Struct ZwpLinuxDmabufV1

pub struct ZwpLinuxDmabufV1 { /* private fields */ }

Available on crate feature server only.

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 Request enum for this interface.

Implementations

impl ZwpLinuxDmabufV1

pub fn format(&self, format: u32)

supported buffer format

This event advertises one buffer format that the server supports. All the supported formats are advertised once when the client binds to this interface. A roundtrip after binding guarantees that the client has received all supported formats.

For the definition of the format codes, see the zwp_linux_buffer_params_v1::create request.

Starting version 4, the format event is deprecated and must not be sent by compositors. Instead, use get_default_feedback or get_surface_feedback.

pub fn modifier(&self, format: u32, modifier_hi: u32, modifier_lo: u32)

supported buffer format modifier

This event advertises the formats that the server supports, along with the modifiers supported for each format. All the supported modifiers for all the supported formats are advertised once when the client binds to this interface. A roundtrip after binding guarantees that the client has received all supported format-modifier pairs.

For legacy support, DRM_FORMAT_MOD_INVALID (that is, modifier_hi == 0x00ffffff and modifier_lo == 0xffffffff) is allowed in this event. It indicates that the server can support the format with an implicit modifier. When a plane has DRM_FORMAT_MOD_INVALID as its modifier, it is as if no explicit modifier is specified. The effective modifier will be derived from the dmabuf.

A compositor that sends valid modifiers and DRM_FORMAT_MOD_INVALID for a given format supports both explicit modifiers and implicit modifiers.

For the definition of the format and modifier codes, see the zwp_linux_buffer_params_v1::create and zwp_linux_buffer_params_v1::add requests.

Starting version 4, the modifier event is deprecated and must not be sent by compositors. Instead, use get_default_feedback or get_surface_feedback.

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 Resource for ZwpLinuxDmabufV1

type Request = Request

The request enum for this interface

type Event<'event> = 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: 'static>(&self) -> Option<&U>

Access the user-data associated with this object

fn object_data(&self) -> Option<&Arc<dyn Any + Send + Sync>>

Access the raw data associated with this object.

fn handle(&self) -> &WeakHandle

Access the backend handle associated with this object

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

Create an object resource from its ID

fn send_event(&self, evt: Self::Event<'_>) -> Result<(), InvalidId>

Send an event to this object

fn parse_request( conn: &DisplayHandle, msg: Message<ObjectId, OwnedFd>, ) -> Result<(Self, Self::Request), DispatchError>

Parse a event for this object

fn write_event<'a>( &self, conn: &DisplayHandle, msg: Self::Event<'a>, ) -> Result<Message<ObjectId, BorrowedFd<'a>>, InvalidId>

Serialize an event for this object

fn client(&self) -> Option<Client>

The client owning this object

fn is_alive(&self) -> bool

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

fn post_error(&self, code: impl Into<u32>, error: impl Into<String>)

Trigger a protocol error on this object

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

Creates a weak handle to this object

impl Eq for ZwpLinuxDmabufV1