libliftoff/README.md
Simon Ser d98ae24328 Switch to "meson setup"
Fixes this warning:

    WARNING: Running the setup command as `meson [options]` instead of `meson setup [options]` is ambiguous and deprecated.
2023-02-22 10:57:03 +01:00

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# libliftoff
[![builds.sr.ht status](https://builds.sr.ht/~emersion/libliftoff/commits/master.svg)](https://builds.sr.ht/~emersion/libliftoff/commits/master)
Lightweight KMS plane library.
libliftoff eases the use of KMS planes from userspace without standing in your
way. Users create "virtual planes" called layers, set KMS properties on them,
and libliftoff will pick hardware planes for these layers if possible.
Resources:
* [Blog post introducing the project][intro-post]
* [FOSDEM 2020 talk][fosdem-2020]
libliftoff is used in production by [gamescope] on Steam Deck devices, and work
is underway to integrate it with [wlroots].
## Building
Depends on libdrm. Requires universal planes and atomic.
meson setup build/
ninja -C build/
## Usage
See [`liftoff.h`][liftoff.h] and the [`example/`][example] directory. See
[`doc/compositor.md`][doc/compositor] for compositor guidelines.
Here's the general idea:
```c
struct liftoff_device *device;
struct liftoff_output *output;
struct liftoff_layer *layer;
drmModeAtomicReq *req;
int ret;
device = liftoff_device_create(drm_fd);
output = liftoff_output_create(device, crtc_id);
liftoff_device_register_all_planes(device);
layer = liftoff_layer_create(output);
liftoff_layer_set_property(layer, "FB_ID", fb_id);
/* Probably setup more properties and more layers */
req = drmModeAtomicAlloc();
ret = liftoff_output_apply(output, req);
if (ret < 0) {
perror("liftoff_output_apply");
exit(1);
}
ret = drmModeAtomicCommit(drm_fd, req, DRM_MODE_ATOMIC_NONBLOCK, NULL);
if (ret < 0) {
perror("drmModeAtomicCommit");
exit(1);
}
drmModeAtomicFree(req);
```
## Contributing
Report bugs and send pull requests on [GitLab][gitlab].
We use the Wayland/Weston style and contribution guidelines, see [Weston's
contributing document][weston-contributing].
## License
MIT
[liftoff.h]: https://gitlab.freedesktop.org/emersion/libliftoff/-/blob/master/include/libliftoff.h
[example]: https://gitlab.freedesktop.org/emersion/libliftoff/-/tree/master/example
[doc/compositor]: https://gitlab.freedesktop.org/emersion/libliftoff/-/blob/master/doc/compositor.md
[intro-post]: https://emersion.fr/blog/2019/xdc2019-wrap-up/#libliftoff
[fosdem-2020]: https://fosdem.org/2020/schedule/event/kms_planes/
[gitlab]: https://gitlab.freedesktop.org/emersion/libliftoff
[weston-contributing]: https://gitlab.freedesktop.org/wayland/weston/-/blob/master/CONTRIBUTING.md
[gamescope]: https://github.com/Plagman/gamescope
[wlroots]: https://gitlab.freedesktop.org/wlroots/wlroots