SPDX-FileCopyrightText: 2021 Méven Car
SPDX-FileCopyrightText: 2023 Xaver Hugl
SPDX-License-Identifier: MIT-CMU
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This interface enables clients to set properties of output devices for screen
configuration purposes via the server. To this end output devices are referenced
by global kde_output_device_v2 objects.
outputmanagement (wl_global)
--------------------------
request:
* create_configuration -> outputconfiguration (wl_resource)
outputconfiguration (wl_resource)
--------------------------
requests:
* enable(outputdevice, bool)
* mode(outputdevice, mode)
* transformation(outputdevice, flag)
* position(outputdevice, x, y)
* apply
events:
* applied
* failed
The server registers one outputmanagement object as a global object. In order
to configure outputs a client requests create_configuration, which provides a
resource referencing an outputconfiguration for one-time configuration. That
way the server knows which requests belong together and can group them by that.
On the outputconfiguration object the client calls for each output whether the
output should be enabled, which mode should be set (by referencing the mode from
the list of announced modes) and the output's global position. Once all outputs
are configured that way, the client calls apply.
At that point and not earlier the server should try to apply the configuration.
If this succeeds the server emits the applied signal, otherwise the failed
signal, such that the configuring client is noticed about the success of its
configuration request.
Through this design the interface enables atomic output configuration changes if
internally supported by the server.
Warning! The protocol described in this file is a desktop environment implementation
detail. Regular clients must not use this protocol. Backward incompatible
changes may be added without bumping the major version of the extension.
Request an outputconfiguration object through which the client can configure
output devices.
For details, see the description of kde_mode_list_v2 and
kde_output_configuration_v2.set_custom_modes.
outputconfiguration is a client-specific resource that can be used to ask
the server to apply changes to available output devices.
The client receives a list of output devices from the registry. When it wants
to apply new settings, it creates a configuration object from the
outputmanagement global, writes changes through this object's enable, scale,
transform and mode calls. It then asks the server to apply these settings in
an atomic fashion, for example through Linux' DRM interface.
The server signals back whether the new settings have applied successfully
or failed to apply. outputdevice objects are updated after the changes have been
applied to the hardware and before the server side sends the applied event.
These error can be emitted in response to kde_output_configuration_v2 requests.
Mark the output as enabled or disabled.
Sets the mode for a given output.
Sets the transformation for a given output.
Sets the position for this output device. (x,y) describe the top-left corner
of the output in global space, whereby the origin (0,0) of the global space
has to be aligned with the top-left corner of the most left and in case this
does not define a single one the top output.
There may be no gaps or overlaps between outputs, i.e. the outputs are
stacked horizontally, vertically, or both on each other.
Sets the scaling factor for this output device.
Asks the server to apply property changes requested through this outputconfiguration
object to all outputs on the server side.
The output configuration can be applied only once. The already_applied protocol error
will be posted if the apply request is called the second time.
Sent after the server has successfully applied the changes.
.
Sent if the server rejects the changes or failed to apply them.
Set the overscan value of this output device with a value in percent.
Describes when the compositor may employ variable refresh rate
Set what policy the compositor should employ regarding its use of
variable refresh rate.
Whether this output should use full or limited rgb.
Whether full or limited color range should be used
Set the position of the output in the output order list, with lower values
being earlier in the list. There's no specific value the list has to start
at, this value is only used in sorting outputs.
The order of outputs can be used to assign desktop environment components
to a specific screen, see kde_output_order_v1 and kde-output-device-v2 for
details. Note that for consistent behavior, the priority value needs to be
unique among all enabled outputs.
Sets whether or not the output should be set to HDR mode.
Sets the brightness of standard dynamic range content in nits. Only has an effect while the output is in HDR mode.
Note that while the value is in nits, that doesn't necessarily translate to the same brightness on the screen.
Whether or not the output should use a wide color gamut
This can be used to provide the colors users assume sRGB applications should have based on the
default experience on many modern sRGB screens.
Set the brightness modifier of the output. It doesn't specify
any absolute values, but is merely a multiplier on top of other
brightness values, like sdr_brightness and brightness_metadata.
0 is the minimum brightness (not completely dark) and 10000 is
the maximum brightness.
This is supported while HDR is active in versions 8 and below,
or when the device supports the "brightness" capability in
versions 9 and above.
The compositor can do a lot of things that trade between
performance, power and color accuracy. This setting describes
a high level preference from the user about in which direction
that tradeoff should be made.
Set the dimming multiplier of the output. This is similar to the
brightness setting, except it's meant to be a temporary setting
only, not persistent and may be implemented differently depending
on the display.
0 is the minimum dimming factor (not completely dark) and 10000
means the output is not dimmed.
This is supported only when the "brightness" capability is
also supported.
Describes why applying the output configuration failed. Is only
sent before the failure event.
Set the source output that the outputdevice should mirror its
viewport from.
This limits the amount of bits per color that are sent to the display.
When EDR is enabled, the compositor may increase the backlight beyond
the user-specified setting, in order to present HDR content on displays
without native HDR support.
This will usually result in better visuals, but also increases battery
usage.
This is the sharpness modifier of the output.
0 is sharpness disabled and 10000 is the maximum sharpness
Set the list of custom modes for this output. The compositor
will in response generate the requested modes and add them to
the output (or delete ones no longer in the list).
This can be useful for overclocking displays, or for working
around broken EDIDs.
Note that there is no guarantee for any custom mode to
actually work, or even to leave the display undamaged (in the
case of CRTs). It's entirely the responsibility of the user
to ensure each added mode is the right one for their display.
Adaptive backlight modulation is a feature that reduces the backlight
and increases contrast of colors on the screen to improve power usage.
This list is populated by first setting each relevant property,
and then calling add_mode to add a mode with these properties.
One would for example call
- set_resolution
- set_refresh_rate
- set_reduced_blanking
- add_mode
add_mode does not reset the properties that were previously set,
they are valid until the object is destroyed.
The compositor may additionally have sensible defaults for some
properties like reduced_blanking, but for consistent results,
it's best to always set each known property every time.
One can also specify custom modes with CVT timings, for example
- add_cvt
- add_cvt
The parameters resolution and refresh rate are required, if they
are not set, the missing_parameters error will be emitted.
These errors can be emitted in response to add_mode requests.
Reduced blanking is an optimization that can reduce bandwidth / timing
requirements for a display mode by reducing the time vblank takes.
As not all displays support it, it may be desired to still turn it off
though (like with CRTs, where full blanking is required).
Adds a new mode with the specified CVT timings.