nCine: a world with custom in-house engines is possible

class: middle, center

# nCine: a world with custom in-house engines **is** possible
Angelo "_Encelo_" Theodorou

!["nCine banner"](img/ncine/banner.png)

---

# The author 👴

- Born in 1983, grown up with C= Amigas for ten years (1991- 2001)
  - Fell in love with Amiga games and its demoscene
- An everyday desktop *nix user for almost 25 years
  - Using Arch Linux daily since 2005
- Interested in low-level coding and computer graphics
- Engine and graphics programmer for mobile and console games
  - Natural Motion's Echo engine (Clumsy Ninja, Dawn of Titans)
  - EA Frostbite (FIFA 18-20, Battlefield V, Battlefront II, Anthem)
  - Bethesda's Creation Engine 2 (Starfield)
- Developing the nCine since June 2011

---

## What is a custom in-house engine? 🤔

- Custom: developed alongside a game to serve its needs
- In-house: tech and game teams work under the same roof

- With lots of **exceptions**:
  - Can be reused for multiple games (RAGE)
  - Can be licensed to other studios (id Tech)
  - Can be developed by a specific division within a company (Frostbite)

- The **opposite** of this is a generic software technology
  - Can be used to develop different types of games
  - Distributed or sold by a specialized (sometimes non-game) company
  - Think of Unreal, Unity, CryEngine, Godot, GameMaker, …

- Custom engines are especially employed in AAA games
  - But there are some notable indie exceptions 💪

---

## Can't you just use Unity/Unreal like everyone else?
### Yes, but also no. 😏

---

## Can't you just use Unity/Unreal like everyone else? #0

![:scale 720px](img/Unity_pricing.png)

![:scale 720px](img/Unity_cancels_fee.png)

Well, we all know how well it went... 😅

---

## Can't you just use Unity/Unreal like everyone else? #1

Articles on this theme:
- [On the Perceived Inevitability of Unreal](https://alextardif.com/Unreal.html) by _Alex Tardif_
- [Ships, Icebergs, Game Engines](https://www.rfleury.com/p/ships-icebergs-game-engines) by _Ryan Fleury_
- [A case for building your own tech | Opinion](https://www.gamesindustry.biz/a-case-for-building-your-own-tech-opinion) by _Dan Baker_
- [Handmade Network](https://handmade.network/)

List of game engines and frameworks:
- [Custom Game Engines: A Small Study](https://gist.github.com/raysan5/909dc6cf33ed40223eb0dfe625c0de74) by _raysan5_
- [Indie Bookmarks: some indie games and their technology](https://docs.google.com/spreadsheets/d/1z1RV6w4HjPODFcao34h72Vw-9KxtQ9rv0ZM7folTUMU/edit#gid=0) by _Encelo_

---

## Can't you just use Unity/Unreal like everyone else? #2

The author is a Lead Graphics Programmer at ZeniMax Online Studios.
- In-house engine development has declined over the last decade
- The pool of game engine and graphics talent is shrinking
- Independent game middlewares are dead (bought by Unity/Epic)
- The framework and tooling infrastructure is too much work

(From "_On the Perceived Inevitability of Unreal_" by Alex Tardif)

---

## Can't you just use Unity/Unreal like everyone else? #3

Written just after _The Machinery_ was obliterated from the face of the Earth.
- When you give up ownership, you give up your rights
- You lose your agency over time, money, professional development
- Something that is more abstract exposes fewer capabilities
  - Not everything you could do in your own engine is possible in a pre-built game engine
- The "_don't reinvent the wheel_" mantra diminishes ownership and scoffs at self-reliance

(From "_Ships, Icebergs, Game Engines_" by Ryan Fleury)

---

## Can't you just use Unity/Unreal like everyone else? #4

Written by Oxide Games' co-founder and CTO.
- Innovation and unique gameplay: build a game that breaks the mold
- Attract top devs who want to leave a mark, solve novel problems, work on cutting-edge technology
- Custom tech can be initially expensive, but the investments can yield long-term savings
- It seems Unity and Unreal won't stay inexpensive and perpetual
- A custom engine usually compiles faster and runs faster in debug
- Some games have technological requirements that off-the-shelf engines cannot satisfy
- Even off-the-shelf solutions need a technical investment for customization

(From "_A case for building your own tech | Opinion_" by Dan Baker)

---

## Can't you just use Unity/Unreal like everyone else? #5

- Computers are amazing
- So why is software so terrible?
  - Slow to load, thirsty on batteries, crashes all the time
- We made it terrible
  - We ignored the hardware, we glued together libraries so we didn't have to learn, we built layers on top of layers until no one knew how anything worked
  - We're building Rube Goldberg machines, and users are paying the cost.
- But there is another way
  - We can build software that works with the computer, not against it. All you need is an open mind and a sense of curiosity.

(From the _Handmade Network Manifesto_)

![:scale 240px](img/RubeGoldberg.png)

---

# They didn't use Unity/Unreal
## Some examples from the indie ecosystem

---

# They didn't use Unity/Unreal #1

**Spelunky Classic**, 21/12/2008 (GameMaker)

![:scale 720px](img/games/Spelunky.jpg)

**Spelunky HD** and **Spelunky 2** use a custom engine

---

# They didn't use Unity/Unreal #2

**Legend of Grimrock**, 11/04/2012, by _Almost Human Games_ (Custom)

![:scale 720px](img/games/Legend_of_Grimrock.jpg)

**Legend of Grimrock 2** also made with the same custom engine

---

# They didn't use Unity/Unreal #3

**Little Inferno**, 19/11/2012, by _Tomorrow Corporation_ (Custom)

![:scale 720px](img/games/Little_Inferno.jpg)

**World of Goo**, **Human Resource Machine**, and **7 Billion Humans** are all based on a custom engine too

---

# They didn't use Unity/Unreal #4

**Guacamelee!**, 09/04/2013, by _DrinkBox Studios_ (Custom)

![:scale 720px](img/games/Guacamelee.jpg)

**Guacamelee! 2** also on a custom engine

---

# They didn't use Unity/Unreal #5

**Don't Starve**, 23/04/2013, by _Klei Entertainment_ (Custom)

![:scale 720px](img/games/Dont_Starve.jpg)

Most of their games are made with custom technology (**Mark of the Ninja**, **Invisible, Inc.**, **Griftlands**), **Oxygen Not Included** is made with Unity 😢

---

# They didn't use Unity/Unreal #6

**Hammerwatch**, 12/08/2013, by _Crackshell_ (Custom)

![:scale 720px](img/games/Hammerwatch.jpg)

**Heroes of Hammerwatch** and **Hammerwatch 2** use a custom engine too

---

# They didn't use Unity/Unreal #7

**Banished**, 18/02/2014, by _Shining Rock Software_ (Custom)

![:scale 720px](img/games/Banished.jpg)

His next solo game also runs on custom technology

---

# They didn't use Unity/Unreal #8

**Shovel Knight**, 26/06/2014, by _Yacht Club Games_ (Custom)

![:scale 720px](img/games/Shovel_Knight.jpg)

**Pocket Dungeon** made with GameMaker Studio, **Mina the Hollower** with a custom engine

---

# They didn't use Unity/Unreal #9

**Crypt of the Necrodancer**, 23/04/2015, by _Brace Yourself Games_ (Custom)

![:scale 720px](img/games/Crypt_of_the_Necrodancer.jpg)

**Industries of Titan** made with UE4 🤷

---

# They didn't use Unity/Unreal #10

**Victor Vran ARPG**, 24/07/2015, by _Haemimont Games_ (HaemimontSol)

![:scale 720px](img/games/Victor_Vran.jpg)

All their games are made with their custom engine, including **Surviving Mars**, **Tropico 3-4-5**, **Jagged Alliance 3**

---

# They didn't use Unity/Unreal #11

**Prison Architect**, 06/10/2015, by _Introversion Software_ (Custom)

![:scale 720px](img/games/Prison_Architect.jpg)

---

# They didn't use Unity/Unreal #12

**Darkest Dungeon**, 19/01/2016, by _Red Hook Studios_ (Custom)

![:scale 720px](img/games/Darkest_Dungeon.jpg)

**Darkest Dungeon 2** runs on Unity 😢

---

# They didn't use Unity/Unreal #13

**Stardew Valley**, 26/02/2016, by _ConcernedApe_ (XNA, then MonoGame)

![:scale 720px](img/games/Stardew_Valley.webp)

**Haunted Chocolatier** is in development using MonoGame

---

# They didn't use Unity/Unreal #14

**Celeste**, 25/01/2018, by _Matt Makes Games_ (FNA and MonoGame)

![:scale 720px](img/games/Celeste.jpg)

---

# They didn't use Unity/Unreal #15

**Into the Breach**, 27/02/2018, by _Subset Games_ (Custom)

![:scale 720px](img/games/Into_The_Breach.jpg)

**Faster Than Light** also made with a custom engine

---

# They didn't use Unity/Unreal #16

**Yoku's Island Express**, 29/05/2018, by _Villa Gorilla_ (Custom)

![:scale 720px](img/games/Yokus_Island_Express.jpg)

---

# They didn't use Unity/Unreal #17

**Dead Cells**, 06/08/2018, by _Motion Twin_ ([Heaps](https://heaps.io/))

![:scale 720px](img/games/Dead_Cells.png)

All _Shiro Games_ titles are made with Heaps too (**Evoland**, **Evoland 2**, **Northgard**, **Darksburg**, **Dune: Spice Wars**)

---

# They didn't use Unity/Unreal #18

**Wargroove**, 01/02/2019, by _Chucklefish Games_ ([Halley](https://github.com/amzeratul/halley))

![:scale 720px](img/games/Wargroove.jpg)

**Wargroove2** and **Witchbrook** also on the same engine

---

# They didn't use Unity/Unreal #19

**Pathway**, 11/04/2019, by _Robotality_ (Custom)

![:scale 720px](img/games/Pathway.jpg)

[Devlog #18: The Art and Tech behind Pathway](https://steamcommunity.com/games/546430/announcements/detail/1700601856676355706)

---

# They didn't use Unity/Unreal #20

**Factorio**, 14/08/2020, by _Wube Software_ (Custom)

![:scale 720px](img/games/Factorio.jpg)

---

# They didn't use Unity/Unreal #21

**Hades**, 17/09/2020, by _Supergiant Games_ ([The Forge](https://theforge.dev/))

![:scale 720px](img/games/Hades.jpg)

Previous games are all made with XNA or MonoGame (**Bastion**, **Transistor**, **Pyre**)

---

# They didn't use Unity/Unreal #22

**Eastward**, 16/09/2021, by _Pixpil_ (MOAI)

![:scale 720px](img/games/Eastward.jpg)

"Behind the garage scene. Showing deferred buffers." from [Twitter](https://twitter.com/pixpilgames/status/661845634845020161)

---

# They didn't use Unity/Unreal #23

**The Riftbraker**, 14/10/2021, by _EXOR Studios_ (Custom)

![:scale 720px](img/games/The_Riftbraker.jpg)

---

# They didn't use Unity/Unreal #24

**Teardown**, 21/04/2022, by _Tuxedo Labs_ (Custom)

![:scale 720px](img/games/Teardown.jpg)

---

# They didn't use Unity/Unreal #25

**Return To Monkey Island**, 19/09/2022, by _Terrible Toybox_ (Custom)

![:scale 720px](img/games/RTMI.jpg)

**Thimbleweed Park** also made with the same custom engine

---

# They didn't use Unity/Unreal #26

**Balatro**, 20/02/2024, by _LocalThunk_ (LÖVE)

![:scale 720px](img/games/Balatro.jpg)

---

# They didn't use Unity/Unreal #27

**Norland**, 16/05/2024, by _Long Jaunt_ (GameMaker Studio)

![:scale 720px](img/games/Norland.jpg)

[The Four Elements and Their Graphic Effects: Exploring Shaders in a 2D Game](https://hackernoon.com/the-four-elements-and-their-graphic-effects-exploring-shaders-in-a-2d-game)
[Simulation of three-dimensional buildings in a 2D game](https://www.norlandgame.com/post/simulation-of-three-dimensional-buildings-in-a-2d-game)

---

# The nCine ⚙️

---

# What is nCine?

- Encelo + engine = nCine 😏
- Cross-platform 2D game framework
  - Linux, Windows, macOS, Android, Emscripten, MinGW-w64
  - Tested on: Nvidia Shield, Asus ZenWatch 1, Raspberry Pi, Steam Deck
  - Supports multiple compilers: GCC, Clang, MSVC, AppleClang
- Suitable for games, prototypes, tools, demos
- [Open source](https://github.com/nCine) with a MIT license
- Small enough to be fully understood by one person

---

# Main Features #1

- Written in C++11 but can be scripted with Lua
- Uses OpenGL 3.3 and ES 3.0 for graphics, OpenAL for the audio
- Can load and save PNG and WebP images (via libpng and libwebp)
  - Can also load GPU-compressed formats like ASTC, ETC2, PVR, DXT, etc.
- Can load WAVE sounds or stream Vorbis music (via libogg and libvorbis)
- Automatic culling and batching of sprites
  - Sprites can be rectangles or 2D meshes, with spritesheet animations
- Custom user shaders without sacrificing automatic batching
- Multiple viewports (for split-screen or post-processing)
- Bitmap font rendering with kerning pairs and Unicode characters
- Logging system with multiple levels, and console or file output

---

# Main Features #2

- nCTL custom template library used in place of STL
  - Containers (arrays, lists, hashmaps, sparse sets), iterators, algorithms
  - Unique and shared smart pointers
- Basic math library for vectors, 4x4 matrices and quaternions
- Custom code for strings, atomic operations, monotonic clocks
- Custom memory allocators (linear, stack, pool, free-list)
- Filesystem functions for queries and operations on files and directories
- Thread pool creation, synchronization, and affinity assignment
- Can use GLFW, SDL2, or Qt5 as desktop backends
- Gamepad support with SDL2 gamepad mapping strings on all backends
- Integration with [Dear ImGui](https://github.com/ocornut/imgui) and [Nuklear](https://github.com/Immediate-Mode-UI/Nuklear) for user interfaces
- Integration with [RenderDoc](https://renderdoc.org/) (gfx debugger) and [Tracy](https://bitbucket.org/wolfpld/tracy) (frame profiler)

---

# Main Features (screenshots #1)

![:scale 360px](img/ncine/RenderDoc_capture.png)
![:scale 360px](img/ncine/tracy.png)
![:scale 360px](img/ncine/apptest_camera_debug.png)
![:scale 360px](img/ncine/lua_scripting.png)

Sprite batching, Tracy integration, ImGui debug overlay, Lua scripting

---

# Main Features (screenshots #2)

![:scale 360px](img/ncine/apptest_viewports.png)
[![:scale 360px](img/ncine/apptest_shaders.png)](https://www.youtube.com/watch?v=T1XRrK77u6M)
[![:scale 360px](img/ncine/apptest_allocators.png)](https://www.youtube.com/watch?v=2kAoyVvgLyo)
![:scale 360px](img/ncine/apptest_font.png)

Multiple viewports, custom shaders, custom allocators test, text rendering

---

# Development Tools

- [CMake](https://cmake.org/) and CPack for build and installation on all platforms
- [Google Test](https://github.com/google/googletest) for unit testing and [Benchmark](https://github.com/google/benchmark) for micro-benchmarks
- [Gcovr](http://gcovr.com/) for unit test coverage
- [GitHub Actions](https://github.com/features/actions) for Continuous Integration
- [Cppcheck](http://cppcheck.sourceforge.net/) for static C/C++ code analysis
- [Valgrind](http://valgrind.org/) and AddressSanitizer (ASAN) for memory debugging
- [clang-format](https://clang.llvm.org/docs/ClangFormat.html) for automatic code formatting
- [Doxygen](http://www.stack.nl/~dimitri/doxygen/) for documentation (extracted from source comments)

---

# Development Tools (screenshots)

![:scale 360px](img/ncine/coverage.png)
![:scale 360px](img/ncine/doxygen.png)
![:scale 360px](img/ncine/gtest.png)
![:scale 360px](img/ncine/valgrind.png)

Gcovr, Doxygen, Google Test, Valgrind

---

# Lines of code

```
/-------------------------------------------------------------------------------\
|Language                     files          blank        comment           code|
|-------------------------------------------------------------------------------|
|C++                            376          16634           3186          81469|
|C/C++ Header                   343           7334           4097          30250|
|CMake                           44            711            386           5648|
|YAML                             7            177             12            883|
|XML                              2              0              1            722|
|Lua                              8            137              5            531|
|GLSL                            21             67              0            340|
|Markdown                         1             10              0             63|
|Gradle                           2              1              0             23|
|INI                              1              2              0             10|
|-------------------------------------------------------------------------------|
|SUM:                           805          25073           7687         119939|
\-------------------------------------------------------------------------------/
```

Just the main `nCine` repository, not including any external projects

---

# Some projects #1

[![:scale 720px](img/ncine/jazz2.png)](https://www.youtube.com/watch?v=kiZKZnbqo6I)

[Jazz² Resurrection](http://deat.tk/jazz2/), a Jazz Jackrabbit 2 reimplementation by _deathkiller_

---

# Some projects #2

[![:scale 720px](img/ncine/ncJugiMapFrameworkDemo.png)](https://www.youtube.com/watch?v=3TBFN3VwXZ4)

[JugiMap](http://jugimap.com/), a level editor that integrates with nCine, by _Jugilus_

---

# Some projects #3

[![:scale 720px](img/ncine/ncJump.png)](https://www.youtube.com/watch?v=ZKdDtJiIUdo)

[ncJump](https://www.antoniocaggiano.eu/posts/ncjump-devlog/), a platform with Box2D physics and integrated editor, by _Fahien_

---

# Some projects #4

[![:scale 720px](img/ncine/SpookyGhost.png)](https://www.youtube.com/watch?v=PqrigZ-3JoM)

[SpookyGhost](https://encelo.itch.io/spookyghost), a tool to create procedural animations for sprites, by _Encelo_

---

# Some projects #5

![:scale 720px](img/ncine/ncTracer.png)

[ncTracer](https://github.com/encelo/ncTracer), a simple brute-force multi-threaded CPU path tracer

---

# Some projects #6

![:scale 720px](img/ncine/ncTiledViewer.png)

[ncTiledViewer](https://github.com/nCine/ncTiledViewer), a loader for the Tiled TMX map format (using `pugixml`)

---

# Some projects #7

[![:scale 720px](img/ncine/ncParticleEditor.png)](https://www.youtube.com/watch?v=RLNI5NMCJ1E)

[ncParticleEditor](https://github.com/nCine/ncParticleEditor), an ImGui editor for the nCine particle system

---

# Some projects #8

[![:scale 720px](img/ncine/ncInvaders.png)](https://www.youtube.com/watch?v=31k4adykiNA)

[ncInvaders](https://github.com/nCine/ncInvaders), a simple version of Space Invaders

---

# Some projects #9

[![:scale 720px](img/ncine/ncPong.png)](https://www.youtube.com/watch?v=5lSYZtRQhgQ)

[ncPong](https://github.com/nCine/ncPong), an example game also available in Lua

---

# Recent developments

- Latest big features added:
  - Binary shader cache (helps with slow shader compilation time with ANGLE on UWP/Xbox)
  - OpenAL EAX/EFX audio effects and filters
- On hold but nearly complete:
  - [Crashpad](https://chromium.googlesource.com/crashpad/crashpad/) integration for crash reporting (probably with missing Android support 😢)
- Work in progress:
  - Multi-threading job system (lock-free queue with job stealing, parent/children jobs, continuations, parallel for)
- What's next:
  - An editor? Vulkan support? ECS with data oriented design? a game?

---

# Future tasks and ideas

- Better documentation, tutorials, and site presentation
- Full-fledged ImGui editor
- Graphics API abstraction and Vulkan backend
- Lock-free multi-threaded jobs system and data-oriented ECS
- Bindings for Rust/Haxe, scripting integration with Wren/AngelScript
- A simple free game to release on Itch.io and/or Steam
- Box2D integration for physics and collisions
- Metal backend and thus iOS port
- A game jam with prizes

---

# Links

- Site: https://ncine.github.io/
- GitHub: https://github.com/nCine/
- Twitter: https://twitter.com/nCine2D
- Discord: https://discord.gg/495ab6Y
- YouTube: https://www.youtube.com/@ncine
- Blog: https://encelo.github.io/tags/#nCine

### Questions?