bitmask of flags in presented event More...

#include <wayland-client-protocol-extra.hpp>

Inherits wayland::detail::bitfield< size, id >.

Static Public Attributes
static const detail::bitfield< 4, 1 >	vsync {0x1}
	presentation was vsync'd More...

static const detail::bitfield< 4, 1 >	hw_clock {0x2}
	hardware provided the presentation timestamp More...

static const detail::bitfield< 4, 1 >	hw_completion {0x4}
	hardware signalled the start of the presentation More...

static const detail::bitfield< 4, 1 >	zero_copy {0x8}
	presentation was done zero-copy More...

Detailed Description

bitmask of flags in presented event

These flags provide information about how the presentation of
the related content update was done. The intent is to help
clients assess the reliability of the feedback and the visual
quality with respect to possible tearing and timings. The
flags are:

VSYNC:
The presentation was synchronized to the "vertical retrace" by
the display hardware such that tearing does not happen.
Relying on user space scheduling is not acceptable for this
flag. If presentation is done by a copy to the active
frontbuffer, then it must guarantee that tearing cannot
happen.

HW_CLOCK:
The display hardware provided measurements that the hardware
driver converted into a presentation timestamp. Sampling a
clock in user space is not acceptable for this flag.

HW_COMPLETION:
The display hardware signalled that it started using the new
image content. The opposite of this is e.g. a timer being used
to guess when the display hardware has switched to the new
image content.

ZERO_COPY:
The presentation of this update was done zero-copy. This means
the buffer from the client was given to display hardware as
is, without copying it. Compositing with OpenGL counts as
copying, even if textured directly from the client buffer.
Possible zero-copy cases include direct scanout of a
fullscreen surface and a surface on a hardware overlay.

Definition at line 325 of file wayland-client-protocol-extra.hpp.