The Raylib C Library for Game Development with Ramon Santamaria

0:00Raylib is a lightweight, beginner-friendly, and open-source C library for game development, known for its simplicity and lack of external dependencies. It's designed to streamline the creation of 2D and 3D games, and has an intuitive API for managing graphics, audio, and input. Ramon Santamaria is the founder and lead developer of Raylib. He joins the show with Joe Nash to talk about the Raylib project. Joe Nash is a developer, educator, and award-winning community builder who has worked at companies including GitHub, Twilio, Unity, and PayPal. Joe got his start in software development by creating mods and running servers for Gary's mod.

0:39And game development remains his favorite way to experience and explore new technologies and concepts.

0:58Ray, welcome to the show. Thank you for joining me today. Hello, Joe. Thanks for having me. It's a pleasure. too. So as we mentioned, you are a developer of Raylib, which I'm sure lots of our audience are familiar with, a fantastic C library for game development and all kinds of other, I guess, graphical application development. What I want to start with is the path leading up to Raylib, which as I understand it is 11 years old today, so we've got quite a journey. Where did your interest in game development come from? Like way back before Raylib, what led you to where we are today? Well, actually before Raylib, I was working in video games development.

1:29I worked in EA for some years and also work in small companies. I also tried to create my own company, published a couple of mobile games for Windows Phone at that moment. And after that, I got a job as a professor in a private education institution. Actually, it was the first one to start teaching video games, an official video game development course here in Spain, I think, actually. And My task was teaching video games programming to mostly art students. That was a challenge because usually the art students were not that interested in programming. The first option was using some kind of no-code tool like drag and drop.

2:17At the moment, it was kind of the beginning of Unity getting into the market. but I decided to go low level and I really tried to teach actual programming to art students and to do so I did some tests, I started with C and I checked some libraries out there and after some months of trying different approaches I found one that actually worked that was a very, very old library called Portland BGI Graphics that's from the 70s maybe and surprisingly it worked extremely well because it was super simple like init, close, draw. It was super simple. After that first year teaching I decided to create an alternative to VGI but more adapted to modern times.

3:08Well modern times at the moment mean OpenGL and I did so. It was a weekend project, actually, really. And just in a couple of months, I got a first version quite complete with a lot of functionality to do some 2D, to do some 3D and everything. I started testing or using it with the students. And also surprisingly, it worked super, super good. The students were super engaged with the library and almost all the students were able to create a Pong. At that moment was the assignment in the subject. And they really enjoyed programming, but not only they enjoyed creating games, but they enjoyed the fact of writing code, writing code in a quite raw way with Notepad and compiling and running their games.

3:56And yeah, that was the origin of the library. But from there, I start getting a lot, a lot of feedback because the students were quite excited about the library. I started asking for improvements, reporting bugs, letting other students from other institutions know about the library. And the library started growing. And well, at that point, I thought that it could be interesting to keep working on it. I actually released it as open source because I thought it was the best option for education and to reach a wider audience. And yeah, and it started growing. At that moment, I was reactivating my company.

4:35The previous one that I had published, Windows Phone Games. But at that moment, I just started working in the library with fewer students. The plan was to keep working on games in this development. Actually, we released a PS Vita game at that time, but most of the day was working in Graylib. So it was like six hours per day working in the school, teaching with Graylib, but then there was another six hours every day working in the office with some students, developing GreyLib. Incredible. Yeah, and it worked for about six years that way, something like that, five, six years. And yeah, and GreyLib kept growing and growing and growing.

5:17And then at some point after those first five, six years, I got an email from Google that they were giving me an award for the open source project. And yeah, the library started getting recognition in a lot of places and start to grow really, really, well, becoming really, really big. And yeah, since that moment, for the last five years, actually, I quit at that moment teaching to focus 100 % in the company to not only develop Rilead, but also develop an ecosystem around Rilead with some auxiliary libraries and to develop tools focused for video games development. but always using RayLib as the base technology.

6:03So the technology kept growing along all the other products around it also were built. Yeah, that's mostly today. At this moment, RayLib is super big. Yeah, it's unbelievable the point it has reached right now. Yeah, for sure. It's unbelievable that I've been living years doing that. Yeah, it's a huge achievement. I think I saw, so we'll be talking about it a bit today, but you've just released Raylib 5.5. And I think I saw, was it 150 contributors to 5.5? Yeah, about 150 for this release alone. Yeah. But about 650 overall. That's awesome. Of the years. Yeah, that is a huge achievement. And also, you know, just going back to that, you know, the early days in that first class, I think you must have had the most engaged class of students in the world to like share the library and start contributing to it.

7:00That's awesome. I definitely want to ask you, you know, just from an educator's perspective about how you approach that task of, you know, choosing C to teach art students. So we'll get to that later on. But for now, I guess I'll settle on Raylib. Before we get into all of the details, I guess for folks who aren't aware, can you run us briefly through how Raylib works, what it is and what it does and what it's used for? Kind of a high level introduction to the library, I guess. Yeah, actually, the library itself is quite simple in terms of programming. I mean, not internally, but the API, it's quite simple.

7:35It's a C library. So there is no any kind of abstraction like object-oriented programming or anything. It's just functions, procedural programming, and structures with data. Mostly all the structures are completely transparent. I mean, they are not open pointers to some internal structures. So you can, when you create an image or a text tool, you just define it like any other kind of variable and you have directly access to my image point, width, height, format, and everything. So it's all the library itself is kept, or I try to keep it as much simple as possible. always thinking in those first users of the library.

8:16The students are not any kind of students, students that mostly have an art profile and they usually start not interested in code. But many of them actually, after some courses, have ended up working as a programmer in different companies. So that's amazing. So simplicity is one of the key points of the library. Beside that, the library tries to cover mostly the basic functionality that you need to make a small or mid-sized game. You've got functionality to manage the window, the inputs, all kinds of inputs, keyboard, mouse, gamepad. You have functionality to load images, to upload them into GPU as textures, to load models, the meshes, the materials.

9:03Well, that's kind of the most about functionality that has been added along the years. Then you have some basic collision detection functionality. You also got a small math library included that actually is portable that can be used outside of Raylib. And you also have some basic functionality to draw textures, models, and to play audio, to load audio and to play audio. So it covers most of the basic functionalities that you need for video games development. about the architecture of the library. Since the beginning, it was designed in a way that it was very, very modular. I always thought, okay, it only has seven modules, and that means seven C files.

9:50So that's intended to simplify the build system because in the past, I struggled a lot with build systems, and I decided to simplify that. Actually, when I was at EA, I was in charge of build pipelines and text pipelines, audio pipelines, and I know how complex can it be, actually. And I try to simplify building at maximum. So I try to keep all the library very small and self-contained in terms of architecture. But I also try to make all the modules independent from each other and being able to use them as much as possible as an independent library that you can take out from Raylib and include into your engine or into your program to just do some of the functionality that you need.

10:34For example, the audio module, it's completely self-contained, decoupled of anything. So you can just pick up the audio module that are a C file with some header dependencies. You need the audio device, load some audio file, multiple formats are supported. It's configurable also. Play the audio and close the audio device. So it's focused on that kind of simplicity. The same for the Shapes module. In the Shapes module, it's quite self-contained. It only depends on a bunch of functions to create vertex. Well, I think it depends on six, seven basic functions to define the vertex data. But then the module itself contains.

11:15So if you want a module to create shapes or kind of shapes like circles, rings, rectangles, rounded border rectangles, well, lots, lots of types of shapes, you can just pick that module. And again, it's the same. Okay, you have to provide like seven functions, but mostly any engine already gives you those seven functions. And well, that's the same with every module. Then another of the important parts of the library, it's an abstraction layer over OpenGL. That's one of the key parts of the library. It's called RGLLGL. and it's a kind of a mapping of multiple OpenGL versions from legacy OpenGL to modern OpenGL into immediate mode OpenGL kind of.

12:01Okay, you also have all the extra functionality to load the meshes and the vertex buffer and everything, but it has a small set of functions that let you just use that library like the immediate mode OpenGL 1.1. and actually that proved to be very very very useful because in this latest release i saw that some people ported right lip to work on all consoles on retro consoles and on new consoles and that was thanks to that support for the open gl 1.1 well back end because it's one of the back ends it's not the default one by default it uses open gl 3.3 and open gl es 2.0 on web android than Raspberry Pi or embedded devices.

12:47But yeah, that was one of the modules that I think it's more useful. But well, summarizing all together because I think I am going into many topics. The library itself, it's intended to basically draw anything on any kind of display. It could be a game. It could be a demo. It could be some kind of multimedia application. It could be a tool or, yeah, anything. And considering it's C and it supports a really wide number of platforms, yeah, actually, I've seen the library used for many, many, many kinds of applications, not only games. And actually, I'm an electronic engineer, and I love seeing the library running on embedded devices for some kind of display or anything.

13:36and yeah that i love every time i see that running in an event device yeah that's always exciting i always think of you know i think that the classic example is like people putting doom on silly things right and i whenever there's like that on a new on a new thing i always get excited by it so i can only imagine when it's your library that ends up being on you know like a pregnancy test or whatever it is people are putting putting stuff on that's awesome okay god so much to talk about so i want to come back to things like the console support and some of the features of the library that you mentioned like collision detection but i guess to start with you started at the beginning talking about you know your principles of the api design and you know wanting to keep things simple given the background of the project that totally makes sense but you know it's been 11 years you've had like loads of different users come the library the audience has really grown so i'm really interested in, you know, in how you approach API design in design, you know, there's what, 350, 380 functions, there was an update in 5.5, there's like a lot of functions now, there's a big API surface area.

14:36So how do you think about the design of the API now, you know, with the past, present and future audiences? Well, that's a good question. Actually, at the moment, Rayleigh 1.0 started with 80 functions, only 80 functions that I thought that was enough to make many kinds of games but Riley 5.5 has reached the 580 functions so it was a little bit off yeah that's that's great that's awesome but I also have to say that a couple of years ago I did an analysis of the market and I look for all the open source GitHub repos using Rylib that I could found. And I compiled like 200 repos or so. And I did some text analysis, text scrapping, and I listed the most used Rylib functions in all the source files found in those 200 repos.

15:31And guess what? What was the surprise? Were the most used functions. Actually, were the 84th functions from the library. That's such a cool idea as well. Yeah, you need window, closed window, draw rectangle, begin drawing and drawing, draw circle. I mean, load texture, draw texture. I mean, the simple ones were the most used ones. I mean, also there is some bias here, obviously, because at that moment, the library has been in the market for eight years. And yeah, people start and they use the first function. So there is some bias in that analysis, obviously. But many of the advanced functions added to the library were barely used, actually.

16:18There were not many people using them. And yeah, it was surprising. But as I'm answering your question now, how I approach the API, simplicity is always the key for me. And sometimes I have some discussions about that on the Discord or with the contributors of the library. because sometimes they try to add more functionality and I have to say no, not because it's not useful, but because it belongs to another level. I try to keep the library at kind of a low level and it's recommended that if you want to use it to make a mid-game, you build your small engine over it and add that functionality in that level, but not in the low level.

17:05So I try to keep the library at low level. About things that I always keep in mind, for example, the function names. Function names always follow the same pattern. They try to follow the natural language. So as much as possible, do not follow a programmer language. Because when you code, you tend to use the technical terms that you should use to name everything. and sometimes if you think of the people that is going to use the library that maybe it's people with not that much experience, it's easier for them to name the functions with some easier names. All the functions you already follow the pattern that verb, subject, and object.

17:47There are usually two, three words at maximum. Sometimes maybe four words, but I try to keep it in that way always. Always the same. Also, in the name of parameters, I try to keep always under five, six parameters. Always.

18:08Yeah, that's a great thing. That's Malik. So I try to keep it simple all the time. That's my objective. Sometimes it's not easy because you have to do things that get complicated. Yeah, it's not easy to always keep it simple. But that's the objective. If things turn to be too complicated or the functionality to add turns to be too complicated, I try to abstract as much as possible. If it's a low-level functionality, I try to keep internal of our lib and just expose the minimum required for most of the users. And then maybe allow some flags, some build flags, or some additional configuration options to configure more advanced functions.

18:51or otherwise I evaluate if that functionality maybe belongs to a lower level and then it shouldn't be in Rayleigh but maybe in an auxiliary library or a secondary library. I actually got some of those secondary libraries. I got right with that it's a library to create UIs mostly intended for tooling but it has a lot of immediate mode UI functionality. Got also REST for resources packaging. That's also another library. Well, I got random number generator. I got several auxiliary libraries that, well, are kind of in that RightLip ecosystem and are intended for users that need that extra functionality for their specific project can use those libraries.

19:34Actually, that's a year or so, like one year ago or one year and a half ago, one RightLib developer in the community created a separate organization, a separate repository called RightLib Extras that has proven to be very, very, very useful. because for all that people that came to the community asking for advanced functionality, a common answer is, oh, maybe not for RightLip, but you can add that to RightLip Extras. And it's usually an additional library or additional template or whatever module that does not need to be in the core library because maybe it's not useful for many, many people. But it could be interesting to have it.

20:17Sometimes, well, like a binary partition or some kind of additional functionality that, for example, in the community, there are a lot of people coming wanting to make a Minecraft. Okay, that's very common. I did notice that the cover image in your Discord was like a voxel, like rendering. Yeah, there is a lot of users that are starting with Rayleigh and come to the community and, oh, I want to make a Minecraft. And it's, okay. And they start, okay, so what we need, we need some kind of OCT3 and all that. Well, in Reilip Extras, actually, there is a kind of a Minecraft template with everything set up with a lot of extra functionality.

20:58And it can be used as a reference. So not everything has to be in Reilip. Yeah. And we'll come back to community management a bit as well, because I think the way you manage the ecosystem is really incredible. But just that concept of like, hey, I'm an open source maintainer with a very well specified focus project. And lots of people have lots of enthusiasm. so there's a space where they can have that enthusiasm that's separate that is a very nifty solution so going back to one of the things you mentioned you mentioned parameters this is one of the areas i think is really interesting particularly about well api design with c but also particularly for your audience which is you know when you get to thinking about your data structures and c and teaching beginners and people who aren't programmers and dealing with pointers and dealing with how you parameterize your functions what is your approach to that because that just seems like an area of endless foot guns for library designers in C trying to teach beginners.

21:51Well, actually, I forgot to mention about that. The objective, the beginning was avoiding pointers at all. So the first set of functions for Relief had no pointers at all. All the data extractors were just passed to the different functions by value. That's it. It has some problems related to that, But yeah, they are not that bad. What I tried was minimize the size of all the structures provided. Actually, the structures are quite small, usually under 32, 48 bytes. So it's acceptable to pass them by value. And yeah, that was one of the objectives. With the year, the library has kept growing. And now, yeah, obviously you have some more advanced functions that require pointers.

22:43But I think they are out maybe 20 or 30 out of 580. So it's in some cases where you really need pointers because obviously you have to load data. For example, in an image, you have to load data. Then the pointer is just kept inside the structure. So you've got the structure with width, height, format, midmaps, and the pointer to data. Or if it's textures, well, the data is already in the GPU, so you've got the identifier. So that's easier. But what I try is to keep it simple for those students. Later on, in the last few years, I've been also teaching programming in the university for computer science students.

23:25And yeah, that's a completely different mentality because, I mean, for them, they usually love programming and they usually love to go as much technical as possible and go into details. But actually, even though the beginning of this year I was teaching in the university to computer science students, well, I actually was teaching Unity. But I had to teach in the syllabus about programming patterns, solid concepts, and all this information. And I'm so used to coding C with a procedural way with just data inside everything and functions that operate on data. That when I was teaching all those concepts, it was kind of, oh, really?

24:15Yeah, I had to tell that. So I told them, but I let the students know that that's an option. There's another way. Yeah. Yeah, that's another way. And actually procedural programming, it's so enjoyable because you really see everything that's happening in the low level. You focus on data. But for me, it's everything. It's the most important thing. At the end of the day, it's what you have, and then it's just operating over that data. And that's a bit the philosophy of right-leaf. You've got data that you move around, and you just call functions that operate over that data, and sometimes they retard you a value.

24:51I think that after many years working in that project, my mentality is so focused on that way of programming that when I look at the different abstractions of the programming, C++, the solution of C++, the solid and the solid concepts and everything, it's kind of, wow, no, no way. i mean programming can be way simple than that and works you know yeah no no it's you know it's something we talk about a fair amount with guests on the show i guess which is like one of the nice things about game development is sometimes it feels like it gives you an opportunity to get down to like you know the lower level and to get down to like simple abstractions and to just like you know it just has to render once and render once on the screen and like you don't have to maintain it for a million years and this kind of stuff right so yeah but it's also it's really interesting so first of all uh complete tangent you taught at upc right not this time okay cool i've been in several universities yeah because i usually tout for some time maybe one year two years i make some money and then i can be sometimes yeah well working on raylib and the tools and all the ecosystem so this last time i was working in it's called techno campus cool that is another university that is near Barcelona that they also have a video games degree and a computer science degree and this time I was teaching there but before that I was in the UPC for for two years cool it was 2020 to 2022 something nice awesome cool yeah they have a I guess you would have been the reason I ask is because UPC has a very famous student-run hackathon but I guess they wouldn't have been running when you were there due to COVID oh but yeah that would they would have been a great audience for Aleb so you know you mentioned teaching unity and I think it's you know you summarized i guess the challenges of teaching something like unity to game dev students very well which is just like there's so many concepts so many abstractions but i guess a more like holistic level a higher level when you just think about introducing people to game dev like how do you explain to new developers like hey here is why you would choose raylib versus why you would choose a unity a godot an unreal like a full-fledged engine well i think that i mean And RayLib can teach you not only the basis of how things work in the inside, but also, well, be a guide to start your path.

27:18I mean, actually, those first six, seven years that I was teaching with RayLib, RayLib was a pretty small part of the syllabus. It was like 60 hours in total. Then we jumped into, at that moment, it was into monogame. And after that, we jumped into unity. and I thought that was a great path because Riley Wells low level was C then you jump into mono game that actually Riley Pete's very inspiring in mono game with the naming conventions and the structures and everything and with mono game you can learn C sharp you can learn some object oriented programming and some more advanced concepts and then when you understand that you can jump into Unity because then all the game loop and everything gets abstracted into Unity internal structure but you can start working in a higher level, just managing the logic of the game and the assets and the data and the different scenes.

28:12So I think that's a great path, in my opinion. Start in a low level, try to understand how things really work. If possible, try to go a bit deeper because that's another point about RightLib. It's designed in a way that the source code, it's very, very, very simple to read. It has lots of comments, avoids any kind of complex programming techniques. It's very simple in terms of code. So students that want to dig further, actually, I had many students that had gone inside DriveLib and then had sent improvements and have, well, improved the library. Yeah, that's it. You can go inside and learn a bit deeper, different concepts, maybe about 3D, about models, about animation, about audio.

29:01you can go deeper but after that you can move on and you can move to other upper level frameworks or engines and i think that's a great path actually yeah i agree that does sound really fantastic and i guess along that way as well people there's like this perpetual issue in computer science education where like they try to teach the abstractions before the student has encountered the problem that requires the abstraction i always think about this with like git and version control right like the universities try to teach version control before students have worked on big code bases with lots of people and understand why it's helpful to them and so it's just another thing in the way but in that path that you describe you know you get to see the low level and then you get introduced to monogame and you see like okay that takes away some of the low level i know how the low level works but now i know why i want this abstraction and then you get to the scenes in unity so i think that's a really great approach that's awesome yeah actually this is another point that didn't mention i got it in the head since the beginning It's about building systems.

30:01Because usually, in my experience, that's the point where most students struggle a lot with the build systems. I don't know in the different places I've been teaching. Usually, I've seen a lot of problems in the students understanding how everything works. In the sense that, not how everything works, but how to configure properly a complete development environment. I mean, not only maybe starting with compiling in the command line, but then setting up some, I don't know, make file or some basic script. From there, try to grow it up. Maybe, I don't like CMake, but maybe CMake or even Visual Studio that is kind of a standard in the industry, I think.

30:43How to properly configure a project in Visual Studio. And then from there, move on and not only use the control version system, but even set up some continuous integration, continuous delivery that nowadays it's quite standard and quite simple to set up these kind of systems. That's one of the problems I found with the students. And, well, I try to address as better as possible. But, yeah, I think it's super important because at the end of the day, many students just want to write code and press the play button. That's the easy part, actually. Usually, if you are in a big company, there are many, many, many other side methods and processes that are as important as just compiling the code that need to be done and need to be understood.