Struct ZwpLinuxDmabufV1

pub struct ZwpLinuxDmabufV1 { /* private fields */ }

factory for creating dmabuf-based wl_buffers

Following the interfaces from: https://www.khronos.org/registry/egl/extensions/EXT/EGL_EXT_image_dma_buf_import.txt https://www.khronos.org/registry/EGL/extensions/EXT/EGL_EXT_image_dma_buf_import_modifiers.txt and the Linux DRM sub-system’s AddFb2 ioctl.

This interface offers ways to create generic dmabuf-based wl_buffers.

Clients can use the get_surface_feedback request to get dmabuf feedback for a particular surface. If the client wants to retrieve feedback not tied to a surface, they can use the get_default_feedback request.

The following are required from clients:

• Clients must ensure that either all data in the dma-buf is coherent for all subsequent read access or that coherency is correctly handled by the underlying kernel-side dma-buf implementation.

• Don’t make any more attachments after sending the buffer to the compositor. Making more attachments later increases the risk of the compositor not being able to use (re-import) an existing dmabuf-based wl_buffer.

The underlying graphics stack must ensure the following:

• The dmabuf file descriptors relayed to the server will stay valid for the whole lifetime of the wl_buffer. This means the server may at any time use those fds to import the dmabuf into any kernel sub-system that might accept it.

However, when the underlying graphics stack fails to deliver the promise, because of e.g. a device hot-unplug which raises internal errors, after the wl_buffer has been successfully created the compositor must not raise protocol errors to the client when dmabuf import later fails.

To create a wl_buffer from one or more dmabufs, a client creates a zwp_linux_dmabuf_params_v1 object with a zwp_linux_dmabuf_v1.create_params request. All planes required by the intended format are added with the ‘add’ request. Finally, a ‘create’ or ‘create_immed’ request is issued, which has the following outcome depending on the import success.

The ‘create’ request,

• on success, triggers a ‘created’ event which provides the final wl_buffer to the client.
• on failure, triggers a ‘failed’ event to convey that the server cannot use the dmabufs received from the client.

For the ‘create_immed’ request,

• on success, the server immediately imports the added dmabufs to create a wl_buffer. No event is sent from the server in this case.
• on failure, the server can choose to either:
• terminate the client by raising a fatal error.
• mark the wl_buffer as failed, and send a ‘failed’ event to the client. If the client uses a failed wl_buffer as an argument to any request, the behaviour is compositor implementation-defined.

For all DRM formats and unless specified in another protocol extension, pre-multiplied alpha is used for pixel values.

Unless specified otherwise in another protocol extension, implicit synchronization is used. In other words, compositors and clients must wait and signal fences implicitly passed via the DMA-BUF’s reservation mechanism.

See also the Event enum for this interface.

Implementations

impl ZwpLinuxDmabufV1

pub fn destroy(&self)

unbind the factory

Objects created through this interface, especially wl_buffers, will remain valid.

pub fn create_params<U: Send + Sync + 'static, D: Dispatch<ZwpLinuxBufferParamsV1, U> + 'static>( &self, qh: &QueueHandle<D>, udata: U, ) -> ZwpLinuxBufferParamsV1

create a temporary object for buffer parameters

This temporary object is used to collect multiple dmabuf handles into a single batch to create a wl_buffer. It can only be used once and should be destroyed after a ‘created’ or ‘failed’ event has been received.

pub fn get_default_feedback<U: Send + Sync + 'static, D: Dispatch<ZwpLinuxDmabufFeedbackV1, U> + 'static>( &self, qh: &QueueHandle<D>, udata: U, ) -> ZwpLinuxDmabufFeedbackV1

get default feedback

This request creates a new wp_linux_dmabuf_feedback object not bound to a particular surface. This object will deliver feedback about dmabuf parameters to use if the client doesn’t support per-surface feedback (see get_surface_feedback).

pub fn get_surface_feedback<U: Send + Sync + 'static, D: Dispatch<ZwpLinuxDmabufFeedbackV1, U> + 'static>( &self, surface: &WlSurface, qh: &QueueHandle<D>, udata: U, ) -> ZwpLinuxDmabufFeedbackV1

get feedback for a surface

This request creates a new wp_linux_dmabuf_feedback object for the specified wl_surface. This object will deliver feedback about dmabuf parameters to use for buffers attached to this surface.

If the surface is destroyed before the wp_linux_dmabuf_feedback object, the feedback object becomes inert.

Trait Implementations

impl Borrow<ObjectId> for ZwpLinuxDmabufV1

fn borrow(&self) -> &ObjectId

Immutably borrows from an owned value.

impl Clone for ZwpLinuxDmabufV1

fn clone(&self) -> ZwpLinuxDmabufV1

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ZwpLinuxDmabufV1

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for ZwpLinuxDmabufV1

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq<Weak<ZwpLinuxDmabufV1>> for ZwpLinuxDmabufV1

fn eq(&self, other: &Weak<ZwpLinuxDmabufV1>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq for ZwpLinuxDmabufV1

fn eq(&self, other: &ZwpLinuxDmabufV1) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Proxy for ZwpLinuxDmabufV1

type Request<'request> = Request<'request>

The request enum for this interface

type Event = Event

The event enum for this interface

fn interface() -> &'static Interface

The interface description

fn id(&self) -> ObjectId

The ID of this object

fn version(&self) -> u32

The version of this object

fn data<U: Send + Sync + 'static>(&self) -> Option<&U>

Access the user-data associated with this object

fn object_data(&self) -> Option<&Arc<dyn ObjectData>>

Access the raw data associated with this object.

fn backend(&self) -> &WeakBackend

Access the backend associated with this object

fn send_request(&self, req: Self::Request<'_>) -> Result<(), InvalidId>

Send a request for this object.

fn send_constructor<I: Proxy>( &self, req: Self::Request<'_>, data: Arc<dyn ObjectData>, ) -> Result<I, InvalidId>

Send a request for this object that creates another object.

fn from_id(conn: &Connection, id: ObjectId) -> Result<Self, InvalidId>

Create an object proxy from its ID

fn inert(backend: WeakBackend) -> Self

Create an inert object proxy

fn parse_event( conn: &Connection, msg: Message<ObjectId, OwnedFd>, ) -> Result<(Self, Self::Event), DispatchError>

Parse a event for this object

fn write_request<'a>( &self, conn: &Connection, msg: Self::Request<'a>, ) -> Result<(Message<ObjectId, BorrowedFd<'a>>, Option<(&'static Interface, u32)>), InvalidId>

Serialize a request for this object

fn is_alive(&self) -> bool

Checks if the Wayland object associated with this proxy is still alive

fn downgrade(&self) -> Weak<Self>

Creates a weak handle to this object

impl Eq for ZwpLinuxDmabufV1