core/window: allow explicit surface format selection

src/wayland/wlr_layershell.cpp

@@ -196,6 +196,7 @@ WaylandPanelInterface::WaylandPanelInterface(QObject* parent)
 	QObject::connect(this->layer, &ProxyWindowBase::windowTransformChanged, this, &WaylandPanelInterface::windowTransformChanged);
 	QObject::connect(this->layer, &ProxyWindowBase::colorChanged, this, &WaylandPanelInterface::colorChanged);
 	QObject::connect(this->layer, &ProxyWindowBase::maskChanged, this, &WaylandPanelInterface::maskChanged);
+	QObject::connect(this->layer, &ProxyWindowBase::surfaceFormatChanged, this, &WaylandPanelInterface::surfaceFormatChanged);
 
 	// panel specific
 	QObject::connect(this->layer, &WlrLayershell::anchorsChanged, this, &WaylandPanelInterface::anchorsChanged);
@@ -232,6 +233,7 @@ proxyPair(qint32, height, setHeight);
 proxyPair(QuickshellScreenInfo*, screen, setScreen);
 proxyPair(QColor, color, setColor);
 proxyPair(PendingRegion*, mask, setMask);
+proxyPair(QsSurfaceFormat, surfaceFormat, setSurfaceFormat);
 
 // panel specific
 proxyPair(Anchors, anchors, setAnchors);

src/wayland/wlr_layershell.hpp

@@ -155,6 +155,9 @@ public:
 	[[nodiscard]] PendingRegion* mask() const override;
 	void setMask(PendingRegion* mask) override;
 
+	[[nodiscard]] QsSurfaceFormat surfaceFormat() const override;
+	void setSurfaceFormat(QsSurfaceFormat mask) override;
+
 	[[nodiscard]] QQmlListProperty<QObject> data() override;
 
 	// panel specific

src/window/floatingwindow.cpp

@@ -36,6 +36,7 @@ FloatingWindowInterface::FloatingWindowInterface(QObject* parent)
 	QObject::connect(this->window, &ProxyWindowBase::windowTransformChanged, this, &FloatingWindowInterface::windowTransformChanged);
 	QObject::connect(this->window, &ProxyWindowBase::colorChanged, this, &FloatingWindowInterface::colorChanged);
 	QObject::connect(this->window, &ProxyWindowBase::maskChanged, this, &FloatingWindowInterface::maskChanged);
+	QObject::connect(this->window, &ProxyWindowBase::surfaceFormatChanged, this, &FloatingWindowInterface::surfaceFormatChanged);
 	// clang-format on
 }
 
@@ -64,6 +65,7 @@ proxyPair(qint32, height, setHeight);
 proxyPair(QuickshellScreenInfo*, screen, setScreen);
 proxyPair(QColor, color, setColor);
 proxyPair(PendingRegion*, mask, setMask);
+proxyPair(QsSurfaceFormat, surfaceFormat, setSurfaceFormat);
 
 #undef proxyPair
 // NOLINTEND

src/window/floatingwindow.hpp

@@ -4,6 +4,7 @@
 #include <qtmetamacros.h>
 
 #include "proxywindow.hpp"
+#include "windowinterface.hpp"
 
 class ProxyFloatingWindow: public ProxyWindowBase {
 	Q_OBJECT;
@@ -50,6 +51,9 @@ public:
 	[[nodiscard]] PendingRegion* mask() const override;
 	void setMask(PendingRegion* mask) override;
 
+	[[nodiscard]] QsSurfaceFormat surfaceFormat() const override;
+	void setSurfaceFormat(QsSurfaceFormat mask) override;
+
 	[[nodiscard]] QQmlListProperty<QObject> data() override;
 	// NOLINTEND
 

src/window/panelinterface.hpp

@@ -13,7 +13,8 @@ class Anchors {
 	Q_PROPERTY(bool right MEMBER mRight);
 	Q_PROPERTY(bool top MEMBER mTop);
 	Q_PROPERTY(bool bottom MEMBER mBottom);
-	QML_VALUE_TYPE(anchors);
+	QML_VALUE_TYPE(panelAnchors);
+	QML_STRUCTURED_VALUE;
 
 public:
 	[[nodiscard]] bool horizontalConstraint() const noexcept { return this->mLeft && this->mRight; }
@@ -40,7 +41,8 @@ class Margins {
 	Q_PROPERTY(qint32 right MEMBER mRight);
 	Q_PROPERTY(qint32 top MEMBER mTop);
 	Q_PROPERTY(qint32 bottom MEMBER mBottom);
-	QML_VALUE_TYPE(margins);
+	QML_VALUE_TYPE(panelMargins);
+	QML_STRUCTURED_VALUE;
 
 public:
 	[[nodiscard]] bool operator==(const Margins& other) const noexcept {

src/window/proxywindow.cpp

@@ -6,10 +6,13 @@
 #include <qobject.h>
 #include <qqmlcontext.h>
 #include <qqmlengine.h>
+#include <qqmlinfo.h>
 #include <qqmllist.h>
 #include <qquickitem.h>
 #include <qquickwindow.h>
 #include <qregion.h>
+#include <qsurfaceformat.h>
+#include <qtenvironmentvariables.h>
 #include <qtmetamacros.h>
 #include <qtypes.h>
 #include <qvariant.h>
@@ -50,7 +53,7 @@ ProxyWindowBase::~ProxyWindowBase() { this->deleteWindow(true); }
 void ProxyWindowBase::onReload(QObject* oldInstance) {
 	this->window = this->retrieveWindow(oldInstance);
 	auto wasVisible = this->window != nullptr && this->window->isVisible();
-	if (this->window == nullptr) this->window = this->createQQuickWindow();
+	this->ensureQWindow();
 
 	// The qml engine will leave the WindowInterface as owner of everything
 	// nested in an item, so we have to make sure the interface's children
@@ -85,10 +88,55 @@ void ProxyWindowBase::postCompleteWindow() { this->setVisible(this->mVisible); }
 
 ProxiedWindow* ProxyWindowBase::createQQuickWindow() { return new ProxiedWindow(this); }
 
-void ProxyWindowBase::createWindow() {
+void ProxyWindowBase::ensureQWindow() {
-	if (this->window != nullptr) return;
+	auto format = QSurfaceFormat::defaultFormat();
-	this->window = this->createQQuickWindow();
 
+	{
+		// match QtQuick's default format, including env var controls
+		static const auto useDepth = qEnvironmentVariableIsEmpty("QSG_NO_DEPTH_BUFFER");
+		static const auto useStencil = qEnvironmentVariableIsEmpty("QSG_NO_STENCIL_BUFFER");
+		static const auto enableDebug = qEnvironmentVariableIsSet("QSG_OPENGL_DEBUG");
+		static const auto disableVSync = qEnvironmentVariableIsSet("QSG_NO_VSYNC");
+
+		if (useDepth && format.depthBufferSize() == -1) format.setDepthBufferSize(24);
+		else if (!useDepth) format.setDepthBufferSize(0);
+
+		if (useStencil && format.stencilBufferSize() == -1) format.setStencilBufferSize(8);
+		else if (!useStencil) format.setStencilBufferSize(0);
+
+		auto opaque = this->qsSurfaceFormat.opaqueModified ? this->qsSurfaceFormat.opaque
+		                                                   : this->mColor.alpha() >= 255;
+
+		if (opaque) format.setAlphaBufferSize(0);
+		else format.setAlphaBufferSize(8);
+
+		if (enableDebug) format.setOption(QSurfaceFormat::DebugContext);
+		if (disableVSync) format.setSwapInterval(0);
+
+		format.setSwapBehavior(QSurfaceFormat::DoubleBuffer);
+		format.setRedBufferSize(8);
+		format.setGreenBufferSize(8);
+		format.setBlueBufferSize(8);
+	}
+
+	this->mSurfaceFormat = format;
+
+	auto useOldWindow = this->window != nullptr;
+
+	if (useOldWindow) {
+		if (this->window->requestedFormat() != format) {
+			useOldWindow = false;
+		}
+	}
+
+	if (useOldWindow) return;
+	delete this->window;
+	this->window = this->createQQuickWindow();
+	this->window->setFormat(format);
+}
+
+void ProxyWindowBase::createWindow() {
+	this->ensureQWindow();
 	this->connectWindow();
 	this->completeWindow();
 	emit this->windowConnected();
@@ -320,6 +368,8 @@ void ProxyWindowBase::setColor(QColor color) {
 		);
 
 		this->window->setColor(premultiplied);
+		// setColor also modifies the alpha buffer size of the surface format
+		this->window->setFormat(this->mSurfaceFormat);
 	}
 }
 
@@ -343,6 +393,17 @@ void ProxyWindowBase::setMask(PendingRegion* mask) {
 	emit this->maskChanged();
 }
 
+void ProxyWindowBase::setSurfaceFormat(QsSurfaceFormat format) {
+	if (format == this->qsSurfaceFormat) return;
+	if (this->window != nullptr) {
+		qmlWarning(this) << "Cannot set window surface format.";
+		return;
+	}
+
+	this->qsSurfaceFormat = format;
+	emit this->surfaceFormatChanged();
+}
+
 void ProxyWindowBase::onMaskChanged() {
 	if (this->window != nullptr) this->updateMask();
 }

src/window/proxywindow.hpp

@@ -9,6 +9,7 @@
 #include <qqmlparserstatus.h>
 #include <qquickitem.h>
 #include <qquickwindow.h>
+#include <qsurfaceformat.h>
 #include <qtmetamacros.h>
 #include <qtypes.h>
 #include <qwindow.h>
@@ -29,6 +30,7 @@ class ProxiedWindow;
 /// [FloatingWindow]: ../floatingwindow
 class ProxyWindowBase: public Reloadable {
 	Q_OBJECT;
+	// clang-format off
 	/// The QtQuick window backing this window.
 	///
 	/// > [!WARNING] Do not expect values set via this property to work correctly.
@@ -46,7 +48,9 @@ class ProxyWindowBase: public Reloadable {
 	Q_PROPERTY(PendingRegion* mask READ mask WRITE setMask NOTIFY maskChanged);
 	Q_PROPERTY(QObject* windowTransform READ windowTransform NOTIFY windowTransformChanged);
 	Q_PROPERTY(bool backingWindowVisible READ isVisibleDirect NOTIFY backerVisibilityChanged);
+	Q_PROPERTY(QsSurfaceFormat surfaceFormat READ surfaceFormat WRITE setSurfaceFormat NOTIFY surfaceFormatChanged);
 	Q_PROPERTY(QQmlListProperty<QObject> data READ data);
+	// clang-format on
 	Q_CLASSINFO("DefaultProperty", "data");
 
 public:
@@ -59,6 +63,7 @@ public:
 	void operator=(ProxyWindowBase&&) = delete;
 
 	void onReload(QObject* oldInstance) override;
+	void ensureQWindow();
 	void createWindow();
 	void deleteWindow(bool keepItemOwnership = false);
 
@@ -98,6 +103,9 @@ public:
 	[[nodiscard]] PendingRegion* mask() const;
 	virtual void setMask(PendingRegion* mask);
 
+	[[nodiscard]] QsSurfaceFormat surfaceFormat() const { return this->qsSurfaceFormat; }
+	void setSurfaceFormat(QsSurfaceFormat format);
+
 	[[nodiscard]] QObject* windowTransform() const { return nullptr; } // NOLINT
 
 	[[nodiscard]] QQmlListProperty<QObject> data();
@@ -115,6 +123,7 @@ signals:
 	void screenChanged();
 	void colorChanged();
 	void maskChanged();
+	void surfaceFormatChanged();
 
 protected slots:
 	virtual void onWidthChanged();
@@ -135,6 +144,8 @@ protected:
 	QQuickItem* mContentItem = nullptr;
 	bool reloadComplete = false;
 	bool ranLints = false;
+	QsSurfaceFormat qsSurfaceFormat;
+	QSurfaceFormat mSurfaceFormat;
 
 private:
 	void polishItems();

src/window/windowinterface.hpp

@@ -15,6 +15,26 @@
 class ProxyWindowBase;
 class QsWindowAttached;
 
+class QsSurfaceFormat {
+	Q_GADGET;
+	QML_VALUE_TYPE(surfaceFormat);
+	QML_STRUCTURED_VALUE;
+	Q_PROPERTY(bool opaque MEMBER opaque WRITE setOpaque);
+
+public:
+	bool opaque = false;
+	bool opaqueModified = false;
+
+	void setOpaque(bool opaque) {
+		this->opaque = opaque;
+		this->opaqueModified = true;
+	}
+
+	[[nodiscard]] bool operator==(const QsSurfaceFormat& other) const {
+		return other.opaqueModified == this->opaqueModified && other.opaque == this->opaque;
+	}
+};
+
 ///! Base class of Quickshell windows
 /// Base class of Quickshell windows
 /// ### Attached properties
@@ -46,6 +66,10 @@ class WindowInterface: public Reloadable {
 	/// along with map[To|From]Item (which is not reactive).
 	Q_PROPERTY(QObject* windowTransform READ windowTransform NOTIFY windowTransformChanged);
 	/// The background color of the window. Defaults to white.
+	///
+	/// > [!WARNING] If the window color is opaque before it is made visible,
+	/// > it will not be able to become transparent later unless @@surfaceFormat$.opaque
+	/// > is false.
 	Q_PROPERTY(QColor color READ color WRITE setColor NOTIFY colorChanged);
 	/// The clickthrough mask. Defaults to null.
 	///
@@ -90,6 +114,16 @@ class WindowInterface: public Reloadable {
 	/// }
 	/// ```
 	Q_PROPERTY(PendingRegion* mask READ mask WRITE setMask NOTIFY maskChanged);
+	/// Set the surface format to request from the system.
+	///
+	/// - `opaque` - If the requested surface should be opaque. Opaque windows allow
+	/// the operating system to avoid drawing things behind them, or blending the window
+	/// with those behind it, saving power and GPU load. If unset, this property defaults to
+	/// true if @@color is opaque, or false if not. *You should not need to modify this
+	/// property unless you create a surface that starts opaque and later becomes transparent.*
+	///
+	/// > [!NOTE] The surface format cannot be changed after the window is created.
+	Q_PROPERTY(QsSurfaceFormat surfaceFormat READ surfaceFormat WRITE setSurfaceFormat NOTIFY surfaceFormatChanged);
 	Q_PROPERTY(QQmlListProperty<QObject> data READ data);
 	// clang-format on
 	Q_CLASSINFO("DefaultProperty", "data");
@@ -124,6 +158,9 @@ public:
 	[[nodiscard]] virtual PendingRegion* mask() const = 0;
 	virtual void setMask(PendingRegion* mask) = 0;
 
+	[[nodiscard]] virtual QsSurfaceFormat surfaceFormat() const = 0;
+	virtual void setSurfaceFormat(QsSurfaceFormat format) = 0;
+
 	[[nodiscard]] virtual QQmlListProperty<QObject> data() = 0;
 
 	static QsWindowAttached* qmlAttachedProperties(QObject* object);
@@ -138,6 +175,7 @@ signals:
 	void windowTransformChanged();
 	void colorChanged();
 	void maskChanged();
+	void surfaceFormatChanged();
 };
 
 class QsWindowAttached: public QObject {

src/x11/panel_window.cpp

@@ -482,6 +482,7 @@ XPanelInterface::XPanelInterface(QObject* parent)
 	QObject::connect(this->panel, &ProxyWindowBase::windowTransformChanged, this, &XPanelInterface::windowTransformChanged);
 	QObject::connect(this->panel, &ProxyWindowBase::colorChanged, this, &XPanelInterface::colorChanged);
 	QObject::connect(this->panel, &ProxyWindowBase::maskChanged, this, &XPanelInterface::maskChanged);
+	QObject::connect(this->panel, &ProxyWindowBase::surfaceFormatChanged, this, &XPanelInterface::surfaceFormatChanged);
 
 	// panel specific
 	QObject::connect(this->panel, &XPanelWindow::anchorsChanged, this, &XPanelInterface::anchorsChanged);
@@ -516,6 +517,7 @@ proxyPair(qint32, height, setHeight);
 proxyPair(QuickshellScreenInfo*, screen, setScreen);
 proxyPair(QColor, color, setColor);
 proxyPair(PendingRegion*, mask, setMask);
+proxyPair(QsSurfaceFormat, surfaceFormat, setSurfaceFormat);
 
 // panel specific
 proxyPair(Anchors, anchors, setAnchors);

src/x11/panel_window.hpp

@@ -136,6 +136,9 @@ public:
 	[[nodiscard]] PendingRegion* mask() const override;
 	void setMask(PendingRegion* mask) override;
 
+	[[nodiscard]] QsSurfaceFormat surfaceFormat() const override;
+	void setSurfaceFormat(QsSurfaceFormat mask) override;
+
 	[[nodiscard]] QQmlListProperty<QObject> data() override;
 
 	// panel specific