https://github.com/gugdun/crank
Game engine built around BSP maps, written in C and powered by Raylib
https://github.com/gugdun/crank
bsp c cross-platform game-engine raylib
Last synced: 6 days ago
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Game engine built around BSP maps, written in C and powered by Raylib
- Host: GitHub
- URL: https://github.com/gugdun/crank
- Owner: gugdun
- License: gpl-2.0
- Created: 2026-05-10T21:42:55.000Z (about 2 months ago)
- Default Branch: main
- Last Pushed: 2026-05-25T09:41:21.000Z (about 1 month ago)
- Last Synced: 2026-05-25T11:25:33.951Z (about 1 month ago)
- Topics: bsp, c, cross-platform, game-engine, raylib
- Language: C
- Homepage:
- Size: 416 KB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Agents: AGENTS.md
Awesome Lists containing this project
README
# Crank
Game engine built around Quake II BSP maps, written in C and
powered by [Raylib](https://www.raylib.com/).
## Features
- Quake II BSP (version 38) loader with entity, visibility, and brush parsing
- World mesh built once at load time and uploaded to the GPU
- Static lightmap atlas with shelf packing and 1-luxel padding
- Diffuse * lightmap shading via a custom GLSL shader
- Six-face skybox rendering
- Minimal ECS runtime for entity/component management
- JSON entity archetypes: BSP entities are matched to JSON definitions
and spawned into the world automatically
- GoldSrc-style first-person physics (walk, air-move, step-slide, jump,
noclip fly mode)
- Fixed-rate physics (128 Hz) with render-time interpolation
- PVS + frustum culling with dynamic per-surface index buffers
## Asset directories
These are NOT committed to the repository. Create them in the working
directory before running the engine:
- **`maps/`** — Quake II `.bsp` files. The map name passed on the command
line is resolved as `maps/.bsp`.
- **`textures/`** — Diffuse textures as `.png` files. The directory
structure must mirror the texture names referenced in the BSP's texinfo
lump. For example, if a face references `e1u1/floor1_2`, place the image
at `textures/e1u1/floor1_2.png`.
- **`env/`** — Skybox textures as `.png` files, one per face,
named `.png` where suffix is one of `ft`, `bk`, `lf`,
`rt`, `up`, `dn`. The sky name is read from the `worldspawn` entity's
`sky` key, defaulting to `unit1_`.
- **`entities/`** — JSON entity archetype files. Each file is named
`.json` and defines the components that make up that entity
type. When a map is loaded, every entity in the BSP entity lump is
matched to a JSON file by its `classname` and spawned into the ECS world.
The `shaders/` directory IS in the repository and is copied next to the
executable automatically by the CMake build.
## Building
Requirements:
- CMake 3.21 or newer
- A C11-capable C compiler (GCC or Clang)
- An OpenGL 3.3 capable GPU and drivers
- Build dependencies needed by Raylib's bundled GLFW
(X11 headers on Linux: `libx11-dev`, `libxrandr-dev`, `libxinerama-dev`,
`libxcursor-dev`, `libxi-dev`)
Raylib itself is fetched and built automatically by CMake.
```sh
cmake -S . -B build
cmake --build build
```
The output binary is `build/crank`.
## Running
From the project root (so the executable can see the asset directories
either by symlink or by being placed alongside them):
```sh
mkdir -p maps textures env entities # if you haven't already
# ... drop your assets in ...
./build/crank c1a0
```
If no map name is given, the engine tries `c1a0`. Working directory must
contain `maps/`, `textures/`, `env/`, `entities/`, and `shaders/`.