swc_snap

version 2

raw screen capture into client buffers

gives a screen capture capability where the client supplies a wl_shm buffer and the compositor fills it with a raw frame.

Type: destructor

destroy()

destroy the capture object

capture(buffer: object<wl_buffer>, flags: uint)

Argument	Type	Description
buffer	object<wl_buffer>	client-provided wl_shm buffer to fill
flags	uint	bitmask of swc_snap.flags

capture a frame into a client buffer

captures the current primary screen into the supplied wl_shm buffer. The compositor writes raw pixels and reports ready or failed state

buffer(width: uint, height: uint, format: uint)

current capture frame metadata

describes the current frame geometry and pixel format expected by the capture stream

ready(tv_sec: uint, tv_nsec: uint)

Argument	Type	Description
tv_sec	uint	CLOCK_MONOTONIC seconds
tv_nsec	uint	CLOCK_MONOTONIC nanoseconds

capture complete

the requested buffer has been filled and is ready for client

failed(reason: uint)

Argument	Type	Description
reason	uint	swc_snap.failure_reason value

capture failed

the capture request failed, the object still usable and the client may retry with another buffer or after a mode change

bitfield

flags { overlay_cursor }

Argument	Value	Description
overlay_cursor	1	composite the current cursor into the frame

pixel_format { xrgb8888, argb8888 }

Argument	Value	Description
xrgb8888	0	WL_SHM_FORMAT_XRGB8888
argb8888	1	WL_SHM_FORMAT_ARGB8888

failure_reason { no_screen, unsupported_buffer, size_mismatch, internal }

Argument	Value	Description
no_screen	0	no captureable screen is available
unsupported_buffer	1	buffer is not a wl_shm xrgb/argb8888 buffer
size_mismatch	2	buffer dimensions are too small for the screen
internal	3	compositor capture failed

No compositor support found