commit | b85dc4534ad3a3689e26ea0b7c60511f66ae3981 | [log] [tgz] |
---|---|---|
author | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Sun May 26 07:08:49 2024 +0000 |
committer | Android Build Coastguard Worker <android-build-coastguard-worker@google.com> | Sun May 26 07:08:49 2024 +0000 |
tree | 79525a35c51bfb6416a7a93830f026dcacc68840 | |
parent | 83e44d41fbd996be3f1600fe48d5698122bcf096 [diff] | |
parent | 2469df47314ebb4d5c7dbe36307dbc6abc43bfaa [diff] |
Snap for 11878398 from 2469df47314ebb4d5c7dbe36307dbc6abc43bfaa to busytown-mac-infra-release Change-Id: I389701fff1c5edda995dc667530e0c192b26baae
A safe interface to the Direct Rendering Manager.
The Direct Rendering Manager is a subsystem found on multiple Unix-based operating systems that provides a userspace API to graphics hardware. See the Wikipedia article for more details.
The DRM is accessed using ioctls on a file representing a graphics card. These can normally be found in /dev/dri
, but can also be opened in other ways (ex. udev).
This crate does not provide a method of opening these files. Instead, the user program must provide a way to access the file descriptor representing the device through the AsFd trait. Here is a basic example using File
as a backend:
/// A simple wrapper for a device node. pub struct Card(std::fs::File); /// Implementing [`AsFd`] is a prerequisite to implementing the traits found /// in this crate. Here, we are just calling [`File::as_fd()`] on the inner /// [`File`]. impl AsFd for Card { fn as_fd(&self) -> BorrowedFd<'_> { self.0.as_fd() } } /// Simple helper methods for opening a `Card`. impl Card { pub fn open(path: &str) -> Self { let mut options = std::fs::OpenOptions::new(); options.read(true); options.write(true); Card(options.open(path).unwrap()) } }
Finally, you can implement drm::Device
to gain access to the basic DRM functionality:
impl drm::Device for Card {} fn main() { let gpu = Card::open("/dev/dri/card0"); println!("{:#?}", gpu.get_driver().unwrap()); }
See drm::control::Device
as well as our mode-setting examples: atomic_modeset
and legacy_modeset
Rendering is done by creating and attaching framebuffers to crtcs.
A framebuffer is created from anything implementing Buffer
like the always available, but very limited, DumbBuffer
.
For faster hardware-backed buffers, checkout gbm.rs.