# YASL — Yet Another Surface Library

YASL is a small C desktop surface and input library for applications that own
their event loop and renderer. It supports Wayland, X11, and Cocoa, with CPU
images, optional EGL/OpenGL contexts on Linux, Vulkan window surfaces, and direct
Metal layers on macOS.
Pen input includes tool identity, proximity/contact, pressure, tilt, and available
rotation/distance/tangential/wheel axes. It also supplies IME composition/editing,
clipboard text, popups, file drops, and surface drags.

The first surface initializes a shared backend. Surface operations use ordinary
arguments; there are no public display objects, creation descriptors, frame
objects, point/size/string wrappers, or mandatory application runner.

```c
yasl_surface *surface = yasl_surface_create("Example", 800, 600, 0);
```

Flags zero creates a GPU window without choosing a graphics API. The application
attaches a Vulkan surface or Metal layer, or uses `yasl_gl_surface_create` to create
an OpenGL window/context on Linux. `YASL_SURFACE_CPU` gives the window a pixel buffer: draw into
`yasl_cpu_pixels` and call `yasl_cpu_present`. Native handles are available through typed extension headers.

**Status:** pre-release 0.1; source and ABI compatibility are not promised.
Use matching headers and library. Supported operations depend on the backend,
server, and optional dependencies; check results and `yasl_get_error`.

Build with a C23 compiler, Meson 1.6+, and Ninja:

```sh
meson setup build
meson compile -C build
./build/yasl-hello
meson test -C build --print-errorlogs
```

Linux needs Wayland or X11 development packages; EGL and wayland-egl enable GL,
and the Vulkan SDK enables its typed bridge. Cocoa needs macOS 14+ and its SDK.

- [Getting started](docs/getting-started.md): creation, linking, and rendering.
- [Application guide](docs/guide.md): ownership, events, GPUs, pen, and backend limits.
- [Testing](docs/testing.md): unit tests and isolated GPU/backend tests.
- [API policy](docs/api-policy.md) and [contributing](CONTRIBUTING.md).
- Public headers live in [include/yasl](include/yasl); examples live in [examples](examples).

MIT licensed; see [LICENSE](LICENSE).