This protocol specifies a set of interfaces used to control the alpha compositing and blending of surface contents, based on the Chromium Wayland protocol of the same name [1].
Signed-off-by: Scott Anderson <[email protected]> [1] https://chromium.googlesource.com/chromium/src/+/master/third_party/wayland-protocols/unstable/alpha-compositing/alpha-compositing-unstable-v1.xml --- Changes in v3: - Rename "blending" event to "blending_equation" - Add enum specifier to "blending_equation" event and "set_blending" request. - Fix typos Changes in v2: - Add additional "fromsource" blending equation used by [3] - Allow the server to advertise which blending equations it supports - Added a protocol error for using an unsupported equation - Added a protocol error for using an invalid alpha value - Added clarification about wl_surface.set_opaque_region - Added clarification about per-pixel alpha values Makefile.am | 1 + unstable/alpha-compositing/README | 5 + .../alpha-compositing-unstable-v1.xml | 175 ++++++++++++++++++ 3 files changed, 181 insertions(+) create mode 100644 unstable/alpha-compositing/README create mode 100644 unstable/alpha-compositing/alpha-compositing-unstable-v1.xml diff --git a/Makefile.am b/Makefile.am index 6394e26..ac6c9f8 100644 --- a/Makefile.am +++ b/Makefile.am @@ -21,6 +21,7 @@ unstable_protocols = \ unstable/xdg-output/xdg-output-unstable-v1.xml \ unstable/input-timestamps/input-timestamps-unstable-v1.xml \ unstable/xdg-decoration/xdg-decoration-unstable-v1.xml \ + unstable/alpha-compositing/alpha-compositing-unstable-v1.xml \ $(NULL) stable_protocols = \ diff --git a/unstable/alpha-compositing/README b/unstable/alpha-compositing/README new file mode 100644 index 0000000..5826967 --- /dev/null +++ b/unstable/alpha-compositing/README @@ -0,0 +1,5 @@ +Alpha compositing protocol + +Maintainers: +David Reveman <[email protected]> +Alexandros Frantzis <[email protected]> diff --git a/unstable/alpha-compositing/alpha-compositing-unstable-v1.xml b/unstable/alpha-compositing/alpha-compositing-unstable-v1.xml new file mode 100644 index 0000000..d3c41d5 --- /dev/null +++ b/unstable/alpha-compositing/alpha-compositing-unstable-v1.xml @@ -0,0 +1,175 @@ +<?xml version="1.0" encoding="UTF-8"?> +<protocol name="alpha_compositing_unstable_v1"> + + <copyright> + Copyright 2016 The Chromium Authors. + Copyright 2017-2018 Collabora Ltd + Copyright 2018 NXP + + Permission is hereby granted, free of charge, to any person obtaining a + copy of this software and associated documentation files (the "Software"), + to deal in the Software without restriction, including without limitation + the rights to use, copy, modify, merge, publish, distribute, sublicense, + and/or sell copies of the Software, and to permit persons to whom the + Software is furnished to do so, subject to the following conditions: + + The above copyright notice and this permission notice (including the next + paragraph) shall be included in all copies or substantial portions of the + Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + DEALINGS IN THE SOFTWARE. + </copyright> + + <description summary="Protocol for more advanced compositing and blending"> + This protocol specifies a set of interfaces used to control the alpha + compositing and blending of surface contents. + + 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. + </description> + + <interface name="zwp_alpha_compositing_v1" version="1"> + <description summary="alpha compositing"> + The global interface exposing compositing and blending capabilities is + used to instantiate an interface extension for a wl_surface object. + This extended interface will then allow the client to specify the + blending equation and alpha value used for compositing the wl_surface. + </description> + + <enum name="error"> + <entry name="blending_exists" value="0" + summary="the surface already has a blending object associated"/> + </enum> + + <request name="destroy" type="destructor"> + <description summary="unbind from the blending interface"> + Informs the server that the client will not be using this + protocol object anymore. This does not affect any other objects, + blending objects included. + </description> + </request> + + <request name="get_blending"> + <description summary="extend surface interface for blending"> + Instantiate an interface extension for the given wl_surface to + provide surface blending. If the given wl_surface already has + a blending object associated, the BLENDING_EXISTS protocol error + is raised. + </description> + + <arg name="id" type="new_id" interface="zwp_blending_v1" + summary="the new blending interface id"/> + <arg name="surface" type="object" interface="wl_surface" + summary="the surface"/> + </request> + + <event name="blending_equation"> + <description summary="supported blending equations"> + This event advertises the blending equations that the server + supports. All the supported blending equations are advertised once + when the client binds to this interface. A roundtrip after binding + guarantees that the client has received all supported blending + equations. + + For the definition of the blending equations, see the + zwp_blending_v1.blending_equation enum. + + The server must always advertise the 'none' blending equation. + </description> + <arg name="blending_equation" type="uint" + enum="zwp_blending_v1.blending_equation" + summary="the blending equation"/> + </event> + </interface> + + <interface name="zwp_blending_v1" version="1"> + <description summary="blending interface to a wl_surface"> + An additional interface to a wl_surface object, which allows the + client to specify the blending equation used for compositing and + an alpha value applied to the whole surface. + + When the blending object is created its blending equation is + 'none' and its alpha is 1.0, i.e., it's inactive by default. Clients + can activate it by setting the blending equation and alpha value. + + Use of this interface has no effect on the surface's opaque region + as set by wl_surface.set_opaque_region. Clients must make sure to set + their opaque region correctly to prevent repaint artifacts. + + If the wl_surface associated with the blending object is destroyed, + the blending object becomes inert. + + If the blending object is destroyed, the blending state is removed + from the wl_surface. The change will be applied on the next + wl_surface.commit. + </description> + + <enum name="blending_equation"> + <description summary="different blending equations for compositing"> + Blending equations that can be used when compositing a surface. + </description> + <entry name="none" value="0" summary="blending object is inactive"/> + <entry name="opaque" value="1" summary="(one, zero)"/> + <entry name="premultiplied" value="2" summary="(one, one_minus_src_alpha)"/> + <entry name="straight" value="3" summary="(src_alpha, one_minus_src_alpha)"/> + <entry name="fromsource" value="4" summary="(src_alpha, src_alpha)"/> + </enum> + + <enum name="error"> + <entry name="invalid_equation" value="0" + summary="the blending equation is not supported"/> + <entry name="invalid_alpha" value="1" + summary="the requested alpha value is outside the interval [0, 1]"/> + </enum> + + <request name="destroy" type="destructor"> + <description summary="remove blending from the surface"> + The associated wl_surface's blending state is removed. + The change is applied on the next wl_surface.commit. + </description> + </request> + + <request name="set_blending"> + <description summary="set the blending equation"> + Set the blending equation for compositing the wl_surface. + + If the requested format was not advertised by the + zwp_alpha_compositing_v1.blending event, the INVALID_EQUATION protocol + error is raised. + + The blending equation state is double-buffered state, + and will be applied on the next wl_surface.commit. + </description> + <arg name="equation" type="uint" enum="blending_equation" + summary="the new blending equation"/> + </request> + + <request name="set_alpha"> + <description summary="set the alpha value"> + Set the alpha value applied to the whole surface for compositing. This + alpha value is applied as an additional step after the processing of + per-pixel alpha values for the wl_surface. + + If the requested alpha is outside the interval [0, 1], the + INVALID_ALPHA protocol error is raised. + + The alpha value state is double-buffered state, + and will be applied on the next wl_surface.commit. + </description> + <arg name="value" type="fixed" summary="the new alpha value"/> + </request> + </interface> + +</protocol> -- 2.19.1 _______________________________________________ wayland-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/wayland-devel
