Kiln

C99 game engine. Vulkan renderer, archetype ECS, asset pipeline, scene editor. Linux/Win32.

Kyub (the voxel game built on it) lives at zexk/kyub.

Modules

render: Vulkan, dynamic rendering, no render pass objects. HDR offscreen target, bloom (threshold + gaussian + Reinhard), cascaded shadow maps (3 cascades, PCF 3x3), point lights (up to 8, Blinn-Phong), normal mapping, instanced draws, GPU-driven frustum culling (compute), skybox, GPU particles (compute), screenshot readback.

ecs: archetype-based world. query_iter / query_next / query_get.

voxel: chunked voxel world — greedy meshing, per-LOD on-demand remesh, distance-sorted streaming, O(1) slot lookup.

settings: engine + key-binding settings with INI persistence (vsync, fps limit, fov, mouse sensitivity, bloom, rebindable actions).

texture: deduplicating array/layered texture builder over kiln_assets image decode.

platform: window, event loop. X11 and Win32 backends.

core: linalg, AABB, frustum, noise (Perlin + fBm), arena allocator, timer, logging, file I/O.

camera: orbit and FPS.

ui: immediate-mode panels, sliders, buttons, text, graph strip.

gizmo: screen-space translate/rotate/scale gizmo.

assets: OBJ loader, kmesh binary format, STB image, scene serializer (.kscn).

app: scene editor. Orbit/FPS camera, entity spawn from templates, ray-cast pick (AABB + Moller-Trumbore), transform gizmo, scene save/load, light controls, debug panel.

physics: AABB voxel collision.

Build

nix develop
ninja -C build

Without Nix (Linux, X11, Vulkan SDK required):

cmake -B build -G Ninja
ninja -C build

Cross-compile for Windows from Linux:

nix build .#win32

Run

./build/src/app/kiln        # scene editor

Test models are not in git. Fetch them:

bash assets/models/fetch.sh

Downloads CC0 OBJ meshes from alecjacobson/common-3d-test-models and bakes to .kmesh.

Demos

Buffon's Needle: 3D physics simulation estimating pi by dropping needles onto a ruled plane. WASD/mouse to fly, +/- to scale speed, Space to pause, R to reset.

./build/demos/buffon/buffon        # Linux
nix build .#buffon                 # Linux (Nix)
nix build .#buffon-win32           # Windows cross-compile

As a library

Games can pull kiln in as a Nix flake input and use lib.mkKilnGame:

inputs.kiln.url = "github:zexk/kiln";

packages.default = kiln.lib.mkKilnGame {
  inherit pkgs;
  pname = "mygame";
  src = ./.;
};

The game's CMakeLists.txt receives -DKILN_DIR pointing at kiln's store path and links against kiln_renderer, kiln_ecs, kiln_core, etc. For local builds without Nix, set KILN_DIR manually or use kiln as a git submodule at extern/kiln.

Structure

src/
  core/       math, noise, AABB, frustum, arena, timer, log, file I/O
  platform/   X11 / Win32 window and events
  ecs/        archetype ECS
  camera/     orbit + FPS camera
  render/     Vulkan renderer + shaders
  voxel/      chunked voxel world (meshing, LOD, streaming)
  ui/         immediate-mode UI
  gizmo/      transform gizmo
  assets/     OBJ, kmesh, STB image, scene format
  texture/    array/layered texture builder
  settings/   engine + key-binding settings (INI)
  physics/    AABB voxel collision
  app/        scene editor (entry point)
  tools/      kiln-bake (OBJ -> kmesh)
demos/        standalone demos (Buffon's needle, ...)
tests/        unit tests (arena, ECS, math)
assets/
  models/     .kmesh files (gitignored; fetch.sh downloads OBJ sources)

Environment variables

Variable	Purpose
KILN_SHADER_DIR	override compiled .spv search path
KILN_UI_SHADER_DIR	override compiled HUD .spv search path
KILN_ASSET_DIR	override asset root

License

MIT. Test meshes from alecjacobson/common-3d-test-models (CC0).