer, BGFX, or Sokol.

And that was a big struggle I had in my mind until today I realized that… Why not both? I mean, the engine already abstracts the renderer in a way that it doesn’t know and it doesn’t care whether it’s OpenGL, DirectX, Metal, or Vulkan. I did that pretty much on purpose, thank you.

So I can just use that abstraction layer to use SDL2 Renderer, BGFX, and/or Sokol – That’s probably not the most efficient thing, and it will be a bit of a headache to write a Sprite Batcher that works on all of these (I’m assuming!) – But ultimately, that’s better.

But I just listed three options, which one am I going to do? SDL2 Renderer is the easiest, BGFX is probably the most robust, Sokol is probably the one with the least amount of dependencies, so the answer to “which” one am I going to implement is: “I don’t know!”. That was helpful.

I will be experimenting with them all in isolation, doing the hard work of drawing textured squares and then I will think about it.


follow me on twitter because I will be there until the website dies

or follow me on cohost even though I think this website will die because people are going to other weird twitter alternatives, even though cohost is clearly the Better Twitter Alternative

obligatory end-of-the-post music recommendation

make it double!

I will take you on a game engine journey

Remember last post when I said “I’m back mostly because looking back at your progress for the past weeks is just a very good thing to do?! And now I am just going back to the roots of this devlog – I will do whatever I feel like and then I will come here and write about what I’ve done, problems I’ve faced, what I’ve learned and, of course, add some Michael Scott gifs.”? – and then I proceeded to not writing anything for 153 days?

at least one thing on all that was true

I have very important news: remember I was doing a 2D game engine called realiti2D? Yeah, good times, I decided to stop doing realiti2D and start doing another engine, which I decided to call visions2D.

But for what reason someone might decide to stop doing something just to start doing it all over again? You might ask.

Well, there were some things I didn’t really like about realiti2D.

First, I didn’t really like the entrypoint. You have to create a class that extended the “Application” class, and then implement a function pre-defined in the engine, and that would be where your Application would start.

It just feels a bit confusing and unnecessary for me, I changed to a “you do the main function” approach. visions2D will have auxiliary classes to create games and tools, but at the end of the day, you can do whatever you want if you know well the engine architecture.

With that, within visions2D I can create a standalone renderer so I can test things and create tools.

And that was the second big reason, as I learned more about rendering, I noticed that realiti2D’s renderer was pretty bad, and I felt like restarting it would be the better thing to do. But I promised myself that’s the last time I restart an engine, if I face any major issues, which I’m sure I will, I will refactor!

With visions2D I want to not only create a good environment to make games, but to also make tools, and for that I need a well written renderer that can work as a standalone. I also need really good UI code, but that is a future me problem.


How does the current process on visions2D look like? You may ask.

A big thing is that I started with Dear ImGui from the start, and it has been really helpful with debugging and making simple tools!

And recently I have made a simple flappy bird clone on it!

I will do a short youtube video on it so stay tuned.

Random Prototype of the Month

I like working on some occasional prototypes, so recently I picked a course on how to make a simple match-3 game, and you can see the result of it above! There’s not much to it really, it’s a match-3, everyone knows how a match-3 is supposed to work!

My intentions would be to expand it in the future and make something more interesting to it, but for now I just laid down some basic foundations.

That’s the course it was based on, I highly recommend it! I actually recommend all other courses by Wilmer Lin, he’s a very skilled programmer.

What’s next?

I intend to make frequents blog posts! I know I always say that, and it might take 1 week to do another post, or it might take 3 months, but I want to be frequently writing about the process of making this game engine, and also making some occasional game prototypes.

With some time I might think about doing vlogs instead of blog posts like this, but I’m still trying to figure out how to YouTube.

Speaking of how to YouTube.

This is the fourth video I’ve ever made! and It’s about making a roguelike in 72 hours for Ludum Dare 48! Spoiler Alert: It didn’t go too well.

I want to make an YouTube video every 2 weeks. I feel like that’s how much time I need to actually plan what I’m going to do, actually do something for the video, and then record/edit it. If I get the hang of it and it turns out that it’s easy to do that, I might think of doing one video per week, I might do these game engine vlogs, maybe a “monthly coffee time” where I talk about recent game industry news?!

I don’t know, I still have to get the hang of this YouTube thing and figure out to get good lighting, how to get the camera to focus on my face and how to get the microphone to properly capture my voice…

Well, hello there.

Remember on my last post when I said: “First things first, I’m not going to stop with development logs”? – Good times. But fret not, my child. After 216 days I am back! As a smart man once said, I am only alive if I write and if there is a thought, there is a writing. Now, I don’t know who is that “smart man” – These are just sentences that are in my head but I’m pretty sure I’m not the one who came up with them, I must have read that somewhere, anyway.

I’m back mostly because looking back at your progress for the past weeks is just a very good thing to do?! And now I am just going back to the roots of this devlog – I will do whatever I feel like and then I will come here and write about what I’ve done, problems I’ve faced, what I’ve learned and, of course, add some Michael Scott gifs.

Ha. Now. What I’ve been up to recently? Well, the biggest thing I’ve been working on is making a really simple 2D Game Engine using SDL2 and OpenGL called Realiti2D. I wanted to address my weaknesses as a programmer/engineer, which, in my point of view, are: (1) Lack of understanding of low level technologies like: How does a renderer work? How does a collision system works? How does a UI system or a good Input System look like?

And going through the development of an engine, even if simple, is very challenging. A lot of things does not have right or wrong answers, just different approaches, things that perform better in some circumstances and things like that. Which, to be fair, is really close to real life problems engineers are going to solve.

And then, (2) There is a certain process to problem solving which I believe I have a good grasp on, but I believe I could learn some patience, you know, research more options, think about other solutions, understand the impact that this problem has in the project and the impact that my solution will have for future features.

I spent a lot of money on books for that

In this last month I added two new features to Realiti2D: (a) A Collision System; and (b) a Load Level feature from a .json file.

The Collision System

The collision system was an interesting one. It was not the first time doing one, and I opted to do axis-align bounding-boxes (AABB) which is the most simplified way of handling collisions. The biggest questions that arise when doing collisions are: (i) When are all the collisions being checked?; and (ii) How an individual entity handles a collision when it happens?

For the first question, I went with what the book “Game Engine Architecture” by Jason Gregory says, which is to have a Collision World that will, at the end of the application update, check for collisions on all registered Colliders.

How do they work?

And for the second question, I created a callback on the box collider component, like this: std::function<void(BoxCollider*)> CollisionCallback;

And the following macro helps with binding a function to the callback: #define BIND_COLLISION(…) std::bind(VA_ARGS, this, std::placeholders::_1);

And then you have the freedom to create a component that will access the box collider and bind a function to the callback.

m_Collider = Owner->GetComponentOfType<Realiti2D::BoxCollider>();
m_Collider->CollisionCallback = BIND_COLLISION(&PlaneInput::ExecuteThis);

void ExecuteThis(Realiti2D::BoxCollider* Other) {
DEBUG_INFO("Tappy plane collided with {0}", Other->Owner->Name);

I do think this is a weird workflow, but come to think of it, it is very similar to how Unity does things, you inherit the functions from a collider and have to define their behavior on your own components.

A lot of work still has to be done here, Circle Colliders and Raycasts are next on my list.

Load Level feature

This was actually a lot of busy work and reading. The system takes in a .json file, but I’m actually using .r2d as the extension. I’m using rapidjson (https://github.com/Tencent/rapidjson), by Tencent, to process the json files. Here is how one entity looks on the json file:


And then on the application level all you have to do is have a simple function call, such as Realiti2D::LevelLoader::LoadLevel(this, "assets/SampleLevel.r2d"); – The function that loads the level gets the application reference (illustrated by “this”) so it can add entities to the game.

It is still possible to create entities/components in C++ code, as well as get a reference to an entity created by a file and add other components to it. But my intention is the future is to have a scene editor that will generate those json files correctly.

As for the logic, it’s actually simple, it just reads the json using rapidjson, processes the version, global properties, and then iterates over every entity, and on each entity iterates over its components, and this raises an interesting question: “How to efficiently map a component entry in json to the creation of a new class?”

The approach I’m taking currently is:

if (ComponentType == "Transform") { ComponentFactory::AddTransformComponent(e, Component); }

Which is basically mapping a string to a function on a factory class. The big question when doing something like this is: “If I create a new component, what do I have to do for it to be recognized by the Level Loader?” – In my implementation, I have to create a function on the Component Factory and add an if-else case on the Level Loader, which is sort of annoying and error-prone. I might look into better solutions on a later date.

Also, Realiti2D source code can be found at: https://github.com/guilhermepo2/realiti2D

No one expects a random update

In my last update, I briefly mentioned that I would come back here to discuss the future direction of this blog.

I have been writing about my game development journey for more than 3 years now. And my goal started as: “I want to make a game”, but eventually it turned into “I want to work in the games industry” as I graduated from Computer Science, moved to the US and started a Master’s in Game Design.

It was a long journey, it was fun at times and very stressing at others. And going straight to the point, this week was my first week as a Software Engineer at Visual Concepts, the company behind NBA 2K.

This week is being a lot of set up, getting a workstation, dev kit, and what not, but hopefully next week I will be ready to jump into action and contribute to NBA 2K21!

Now What?!

First things first, I’m not going to stop with development logs, I will not stop using my personal time to create game prototypes, try different things, learn new things, etc – I’m too passionate about being creative and programming to ever stop doing that.

But now that I work in the industry, the direction will surely change. A lot of my efforts were into making games and expanding my knowledge in C/C++, because those are required things to land that job.

But what is the new direction, you might ask? And to that I say: I don’t know either! I will surely hold off for a little while, I’m in a temporary place where I don’t really have a good place to work, so at the end of the workday I just want to sit on bed or on a couch, but when I move to a new apartment (around 1 month from now?) I will have an office space where I can work comfortably.

And there are lots of things that I want to do and that I can do, such as:

  • Continue with Peanut Butter Engine and creating games in C/C++;
  • I’m looking into creating a 3D Renderer;
  • And with a 3D Renderer, who knows a simple 3D Engine;
  • I also have thoughts of transforming my raycasting implementation (last post) into an engine itself.

But that’s not all, there are new things I have been wanting to explore for a long time now, such as:

  • Learning and doing something in Godot;
  • Doing something small in GameMaker;
  • Learn Tools Development in Unity;
  • Do small things in Unity just for the sake of it;
  • Do experimental projects in Unity;
  • Learn Tools Development in .NET/C# and use that to create tools for Peanut Butter, or other engines

And there is also other hobbies that I’ve tried in the past and that come back to my mind frequently, these are:

  • Learning to draw to a point where I can create character concepts;
  • Creating music for video games;
  • Start a YouTube channel talking about more intermediate topics on programming – where the idea is not only having tutorials, but also having videos that more similar to a “livestream” and maybe with comedic tones.

I have to say that the idea of having a YouTube channel is growing on me lately, there is too much beginner content there, not a lot of intermediate/advanced, and I have some ideas that I think can teach and be entertaining at the same time.

As you can see, I have plenty of ideas, and possibly I will tackle a lot of them through the times, but which ones I will be doing first and how I will use my time, that is for future me to decide!

Alright, that’s all for this random update!

How the turn tables – May Update

Oh hi it’s me here again with the occasional monthly game development log post! What happened last month? not much, not much. Just kept looking for jobs, working in an Unreal game with people from my Master’s degree and I don’t know where all my free time went.


I haven’t been really active lately on my personal game development studies, I’ve been trying some things and getting geeky in C++.

Peanut Butter PONG

Last blog post I mentioned Peanut Butter Engine, hey, it’s my own engine!

After advancing a little bit with it, adding particle effects and working a little bit more on the structure, I started to make the first game using Peanut Butter Engine! Which is… Peanut Butter PONG! You can see a gif right above.

I still have a long way to go through, here is what’s on my wishlist for Peanut Butter Engine (and PONG)

  • Clickable UI Buttons (which call a function and executes something)
  • Scenes/Levels/Transitions (Working on integrating Lua in the engine for that)
  • Pause Functionality
  • In Game UI (Such as Panels)

And after all those things, I have a little backlog of games I want to do with Peanut Butter Engine

  • Asteroids
  • Space Invaders
  • Pac Man
  • A Platformer

And after doing all these, my engine will probably have a good architecture, after that I want to worry about exporting games to windows, and the dream would be building games for web.

Raycaster in C

I also worked in this Raycaster in C, I won’t extending myself too much talking about it, just appreciate the end product on this tweet right above!

As you might know, all of those things are open source on my GitHub!




I will cut my update short this month, and I want to make another post here in a week or two and possibly discuss the future of this devlog!

I swear I’m still here – April Update

Life has been crazy recently, I graduated a few weeks ago, released a game, had to move to a temporary place, job hunting has been crazy and the “omg I need a job” anxiety is kicking in really hard, but anyway, this is not the place to talk about those things, this is the place to talk about game development!

Your Human is Sick!

During my Master’s in Game Design, I was part of the Serious Games Capstone, and I had to opportunity to develop a game that I pitched, created all the documentation, acted as director and programmer. And that now is on Steam!


Link on Steam: https://store.steampowered.com/app/1290510/Your_Human_is_Sick/

This is how I feel

The game has its problems and I’m working on bug fixes and possible updates, but as of right now I’m really happy to have this game on Steam!

Now let’s talk about personal projects and what I’ve been up to!

LDJam 48

Participating in a Ludum Dare is something that I always wanted to do since… 2018? Or something like that, and this time, this year, this April, I decided that was it, I was going to make it!

And I made it, I finished a small turn-based game for Ludum Dare 48, called escars. You can play it on itch.io: https://gueepo.itch.io/escars

Sadly enough, I forgot to play other Ludum Dare games, which is sad, because the ~10 games I played were really interesting and entertaining, so because I didn’t play enough games, my game did not get an official rating, maybe next time!

Peanut Butter

Peanut Butter Engine

I’ve been talking about improving my C++ skills here for a long time, and that journey took me to sites like HackerRank, where I could practice algorithms and C++, and then it took me to Unreal Engine, which was a nice journey.

But getting deeper into that hole, I noticed that the next step, the next thing that would make me improve in C++ and further improve me on game development was… making my own engine.

I didn’t want to get into 3D, so I decided on making a 2D game engine to create tile-based games, and decided to call it Peanut Butter Engine! and I also wanted to make it open-source and a project that I will be working through the time!

Link to the Peanut Butter repository: https://github.com/guilhermepo2/PeanutButter

I am using a lot of references to make this engine, and they are all cited on the README.md on the repository, so feel free to take a look! Future plans and directions are also included there.

What comes next?

The biggest thing for me when answering this question, is to also answer the question: “What if I don’t get a job?” – If that happens it will mean I won’t have an income in the future and there is a lot of consequences on that. Anyway, here’s what’s currently on my mind:

  • I’ve been dabbling on different ideas and prototypes to come up with games that can be commercialized and could potentially generate some revenue so I can sustain myself, maybe I will have something by next month?!
  • I’ve been studying Multiplayer in Unreal Engine, and I would like to maybe come up with a prototype of a deathmatch third-person shooter, or anything simple but that can be a multiplayer game.
  • As for Peanut Butter, I feel like I have a good framework set-up, I’m currently going through the book “Game Programming in C++” so I can learn a little bit more, after that I still have to do some work on the Sprites/Animations modules, because I currently don’t like how it works. And then I have to fix some dependencies using premake and start making games with it! The first one I want to make is Pong, and then maybe the remake of an old platformer of mine, happily(never)after.

That’s it for April and (a little bit of) May, I will see you next month and hopefully, I won’t be too late for next month! Now back to my Island in Animal Crossing!


Yes, I’m still here – March Update

I skipped the February update, oh well. Not that I had done a lot, no, all I had for that month was a shooting prototype in Unreal I made in a few hours.

Having time to do side projects in game development has been a Herculean task lately, I’m in between school, which pretty much demands me the same as a full time work, and it is about game development, so also working on it on my side project has a potential to burn me out. On top of that, I still have homework/assignments! On top of that, job hunting has taken a lot of my time lately, and on top of all that, I’m binge-watching The Office.

With all that together, I haven’t been able to have any good progress or anything interesting that I developed in my free time. And the problem here is that I’m taking it too seriously, and I do that a lot, my mindset is always “How can I do an interesting game that can take 2~3 months?”, “What mechanics are interesting for a new game?”, “How to make an interesting progression system so a game can entertain people for hours and hours?”.

And I think the key is to not take it seriously. So my approach now will be prototyping mechanics, simple ideas, prototyping anything, not spending a lot of time and not committing to anything because the purpose of a prototype is to throw it away anyways.

So, anyway, here are some ideas that I tried bouncing off lately.

I was trying to come up with a combat mechanic that plays similar to Astral Chain, which is, I know, very hard, I just started doing it and started playing with launching the character on the attack and transitioning to/from attack animations.

This is a really really simple top-down shooter, I was just messing with the dot product and trying different things and I came up with the idea of a shooter that you can only hit your enemies from behind. Imagine an 8 person match (you and 7 bots, or multiplayer, who knows!) with that idea – It could be a quick and fun small game, 2 minutes of fun!

So that’s what I had for this month! I wrote down a list of small ideas/mechanics/things to prototype, and who knows what is going to be here next month!

I’m still here – January Update

A lot of things happened in January! Most of them good, so I got that going for me at least! But I’m already very late to write this post. I swear I didn’t give up on this and I will get back into doing projects and working on stuff!!

wordpress waiting for me to do my monthly post

Around January 5th I got back to the US to finish my Master’s in Game Design, and for some time I had to make an effort and focus on updating my portfolio and resume, so I can get to a good point where I can apply to jobs, I did all that, so now I have to just keep them updated and keep searching for jobs! But while making this effort, I didn’t have the best of times to work on side projects, and after I made all these efforts, I just took it easy for week, so I had a lazy week (A week where I only work on everything that is required from my Capstone and Master’s Degree). Anyway…



Defensees is finally out! Play it on itch.io! – That’s the tower-defense with roguelike elements that I talked about last month. I had a lot of concerns with this game idea but ultimately I wanted to make something out of it and release a game. It is very basic, it contains a simple turn-based system and simple wave spawning and progression system.

The major concerns are still there, no mastery, no secondary goals, no whatsoever, it’s just you slaying some dungeon monsters trying to not die and trying to not get the door destroyed. But I didn’t want to postpone this game too much and I’m actually proud of this little project.

There are plenty of directions this game can take and there are many versions of it in my head where it is a more complex game with more roguelike elements, but unfortunately, right now, Unity and C# is not something that I want to work on and I don’t think it’s something that would push me as a Gameplay Programmer.

So… now what?

“Now what?” is a very good question right now – It’s very simple actually – I have to make things that will make me improve or showcase my skills in gameplay programming and C++, and I already talked about that in a previous post, and it would be even better if in this project I could add some interesting systems, practice some 3D math, things like that!

Here’s the options that go through my head right now:

  1. Making a Gameplay Demo in Unreal Engine.
    1. This is similar to what I was previously doing, but now it would be something more serious and I would put more consistent effort and work on it longer.
    2. For this, I would buy an animation asset in Unreal Marketplace and work on making combat gameplay (Action RPG, inspired on Dark Souls or Astral Chain, there’s these two possibilities) or making something more inspired by a shooter game (Resident Evil 2 or Tomb Raider).
  2. Making a full game in Unreal Engine.
    1. That’s a longer route, I would have to come up with a gameplay mechanic and a gameplay loop and make it not be too long somehow.
    2. I also would need to search extensively for 3D assets to use, probably what I found and what I can buy will dictate what I will be able to do.
    3. If I find good enough assets, maybe I can do a 3D version of Defensees!
  3. Make a roguelike in pure C++.
    1. Yeah, I just love Roguelikes.
    2. They are interesting games full of systems, and I would have to code some interesting systems and create my very own small engine, which would be very interesting.

Anyway, next month I will be talking about which direction I went (there’s a high chance it’s going to be one of the first two AND a roguelike in pure C++, I just love roguelikes and I always wanted to kind of create my own engine… so…. it fits well.)

Anyway, thanks for reading until here!


Christmas Time – December Update

After a lot of time in the US, I’m back at home in Brazil during my Winter Break! It’s just two quick weeks here and then I will have to face 24 hours of airports all over again to get back and finish my masters the following year.

Merry Christmas! Or have a wonderful day if you are into that!

Last months I’ve been more on easy gear, I will use this time to have some more-than-needed rest and then get back at my pace, lots have to be done in the following months!

Creativity is weird


I said here last month that I wouldn’t be working on Aglarond anymore, I also said I maybe would still work on game projects that would be even smaller scope. The thought that I had an interesting and fun turn-based combat system coded (well, it is interesting and fun at least for me) but wouldn’t make anything with it kinda made me upset. But to be honest, I was ok with it.

But suddenly, my brain threw me an idea. Well, not really suddenly, related ideas applied to other genres are something that I discussed a lot with fellow teammates on the studio I attend for my Master’s.

The idea is really simple:

  • It all happens in a room. So no room generation and no level design, well, there is a minimal aspect of level design, but this is something I’m fully capable of.
  • Defend something. In this case, I think I will go with the door, or the throne, it doesn’t really matter.
  • Monster spawn from specific places in the dungeon. In the gif, the iron door is where the monsters would be spawn, but ideally, maps should have 2 or 3 spawn points.
  • Monsters spawn in waves. The first wave has 4 monsters, the second wave has 6 monsters, and so on and so forth. Waves get increasingly difficult and in between waves is when you recover some health and give your brain a little break.
  • Monsters want to destroy what you must protect. Have to have some conflict, right? I can experiment with different flavors of monsters, some can attack you, some can change goals, etc…

And also, I bought some pixel art roguelike assets for the game, and I might buy some sound effects, I just don’t want to spend time anymore doing things that won’t push me as a Gameplay Programmer, and also, these assets are way better than anything I would ever be able to do anyways.

There are some problems I can see with this game and I will point them now, but before pointing them I just wanna state that I don’t care, I will make this game and release it, and if I can improve some of these points, good, if not, then, well, at least I still think it can be a quick fun game!

  • It doesn’t have mastery. This is the biggest one, Roguelikes are a lot about mastery, and although this is not a roguelike, it draws pretty obvious inspiration from the genre. How the 100th hour playing this game differs from the first hour? What are you learning about the systems? What are you learning about strategies? There’s not much to learn so not much room to achieve mastery.
  • There are no secondary goals. Right now it is all about killing monsters before the monsters kill the door, or the throne, or you, there’s not much to strategize, I’m afraid the game will be just a “slaughter the monsters until you are mathematically not able to survive”

There are some ways to try to remediate those issues, which are:

  1. Adding spawn locations for health pickups in the middle of a wave. This can create situations where players have to decide whether to engage in combat or get a health pickup in order to survive longer.
  2. Adding random power-ups at the end of a wave and/or in the middle of a wave. I can easily have power-ups that make player health regen faster, double the damage for a while, make their speed bigger for a while, give immunity for a while, make the player take less damage. This can create both mastery of the system and secondary goals, as well as changing the playstyle according to what power-up the player has at the moment.
  3. Having more than one level. I’m probably going to do this anyway, but I can have different levels for the game, with different amount of doors, different layouts, and whatnot, these can make players strategize and play in a different way, also make the environment less boring.
  4. Adding doors that can be locked/unlocked. If the door is unlocked, enemies spawn from them, if it is locked, no enemies spawn from it. This can make me explore more enemy variety because I can add an enemy that sole purpose is to open any closed doors. This also adds strategizing for the player in the form of “Should I guard the door or should I go lock that door?”, “Should I protect this spot or go kill the enemy that will try to open the door?”

… At this point I just noticed I turned my monthly update post in a short Game Design Document for this game, well, that’s fine. I just wanted to describe what it is, some concerns I have and some possible mitigations for those risks. All in all, I think this was informative and some good bits on the game design process.

Quick Unreal update

Besides that, I’m working on an Unreal Gameplay demo to practice my gameplay programming skills, create portfolio pieces and flex my C++ muscles. I’m trying to create gameplay for the Paragon hero asset Sparrow.


It has its problems, such as: (1) there’s no animation for walking sideways with the bow down, (2) the camera doesn’t follow the character when moving to the left or right when the bow is down, (3) shooting have no impact (and no code for hitting anything at all)

I wanted it to be a demo of a game where shooting is meaningful, it would be a stealth game where you only use your bow when absolutely necessary, so using it should feel thoughtful and powerful. But anyway, this is something that I still will work a lot on and improve a lot!

Anyway, that’s it for my monthly update, thanks for reading!