feat: use custom wayland layer-shell to render wallpaper to reduce vram

Modules/ServiceLoader.qml

@@ -0,0 +1,9 @@
+import Quickshell
+import QtQuick
+import qs.Modules.Wallpaper
+
+Scope {
+	Component.onCompleted: {
+		Wallpaper;
+	}
+}

Modules/Settings/Common/DialogRowButton.qml

@@ -139,12 +139,13 @@ Item {
 			id: dialogBg
 
 			anchors.fill: parent
-			bottomLeftRadius: Tokens.rounding.largeIncreased
+			bottomLeftRadius: root.last ? Tokens.rounding.largeIncreased : Tokens.rounding.extraSmall
-			bottomRightRadius: Tokens.rounding.largeIncreased
+			bottomRightRadius: root.last ? Tokens.rounding.largeIncreased : Tokens.rounding.extraSmall
 			deformScale: 0
 			group: blobGroup
 			opacity: blobGroup.color.a * (root.enabled ? 1 : 0.5)
-			radius: Tokens.rounding.extraSmall
+			topLeftRadius: root.first ? Tokens.rounding.largeIncreased : Tokens.rounding.extraSmall
+			topRightRadius: root.first ? Tokens.rounding.largeIncreased : Tokens.rounding.extraSmall
 		}
 
 		RowButton {
@@ -153,9 +154,11 @@ Item {
 			anchors.left: parent.left
 			anchors.right: parent.right
 			color: "transparent"
-			height: Math.min(implicitHeight, parent.height) // Clamp to parent height due to overshoot anim
+			first: root.first
+			height: Math.min(implicitHeight, parent.height)
 			icon: root.icon
-			last: true
+			last: root.last
+			subtext: root.subtext
 			text: root.label
 
 			transform: Matrix4x4 {

Modules/Wallpaper/WallBackground.qml

@@ -1,51 +0,0 @@
-pragma ComponentBehavior: Bound
-
-import Quickshell
-import Quickshell.Hyprland
-import QtQuick
-import qs.Components
-import qs.Helpers
-import ZShell.Internal
-
-Item {
-	id: root
-
-	readonly property var displayData: Wallpapers.getCrop(screen.name)
-	required property ShellScreen screen
-	property size screenResolution: Qt.size(screen.width * screenScale, screen.height * screenScale)
-	property real screenScale: Hyprland.monitorFor(screen).scale
-
-	anchors.fill: parent
-
-	Component.onCompleted: Hyprland.refreshMonitors()
-
-	WallpaperImage {
-		id: img
-
-		anchors.fill: parent
-		cropHeight: root.displayData?.height ?? 1.0
-		cropWidth: root.displayData?.width ?? 1.0
-		cropX: root.displayData?.x ?? 0.0
-		cropY: root.displayData?.y ?? 0.0
-		fadeDuration: 150
-		screenResolution: root.screenResolution
-		source: Wallpapers.current
-
-		Behavior on cropHeight {
-			Anim {
-			}
-		}
-		Behavior on cropWidth {
-			Anim {
-			}
-		}
-		Behavior on cropX {
-			Anim {
-			}
-		}
-		Behavior on cropY {
-			Anim {
-			}
-		}
-	}
-}

Modules/Wallpaper/Wallpaper.qml

@@ -1,46 +1,49 @@
+pragma Singleton
+
 import Quickshell
 import QtQuick
-import Quickshell.Wayland
+import ZShell.Internal
-import ZShell.Config
+import qs.Components
-import qs.Modules.DesktopIcons
+import qs.Helpers
 
-Loader {
+Singleton {
-	active: Config.background.enabled
-	asynchronous: false
-
-	sourceComponent: Variants {
-		model: Quickshell.screens
-
-		PanelWindow {
 	id: root
 
+	WallpaperService {
+		id: wallpaper
+
+		path: Wallpapers.current
+	}
+
+	Variants {
+		model: Quickshell.screens
+
+		WallpaperObject {
+			readonly property var crops: Wallpapers.getCrop(modelData.name)
 			required property var modelData
 
-			WlrLayershell.exclusionMode: ExclusionMode.Ignore
+			cropHeight: crops?.height ?? 1.0
-			WlrLayershell.layer: WlrLayer.Background
+			cropWidth: crops?.width ?? 1.0
-			WlrLayershell.namespace: "ZShell-Wallpaper"
+			cropX: crops?.x ?? 0.0
-			color: "transparent"
+			cropY: crops?.y ?? 0.0
-			screen: modelData
+			screen: modelData.name
-			surfaceFormat.opaque: true
+			service: wallpaper
+			zoom: crops?.zoom ?? 1.0
 
-			anchors {
+			Behavior on cropHeight {
-				bottom: true
+				Anim {
-				left: true
-				right: true
-				top: true
 				}
-
-			WallBackground {
-				screen: root.screen
 			}
-
+			Behavior on cropWidth {
-			Loader {
+				Anim {
-				id: loader
+				}
-
+			}
-				active: Config.general.desktopIcons
+			Behavior on cropX {
-				anchors.fill: parent
+				Anim {
-
+				}
-				sourceComponent: DesktopIcons {
+			}
+			Behavior on cropY {
+				Anim {
 				}
 			}
 		}

Plugins/CMakeLists.txt

@@ -1,5 +1,24 @@
-find_package(Qt6 REQUIRED COMPONENTS ShaderTools Core Qml Gui Quick QuickPrivate Concurrent Sql Network DBus CanvasPainter)
+find_package(Qt6 REQUIRED COMPONENTS
+	ShaderTools
+	Core
+	Qml
+	Gui
+	GuiPrivate
+	Quick
+	QuickPrivate
+	Concurrent
+	Sql
+	Network
+	DBus
+	CanvasPainter
+	WaylandClient
+	WaylandClientPrivate
+)
 find_package(PkgConfig REQUIRED)
+pkg_check_modules(WAYLAND_CLIENT REQUIRED IMPORTED_TARGET wayland-client)
+pkg_check_modules(EGL REQUIRED IMPORTED_TARGET egl)
+pkg_check_modules(WAYLAND_EGL REQUIRED IMPORTED_TARGET wayland-egl)
+pkg_check_modules(GL REQUIRED IMPORTED_TARGET gl)
 pkg_check_modules(Qalculate IMPORTED_TARGET libqalculate REQUIRED)
 pkg_check_modules(Pipewire IMPORTED_TARGET libpipewire-0.3 REQUIRED)
 pkg_check_modules(Aubio IMPORTED_TARGET aubio REQUIRED)
@@ -17,6 +36,7 @@ qt_standard_project_setup(REQUIRES 6.9)
 
 include(cmake/pch.cmake)
 include(cmake/qml-module.cmake)
+include(cmake/wayland-protocol.cmake)
 
 add_library(zshell-util INTERFACE)
 target_include_directories(zshell-util INTERFACE "${CMAKE_CURRENT_SOURCE_DIR}/include")

Plugins/ZShell/Internal/CMakeLists.txt

@@ -1,3 +1,9 @@
+wl_proto(wlp-layer-shell wlr-layer-shell-unstable-v1 "${CMAKE_CURRENT_SOURCE_DIR}/protocols")
+wl_proto(wlp-viewporter viewporter "${WAYLAND_PROTOCOLS}/stable/viewporter")
+wl_proto(wlp-fractional-scale fractional-scale-v1 "${WAYLAND_PROTOCOLS}/staging/fractional-scale")
+
+wl_proto(wlp-xdg-shell xdg-shell "${WAYLAND_PROTOCOLS}/stable/xdg-shell")
+
 qml_module(ZShell-internal
 	URI ZShell.Internal
 	INCLUDE_PREFIX internal
@@ -9,6 +15,9 @@ qml_module(ZShell-internal
 		circularbuffer.hpp circularbuffer.cpp
 		arcgauge.hpp arcgauge.cpp
 		wallpaperimage.hpp wallpaperimage.cpp
+		wallpaperservice.hpp wallpaperservice.cpp
+		wallpapersurface.hpp wallpapersurface.cpp
+		wallpaperobject.hpp wallpaperobject.cpp
 		lidwatcher.hpp lidwatcher.cpp
 		visualizerbars.hpp visualizerbars.cpp
 		linearindicatormanager.hpp linearindicatormanager.cpp
@@ -23,4 +32,12 @@ qml_module(ZShell-internal
 		Qt::Network
 		Qt::DBus
 		Qt::CanvasPainter
+		Qt::GuiPrivate
+		wlp-layer-shell
+		wlp-xdg-shell
+		wlp-viewporter
+		wlp-fractional-scale
+		PkgConfig::EGL
+		PkgConfig::WAYLAND_EGL
+		PkgConfig::GL
 )

Plugins/ZShell/Internal/protocols/wlr-layer-shell-unstable-v1.xml

@@ -0,0 +1,407 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<protocol name="wlr_layer_shell_unstable_v1">
+  <copyright>
+    Copyright © 2017 Drew DeVault
+
+    Permission to use, copy, modify, distribute, and sell this
+    software and its documentation for any purpose is hereby granted
+    without fee, provided that the above copyright notice appear in
+    all copies and that both that copyright notice and this permission
+    notice appear in supporting documentation, and that the name of
+    the copyright holders not be used in advertising or publicity
+    pertaining to distribution of the software without specific,
+    written prior permission.  The copyright holders make no
+    representations about the suitability of this software for any
+    purpose.  It is provided "as is" without express or implied
+    warranty.
+
+    THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+    SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+    FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+    SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+    AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
+    ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
+    THIS SOFTWARE.
+  </copyright>
+
+  <interface name="zwlr_layer_shell_v1" version="5">
+    <description summary="create surfaces that are layers of the desktop">
+      Clients can use this interface to assign the surface_layer role to
+      wl_surfaces. Such surfaces are assigned to a "layer" of the output and
+      rendered with a defined z-depth respective to each other. They may also be
+      anchored to the edges and corners of a screen and specify input handling
+      semantics. This interface should be suitable for the implementation of
+      many desktop shell components, and a broad number of other applications
+      that interact with the desktop.
+    </description>
+
+    <request name="get_layer_surface">
+      <description summary="create a layer_surface from a surface">
+        Create a layer surface for an existing surface. This assigns the role of
+        layer_surface, or raises a protocol error if another role is already
+        assigned.
+
+        Creating a layer surface from a wl_surface which has a buffer attached
+        or committed is a client error, and any attempts by a client to attach
+        or manipulate a buffer prior to the first layer_surface.configure call
+        must also be treated as errors.
+
+        After creating a layer_surface object and setting it up, the client
+        must perform an initial commit without any buffer attached.
+        The compositor will reply with a layer_surface.configure event.
+        The client must acknowledge it and is then allowed to attach a buffer
+        to map the surface.
+
+        You may pass NULL for output to allow the compositor to decide which
+        output to use. Generally this will be the one that the user most
+        recently interacted with.
+
+        Clients can specify a namespace that defines the purpose of the layer
+        surface.
+      </description>
+      <arg name="id" type="new_id" interface="zwlr_layer_surface_v1"/>
+      <arg name="surface" type="object" interface="wl_surface"/>
+      <arg name="output" type="object" interface="wl_output" allow-null="true"/>
+      <arg name="layer" type="uint" enum="layer" summary="layer to add this surface to"/>
+      <arg name="namespace_" type="string" summary="namespace for the layer surface"/>
+    </request>
+
+    <enum name="error">
+      <entry name="role" value="0" summary="wl_surface has another role"/>
+      <entry name="invalid_layer" value="1" summary="layer value is invalid"/>
+      <entry name="already_constructed" value="2" summary="wl_surface has a buffer attached or committed"/>
+    </enum>
+
+    <enum name="layer">
+      <description summary="available layers for surfaces">
+        These values indicate which layers a surface can be rendered in. They
+        are ordered by z depth, bottom-most first. Traditional shell surfaces
+        will typically be rendered between the bottom and top layers.
+        Fullscreen shell surfaces are typically rendered at the top layer.
+        Multiple surfaces can share a single layer, and ordering within a
+        single layer is undefined.
+      </description>
+
+      <entry name="background" value="0"/>
+      <entry name="bottom" value="1"/>
+      <entry name="top" value="2"/>
+      <entry name="overlay" value="3"/>
+    </enum>
+
+    <!-- Version 3 additions -->
+
+    <request name="destroy" type="destructor" since="3">
+      <description summary="destroy the layer_shell object">
+        This request indicates that the client will not use the layer_shell
+        object any more. Objects that have been created through this instance
+        are not affected.
+      </description>
+    </request>
+  </interface>
+
+  <interface name="zwlr_layer_surface_v1" version="5">
+    <description summary="layer metadata interface">
+      An interface that may be implemented by a wl_surface, for surfaces that
+      are designed to be rendered as a layer of a stacked desktop-like
+      environment.
+
+      Layer surface state (layer, size, anchor, exclusive zone,
+      margin, interactivity) is double-buffered, and will be applied at the
+      time wl_surface.commit of the corresponding wl_surface is called.
+
+      Attaching a null buffer to a layer surface unmaps it.
+
+      Unmapping a layer_surface means that the surface cannot be shown by the
+      compositor until it is explicitly mapped again. The layer_surface
+      returns to the state it had right after layer_shell.get_layer_surface.
+      The client can re-map the surface by performing a commit without any
+      buffer attached, waiting for a configure event and handling it as usual.
+    </description>
+
+    <request name="set_size">
+      <description summary="sets the size of the surface">
+        Sets the size of the surface in surface-local coordinates. The
+        compositor will display the surface centered with respect to its
+        anchors.
+
+        If you pass 0 for either value, the compositor will assign it and
+        inform you of the assignment in the configure event. You must set your
+        anchor to opposite edges in the dimensions you omit; not doing so is a
+        protocol error. Both values are 0 by default.
+
+        Size is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="width" type="uint"/>
+      <arg name="height" type="uint"/>
+    </request>
+
+    <request name="set_anchor">
+      <description summary="configures the anchor point of the surface">
+        Requests that the compositor anchor the surface to the specified edges
+        and corners. If two orthogonal edges are specified (e.g. 'top' and
+        'left'), then the anchor point will be the intersection of the edges
+        (e.g. the top left corner of the output); otherwise the anchor point
+        will be centered on that edge, or in the center if none is specified.
+
+        Anchor is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="anchor" type="uint" enum="anchor"/>
+    </request>
+
+    <request name="set_exclusive_zone">
+      <description summary="configures the exclusive geometry of this surface">
+        Requests that the compositor avoids occluding an area with other
+        surfaces. The compositor's use of this information is
+        implementation-dependent - do not assume that this region will not
+        actually be occluded.
+
+        A positive value is only meaningful if the surface is anchored to one
+        edge or an edge and both perpendicular edges. If the surface is not
+        anchored, anchored to only two perpendicular edges (a corner), anchored
+        to only two parallel edges or anchored to all edges, a positive value
+        will be treated the same as zero.
+
+        A positive zone is the distance from the edge in surface-local
+        coordinates to consider exclusive.
+
+        Surfaces that do not wish to have an exclusive zone may instead specify
+        how they should interact with surfaces that do. If set to zero, the
+        surface indicates that it would like to be moved to avoid occluding
+        surfaces with a positive exclusive zone. If set to -1, the surface
+        indicates that it would not like to be moved to accommodate for other
+        surfaces, and the compositor should extend it all the way to the edges
+        it is anchored to.
+
+        For example, a panel might set its exclusive zone to 10, so that
+        maximized shell surfaces are not shown on top of it. A notification
+        might set its exclusive zone to 0, so that it is moved to avoid
+        occluding the panel, but shell surfaces are shown underneath it. A
+        wallpaper or lock screen might set their exclusive zone to -1, so that
+        they stretch below or over the panel.
+
+        The default value is 0.
+
+        Exclusive zone is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="zone" type="int"/>
+    </request>
+
+    <request name="set_margin">
+      <description summary="sets a margin from the anchor point">
+        Requests that the surface be placed some distance away from the anchor
+        point on the output, in surface-local coordinates. Setting this value
+        for edges you are not anchored to has no effect.
+
+        The exclusive zone includes the margin.
+
+        Margin is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="top" type="int"/>
+      <arg name="right" type="int"/>
+      <arg name="bottom" type="int"/>
+      <arg name="left" type="int"/>
+    </request>
+
+    <enum name="keyboard_interactivity">
+      <description summary="types of keyboard interaction possible for a layer shell surface">
+        Types of keyboard interaction possible for layer shell surfaces. The
+        rationale for this is twofold: (1) some applications are not interested
+        in keyboard events and not allowing them to be focused can improve the
+        desktop experience; (2) some applications will want to take exclusive
+        keyboard focus.
+      </description>
+
+      <entry name="none" value="0">
+        <description summary="no keyboard focus is possible">
+          This value indicates that this surface is not interested in keyboard
+          events and the compositor should never assign it the keyboard focus.
+
+          This is the default value, set for newly created layer shell surfaces.
+
+          This is useful for e.g. desktop widgets that display information or
+          only have interaction with non-keyboard input devices.
+        </description>
+      </entry>
+      <entry name="exclusive" value="1">
+        <description summary="request exclusive keyboard focus">
+          Request exclusive keyboard focus if this surface is above the shell surface layer.
+
+          For the top and overlay layers, the seat will always give
+          exclusive keyboard focus to the top-most layer which has keyboard
+          interactivity set to exclusive. If this layer contains multiple
+          surfaces with keyboard interactivity set to exclusive, the compositor
+          determines the one receiving keyboard events in an implementation-
+          defined manner. In this case, no guarantee is made when this surface
+          will receive keyboard focus (if ever).
+
+          For the bottom and background layers, the compositor is allowed to use
+          normal focus semantics.
+
+          This setting is mainly intended for applications that need to ensure
+          they receive all keyboard events, such as a lock screen or a password
+          prompt.
+        </description>
+      </entry>
+      <entry name="on_demand" value="2" since="4">
+        <description summary="request regular keyboard focus semantics">
+          This requests the compositor to allow this surface to be focused and
+          unfocused by the user in an implementation-defined manner. The user
+          should be able to unfocus this surface even regardless of the layer
+          it is on.
+
+          Typically, the compositor will want to use its normal mechanism to
+          manage keyboard focus between layer shell surfaces with this setting
+          and regular toplevels on the desktop layer (e.g. click to focus).
+          Nevertheless, it is possible for a compositor to require a special
+          interaction to focus or unfocus layer shell surfaces (e.g. requiring
+          a click even if focus follows the mouse normally, or providing a
+          keybinding to switch focus between layers).
+
+          This setting is mainly intended for desktop shell components (e.g.
+          panels) that allow keyboard interaction. Using this option can allow
+          implementing a desktop shell that can be fully usable without the
+          mouse.
+        </description>
+      </entry>
+    </enum>
+
+    <request name="set_keyboard_interactivity">
+      <description summary="requests keyboard events">
+        Set how keyboard events are delivered to this surface. By default,
+        layer shell surfaces do not receive keyboard events; this request can
+        be used to change this.
+
+        This setting is inherited by child surfaces set by the get_popup
+        request.
+
+        Layer surfaces receive pointer, touch, and tablet events normally. If
+        you do not want to receive them, set the input region on your surface
+        to an empty region.
+
+        Keyboard interactivity is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="keyboard_interactivity" type="uint" enum="keyboard_interactivity"/>
+    </request>
+
+    <request name="get_popup">
+      <description summary="assign this layer_surface as an xdg_popup parent">
+        This assigns an xdg_popup's parent to this layer_surface.  This popup
+        should have been created via xdg_surface::get_popup with the parent set
+        to NULL, and this request must be invoked before committing the popup's
+        initial state.
+
+        See the documentation of xdg_popup for more details about what an
+        xdg_popup is and how it is used.
+      </description>
+      <arg name="popup" type="object" interface="xdg_popup"/>
+    </request>
+
+    <request name="ack_configure">
+      <description summary="ack a configure event">
+        When a configure event is received, if a client commits the
+        surface in response to the configure event, then the client
+        must make an ack_configure request sometime before the commit
+        request, passing along the serial of the configure event.
+
+        If the client receives multiple configure events before it
+        can respond to one, it only has to ack the last configure event.
+
+        A client is not required to commit immediately after sending
+        an ack_configure request - it may even ack_configure several times
+        before its next surface commit.
+
+        A client may send multiple ack_configure requests before committing, but
+        only the last request sent before a commit indicates which configure
+        event the client really is responding to.
+      </description>
+      <arg name="serial" type="uint" summary="the serial from the configure event"/>
+    </request>
+
+    <request name="destroy" type="destructor">
+      <description summary="destroy the layer_surface">
+        This request destroys the layer surface.
+      </description>
+    </request>
+
+    <event name="configure">
+      <description summary="suggest a surface change">
+        The configure event asks the client to resize its surface.
+
+        Clients should arrange their surface for the new states, and then send
+        an ack_configure request with the serial sent in this configure event at
+        some point before committing the new surface.
+
+        The client is free to dismiss all but the last configure event it
+        received.
+
+        The width and height arguments specify the size of the window in
+        surface-local coordinates.
+
+        The size is a hint, in the sense that the client is free to ignore it if
+        it doesn't resize, pick a smaller size (to satisfy aspect ratio or
+        resize in steps of NxM pixels). If the client picks a smaller size and
+        is anchored to two opposite anchors (e.g. 'top' and 'bottom'), the
+        surface will be centered on this axis.
+
+        If the width or height arguments are zero, it means the client should
+        decide its own window dimension.
+      </description>
+      <arg name="serial" type="uint"/>
+      <arg name="width" type="uint"/>
+      <arg name="height" type="uint"/>
+    </event>
+
+    <event name="closed">
+      <description summary="surface should be closed">
+        The closed event is sent by the compositor when the surface will no
+        longer be shown. The output may have been destroyed or the user may
+        have asked for it to be removed. Further changes to the surface will be
+        ignored. The client should destroy the resource after receiving this
+        event, and create a new surface if they so choose.
+      </description>
+    </event>
+
+    <enum name="error">
+      <entry name="invalid_surface_state" value="0" summary="provided surface state is invalid"/>
+      <entry name="invalid_size" value="1" summary="size is invalid"/>
+      <entry name="invalid_anchor" value="2" summary="anchor bitfield is invalid"/>
+      <entry name="invalid_keyboard_interactivity" value="3" summary="keyboard interactivity is invalid"/>
+      <entry name="invalid_exclusive_edge" value="4" summary="exclusive edge is invalid given the surface anchors"/>
+    </enum>
+
+    <enum name="anchor" bitfield="true">
+      <entry name="top" value="1" summary="the top edge of the anchor rectangle"/>
+      <entry name="bottom" value="2" summary="the bottom edge of the anchor rectangle"/>
+      <entry name="left" value="4" summary="the left edge of the anchor rectangle"/>
+      <entry name="right" value="8" summary="the right edge of the anchor rectangle"/>
+    </enum>
+
+    <!-- Version 2 additions -->
+
+    <request name="set_layer" since="2">
+      <description summary="change the layer of the surface">
+        Change the layer that the surface is rendered on.
+
+        Layer is double-buffered, see wl_surface.commit.
+      </description>
+      <arg name="layer" type="uint" enum="zwlr_layer_shell_v1.layer" summary="layer to move this surface to"/>
+    </request>
+
+    <!-- Version 5 additions -->
+
+    <request name="set_exclusive_edge" since="5">
+      <description summary="set the edge the exclusive zone will be applied to">
+        Requests an edge for the exclusive zone to apply. The exclusive
+        edge will be automatically deduced from anchor points when possible,
+        but when the surface is anchored to a corner, it will be necessary
+        to set it explicitly to disambiguate, as it is not possible to deduce
+        which one of the two corner edges should be used.
+
+        The edge must be one the surface is anchored to, otherwise the
+        invalid_exclusive_edge protocol error will be raised.
+      </description>
+      <arg name="edge" type="uint" enum="anchor"/>
+    </request>
+  </interface>
+</protocol>

Plugins/ZShell/Internal/wallpaperobject.cpp

@@ -0,0 +1,83 @@
+#include "wallpaperobject.hpp"
+
+namespace ZShell::internal {
+
+WallpaperObject::WallpaperObject(QObject* parent) : QObject(parent) {}
+
+WallpaperObject::~WallpaperObject() {
+	if (m_service && !m_screen.isEmpty()) m_service->removeScreen(m_screen);
+}
+
+void WallpaperObject::registerScreen() {
+	if (!m_service || m_screen.isEmpty()) return;
+
+	m_service->addScreen(m_screen);
+}
+
+void WallpaperObject::setService(WallpaperService* service) {
+	if (m_service == service) return;
+	m_service = service;
+	emit serviceChanged();
+
+	registerScreen();
+	push();
+}
+
+void WallpaperObject::setScreen(const QString& screen) {
+	if (m_screen == screen) return;
+	m_screen = screen;
+	emit screenChanged();
+
+	registerScreen();
+	push();
+}
+
+void WallpaperObject::setCropX(qreal x) {
+	if (qFuzzyCompare(m_cropX, x)) return;
+	m_cropX = x;
+	emit cropXChanged();
+	push();
+}
+
+void WallpaperObject::setCropY(qreal y) {
+	if (qFuzzyCompare(m_cropY, y)) return;
+	m_cropY = y;
+	emit cropYChanged();
+	push();
+}
+
+void WallpaperObject::setCropWidth(qreal w) {
+	if (qFuzzyCompare(m_cropWidth, w)) return;
+	m_cropWidth = w;
+	emit cropWidthChanged();
+	push();
+}
+
+void WallpaperObject::setCropHeight(qreal h) {
+	if (qFuzzyCompare(m_cropHeight, h)) return;
+	m_cropHeight = h;
+	emit cropHeightChanged();
+	push();
+}
+
+void WallpaperObject::setZoom(qreal zoom) {
+	if (qFuzzyCompare(m_zoom, zoom)) return;
+	m_zoom = zoom;
+	emit zoomChanged();
+	push();
+}
+
+void WallpaperObject::push() {
+	if (!m_service || m_screen.isEmpty()) return;
+
+	QVariantMap crop;
+	crop.insert("x", m_cropX);
+	crop.insert("y", m_cropY);
+	crop.insert("width", m_cropWidth);
+	crop.insert("height", m_cropHeight);
+	crop.insert("zoom", m_zoom);
+
+	m_service->setCrop(m_screen, crop);
+}
+
+} // namespace ZShell::internal

Plugins/ZShell/Internal/wallpaperobject.hpp

@@ -0,0 +1,82 @@
+#pragma once
+
+#include <QObject>
+#include <QPointer>
+#include <QString>
+#include <QVariantMap>
+#include <QtQml/qqml.h>
+#include <qtmetamacros.h>
+
+#include "wallpaperservice.hpp"
+
+namespace ZShell::internal {
+
+class WallpaperObject : public QObject {
+	Q_OBJECT
+	QML_ELEMENT
+
+	Q_PROPERTY(
+		WallpaperService* service READ service WRITE setService NOTIFY
+			serviceChanged)
+	Q_PROPERTY(QString screen READ screen WRITE setScreen NOTIFY screenChanged)
+
+	Q_PROPERTY(qreal cropX READ cropX WRITE setCropX NOTIFY cropXChanged)
+	Q_PROPERTY(qreal cropY READ cropY WRITE setCropY NOTIFY cropYChanged)
+	Q_PROPERTY(
+		qreal cropWidth READ cropWidth WRITE setCropWidth NOTIFY
+			cropWidthChanged)
+	Q_PROPERTY(
+		qreal cropHeight READ cropHeight WRITE setCropHeight NOTIFY
+			cropHeightChanged)
+	Q_PROPERTY(qreal zoom READ zoom WRITE setZoom NOTIFY zoomChanged)
+
+	public:
+	explicit WallpaperObject(QObject* parent = nullptr);
+	~WallpaperObject() override;
+
+	WallpaperService* service() const { return m_service; }
+	void setService(WallpaperService* service);
+
+	QString screen() const { return m_screen; }
+	void setScreen(const QString& screen);
+
+	qreal cropX() const { return m_cropX; }
+	void setCropX(qreal x);
+
+	qreal cropY() const { return m_cropY; }
+	void setCropY(qreal y);
+
+	qreal cropWidth() const { return m_cropWidth; }
+	void setCropWidth(qreal w);
+
+	qreal cropHeight() const { return m_cropHeight; }
+	void setCropHeight(qreal h);
+
+	qreal zoom() const { return m_zoom; }
+	void setZoom(qreal zoom);
+
+	signals:
+	void serviceChanged();
+	void screenChanged();
+	void cropXChanged();
+	void cropYChanged();
+	void cropWidthChanged();
+	void cropHeightChanged();
+	void zoomChanged();
+
+	private:
+	void registerScreen();
+
+	void push();
+
+	QPointer<WallpaperService> m_service;
+	QString m_screen;
+
+	qreal m_cropX = 0.0;
+	qreal m_cropY = 0.0;
+	qreal m_cropWidth = 1.0;
+	qreal m_cropHeight = 1.0;
+	qreal m_zoom = 1.0;
+};
+
+} // namespace ZShell::internal

Plugins/ZShell/Internal/wallpaperservice.cpp

@@ -0,0 +1,749 @@
+#define EGL_EGLEXT_PROTOTYPES
+#define GL_GLEXT_PROTOTYPES
+
+#include "wallpaperservice.hpp"
+
+#include <EGL/eglext.h>
+#include <GL/gl.h>
+#include <GL/glext.h>
+
+#include <fcntl.h>
+#include <poll.h>
+#include <unistd.h>
+
+#include <QDebug>
+#include <QGuiApplication>
+#include <QImageReader>
+#include <QScreen>
+
+#include <qguiapplication_platform.h>
+
+#include <private/qwaylandscreen_p.h>
+
+#include <cstring>
+
+namespace ZShell::internal {
+
+namespace {
+
+const char* kVertexShader = R"(
+#version 300 es
+void main() {
+	// The corners are (-1,-1), (3,-1) and (-1,3), which cover the whole buffer.
+	vec2 corner = vec2(float((gl_VertexID << 1) & 2), float(gl_VertexID & 2));
+	gl_Position = vec4(corner * 2.0 - 1.0, 0.0, 1.0);
+}
+)";
+
+const char* kFragmentShader = R"(
+#version 300 es
+precision highp float;
+uniform sampler2D source;
+uniform vec2 size;
+uniform vec4 crop;
+out vec4 outColor;
+void main() {
+	// The pixels are stored top-down, so the fragment coordinate is flipped.
+	vec2 p = vec2(gl_FragCoord.x, size.y - gl_FragCoord.y) / size;
+	outColor = texture(source, crop.xy + p * crop.zw);
+}
+)";
+
+constexpr int kWaitTimeoutMs = 20;
+
+void logShader(uint32_t object, bool program) {
+	int ok = 0;
+	if (program)
+		glGetProgramiv(object, GL_LINK_STATUS, &ok);
+	else
+		glGetShaderiv(object, GL_COMPILE_STATUS, &ok);
+
+	if (ok) return;
+
+	char info[512] = {};
+	if (program)
+		glGetProgramInfoLog(object, int(sizeof(info)), nullptr, info);
+	else
+		glGetShaderInfoLog(object, int(sizeof(info)), nullptr, info);
+
+	qWarning() << "WallpaperService:" << (program ? "linking" : "compiling")
+			   << "failed:" << info;
+}
+
+QVariantMap cropFor(const QVariantMap& crops, const QString& screen) {
+	QVariantMap crop = crops.value(screen).toMap();
+
+	if (crop.isEmpty()) {
+		crop.insert("x", 0.0);
+		crop.insert("y", 0.0);
+		crop.insert("width", 1.0);
+		crop.insert("height", 1.0);
+		crop.insert("zoom", 1.0);
+	}
+
+	return crop;
+}
+
+} // namespace
+
+WallpaperService::WallpaperService(QObject* parent) : QObject(parent) {}
+
+WallpaperService::~WallpaperService() {
+	m_stop = true;
+	wake();
+
+	if (m_thread.joinable()) m_thread.join();
+
+	for (auto* surface : m_surfaces)
+		delete surface;
+	m_surfaces.clear();
+
+	if (m_eglDisplay != EGL_NO_DISPLAY && m_context != EGL_NO_CONTEXT) {
+		if (eglMakeCurrent(
+				m_eglDisplay, EGL_NO_SURFACE, EGL_NO_SURFACE, m_context)) {
+			if (m_texture) glDeleteTextures(1, &m_texture);
+			if (m_program) glDeleteProgram(m_program);
+		}
+
+		eglDestroyContext(m_eglDisplay, m_context);
+	}
+
+	if (m_queue) wl_event_queue_destroy(m_queue);
+
+	if (m_wake[0] >= 0) {
+		close(m_wake[0]);
+		close(m_wake[1]);
+	}
+
+	if (m_layerShell) m_layerShell->destroy();
+	if (m_viewporter) m_viewporter->destroy();
+	if (m_scaleManager) m_scaleManager->destroy();
+	if (m_registry) wl_registry_destroy(m_registry);
+}
+
+QString WallpaperService::path() const {
+	std::lock_guard<std::recursive_mutex> lock(m_mutex);
+	return m_path;
+}
+
+void WallpaperService::setPath(const QString& path) {
+	if (m_path == path) return;
+
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+		m_path = path;
+
+		m_forceDecode = true;
+		m_imageChanged = true;
+	}
+
+	emit pathChanged();
+
+	start();
+	queueAll();
+}
+
+void WallpaperService::addScreen(const QString& screen) {
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+
+		if (m_screens.contains(screen)) return;
+
+		m_screens.append(screen);
+	}
+
+	start();
+
+	queueAll();
+}
+
+void WallpaperService::removeScreen(const QString& screen) {
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+
+		if (!m_screens.removeOne(screen)) return;
+	}
+
+	queueAll();
+}
+
+const QVariantMap& WallpaperService::crops() const {
+	std::lock_guard<std::recursive_mutex> lock(m_mutex);
+	return m_crops;
+}
+
+void WallpaperService::setCrops(const QVariantMap& crops) {
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+
+		if (m_crops == crops) return;
+
+		m_crops = crops;
+	}
+
+	emit cropsChanged();
+	queueAll();
+}
+
+void WallpaperService::setCrop(const QString& screen, const QVariantMap& crop) {
+	WallpaperSurface* surface = nullptr;
+
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+
+		if (m_crops.value(screen) == crop) return;
+
+		m_crops.insert(screen, crop);
+
+		for (auto* candidate : m_surfaces) {
+			if (candidate->screen() == screen) {
+				surface = candidate;
+				break;
+			}
+		}
+	}
+
+	emit cropsChanged();
+
+	if (surface) queue(surface);
+}
+
+void WallpaperService::redraw() {
+	queueAll();
+}
+
+void WallpaperService::start() {
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+
+		if (started || m_path.isEmpty() || m_screens.isEmpty()) return;
+
+		started = true;
+	}
+
+	auto* interface =
+		qApp->nativeInterface<QNativeInterface::QWaylandApplication>();
+	if (!interface) {
+		qWarning() << "WallpaperService: this is not a Wayland session";
+		return;
+	}
+
+	m_display = interface->display();
+	m_compositor = interface->compositor();
+	if (!m_display || !m_compositor) return;
+
+	m_queue = wl_display_create_queue(m_display);
+	if (!m_queue) return;
+
+	if (pipe2(m_wake, O_CLOEXEC) < 0) {
+		qWarning() << "WallpaperService: could not make the pipe to wake on";
+		return;
+	}
+
+	bindGlobals();
+
+	if (!setupGl()) return;
+
+	m_drawing = true;
+	m_thread = std::thread([this] { loop(); });
+
+	wake();
+}
+
+void WallpaperService::wake() {
+	if (m_wake[1] < 0) return;
+
+	char byte = 0;
+
+	if (::write(m_wake[1], &byte, 1) < 0)
+		qWarning() << "WallpaperService: could not wake the drawing thread";
+}
+
+void WallpaperService::queue(WallpaperSurface* surface) {
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+		m_pending.push_back(surface);
+	}
+
+	wake();
+}
+
+void WallpaperService::queueAll() {
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+
+		for (auto* surface : m_surfaces)
+			m_pending.push_back(surface);
+	}
+
+	wake();
+}
+
+void WallpaperService::loop() {
+	while (!m_stop) {
+		present();
+
+		if (wl_display_prepare_read(m_display) == 0) {
+			wl_display_flush(m_display);
+
+			struct pollfd fds[2] = {
+				{wl_display_get_fd(m_display), POLLIN, 0},
+				{m_wake[0], POLLIN, 0},
+			};
+
+			int ready = poll(fds, 2, kWaitTimeoutMs);
+
+			if (ready > 0 && fds[0].revents) {
+				wl_display_read_events(m_display);
+				continue;
+			}
+
+			if (ready > 0 && fds[1].revents) {
+				char byte = 0;
+				::read(m_wake[0], &byte, 1);
+			}
+
+			wl_display_cancel_read(m_display);
+			continue;
+		}
+
+		struct pollfd fds[1] = {{m_wake[0], POLLIN, 0}};
+
+		if (poll(fds, 1, kWaitTimeoutMs) <= 0) continue;
+
+		char byte = 0;
+		::read(m_wake[0], &byte, 1);
+	}
+}
+
+void WallpaperService::present() {
+	wl_display_dispatch_queue_pending(m_display, m_queue);
+
+	addSurfaces();
+
+	ensureDecodeSize();
+
+	std::vector<WallpaperSurface*> pending;
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+		pending.swap(m_pending);
+	}
+
+	for (auto* surface : pending)
+		drawSurface(surface);
+}
+
+void WallpaperService::addSurfaces() {
+	if (!started || !m_layerShell || !m_viewporter || !m_scaleManager) return;
+
+	QList<WallpaperSurface*> gone;
+	QList<QString> needed;
+
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+
+		QList<WallpaperSurface*> kept;
+		for (auto* surface : m_surfaces) {
+			if (m_screens.contains(surface->screen()))
+				kept.append(surface);
+			else
+				gone.append(surface);
+		}
+
+		m_surfaces = kept;
+
+		for (const auto& screen : m_screens) {
+			bool exists = false;
+			for (auto* surface : m_surfaces) {
+				if (surface->screen() == screen) {
+					exists = true;
+					break;
+				}
+			}
+
+			if (!exists) needed.append(screen);
+		}
+	}
+
+	for (auto* surface : gone)
+		delete surface;
+
+	for (const auto& screen : needed)
+		addSurface(screen);
+}
+
+void WallpaperService::registryGlobal(
+	void* data,
+	struct wl_registry* registry,
+	uint32_t name,
+	const char* interface,
+	uint32_t version) {
+	auto* service = static_cast<WallpaperService*>(data);
+
+	void* proxy = nullptr;
+
+	if (strcmp(interface, "zwlr_layer_shell_v1") == 0) {
+		proxy = new QtWayland::zwlr_layer_shell_v1(
+			registry, int(name), int(version));
+	} else if (strcmp(interface, "wp_viewporter") == 0) {
+		proxy = new QtWayland::wp_viewporter(registry, int(name), int(version));
+	} else if (strcmp(interface, "wp_fractional_scale_manager_v1") == 0) {
+		proxy = new QtWayland::wp_fractional_scale_manager_v1(
+			registry, int(name), int(version));
+	} else {
+		return;
+	}
+
+	service->storeGlobal(interface, proxy);
+
+	service->queueAll();
+}
+
+void WallpaperService::storeGlobal(const char* interface, void* proxy) {
+	std::lock_guard<std::recursive_mutex> lock(m_mutex);
+
+	if (strcmp(interface, "zwlr_layer_shell_v1") == 0)
+		m_layerShell = static_cast<QtWayland::zwlr_layer_shell_v1*>(proxy);
+	else if (strcmp(interface, "wp_viewporter") == 0)
+		m_viewporter = static_cast<QtWayland::wp_viewporter*>(proxy);
+	else if (strcmp(interface, "wp_fractional_scale_manager_v1") == 0)
+		m_scaleManager =
+			static_cast<QtWayland::wp_fractional_scale_manager_v1*>(proxy);
+}
+
+void WallpaperService::bindGlobals() {
+	m_registry = wl_display_get_registry(m_display);
+
+	static const struct wl_registry_listener listener = {
+		registryGlobal,
+		nullptr,
+	};
+
+	wl_registry_add_listener(m_registry, &listener, this);
+}
+
+bool WallpaperService::setupGl() {
+	const char* extensions = eglQueryString(EGL_NO_DISPLAY, EGL_EXTENSIONS);
+	if (extensions && strstr(extensions, "EGL_EXT_platform_wayland")) {
+		m_eglDisplay =
+			eglGetPlatformDisplay(EGL_PLATFORM_WAYLAND_EXT, m_display, nullptr);
+	} else {
+		m_eglDisplay =
+			eglGetDisplay(reinterpret_cast<EGLNativeDisplayType>(m_display));
+	}
+
+	if (m_eglDisplay == EGL_NO_DISPLAY) {
+		qWarning() << "WallpaperService: no EGL display";
+		return false;
+	}
+
+	EGLint major = 0, minor = 0;
+	if (!eglInitialize(m_eglDisplay, &major, &minor)) {
+		qWarning() << "WallpaperService: eglInitialize failed";
+		return false;
+	}
+
+	const EGLint configAttributes[] = {
+		EGL_SURFACE_TYPE,
+		EGL_WINDOW_BIT,
+		EGL_RENDERABLE_TYPE,
+		EGL_OPENGL_ES2_BIT,
+		EGL_RED_SIZE,
+		8,
+		EGL_GREEN_SIZE,
+		8,
+		EGL_BLUE_SIZE,
+		8,
+		EGL_ALPHA_SIZE,
+		8,
+		EGL_NONE};
+
+	EGLint count = 0;
+	if (!eglChooseConfig(m_eglDisplay, configAttributes, &m_config, 1, &count) ||
+		count == 0) {
+		qWarning() << "WallpaperService: no EGL config for window surfaces";
+		return false;
+	}
+
+	const EGLint contextAttributes[] = {EGL_CONTEXT_MAJOR_VERSION, 3, EGL_NONE};
+	m_context = eglCreateContext(
+		m_eglDisplay, m_config, EGL_NO_CONTEXT, contextAttributes);
+	if (m_context == EGL_NO_CONTEXT) {
+		qWarning() << "WallpaperService: eglCreateContext failed";
+		return false;
+	}
+
+	return true;
+}
+
+uint32_t WallpaperService::createProgram() {
+	uint32_t vertex = glCreateShader(GL_VERTEX_SHADER);
+	glShaderSource(vertex, 1, &kVertexShader, nullptr);
+	glCompileShader(vertex);
+	logShader(vertex, false);
+
+	uint32_t fragment = glCreateShader(GL_FRAGMENT_SHADER);
+	glShaderSource(fragment, 1, &kFragmentShader, nullptr);
+	glCompileShader(fragment);
+	logShader(fragment, false);
+
+	uint32_t program = glCreateProgram();
+	glAttachShader(program, vertex);
+	glAttachShader(program, fragment);
+	glLinkProgram(program);
+	logShader(program, true);
+
+	if (glGetUniformLocation(program, "size") < 0 ||
+		glGetUniformLocation(program, "crop") < 0) {
+		qWarning() << "WallpaperService: the program does not have the "
+					  "uniforms it needs";
+		glDeleteProgram(program);
+		return 0;
+	}
+
+	m_sizeUniform = glGetUniformLocation(program, "size");
+	m_cropUniform = glGetUniformLocation(program, "crop");
+
+	glDeleteShader(vertex);
+	glDeleteShader(fragment);
+	return program;
+}
+
+void WallpaperService::uploadImage() {
+	if (m_image.isNull()) return;
+
+	if (m_texture == 0) {
+		glGenTextures(1, &m_texture);
+		glBindTexture(GL_TEXTURE_2D, m_texture);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	} else {
+		glBindTexture(GL_TEXTURE_2D, m_texture);
+	}
+
+	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+	glTexImage2D(
+		GL_TEXTURE_2D,
+		0,
+		GL_RGBA8,
+		m_image.width(),
+		m_image.height(),
+		0,
+		GL_RGBA,
+		GL_UNSIGNED_BYTE,
+		m_image.constBits());
+}
+
+bool WallpaperService::decode(const QString& path) {
+	if (path.isEmpty()) return false;
+
+	QImageReader reader(path);
+	reader.setAutoTransform(true);
+
+	QSize size = reader.size();
+	if (size.isValid()) m_sourceSize = size;
+
+	if (!m_decodeSize.isEmpty() && !m_sourceSize.isEmpty())
+		reader.setScaledSize(
+			m_sourceSize.scaled(m_decodeSize, Qt::KeepAspectRatioByExpanding));
+
+	QImage image = reader.read();
+	if (image.isNull()) {
+		qWarning() << "WallpaperService: could not read the image" << path;
+		return false;
+	}
+
+	m_image = image.convertToFormat(QImage::Format_RGBA8888);
+	return !m_image.isNull();
+}
+
+bool WallpaperService::ensureDecodeSize() {
+	QSize largest;
+	QString path;
+
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+
+		largest = largestBufferSize();
+		if (largest.isEmpty()) return false;
+
+		if (!m_forceDecode && !m_decodeSize.isEmpty() &&
+			qint64(largest.width()) * largest.height() <=
+				qint64(m_decodeSize.width()) * m_decodeSize.height())
+			return false;
+
+		QSize target =
+			m_sourceSize.isEmpty()
+				? largest
+				: m_sourceSize.scaled(largest, Qt::KeepAspectRatioByExpanding);
+
+		if (!m_forceDecode && !m_image.isNull() && target == m_image.size())
+			return false;
+
+		m_forceDecode = false;
+		m_decodeSize = largest;
+		path = m_path;
+	}
+
+	if (!decode(path)) return false;
+
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+		m_imageChanged = true;
+	}
+
+	return true;
+}
+
+QSize WallpaperService::largestBufferSize() {
+	QSize largest;
+
+	for (auto* surface : m_surfaces) {
+		QSize buffer = surface->bufferSize();
+		if (buffer.isEmpty()) continue;
+
+		if (largest.isEmpty() || qint64(buffer.width()) * buffer.height() >
+									 qint64(largest.width()) * largest.height())
+			largest = buffer;
+	}
+
+	return largest;
+}
+
+QRectF WallpaperService::sourceRect(
+	const QVariantMap& crops, const QString& screen, const QSize& size) const {
+	QVariantMap crop = cropFor(crops, screen);
+
+	qreal zoom = crop.value("zoom", 1.0).toDouble();
+	if (zoom <= 0.0)
+		zoom = 1.0;
+	else if (zoom > 5.0)
+		zoom = 5.0;
+
+	QRectF rect(
+		crop.value("x", 0.0).toDouble(),
+		crop.value("y", 0.0).toDouble(),
+		crop.value("width", 1.0).toDouble() / zoom,
+		crop.value("height", 1.0).toDouble() / zoom);
+
+	if (size.isEmpty() || rect.isEmpty() || m_image.isNull()) return rect;
+
+	qreal imageWidth = qreal(m_image.width());
+	qreal imageHeight = qreal(m_image.height());
+
+	QRectF pixels(
+		rect.x() * imageWidth,
+		rect.y() * imageHeight,
+		rect.width() * imageWidth,
+		rect.height() * imageHeight);
+
+	qreal targetRatio = qreal(size.width()) / qreal(size.height());
+	qreal rectRatio = pixels.width() / pixels.height();
+
+	if (rectRatio > targetRatio) {
+		qreal newWidth = pixels.height() * targetRatio;
+		pixels.setX(pixels.x() + (pixels.width() - newWidth) / 2.0);
+		pixels.setWidth(newWidth);
+	} else if (rectRatio < targetRatio) {
+		qreal newHeight = pixels.width() / targetRatio;
+		pixels.setY(pixels.y() + (pixels.height() - newHeight) / 2.0);
+		pixels.setHeight(newHeight);
+	}
+
+	return QRectF(
+		pixels.x() / imageWidth,
+		pixels.y() / imageHeight,
+		pixels.width() / imageWidth,
+		pixels.height() / imageHeight);
+}
+
+void WallpaperService::drawSurface(WallpaperSurface* surface) {
+	EGLSurface target = surface->eglSurface();
+	if (m_context == EGL_NO_CONTEXT || target == EGL_NO_SURFACE ||
+		surface->bufferSize().isEmpty())
+		return;
+
+	if (!eglMakeCurrent(m_eglDisplay, target, target, m_context)) {
+		qWarning() << "WallpaperService: the context cannot be made current";
+		return;
+	}
+
+	QVariantMap crops;
+	QSize size;
+	bool upload = false;
+
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+
+		crops = m_crops;
+		size = surface->bufferSize();
+
+		upload = m_imageChanged;
+		m_imageChanged = false;
+	}
+
+	if (size.isEmpty()) return;
+
+	if (m_program == 0) m_program = createProgram();
+	if (m_texture == 0 || upload) uploadImage();
+
+	if (m_program == 0 || m_texture == 0 || m_image.isNull()) return;
+
+	glUseProgram(m_program);
+	glBindTexture(GL_TEXTURE_2D, m_texture);
+
+	glUniform2f(
+		GLint(m_sizeUniform), GLfloat(size.width()), GLfloat(size.height()));
+
+	QRectF rect = sourceRect(crops, surface->screen(), size);
+	glUniform4f(
+		GLint(m_cropUniform),
+		GLfloat(rect.x()),
+		GLfloat(rect.y()),
+		GLfloat(rect.width()),
+		GLfloat(rect.height()));
+
+	glViewport(0, 0, size.width(), size.height());
+	glDrawArrays(GL_TRIANGLES, 0, 3);
+
+	if (!eglSwapBuffers(m_eglDisplay, target))
+		qWarning() << "WallpaperService: eglSwapBuffers failed";
+}
+
+void WallpaperService::addSurface(const QString& screen) {
+	if (!m_layerShell || !m_viewporter || !m_scaleManager) return;
+
+	QScreen* qscreen = nullptr;
+	for (auto* candidate : QGuiApplication::screens()) {
+		if (candidate->name() == screen) {
+			qscreen = candidate;
+			break;
+		}
+	}
+
+	if (!qscreen) {
+		qWarning() << "WallpaperService:" << screen << "is not a screen";
+		return;
+	}
+
+	auto* waylandScreen =
+		dynamic_cast<QtWaylandClient::QWaylandScreen*>(qscreen->handle());
+	if (!waylandScreen || !waylandScreen->output()) {
+		qWarning() << "WallpaperService:" << screen
+				   << "is not a Wayland screen";
+		return;
+	}
+
+	wl_surface* wlSurface = wl_compositor_create_surface(m_compositor);
+	if (!wlSurface) return;
+
+	auto* surface =
+		new WallpaperSurface(this, wlSurface, waylandScreen->output(), screen);
+
+	{
+		std::lock_guard<std::recursive_mutex> lock(m_mutex);
+		m_surfaces.append(surface);
+	}
+}
+
+} // namespace ZShell::internal

Plugins/ZShell/Internal/wallpaperservice.hpp

@@ -0,0 +1,147 @@
+#pragma once
+
+#include <EGL/egl.h>
+
+#include <cstdint>
+#include <mutex>
+#include <thread>
+#include <vector>
+
+#include <QImage>
+#include <QList>
+#include <QRectF>
+#include <QSize>
+#include <QString>
+#include <QStringList>
+#include <QVariantMap>
+#include <QtQml/qqml.h>
+#include <qtmetamacros.h>
+
+#include <qwayland-wlr-layer-shell-unstable-v1.h>
+#include <wayland-client-protocol.h>
+
+#include "wallpapersurface.hpp"
+
+namespace ZShell::internal {
+
+class WallpaperSurface;
+
+class WallpaperService : public QObject {
+	Q_OBJECT
+	QML_ELEMENT
+
+	Q_PROPERTY(QString path READ path WRITE setPath NOTIFY pathChanged REQUIRED)
+	Q_PROPERTY(QVariantMap crops READ crops WRITE setCrops NOTIFY cropsChanged)
+
+	public:
+	explicit WallpaperService(QObject* parent = nullptr);
+	~WallpaperService() override;
+
+	[[nodiscard]] QString path() const;
+	void setPath(const QString& path);
+
+	void addScreen(const QString& screen);
+	void removeScreen(const QString& screen);
+
+	[[nodiscard]] const QVariantMap& crops() const;
+	void setCrops(const QVariantMap& crops);
+
+	Q_INVOKABLE void redraw();
+
+	Q_INVOKABLE void setCrop(const QString& screen, const QVariantMap& crop);
+
+	signals:
+	void pathChanged();
+	void cropsChanged();
+
+	private:
+	friend class WallpaperSurface;
+
+	void bindGlobals();
+	static void registryGlobal(
+		void* data,
+		struct wl_registry* registry,
+		uint32_t name,
+		const char* interface,
+		uint32_t version);
+
+	void storeGlobal(const char* interface, void* proxy);
+
+	[[nodiscard]] bool setupGl();
+	[[nodiscard]] uint32_t createProgram();
+
+	void uploadImage();
+
+	bool decode(const QString& path);
+
+	bool ensureDecodeSize();
+
+	[[nodiscard]] QSize largestBufferSize();
+
+	void queue(WallpaperSurface* surface);
+	void queueAll();
+
+	void startDrawing();
+	void loop();
+
+	void present();
+
+	void drawSurface(WallpaperSurface* surface);
+
+	void wake();
+
+	[[nodiscard]] wl_event_queue* eventQueue() const { return m_queue; }
+
+	[[nodiscard]] QRectF sourceRect(
+		const QVariantMap& crops,
+		const QString& screen,
+		const QSize& size) const;
+
+	void start();
+
+	void addSurfaces();
+	void addSurface(const QString& screen);
+
+	QString m_path;
+	QStringList m_screens;
+	QVariantMap m_crops;
+
+	QImage m_image;
+
+	QSize m_sourceSize;
+	QSize m_decodeSize;
+
+	wl_display* m_display = nullptr;
+	wl_registry* m_registry = nullptr;
+	wl_compositor* m_compositor = nullptr;
+	QtWayland::zwlr_layer_shell_v1* m_layerShell = nullptr;
+	QtWayland::wp_viewporter* m_viewporter = nullptr;
+	QtWayland::wp_fractional_scale_manager_v1* m_scaleManager = nullptr;
+
+	EGLDisplay m_eglDisplay = EGL_NO_DISPLAY;
+	EGLConfig m_config = nullptr;
+	EGLContext m_context = EGL_NO_CONTEXT;
+	uint32_t m_texture = 0;
+	uint32_t m_program = 0;
+	int m_sizeUniform = -1;
+	int m_cropUniform = -1;
+
+	QList<WallpaperSurface*> m_surfaces;
+
+	std::thread m_thread;
+	mutable std::recursive_mutex m_mutex;
+	std::vector<WallpaperSurface*> m_pending;
+	wl_event_queue* m_queue = nullptr;
+
+	int m_wake[2] = {-1, -1};
+
+	bool m_stop = false;
+	bool m_drawing = false;
+
+	bool started = false;
+
+	bool m_forceDecode = false;
+	bool m_imageChanged = false;
+};
+
+} // namespace ZShell::internal

Plugins/ZShell/Internal/wallpapersurface.cpp

@@ -0,0 +1,147 @@
+#include "wallpapersurface.hpp"
+
+#include <QDebug>
+
+#include <cmath>
+
+#include "wallpaperservice.hpp"
+
+namespace ZShell::internal {
+
+const QString kNamespace = "ZShell-Wallpaper";
+
+void setQueue(void* proxy, struct wl_event_queue* queue) {
+	wl_proxy_set_queue(static_cast<struct wl_proxy*>(proxy), queue);
+}
+
+WallpaperSurface::WallpaperSurface(
+	WallpaperService* service,
+	wl_surface* surface,
+	wl_output* output,
+	const QString& screen)
+	: m_service(service), m_screen(screen), m_surface(surface) {
+	if (!surface) {
+		qWarning() << "WallpaperSurface: no surface for" << screen;
+		return;
+	}
+
+	setQueue(m_surface, m_service->eventQueue());
+
+	auto* layer = m_service->m_layerShell->get_layer_surface(
+		m_surface,
+		output,
+		QtWayland::zwlr_layer_shell_v1::layer_background,
+		kNamespace);
+	setQueue(layer, m_service->eventQueue());
+	QtWayland::zwlr_layer_surface_v1::init(layer);
+
+	set_size(0, 0);
+	set_anchor(anchor_top | anchor_bottom | anchor_left | anchor_right);
+	set_exclusive_zone(-1);
+	set_keyboard_interactivity(keyboard_interactivity_none);
+	set_margin(0, 0, 0, 0);
+
+	auto* viewport = m_service->m_viewporter->get_viewport(m_surface);
+	setQueue(viewport, m_service->eventQueue());
+	QtWayland::wp_viewport::init(viewport);
+
+	auto* scale = m_service->m_scaleManager->get_fractional_scale(m_surface);
+	setQueue(scale, m_service->eventQueue());
+	QtWayland::wp_fractional_scale_v1::init(scale);
+
+	wl_surface_commit(m_surface);
+}
+
+WallpaperSurface::~WallpaperSurface() {
+	if (m_eglSurface != EGL_NO_SURFACE)
+		eglDestroySurface(m_service->m_eglDisplay, m_eglSurface);
+
+	if (m_window) wl_egl_window_destroy(m_window);
+
+	if (QtWayland::wp_viewport::isInitialized())
+		QtWayland::wp_viewport::destroy();
+	if (QtWayland::wp_fractional_scale_v1::isInitialized())
+		QtWayland::wp_fractional_scale_v1::destroy();
+	if (QtWayland::zwlr_layer_surface_v1::isInitialized())
+		QtWayland::zwlr_layer_surface_v1::destroy();
+
+	if (m_surface) wl_surface_destroy(m_surface);
+}
+
+void WallpaperSurface::redraw() {
+	m_service->queue(this);
+}
+
+void WallpaperSurface::zwlr_layer_surface_v1_configure(
+	uint32_t serial, uint32_t width, uint32_t height) {
+	ack_configure(serial);
+
+	if (width == 0 || height == 0) return;
+
+	m_size = QSize(int(width), int(height));
+
+	if (!configured) configured = true;
+
+	updateBuffer();
+}
+
+void WallpaperSurface::wp_fractional_scale_v1_preferred_scale(uint32_t scale) {
+	if (scale == 0) return;
+
+	qreal newScale = qreal(scale) / 120.0;
+	if (qFuzzyCompare(newScale, m_scale)) return;
+
+	m_scale = newScale;
+	updateBuffer();
+}
+
+void WallpaperSurface::zwlr_layer_surface_v1_closed() {}
+
+void WallpaperSurface::updateBuffer() {
+	if (m_size.isEmpty()) return;
+
+	QSize buffer = QSize(
+		int(std::llround(m_size.width() * m_scale)),
+		int(std::llround(m_size.height() * m_scale)));
+
+	if (buffer.isEmpty()) return;
+
+	if (m_bufferSize != buffer) {
+		m_bufferSize = buffer;
+
+		if (m_window) {
+			wl_egl_window_resize(
+				m_window, buffer.width(), buffer.height(), 0, 0);
+		} else {
+			m_window =
+				wl_egl_window_create(m_surface, buffer.width(), buffer.height());
+			if (!m_window) {
+				qWarning()
+					<< "WallpaperSurface: could not make a window surface for"
+					<< m_screen;
+				return;
+			}
+		}
+
+		if (m_eglSurface == EGL_NO_SURFACE) {
+			m_eglSurface = eglCreateWindowSurface(
+				m_service->m_eglDisplay,
+				m_service->m_config,
+				reinterpret_cast<EGLNativeWindowType>(m_window),
+				nullptr);
+			if (m_eglSurface == EGL_NO_SURFACE) {
+				qWarning()
+					<< "WallpaperSurface: eglCreateWindowSurface failed for"
+					<< m_screen;
+				return;
+			}
+		}
+	}
+
+	if (QtWayland::wp_viewport::isInitialized())
+		set_destination(m_size.width(), m_size.height());
+
+	m_service->queue(this);
+}
+
+} // namespace ZShell::internal

Plugins/ZShell/Internal/wallpapersurface.hpp

@@ -0,0 +1,58 @@
+#pragma once
+
+#include <EGL/egl.h>
+#include <wayland-egl.h>
+
+#include <QSize>
+#include <QString>
+
+#include <qwayland-fractional-scale-v1.h>
+#include <qwayland-viewporter.h>
+#include <qwayland-wlr-layer-shell-unstable-v1.h>
+#include <wayland-client-protocol.h>
+
+namespace ZShell::internal {
+
+class WallpaperService;
+
+class WallpaperSurface : public QtWayland::zwlr_layer_surface_v1,
+						 public QtWayland::wp_viewport,
+						 public QtWayland::wp_fractional_scale_v1 {
+	public:
+	WallpaperSurface(
+		WallpaperService* service,
+		wl_surface* surface,
+		wl_output* output,
+		const QString& screen);
+	~WallpaperSurface() override;
+
+	[[nodiscard]] const QString& screen() const { return m_screen; }
+
+	[[nodiscard]] const QSize& size() const { return m_size; }
+	[[nodiscard]] const QSize& bufferSize() const { return m_bufferSize; }
+	[[nodiscard]] EGLSurface eglSurface() const { return m_eglSurface; }
+
+	void redraw();
+
+	private:
+	void zwlr_layer_surface_v1_configure(
+		uint32_t serial, uint32_t width, uint32_t height) override;
+	void zwlr_layer_surface_v1_closed() override;
+	void wp_fractional_scale_v1_preferred_scale(uint32_t scale) override;
+
+	void updateBuffer();
+
+	WallpaperService* m_service;
+	QString m_screen;
+	wl_surface* m_surface;
+	wl_egl_window* m_window = nullptr;
+	EGLSurface m_eglSurface = EGL_NO_SURFACE;
+
+	QSize m_size;
+	QSize m_bufferSize;
+	qreal m_scale = 1.0;
+
+	bool configured = false;
+};
+
+} // namespace ZShell::internal

Plugins/cmake/wayland-protocol.cmake

@@ -0,0 +1,58 @@
+find_program(QTWAYLANDSCANNER_EXECUTABLE qtwaylandscanner REQUIRED)
+find_program(WAYLAND_SCANNER_EXECUTABLE wayland-scanner REQUIRED)
+
+pkg_get_variable(WAYLAND_PROTOCOLS wayland-protocols pkgdatadir)
+if(NOT WAYLAND_PROTOCOLS)
+	message(FATAL_ERROR "wayland-protocols not found")
+endif()
+
+function(wl_proto arg_TARGET arg_PROTOCOL arg_XML_DIR)
+	set(out_dir "${CMAKE_BINARY_DIR}/wayland-protocols/${arg_TARGET}")
+	file(MAKE_DIRECTORY "${out_dir}")
+
+	set(xml "${arg_XML_DIR}/${arg_PROTOCOL}.xml")
+
+	add_custom_command(
+		OUTPUT "${out_dir}/wayland-${arg_PROTOCOL}-client-protocol.h"
+			"${out_dir}/wayland-${arg_PROTOCOL}.c"
+		COMMAND ${WAYLAND_SCANNER_EXECUTABLE} client-header "${xml}"
+			"${out_dir}/wayland-${arg_PROTOCOL}-client-protocol.h"
+		COMMAND ${WAYLAND_SCANNER_EXECUTABLE} private-code "${xml}"
+			"${out_dir}/wayland-${arg_PROTOCOL}.c"
+		DEPENDS "${xml}"
+		COMMENT "Generating ${arg_PROTOCOL} protocol files"
+	)
+
+	add_custom_command(
+		OUTPUT "${out_dir}/qwayland-${arg_PROTOCOL}.h"
+			"${out_dir}/qwayland-${arg_PROTOCOL}.cpp"
+		COMMAND ${QTWAYLANDSCANNER_EXECUTABLE} client-header "${xml}"
+			> "${out_dir}/qwayland-${arg_PROTOCOL}.h"
+		COMMAND ${QTWAYLANDSCANNER_EXECUTABLE} client-code "${xml}"
+			> "${out_dir}/qwayland-${arg_PROTOCOL}.cpp"
+		DEPENDS "${xml}" "${out_dir}/wayland-${arg_PROTOCOL}-client-protocol.h"
+		COMMENT "Generating ${arg_PROTOCOL} client wrapper"
+	)
+
+	add_library(
+		${arg_TARGET}
+		STATIC
+		"${out_dir}/wayland-${arg_PROTOCOL}.c"
+		"${out_dir}/qwayland-${arg_PROTOCOL}.cpp"
+	)
+	set_source_files_properties(
+		"${out_dir}/qwayland-${arg_PROTOCOL}.cpp"
+		PROPERTIES COMPILE_OPTIONS
+			"-Wno-old-style-cast;-Wno-sign-conversion;-Wno-conversion;-Wno-shadow"
+	)
+	set_target_properties(${arg_TARGET} PROPERTIES POSITION_INDEPENDENT_CODE ON)
+	target_include_directories(${arg_TARGET} PUBLIC "${out_dir}")
+	target_link_libraries(
+		${arg_TARGET}
+		PUBLIC
+			Qt::Core
+			Qt::WaylandClient
+			Qt::WaylandClientPrivate
+			PkgConfig::WAYLAND_CLIENT
+	)
+endfunction()

shell.qml

@@ -3,7 +3,6 @@
 // @ pragma DefaultEnv QSG_RHI_BACKEND=vulkan
 //@ pragma DefaultEnv QSG_NO_VSYNC=1
 //@ pragma DefaultEnv QS_NO_RELOAD_POPUP=1
-//@ pragma DefaultEnv QT_SCALE_FACTOR_ROUNDING_POLICY=Round
 //@ pragma DefaultEnv QT_QUICK_FLICKABLE_WHEEL_DECELERATION=10000
 //@ pragma DropExpensiveFonts
 import Quickshell
@@ -25,9 +24,6 @@ ShellRoot {
 	Drawers {
 	}
 
-	Wallpaper {
-	}
-
 	Lock {
 		id: lock
 	}
@@ -48,4 +44,7 @@ ShellRoot {
 		component: BatteryService {
 		}
 	}
+
+	ServiceLoader {
+	}
 }