darmok

C++ game engine combining opensource libraries & tools that I like

currently using:

• bgfx as the renderer
• CMake as the build system
• vcpkg as the package manager
• glm for 3d math
• EnTT as the entity component system
• assimp for generic asset loading (not in runtime)
• sol2 modern C++ bindings for lua
• nlohmann-json for parsing json
• pugixml for parsing xml
• imgui for editor UI
• RmlUI for ingame UI
• ozz for 3d skeletal animations
• cereal for serialization
• Jolt for 3D physics
• miniaudio for audio
• taskflow for multithreading
• tiny-process-lib to run os processes
• mikktspace - to calculate tangents
• middleclass - small object orientation lua lib

planned to use:

• tracy for frame profiling (blocked because of bgfx#3308 and the vcpkg bgfx build not having a profiler feature)
• recast navigation for pathfinding
• BehaviorTree.CPP for behavior trees
• Box2D 2D physics
• ldtk for 2D level editor
• spine for 2d skeletal animations

Trying to target the following platforms:

• desktop (windows, macos, linux)
• mobile (iOS, Android) (pending)

Some philosofical decisions (could be controversial)

• use modern C++ (20) patterns where possible
• use as much stl as possible (need to look into memory management at some point)
• no naked pointers
• throw exceptions for error handling
• try to keep the API similar to Unity3D (where it makes sense) so that it's easy to port game logic

WARNING: currently in early stages of development

Frequently Asked Questions

• Will it have feature X?

Depends on what I need. Anyone is welcome to fork and submit PRs.

Current State

I'm still learning CMake, so if you see something that should be fixed please let me know.

Working features

• bgfx window setup (GLFW on windows & linux)
• update logic methods with delta time
• renderer
  • point, spot, directional & ambient lights
  • forward render
    • unlit, gui
    • basic phong
    • PBR metallic-roughness
  • cascaded shadow mapping
  • spot & point light shadows
  • camera culling (frustum, occlusion seems to be broken)
• entity component scene using entt
  • transform, camera
  • type filtering
  • serialization
  • lights
  • free look
• sprites and spritesheets
• loading models using assimp (FBX, gltf, etc...)
• serializing models from assimp into binary using cereal
• lua scripting
  • lua debugging
  • coroutines similar to unity
• multiple UI options
  • imgui for tooling
  • RmlUI for ingame (support for multiple canvases)
• skeletal animations using ozz (reading from binary)
• 3d physics using jolt
  • rigidbodies
  • character controller
• tool to export asset folders
  • shaders & vertex layouts
  • copy files
  • assimp to custom binary model format
  • ozz skeleton & animations
• dynamic font texture generation
• play sounds and music (wav & mp3)

Upcoming

• frame limiting
• more renderer features
  • bloom
  • deferred, clustered
  • SSAO
• luajit support (maybe compile using importer)
• text improvements
  • finish all the TextRenderConfig options
  • dynamic distance field rendering with border support
• clipboard text support (UTF8)
• asset loading progress (maybe implement progressive loading)
• possible refactors
  • maybe replace Data for std::vector<uint8_t> and DataView for std::span<uint8_t>
  • loaders should return unique_ptr
  • move lua bindings to separate library?
  • C++ coroutines could be useful in some places
• more stuff serialization
  • binary texture atlas
  • material
• custom UI module (rmlui is nice but slow)

In the future

• fix occlusion culling
• more unit tests
• performance profiling
• 2d physics
• instancing
• 3d physics materials
• multithreaded updates (Ubisoft)
• support multiple imgui app components with different transforms
• spine animations
• unify use of allocators everywhere
• progressive asset loaders
• lua debugging would be nice
• particle systems (maybe effekseer)
• more sound options (spatialization, effects)
• animation root motion
• openusd scene format support
• a game editor would be a huge undergoing, but maybe using wxWidgets

Interesting Related Projects

• SuperNovaEngine a very similar engine but much more advanced
• Cluster - PBR shaders for bgfx
• dome engine - minimalist engine with wren as the scripting language
• RaZ engine - C++17 game engine
• meshoptimizer
• forward+ - description of tiled forward renderer in DirectX 11

Example code

function init()
    local program = Program.new(StandardProgramType.Forward)

    local scenes = app:add_component(SceneAppComponent)
    local scene = scenes.scene

    local camEntity = scene:create_entity()
    local camTrans = camEntity:add_component(Transform, { 0, 1, -1 })
    camTrans:look_at({ 0, 0, 0 })
    local cam = camEntity:add_component(Camera)
    cam:set_viewport_perspective(60, 0.3, 1000)
    cam:add_component(ForwardRenderer)
    cam:add_component(LightingRenderComponent)

    local lightEntity = scene:create_entity()
    lightEntity:add_component(AmbientLight, 0.2)
    lightEntity:add_component(Transform, { 1, 1, -1 })
    local light = lightEntity:add_component(PointLight, 2)
    light.radius = 5

    local mesh = MeshData.new_sphere():create_mesh(program.vertex_layout)
    scene:create_entity():add_component(Renderable, mesh, program, Color.green)
end