README.md
# FLAW Engine
[](https://codeclimate.com/github/quyse/flaw)
[github](https://github.com/quyse/flaw) | [haddock](https://flaw.quyse.io/docs/) | [code climate](https://codeclimate.com/github/quyse/flaw) | [itch.io](https://quyse.itch.io/flaw) | [openhub](https://www.openhub.net/p/flaw-engine) | [hlint report](https://flaw.quyse.io/hlint.html) | [hpc report](https://flaw.quyse.io/hpc/combined/all/hpc_index.html)
**FLAW** is a highly experimental open source game engine written in Haskell.
## Motivation
FLAW is heavily based on my experiences from developing [Inanity engine](https://github.com/quyse/inanity). In short, the experiences are: C++ sucks, game development can be done better. It's time to discover new horizons by using Haskell in the area where it hasn't been used a lot (yet).
This project is mostly a playground for absolutely crazy ideas. Surely if someone managed to make a real game out of it, that game would be absolutely crazy too!
## Building
FLAW uses [stack](https://haskellstack.org/) for building. Note the assumption is that the project is to be built with `integer-simple` GHC, to be more commercial-friendly due to concerns about LGPL license of `GMP` library used by stock GHC (especially on Windows where GHC does not support dynamic linking of GMP). See `stack.yaml`, which refers to `integer-simple-snapshot.yaml` containing appropriate adjustments to some packages. If you don't have integer-simple GHC, or don't care about GMP, simply set `resolver` field in `stack.yaml` to desired snapshot directly and remove `ghc-variant: integersimple`.
## Binaries
Some binaries (built from CI) are available on [FLAW itch.io page](https://quyse.itch.io/flaw).
## What works
* Platform support: Windows, Linux, macOS, web (via GHCJS)
* Abstracted graphics API: DirectX 11, OpenGL, WebGL
* Abstracted inline shaders in Haskell, with HLSL and GLSL backends
* TH-generated math library, with efficient unboxed fixed-length vectors/matrices
* TH-based game build, type-safe game assets
* Low-level user input library (via Raw Input on Windows, SDL on Linux and macOS, browser DOM APIs on Web)
* Simple windowing API
* Fast text rendering with subpixel anti-aliasing
* Collada import (rigid and skinned geometries, animations)
* Basic physics (integration with Bullet physics engine)
## In progress
* Visual effects (deferred rendering, materials, lighting, shadowing, etc)
* High-level GUI framework made from scratch (i.e. neither using native GUIs nor frameworks like Qt)
* Real-time collaborative asset editor
* Type-safe multiplayer framework
## Experiments
* TH-based Lua-to-Haskell compiler.
## Plans
* TH-generated bindings for scripting languages
* Vulkan support
## Packages and platform support
Linux is the primary development platform. It also considered the only "server" platform, hence several "server" packages are tested only on Linux, although it's probably possible to compile and run them on Windows or macOS.
Here are all packages in A-Z order. Checkmark against a platform means that the package is being actually built and tested (if it has tests :D) on this platform during CI.
| Package | Description | Linux | Windows | macOS | Web (GHCJS) |
|---------------|-------------------------------------------------------------|:---:|:---:|:---:|:---:|
| `flaw-al` | OpenAL integration - implementation of `flaw-audio` interface | ✔ | ✔ | ✔ | |
| `flaw-app` | Handy engine initialization and main loop routines | ✔ | ✔ | ✔ | ✔ |
| `flaw-asset` | Packing and unpacking assets into asset packs | ✔ | ✔ | ✔ | ✔ |
| `flaw-asset-dxt` | DXT image compression based on [fork](https://gitlab.com/quyse/libsquish) of [libsquish](https://code.google.com/p/libsquish/) library | ✔ | ✔ | ✔ | |
| `flaw-asset-wai` | Asset distribution for web games with perfect caching | ✔ | | | |
| `flaw-audio` | General interface for audio device | ✔ | ✔ | ✔ | ✔ |
| `flaw-base` | Base primitives (resource management, concurrency, etc) | ✔ | ✔ | ✔ | ✔ |
| `flaw-build` | Embedding data into executable | ✔ | ✔ | ✔ | ✔ |
| `flaw-bullet` | Initial integration with Bullet Physics engine | ✔ | ✔ | ✔ | |
| `flaw-canvas` | Very simple 2D drawing | ✔ | ✔ | ✔ | ✔ |
| `flaw-collada` | Importing Collada assets | ✔ | ✔ | ✔ | |
| `flaw-dx11` | DirectX 11 integration - implementation of `flaw-graphics` interface | | ✔ | | |
| `flaw-editor` | Visual asset editor (WIP) | ✔ | ✔ | ✔ | |
| `flaw-ffi` | Interoperation with native code | ✔ | ✔ | ✔ | ✔ |
| `flaw-ffmpeg` | Experimental bindings to `ffmpeg` | ✔ | | ✔ | |
| `flaw-font` | General interface for font rendering | ✔ | ✔ | ✔ | |
| `flaw-font-fhi` | Implementation of `flaw-font` interface using FreeType + Harfbuzz + ICU | ✔ | ✔ | ✔ | |
| `flaw-font-icu` | Separate ICU package | ✔ | ✔ | ✔ | |
| `flaw-game` | Non-finished experimental stuff about game synchronization | ✔ | ✔ | ✔ | ✔ |
| `flaw-gamejolt-webapi` | GameJolt Web API | ✔ | | | |
| `flaw-gl` | OpenGL integration - implementation of `flaw-graphics` interface | ✔ | ✔ | ✔ | ✔ |
| `flaw-gl-mesa` | Experimental MESA integration for offscreen software rendering | ✔ | | | |
| `flaw-gl-sdl` | OpenGL-to-windowing binding via SDL | ✔ | | ✔ | |
| `flaw-gl-win32` | OpenGL-to-windowing binding via Win32 API | | ✔ | | |
| `flaw-graphics` | General interface for graphics | ✔ | ✔ | ✔ | ✔ |
| `flaw-input` | General user input interface | ✔ | ✔ | ✔ | ✔ |
| `flaw-itch-webapi` | Itch.io Web API | ✔ | | | |
| `flaw-js` | Some generic javascript routines | | | | ✔ |
| `flaw-lmdb` | LMDB binding | ✔ | ✔ | ✔ | |
| `flaw-lua` | Experimental Lua-to-Haskell translator | ✔ | ✔ | ✔ | |
| `flaw-lua-refimpl` | Lua reference implementation from lua.org | ✔ | ✔ | ✔ | |
| `flaw-math` | Math library | ✔ | ✔ | ✔ | ✔ |
| `flaw-math-determ` | Deterministic math library | ✔ | ✔ | ✔ | |
| `flaw-network` | Some network socket implementations (WIP) | ✔ | ✔ | ✔ | ✔ |
| `flaw-oil` | Reimplementation of [Oil protocol](https://github.com/quyse/oil) | ✔ | ✔ | ✔ | |
| `flaw-oil-client` | Simple command-line client for Oil protocol | ✔ | ✔ | ✔ | |
| `flaw-oil-server` | Server for Oil protocol | ✔ | | | |
| `flaw-physics` | General interface for physics simulation | ✔ | ✔ | ✔ | ✔ |
| `flaw-script` | Scripting in Haskell | ✔ | ✔ | ✔ | |
| `flaw-sdl` | Integration with SDL 2 | ✔ | | ✔ | |
| `flaw-sl` | Generic shader languages helping code | ✔ | ✔ | ✔ | ✔ |
| `flaw-social` | Some social network integration | ✔ | | | ✔ |
| `flaw-sqlite` | SQLite binding | ✔ | ✔ | ✔ | |
| `flaw-steam` | General definitions for Steam API | ✔ | ✔ | ✔ | |
| `flaw-steam-encryptedticket` | Steam encrypted ticket library bindings | ✔ | | | |
| `flaw-steam-webapi` | Steam Web API | ✔ | | | |
| `flaw-ui` | UI library using `flaw-graphics` for rendering | ✔ | ✔ | ✔ | |
| `flaw-ui-default-style` | Hardcoded "default" UI styles | ✔ | ✔ | ✔ | |
| `flaw-visual` | High-level rendering techniques | ✔ | ✔ | ✔ | |
| `flaw-vulkan` | Vulkan integration - implementation of `flaw-graphics` interface | ✔ | | | |
| `flaw-websocket-client` | Websocket client library | | | | ✔ |
| `flaw-websocket-server` | Websocket server library | ✔ | | | |
| `flaw-window` | Windowing platform bindings and graphics support | ✔ | ✔ | ✔ | ✔ |