factory for creating dmabuf-based wl_buffers More...
#include <wayland-client-protocol-unstable.hpp>
Public Types | |
| enum | wrapper_type { wrapper_type::standard, wrapper_type::display, wrapper_type::foreign, wrapper_type::proxy_wrapper } |
Public Member Functions | |
| zwp_linux_buffer_params_v1_t | create_params () |
| create a temporary object for buffer parameters More... | |
| std::function< void(uint32_t)> & | on_format () |
| supported buffer format More... | |
| std::function< void(uint32_t, uint32_t, uint32_t)> & | on_modifier () |
| supported buffer format modifier More... | |
| uint32_t | get_id () const |
| Get the id of a proxy object. More... | |
| std::string | get_class () const |
| Get the interface name (class) of a proxy object. More... | |
| uint32_t | get_version () const |
| Get the protocol object version of a proxy object. More... | |
| wrapper_type | get_wrapper_type () const |
| Get the type of a proxy object. More... | |
| void | set_queue (event_queue_t queue) |
| Assign a proxy to an event queue. More... | |
| wl_proxy * | c_ptr () const |
| Get a pointer to the underlying C struct. More... | |
| bool | proxy_has_object () const |
| Check whether this wrapper actually wraps an object. More... | |
| operator bool () const | |
| Check whether this wrapper actually wraps an object. More... | |
| bool | operator== (const proxy_t &right) const |
| Check whether two wrappers refer to the same object. More... | |
| bool | operator!= (const proxy_t &right) const |
| Check whether two wrappers refer to different objects. More... | |
| void | proxy_release () |
| Release the wrapped object (if any), making this an empty wrapper. More... | |
Static Public Attributes | |
| static constexpr std::uint32_t | create_params_since_version = 1 |
| Minimum protocol version required for the create_params function. More... | |
Detailed Description
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. Immediately after a client binds to this interface, the set of supported formats and format modifiers is sent with 'format' and 'modifier' events.
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.
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.
Warning! The protocol described in this file is experimental and backward incompatible changes may be made. Backward compatible changes may be added together with the corresponding interface version bump. Backward incompatible changes are done by bumping the version number in the protocol and interface names and resetting the interface version. Once the protocol is to be declared stable, the 'z' prefix and the version number in the protocol and interface names are removed and the interface version number is reset.
Definition at line 1483 of file wayland-client-protocol-unstable.hpp.
Member Enumeration Documentation
◆ wrapper_type
|
stronginherited |
Underlying wl_proxy type and properties of a proxy_t that affect construction, destruction, and event handling
| Enumerator | |
|---|---|
| standard | C pointer is a standard type compatible with wl_proxy*. Events are dispatched and it is destructed when the proxy_t is destructed. User data is set. |
| display | C pointer is a wl_display*. No events are dispatched, wl_display_disconnect is called when the proxy_t is destructed. User data is set. |
| foreign | C pointer is a standard type compatible with wl_proxy*, but another library owns it and it should not be touched in a way that could affect the operation of the other library. No events are dispatched, wl_proxy_destroy is not called when the proxy_t is destructed, user data is not touched. Consequently, there is no reference counting for the proxy_t. Lifetime of such wrappers should preferably be short to minimize the chance that the owning library decides to destroy the wl_proxy. |
| proxy_wrapper | C pointer is a wl_proxy* that was constructed with wl_proxy_create_wrapper. No events are dispatched, wl_proxy_wrapper_destroy is called when the proxy_t is destroyed. Reference counting is active. A reference to the proxy_t creating this proxy wrapper is held to extend its lifetime until after the proxy wrapper is destroyed. |
Definition at line 105 of file wayland-client.hpp.
Member Function Documentation
◆ c_ptr()
|
inherited |
Get a pointer to the underlying C struct.
- Returns
- The underlying wl_proxy wrapped by this proxy_t if it exists, otherwise an exception is thrown
◆ create_params()
| zwp_linux_buffer_params_v1_t zwp_linux_dmabuf_v1_t::create_params | ( | ) |
create a temporary object for buffer parameters
- Returns
- the new temporary
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.
Definition at line 4919 of file wayland-client-protocol-unstable.cpp.
◆ get_class()
|
inherited |
Get the interface name (class) of a proxy object.
- Returns
- The interface name of the object associated with the proxy
◆ get_id()
|
inherited |
◆ get_version()
|
inherited |
Get the protocol object version of a proxy object.
Gets the protocol object version of a proxy object, or 0 if the proxy was created with unversioned API.
A returned value of 0 means that no version information is available, so the caller must make safe assumptions about the object's real version.
display_t will always return version 0.
- Returns
- The protocol object version of the proxy or 0
◆ get_wrapper_type()
|
inlineinherited |
Get the type of a proxy object.
Definition at line 288 of file wayland-client.hpp.
◆ on_format()
| std::function< void(uint32_t)> & zwp_linux_dmabuf_v1_t::on_format | ( | ) |
supported buffer format
- Parameters
-
format DRM_FORMAT code
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.
Warning: the 'format' event is likely to be deprecated and replaced with the 'modifier' event introduced in zwp_linux_dmabuf_v1 version 3, described below. Please refrain from using the information received from this event.
Definition at line 4925 of file wayland-client-protocol-unstable.cpp.
◆ on_modifier()
| std::function< void(uint32_t, uint32_t, uint32_t)> & zwp_linux_dmabuf_v1_t::on_modifier | ( | ) |
supported buffer format modifier
- Parameters
-
format DRM_FORMAT code modifier_hi high 32 bits of layout modifier modifier_lo low 32 bits of layout 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.
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.
Definition at line 4930 of file wayland-client-protocol-unstable.cpp.
◆ operator bool()
|
inherited |
Check whether this wrapper actually wraps an object.
- Returns
- true if there is an underlying object, false if this wrapper is empty
◆ operator!=()
|
inherited |
Check whether two wrappers refer to different objects.
◆ operator==()
|
inherited |
Check whether two wrappers refer to the same object.
◆ proxy_has_object()
|
inherited |
Check whether this wrapper actually wraps an object.
- Returns
- true if there is an underlying object, false if this wrapper is empty
◆ proxy_release()
|
inherited |
Release the wrapped object (if any), making this an empty wrapper.
Note that display_t instances cannot be released this way. Attempts to do so are ignored.
- Examples
- foreign_display.cpp.
◆ set_queue()
|
inherited |
Assign a proxy to an event queue.
- Parameters
-
queue The event queue that will handle this proxy
Assign proxy to event queue. Events coming from proxy will be queued in queue instead of the display's main queue.
See also: display_t::dispatch_queue().
- Examples
- proxy_wrapper.cpp.
Member Data Documentation
◆ create_params_since_version
|
staticconstexpr |
Minimum protocol version required for the create_params function.
Definition at line 1520 of file wayland-client-protocol-unstable.hpp.
The documentation for this class was generated from the following files:
