# cuber

`cuber` is an OpenGL 3D renderer with multiple scenes.

![Screenshot of sphere](./res/preview.png)

## Requirements

- CMake 3.21+
- Ninja
- C++23 compiler

All dependencies (fmt, GLFW, GLAD, asio, GLM, stb) are fetched
automatically via CMake FetchContent.

## Development

**Configure**:

```sh
cmake -S . -B build -GNinja
```

**Build**:

```sh
ninja -C build
```

**Run**:

```sh
./build/cuber
```

## Usage

```
--duration <seconds>  Auto-terminate after N seconds (for testing/CI)
--scene <cube|sphere> Select initial scene (default: cube)
--screenshot          Render one frame, save screenshot, and exit
S key                 Take screenshot (saved as screenshot.png)
1/2 key               Switch between cube/sphere scene
Q key                 Quit
```

## Scenes

- **cube** — spinning colored cube with per-face colors
- **sphere** — cube-to-sphere mapped mesh with per-face colors and
  diffuse lighting