Package org.freedesktop.wayland.client

Class ZwpLinuxDmabufV1Proxy

java.lang.Object

org.freedesktop.wayland.client.Proxy<ZwpLinuxDmabufV1Events>

org.freedesktop.wayland.client.ZwpLinuxDmabufV1Proxy

All Implemented Interfaces:

WaylandObject

public class ZwpLinuxDmabufV1Proxy
extends Proxy<ZwpLinuxDmabufV1Events>

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.

Field Summary

Fields

Modifier and Type	Field	Description
static final String	INTERFACE_NAME

Fields inherited from class org.freedesktop.wayland.client.Proxy

pointer

Constructor Summary

Constructors

Constructor	Description
ZwpLinuxDmabufV1Proxy(MemorySegment pointer)
ZwpLinuxDmabufV1Proxy(MemorySegment pointer, ZwpLinuxDmabufV1Events implementation, int version)

Method Summary

Modifier and Type	Method	Description
ZwpLinuxBufferParamsV1Proxy	createParams(ZwpLinuxBufferParamsV1Events implementation)	create a temporary object for buffer parameters
void	destroy()	unbind the factory
ZwpLinuxDmabufFeedbackV1Proxy	getDefaultFeedback(ZwpLinuxDmabufFeedbackV1Events implementation)	get default feedback
ZwpLinuxDmabufFeedbackV1Proxy	getSurfaceFeedback(ZwpLinuxDmabufFeedbackV1Events implementation, WlSurfaceProxy surface)	get feedback for a surface

Methods inherited from class org.freedesktop.wayland.client.Proxy

equals, getId, getImplementation, getPointer, getVersion, hashCode, marshal, marshal, marshalConstructor, setQueue

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Field Details

INTERFACE_NAME

public static final String INTERFACE_NAME

See Also:

• Constant Field Values

Constructor Details

ZwpLinuxDmabufV1Proxy

public ZwpLinuxDmabufV1Proxy(MemorySegment pointer,
 ZwpLinuxDmabufV1Events implementation,
 int version)

ZwpLinuxDmabufV1Proxy

public ZwpLinuxDmabufV1Proxy(MemorySegment pointer)

Method Details

destroy

public void destroy()

unbind the factory

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

Overrides:

destroy in class Proxy<ZwpLinuxDmabufV1Events>

createParams

public ZwpLinuxBufferParamsV1Proxy createParams(ZwpLinuxBufferParamsV1Events implementation)

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.

Parameters:

implementation - A protocol event listener for the newly created proxy.

getDefaultFeedback

public ZwpLinuxDmabufFeedbackV1Proxy getDefaultFeedback(ZwpLinuxDmabufFeedbackV1Events implementation)

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).

Parameters:

implementation - A protocol event listener for the newly created proxy.

getSurfaceFeedback

public ZwpLinuxDmabufFeedbackV1Proxy getSurfaceFeedback(ZwpLinuxDmabufFeedbackV1Events implementation,
 @Nonnull
 WlSurfaceProxy surface)

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.

Parameters:

implementation - A protocol event listener for the newly created proxy.

surface -