Hello!

Re:creation

This is my old blog and newer can be found here:

https://edw.is/

Here are some things I’ve written and which will be here as an archive.

Dev log

• Week #0: Preparation
• Week #1: Things are getting bigger
• Week #2 and #3. AI stuff and vacation
• Week #4. New graphics, doors, chests and screen transitions
• Week #5. Improved level format and saving system
• Week #6. Art, gold, dialogues, localization issues and mini-quests
• September 2014. Drawing art, being solo dev and fixing bugs
• October 2014. Halloween, ghosts and scripts!
• November 2014. Core game mechanic explained!
• December 2014 – February 2015. Bigger levels, boss and heavy attack
• March 2015. Graphics improvements, entity inheritance, improved state machines and more!
• April-May 2015. Recreation mechanic, archers, event system and more!
• June – October 2015. I’ve made lots of stuff.
• 2015 Summary. The most productive year ever!
• January-February 2016. Better art, sounds, cutscenes and more!
• March-June 2016. Game stuff and Lua/C++ binding changes

Follow me on twitter! @EliasDaler

E-mail: eliasdaler@protonmail.com. Feel free to write and ask questions.

If you like the stuff I do, check this out:

Donations and ways you can help

I also write articles about Lua and C++.

Using Lua in Practice.

• Part 1. Intro to ECS and basic principles
• Part 2. Implementing the basics
• Part 3. Controlling entities in Lua by  calling C++ functions.
• Getting data from scripts and why globals are evil
• Iterating over Lua tables

Using Lua with LuaBridge

• Part 1. LuaBridge
• Part 2. LuaBridge pt. 2

Using Lua with C++ (writing your own binding with Lua C API).

• Part 1. Why Lua is great and why you should use it. Writing simple wrapper/binding and using Lua for configuration files
• Part 2. Getting arrays and calling Lua functions from C++
• Part 2.5. Template getArray function and other modifications
• Part 3. Calling C++ functions and creating C++ objects

Other tutorials and articles

• Creating awesome GUI for your game dev tools with ImGui and SFML. (Part 1, setting up)
• Z-order in top-down 2d games
• Cave Story: the most important indie game

Some sprites on this blog are from Legend of Zelda: A Link to the Past by Nintendo.

I’m moving to https://eliasdaler.github.io

Hello, everyone.

Recently I’ve decided to create a new blog which will be cooler looking and easier for me to modify. So I’m proud to present it to you!

https://eliasdaler.github.io

This will be the blog I’ll be using in the future and then maybe I’ll move to some domain like eliasdaler.com or something like that.

You can find all the info about why I’m moving and what I’m planning to write about next here.

See you there. :)

P.S. This blog will remain as an archive of everything I’ve written before that, but I’m probably going to put big notices at the bottom of the pages to go to newer articles or I’ll just remake some parts of the articles which I consider to be out dated.

Re:creation dev log. March-June 2016. Part one. Game stuff and and some awesome Lua scripting

The last few months I was very busy finishing my bachelor’s degree (it’s over, I got an “A”!). But still, I’ve managed to do some cool stuff and improve the engine structure and tools in the last couple of months.

This dev log will be released in two parts. In this part I’m going to talk about game stuff I did and stuff I changed about Lua/C++ integration. In the second part I’ll talk about engine tools I’ve made with ImGui and different refactoring I’ve done.

Game stuff

Here’s one of the latest screenshots of the game. Houses were previously just big sprites, but right now they’re composed out of tiles which lets me reuse them for other houses and build new buildings more quickly.

Creating awesome GUI for you game dev tools with ImGui and SFML. Part 1.

This is the first part of tutorial about Dear ImGui (AKA ImGui) and it’ll show you how to set it up with SFML. The second part will be library agnostic and will talk about common ways of doing stuff in ImGui, some awesome widgets and some useful STL overloads.

Different ImGui widgets (taken from ImGui’s github page)

Introduction

Having good content creation (level editor, resource editor, etc.) and debugging tools for your game is very important and can lead to productivity and creativity boost.

Here are some examples of tools I managed to make with ImGui for my game:

Level editor:

Animation editor:

(It was possible to add ability to change members of C++ objects with ImGui by doing some template magic, maybe I’ll write an article about that later!)

As you can see there’s a wide range of widgets that ImGui can provide and there are lots of other great examples of how other people use it here.

Re:creation dev log. January-February 2016. Better art, sounds, cutscenes and more!

Just a short info for those who have never heard about my game.
Hello, my name is Elias Daler and I’m a solo developer who is making Re:creation in my free time. It’s done in C++ with SFML and Lua!

Re:creation is an action adventure game about the undead knight who wants to free undeads from the humans who use undeads as slaves or practice dummies. The unique mechanic of the game is called recreation which allows you to control dead people with your ghost gaining their abilities to solve various puzzles. Here’s an example of this puzzle.

Read more about the game here.

 

Back to the dev log…

Two months have passed since the last dev log. I had lots of time to work on the game and here’s what I’ve  managed to work on.

Better art

Yet again, another graphics improvements! Change of the perspective was quite an improvement, but I’ve also realized that I can improve other stuff too.

There’s more depth to characters and surroundings, the colors are used better, etc.
There are more graphics improvements which I’ve done recently (for example, I’ve improved main hero’s sprite a lot), but I’ll show it off a bit later.

Here are some comparison screenshots!

There are also subtle things that made game look better!

Using Lua with C++ in Practice. Iterating over Lua tables

Hello, this is new part of Using Lua with C++!
This part will be short, but very helpful. It will use LuaBridge and Lua C API, but it’s pretty easy to rewrite stuff for other Lua/C++ bindings.

The problem

Suppose you have a Lua table this:

someTable = { 1, 5, 10, 20 }

Suppose that someTableRef is a LuaRef pointing
It’s pretty easy to iterate over it using LuaBridge:

for (int i = 0; someTableRef.length(); ++i) {
    // note the i + 1 here, it's because arrays in Lua start with 1
    LuaRef elementRef = someTableRef[i + 1];
    ... // do something with the element
}

But what if you have a table like this:

someTable = {
    firstKey = "someString",
    anotherKey = { ... -- some stuff }
}

and want to iterate over it?

This can be easily done in Lua:

for k, v in pairs(someTable) do
    ... -- do stuff with k
end

But how do we do the same in C++? I’ve found no way to do it in LuaBridge (and seems like lots of other libraries don’t include this functionality as well), but fortunately we can use lua_next from Lua C API to do the thing for us!

Using Lua with C++ in Practice. Getting data from scripts and why globals are evil.

• Part 1. Intro to ECS and basic principles
• Part 2. Implementing the basics
• Part 3. Controlling entities in Lua by  calling C++ functions
• Iterating over Lua tables.

This part doesn’t depend on the others, so you can read it even if you haven’t read previous parts. (I suggest to check them out, though. You may find some interesting stuff!)

This part will mostly use Lua C API only. LuaBridge is used for a small part to show some cool stuff. (Though you’ll be able to follow with most other bindings)

This part contains one of the most important practices in Lua programming which I discovered pretty recently and felt dumb afterwards because for the last two years I’ve been doing stuff wrong.

Today I’m going to talk about storing Lua tables and variables in scripts.

Storing data in Lua is great. You can easily store stuff in neat way and you can also store functions which you can later call from C++. You can store tables (or other variables) in scripts in two ways: as global variables and as local variables. Let’s talk about each one.

Re:creation dev log. 2015. The most productive year yet.

It’s time to summarize what I’ve done during this year with Re:creation. It has been very good year, I’ve managed to do and learn lots of stuff.

Before I write about the stuff I’ve done I want to thank everyone who followed my progress and provided feedback. This stuff is really important for me and always keeps me motivated. With your support I never feel doubt about my game, I never want to stop making it. Thank you.

Special thanks to SFML community. It turned my dev log thread into a very cool discussion and helped me out with lots of stuff. This level of support is much more than I’ve ever expected and it’s very heartwarming.

I’ll show the most interesting stuff I’ve done and then explain some in more detail.
Some screenshots are taken at different parts of the year, so they may differ a lot!

Some gameplay gifs to get you started:

This one is my favorite gif so far. It really shows a lot of stuff I’ve made this year.

Using Lua with C++ in Practice. Part3. Controlling entities in Lua by calling C++ functions.

• Part 1. Intro to ECS and basic principles
• Part 2. Implementing the basics
• Part 3. Controlling entities in Lua by  calling C++ functions.

If you haven’t read the first part of the tutorial, I suggest you to read it, so you have a clear idea what’s going on. See the second part for the implementation details.

This article uses LuaBridge and if you’re not familiar with it, I suggest you to check out my tutorials about it. (Pt1, Pt2). If you’re using another Lua/C++ binding: that’s fine, you can totally implement everything I’m talking about with other bindings.

Intro

One of the coolest things in Lua is that you can call C++ functions from it. You can even register your own classes and call their member functions!

Suppose you have an entity class which contains a list of components:

class Entity {
    ...
private:
    std::vector<std::unique_ptr<Component>> components;
};

Suppose that you have a function which lets you get a component by its name.
What if you want to change animations in some Lua script? You can do it like this:

function someLuaFunction(entity)
  ...
    local graphics = entity:getComponent("Graphics")
    if(graphics) then
        graphics:setAnimation("someAnimation")
    end
  ...
end

I believe that this is not a greatest way to do things, because exposing components to Lua is not really necessary. Woudn’t it be nice to hide all the implementation details in C++? Here’s how the code above may look:

function someLuaFunction(entity)
  ...
    entity:setAnimation("someAnimation")
  ...
end

Re:creation dev log. June – October 2015. I’ve made lots of stuff.

Almost five months passed since the last dev log on this blog.
Why? That’s because I created SFML forums thread and TIGSource thread and wrote most of the stuff about the game here! But I’ve realized that a monthly summary about what’s going on would be pretty helpful for those who don’t want to read long threads and search the most awesome stuff that’s been happening. Another plus is that I don’t have to write lots of in-depth style here. I will write in-depth stuff in SFML forums and TIGSource threads and link to those posts here, so you don’t have to scroll through stuff that you don’t want to read lots about.

Here’s the best screenshot I can show you at the moment to show where the things are right now.

Okay, let’s start.

Using Lua with C++ in practice. Part 2. Implementing the basics

Source code for this article

• Part 1. Intro to ECS and basic principles
• Part 2. Implementing the basics
• Part 3. Controlling entities in Lua by  calling C++ functions.

Hello, this is a second part of “Using Lua with C++ in Practice” series. I recommend to read the first part to know what’s going on and why using Lua with C++ is awesome! (You’ll see it in this arcticle too, of course).

This tutorial will implement a simple ECS model which I’ll improve and use in other parts of tutorials. Note that this is not the best way to implement ECS. I’m making the most basic ECS which can be used to show the main principles of how things work in my game and how you can use them in general. This is not a tutorial about C++, so I won’t spend too much time discussing C++ parts and I’ll mostly focus on Lua/C++ interaction and binding. Let’s start!