TL;DR: a quick run through all the 3rd-party-code that is used in Oryol as of April 2016, and why it was chosen.

Small Things

These are mostly header/source pairs which are dropped directly into the source directory nearby the Oryol code that uses them.


This is a simple and very small C header/source pair from the LLVM project which converts between UTF-8, UTF-16 and UTF-32 and has no further dependencies.

Oryol’s convention for string data is to use UTF-8 for internal string representation, and only convert to 16- or 32-bit ‘wide-chars’ when talking to external APIs that don’t accept UTF-8.

ConvertUTF is all that’s needed to handle all types of international text I’ve encountered so far (including Arabian, Korean and various Japanese and Chinese text representations). No code-page bullshit or global UNICODE defines like it was hip in Windows a while ago. The use of wchar_t strings is limited to very few places, wchar_t is 16-bits on Windows and 32-bits on UNIX-y platforms, so it is not a useful general representation for text data.

In the past I called the MultiByteToWideChar/WideCharToMultiByte functions on Windows and used the iconv() function on UNIX-like systems to convert between encodings, don’t run into the same trap.


This is also a simple C header/source pair. It’s sole purpose is to provide an absolute path to the own executable on various platforms. This is the most useful way for cross-platform code to find the installation directory of an application (as opposed to hacks like writing to the Windows registry at installation time).

In Oryol this is only used on platforms where the concept of a local filesystem exists.


FlextGL is essentially a python script which generates a single C header/source pair from the downloaded Khronos XML specs for GL. You provide a small text file describing what GL version, profile and extensions are required, and FlextGL generates C glue with just the required code. Before FlextGL I used GLEW but found this way too bloated.

External Dependencies

These are pulled in by fips as external dependencies and live outside the Oryol source tree. Some of them are compiled into static link libs during the Oryol build and some are header-only.


GLM is used for all general CPU vector math code in Oryol. Despite it’s name ‘OpenGL Mathematics’ it is actually a generic math library. The name GL only comes in because it tries to mimic the look of GLSL shader code.

GLM basically ended my 15-year quest for a usable vector math library that can be used well in general code (as opposed to ultra-tight inner loops where it probably isn’t the perfect solution - no math lib is I think).

Before GLM I wrote my own vector/matrix/quaternion classes, sometimes wrapping external libs like XNA Math (yuck).


…as in “GL image loader”. This is my own little header-only library to parse texture data from various compressed-texture file format (DDS, PVR, KTX). It was my first attempt at a header-only library, so there are some quirks in it (I should rewrite it in pure C and use STB header conventions). It doesn’t have any allocations, IO or 3D-API calls in it. You just give it a pointer to texture-file-data in memory, and it fills a simple C++ object with information that can be directly dropped into GL texture creation functions (but Oryol also uses GLIML for all other 3D APIs).

I was considering GLI for texture loading, but that was a bit overkill since it does a lot more than just loading textures.


GLFW is used as platform abstraction wrapper for window and 3D context creation, and for getting input on desktop platforms when the GL rendering backend is used. It will also be used in the upcoming Vulkan rendering backend.

Even on some non-GL desktop targets, bits and pieces from GLFW have been ripped out to get somewhat uniform window- and input-handling across platforms and 3D rendering backends.

The Windows, OSX and Linux window system APIs, and their ugly cousins, the glue that connects 3D APIs to those window systems are among the worst API-contraptions mankind ever came up with, that the GLFW authors are taking one for the team and wrestle with this mess can’t be praised high enough.

If you’re still using GLUT, definitely give GLFW a shot.

Dear Imgui

ImGui is the first-ever UI framework that I used in my entire life that isn’t a royal pain in the ass to write code for. In fact it is highly enjoyable to use. If you’re grumpy and in a bad mood, just write a few lines of ImGui and you’ll be smiling for the rest of the day. That’s how good it is.

And this includes all types of UI frameworks, not just for games.

I would already now use ImGui for everything tools-related. Qt, WPF, WxWidgets and all that overengineered crap be damned. Just whip up a GL window and do all that stuff with a 10th of the code, no mind-boggling event handling crap and butter smooth rendering performance.

The only thing that’s missing for all types of UIs is skinnability. It would be outside the scope of ImGui (one of it’s nicest features is it’s narrow focus), but there should be a separate, skinnable game UI system that just works like ImGui.


SoLoud is a medium-level cross-platform audio lib that’s very well suited for projects that need to keep an eye on code- and asset-sizes. It fits somewhere between system-level sound APIs like OpenAL and high-level artist-centric audio solutions like FMOD. It has a very nicely designed simple and intuitive API which makes simple things simple but complex things possible (yes, really!). Most medium-level features (like playback or streaming of wav files, OGG support, various audio filters, SID, TED, MOD playback or speech generation) are optional in the sense that they don’t bloat your exe size if you don’t use them.

The special thing about SoLoud integration into Oryol is that it is not an ‘integration’ at all. There isn’t any glue code which wraps SoLoud into an Oryol module. Instead you just include the needed SoLoud headers and start using it. There is no need to simplify the API or pick a subset of features to make it ‘compatible’ with Oryol’s design philosophy and style, it just fits in.


Remotery is a runtime profiler in a single C header/source pair with realtime visualization running in a web browser. The code areas to be profiled are annotated with macros, and the Remotery runtime will measure the time between profiling events, aggregates them and sends them out over a WebSocket to the visualization web browser.

TurboBadger UI

I once integrated TurboBadger UI as a ‘game UI’ alternative to Dear ImGui (which is used for debug and tools UIs). Turbobadger is very powerful, it is skinnable, it has an ‘asset file format’ and all sorts of bells and whistles. But it is also a very heavy, old-fashioned UI: it has the traditional ‘big object tree’, thousands of refcounted small C++ objects living in a tree, lots of subclasses with lots of virtual methods, multiple inheritance (yuck) and so on. As such it doesn’t fit well into the Oryol design philosophy.

Of course it is much slimmer than ‘professional’ (ha..ha..) solutions like Scaleform, and I would prefer it over most other UI frameworks currently used in games (including those I wrote myself over the years), but it doesn’t have the immediately obvious brilliance of immediate UIs.

I will most likely move Turbobadger out of core Oryol into an optional addon module one day.


This is the test framework used in Oryol. There is nothing really special or fancy about UnitTest++, it just does it’s job. I guess that’s a good thing to say about a test framework. I would probably prefer it to be header-only so that integration into a project would be easier, so I still keep looking.

  • Source: I haven’t found an official source repo on github, so I just dropped everything into the fips-wrapper directory.
  • Fips Wrapper:
  • Used in: most Oryol modules
  • Platform: all native platforms (I also got it running on emscripten, but it’s a bit hacky and also redundant)


Curl is used to connect to HTTP servers on some platforms where HTTP support isn’t easily provided by the OS. It is very special compared to the other dependencies in that it isn’t compiled with the rest of the project, but instead it has been precompiled into static link libs. The reason is the terribly complex autoconf-based build system setup used by Curl at the time I wrote the Oryol HTTP module.

There is now official cmake support in curl which might make things easier (especially for Android), however even if this is the case I’m still looking for alternatives to curl, since it does much more than what Oryol actually needs (which is: HTTP, and in the future probably HTTPS and HTTP2).

I would love to see an stb-header-style lib that implements a fully conformant HTTP (and HTTP2) client, but this is no trivial task.

Other Great Stuff (TM)

The STB Headers

I’m a bit surprised that I don’t use any of the STB headers directly in Oryol, but I use them in other projects, and they are included in some of the 3rd party code listed here.

In the unlikely case that you never heard of them, the STB headers are basically the Platonic Ideal of what each library should try to achieve: they are header-only, written in plain C, don’t depend on external code, are fully configurable and have a liberal open-source license. All of this together makes them trivial to integrate into C++ projects, which can’t be said of most C++ libs unfortunately.

So far I have mainly used the STB image headers to wipe any dependencies to libjpeg, libpng (ugh) and DevIL, literally replacing hundreds of source files and a handful of complex build system setups with 3 simple headers (stb_image.h, stb_image_resize.h and stb_image_write.h).

There’s a lot more useful stuff, have a look here:

JSMN (JSON parser)

If I ever have to parse a JSON file, I’ll most likely use JSMN. In the past I have used cJSON, but this has (like many other JSON libs) the disadvantage that it performs (at least) one allocation for each JSON node. cJSON does have the advantage that it allows to write JSON files with simple code though.

enkiTS (threaded task scheduler)

So far I haven’t needed a true task system in Oryol yet, but when the time comes I’ll very likely first look into enkiTS. A general problem for Oryol is that emscripten doesn’t support traditional threads (well it does now, but this requires SharedArrayBuffers in browsers, not sure how wide-spread this is yet).

Recast (navigation/pathfinding)

As pathfinding solution I would first consider Recast. I already started to play around with it and wrote a fips wrapper but didn’t pursue this further yet since I didn’t yet have an idea for a cool Oryol sample with pathfinding.

Bullet (physics/collision)

For physics simulation I would start with Bullet since I know that it works well with emscripten. Other then that I haven’t played around with it yet (I only have extensive experience with ODE).

The End

And that’s it. Hopefully I will learn of many other great open source libraries in the future. In my experience, choosing the right middleware (and deciding what to tackle myself, and where to use other people’s code) has a huge effect on ‘programmer happiness’.

In the worst case, wrestling with bad middleware can make you hate your job and there’s already enough of this crap in ‘professional’ game development where middleware decisions are often not made for purely technical or even rational reasons. Don’t let this happen to you :)