fedora

fedora/.config/quickshell/noctalia-shell/Modules/MainScreen/Backgrounds/AllBackgrounds.qml

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+import QtQuick
+import QtQuick.Shapes
+import qs.Commons
+import qs.Services.UI
+import qs.Widgets
+
+/**
+* AllBackgrounds - Unified Shape container for all bar and panel backgrounds
+*
+* Unified shadow system. This component contains a single Shape
+* with multiple ShapePath children (one for bar, one for each panel type).
+*
+* Benefits:
+* - Single GPU-accelerated rendering pass for all backgrounds
+* - Unified shadow system (one MultiEffect for everything)
+*/
+Item {
+  id: root
+
+  // Reference Bar
+  required property var bar
+
+  // Reference to MainScreen (for panel access)
+  required property var windowRoot
+
+  readonly property color panelBackgroundColor: Color.mSurface
+
+  anchors.fill: parent
+
+  // Unified background container
+  Item {
+    anchors.fill: parent
+
+    // When not using separate bar opacity, use unified approach (original behavior)
+    Item {
+      anchors.fill: parent
+      visible: !Settings.data.bar.useSeparateOpacity
+
+      // Enable layer caching to prevent continuous re-rendering
+      layer.enabled: true
+      opacity: Color.adaptiveOpacity(Settings.data.ui.panelBackgroundOpacity)
+
+      Shape {
+        id: unifiedBackgroundsShape
+        anchors.fill: parent
+        preferredRendererType: Shape.CurveRenderer
+        asynchronous: true
+        enabled: false
+
+        Component.onCompleted: {
+          Logger.d("AllBackgrounds", "AllBackgrounds initialized");
+        }
+
+        /**
+        *  Bar
+        */
+        BarBackground {
+          bar: root.bar
+          shapeContainer: unifiedBackgroundsShape
+          windowRoot: root.windowRoot
+          backgroundColor: panelBackgroundColor
+        }
+
+        /**
+        *  Panel Background Slots
+        *  Only 2 slots needed: one for currently open/opening panel, one for closing panel
+        */
+
+        // Slot 0: Currently open/opening panel
+        PanelBackground {
+          assignedPanel: {
+            var p = PanelService.backgroundSlotAssignments[0];
+            // Only render if this panel belongs to this screen
+            return (p && p.screen === root.windowRoot.screen) ? p : null;
+          }
+          shapeContainer: unifiedBackgroundsShape
+          defaultBackgroundColor: panelBackgroundColor
+        }
+
+        // Slot 1: Closing panel (during transitions)
+        PanelBackground {
+          assignedPanel: {
+            var p = PanelService.backgroundSlotAssignments[1];
+            // Only render if this panel belongs to this screen
+            return (p && p.screen === root.windowRoot.screen) ? p : null;
+          }
+          shapeContainer: unifiedBackgroundsShape
+          defaultBackgroundColor: panelBackgroundColor
+        }
+      }
+
+      // Apply shadow to the unified backgrounds
+      NDropShadow {
+        anchors.fill: parent
+        source: unifiedBackgroundsShape
+      }
+    }
+
+    // When using separate bar opacity, separate the rendering
+    Item {
+      anchors.fill: parent
+      visible: Settings.data.bar.useSeparateOpacity
+
+      // Panel backgrounds with panel opacity
+      Item {
+        anchors.fill: parent
+
+        layer.enabled: true
+        opacity: Color.adaptiveOpacity(Settings.data.ui.panelBackgroundOpacity)
+
+        Shape {
+          id: panelBackgroundsShape
+          anchors.fill: parent
+          preferredRendererType: Shape.CurveRenderer
+          asynchronous: true
+          enabled: false
+
+          /**
+          *  Panel Background Slots
+          *  Only 2 slots needed: one for currently open/opening panel, one for closing panel
+          */
+
+          // Slot 0: Currently open/opening panel
+          PanelBackground {
+            assignedPanel: {
+              var p = PanelService.backgroundSlotAssignments[0];
+              // Only render if this panel belongs to this screen
+              return (p && p.screen === root.windowRoot.screen) ? p : null;
+            }
+            shapeContainer: panelBackgroundsShape
+            defaultBackgroundColor: panelBackgroundColor
+          }
+
+          // Slot 1: Closing panel (during transitions)
+          PanelBackground {
+            assignedPanel: {
+              var p = PanelService.backgroundSlotAssignments[1];
+              // Only render if this panel belongs to this screen
+              return (p && p.screen === root.windowRoot.screen) ? p : null;
+            }
+            shapeContainer: panelBackgroundsShape
+            defaultBackgroundColor: panelBackgroundColor
+          }
+        }
+
+        // Apply shadow to the panel backgrounds
+        NDropShadow {
+          anchors.fill: parent
+          source: panelBackgroundsShape
+        }
+      }
+
+      // Bar background with separate opacity
+      Item {
+        anchors.fill: parent
+
+        layer.enabled: true
+        opacity: Settings.data.bar.backgroundOpacity
+
+        Shape {
+          id: barBackgroundShape
+          anchors.fill: parent
+          preferredRendererType: Shape.CurveRenderer
+          asynchronous: true
+          enabled: false
+
+          BarBackground {
+            bar: root.bar
+            shapeContainer: barBackgroundShape
+            windowRoot: root.windowRoot
+            backgroundColor: panelBackgroundColor
+          }
+        }
+
+        NDropShadow {
+          anchors.fill: parent
+          source: barBackgroundShape
+        }
+      }
+    }
+  }
+}

fedora/.config/quickshell/noctalia-shell/Modules/MainScreen/Backgrounds/BarBackground.qml

@@ -0,0 +1,283 @@
+import QtQuick
+import QtQuick.Shapes
+import qs.Commons
+import qs.Modules.MainScreen.Backgrounds
+import qs.Services.UI
+
+/**
+* BarBackground - ShapePath component for rendering the bar background
+*
+* Unified shadow system. This component is a ShapePath that will be
+* a child of the unified AllBackgrounds Shape container.
+*
+* Uses 4-state per-corner system for flexible corner rendering:
+* - State -1: No radius (flat/square corner)
+* - State 0: Normal (inner curve)
+* - State 1: Horizontal inversion (outer curve on X-axis)
+* - State 2: Vertical inversion (outer curve on Y-axis)
+*/
+ShapePath {
+  id: root
+
+  // Required reference to the bar component
+  required property var bar
+
+  // Required reference to AllBackgrounds shapeContainer
+  required property var shapeContainer
+
+  // Required reference to windowRoot for screen access
+  required property var windowRoot
+
+  required property color backgroundColor
+
+  // Check if bar should be visible on this screen
+  readonly property bool shouldShow: {
+    // Check global bar visibility (includes overview state)
+    if (!BarService.effectivelyVisible)
+      return false;
+
+    // Check screen-specific configuration
+    var monitors = Settings.data.bar.monitors || [];
+    var screenName = windowRoot?.screen?.name || "";
+
+    // If no monitors specified, show on all screens
+    // If monitors specified, only show if this screen is in the list
+    return monitors.length === 0 || monitors.includes(screenName);
+  }
+
+  // Corner radius (from Style)
+  readonly property real radius: Style.radiusL
+
+  // Framed bar properties
+  readonly property bool isFramed: Settings.data.bar.barType === "framed"
+  readonly property real frameThickness: Settings.data.bar.frameThickness ?? 12
+  readonly property real frameRadius: Settings.data.bar.frameRadius ?? 20
+
+  // Bar position - since bar's parent fills the screen and Shape also fills the screen,
+  // we can use bar.x and bar.y directly (they're already in screen coordinates)
+  readonly property point barMappedPos: bar ? Qt.point(bar.x, bar.y) : Qt.point(0, 0)
+
+  // Effective dimensions - 0 when bar shouldn't show (similar to panel behavior)
+  readonly property real barWidth: (bar && shouldShow) ? bar.width : 0
+  readonly property real barHeight: (bar && shouldShow) ? bar.height : 0
+
+  // Screen dimensions for frame
+  readonly property real screenWidth: windowRoot?.screen?.width || 0
+  readonly property real screenHeight: windowRoot?.screen?.height || 0
+
+  // Inner hole dimensions for framed mode - always relative to screen
+  readonly property string barPosition: Settings.getBarPositionForScreen(windowRoot?.screen?.name)
+  readonly property bool barIsVertical: barPosition === "left" || barPosition === "right"
+  readonly property real holeX: (barPosition === "left") ? barWidth : frameThickness
+  readonly property real holeY: (barPosition === "top") ? barHeight : frameThickness
+  readonly property real holeWidth: screenWidth - (barPosition === "left" || barPosition === "right" ? (barWidth + frameThickness) : (frameThickness * 2))
+  readonly property real holeHeight: screenHeight - (barPosition === "top" || barPosition === "bottom" ? (barHeight + frameThickness) : (frameThickness * 2))
+
+  // Flatten corners if bar is too small (handle null bar)
+  readonly property bool shouldFlatten: bar ? ShapeCornerHelper.shouldFlatten(barWidth, barHeight, radius) : false
+  readonly property real effectiveRadius: shouldFlatten ? (bar ? ShapeCornerHelper.getFlattenedRadius(Math.min(barWidth, barHeight), radius) : 0) : radius
+
+  // Minimum safe arc radius — prevents zero-displacement zero-radius PathArcs
+  // that crash qTriangulate in CurveRenderer. 0.01px is sub-pixel and invisible.
+  readonly property real _minR: 0.01
+
+  // Helper function for getting corner radius based on state
+  function getCornerRadius(cornerState) {
+    // State -1 = flat corner — use minimum safe radius instead of 0
+    // to prevent degenerate PathArc (zero displacement + zero radius)
+    if (cornerState === -1)
+      return _minR;
+    // All other states use effectiveRadius (clamped to safe minimum)
+    return Math.max(_minR, effectiveRadius);
+  }
+
+  // Per-corner multipliers and radii based on bar's corner states (handle null bar)
+  readonly property real tlMultX: bar ? ShapeCornerHelper.getMultX(bar.topLeftCornerState) : 1
+  readonly property real tlMultY: bar ? ShapeCornerHelper.getMultY(bar.topLeftCornerState) : 1
+  readonly property real tlRadius: bar ? getCornerRadius(bar.topLeftCornerState) : 0
+
+  readonly property real trMultX: bar ? ShapeCornerHelper.getMultX(bar.topRightCornerState) : 1
+  readonly property real trMultY: bar ? ShapeCornerHelper.getMultY(bar.topRightCornerState) : 1
+  readonly property real trRadius: bar ? getCornerRadius(bar.topRightCornerState) : 0
+
+  readonly property real brMultX: bar ? ShapeCornerHelper.getMultX(bar.bottomRightCornerState) : 1
+  readonly property real brMultY: bar ? ShapeCornerHelper.getMultY(bar.bottomRightCornerState) : 1
+  readonly property real brRadius: bar ? getCornerRadius(bar.bottomRightCornerState) : 0
+
+  readonly property real blMultX: bar ? ShapeCornerHelper.getMultX(bar.bottomLeftCornerState) : 1
+  readonly property real blMultY: bar ? ShapeCornerHelper.getMultY(bar.bottomLeftCornerState) : 1
+  readonly property real blRadius: bar ? getCornerRadius(bar.bottomLeftCornerState) : 0
+
+  // True when the bar path has valid, non-degenerate geometry to render.
+  // Mirrors PanelBackground.isRenderable — prevents CurveRenderer crash on zero-area paths.
+  readonly property bool isRenderable: bar !== null && shouldShow && (isFramed ? (screenWidth > 0 && screenHeight > 0) : (barWidth > 0 && barHeight > 0))
+
+  // Edge overshoot: extend bar background beyond screen edges where both adjacent
+  // corners are flat (state -1) to prevent CurveRenderer antialiasing artifacts.
+  // Uses corner state checks instead of radius === 0 since flat corners now have _minR.
+  readonly property real screenEdgeOvershoot: 2
+  readonly property real topEdgeOvs: (!isFramed && shouldShow && bar && bar.topLeftCornerState === -1 && bar.topRightCornerState === -1 && barMappedPos.y <= 0) ? -screenEdgeOvershoot : 0
+  readonly property real bottomEdgeOvs: (!isFramed && shouldShow && bar && bar.bottomLeftCornerState === -1 && bar.bottomRightCornerState === -1 && (barMappedPos.y + barHeight) >= screenHeight) ? screenEdgeOvershoot : 0
+  readonly property real leftEdgeOvs: (!isFramed && shouldShow && bar && bar.topLeftCornerState === -1 && bar.bottomLeftCornerState === -1 && barMappedPos.x <= 0) ? -screenEdgeOvershoot : 0
+  readonly property real rightEdgeOvs: (!isFramed && shouldShow && bar && bar.topRightCornerState === -1 && bar.bottomRightCornerState === -1 && (barMappedPos.x + barWidth) >= screenWidth) ? screenEdgeOvershoot : 0
+
+  // Auto-hide opacity factor for background fade
+  property real opacityFactor: (bar && bar.isHidden) ? 0 : 1
+
+  Behavior on opacityFactor {
+    enabled: bar && bar.autoHide
+    NumberAnimation {
+      duration: Style.animationFast
+      easing.type: Easing.OutQuad
+    }
+  }
+
+  // ShapePath configuration
+  strokeWidth: -1 // No stroke, fill only
+  fillColor: isRenderable ? Qt.rgba(backgroundColor.r, backgroundColor.g, backgroundColor.b, backgroundColor.a * opacityFactor) : "transparent"
+  fillRule: isFramed ? ShapePath.OddEvenFill : ShapePath.WindingFill
+
+  // Starting position — falls back to off-screen when not renderable so that
+  // all subsequent path elements form a valid non-degenerate off-screen square.
+  // Each edge is split between PathLine and PathArc so no arc has zero displacement,
+  // preventing CurveRenderer triangulation crashes on degenerate arcs.
+  // For framed mode the outer path is a full-screen rectangle; _minR offsets at each
+  // corner prevent zero-displacement zero-radius arcs that crash qTriangulate.
+  startX: isRenderable ? (isFramed ? _minR : (barMappedPos.x + leftEdgeOvs + tlRadius * tlMultX)) : -0.75
+  startY: isRenderable ? (isFramed ? 0 : (barMappedPos.y + topEdgeOvs)) : -1
+
+  // ========== PATH DEFINITION ==========
+
+  // 1. Main Bar / Outer Screen Rectangle
+  // When !isRenderable all elements use fallback coordinates forming a valid 1×1
+  // off-screen square with non-degenerate arcs so CurveRenderer never receives
+  // a zero-area, bare-moveto, or zero-displacement arc path.
+  PathLine {
+    x: root.isRenderable ? (root.isFramed ? (root.screenWidth - root._minR) : (root.barMappedPos.x + root.barWidth + root.rightEdgeOvs - root.trRadius * root.trMultX)) : 0
+    y: root.isRenderable ? (root.isFramed ? 0 : (root.barMappedPos.y + root.topEdgeOvs)) : -1
+  }
+
+  // Top-right corner
+  PathArc {
+    x: root.isRenderable ? (root.isFramed ? root.screenWidth : (root.barMappedPos.x + root.barWidth + root.rightEdgeOvs)) : 0
+    y: root.isRenderable ? (root.isFramed ? root._minR : (root.barMappedPos.y + root.topEdgeOvs + root.trRadius * root.trMultY)) : -0.75
+    radiusX: root.isRenderable ? (root.isFramed ? root._minR : root.trRadius) : 0
+    radiusY: root.isRenderable ? (root.isFramed ? root._minR : root.trRadius) : 0
+    direction: ShapeCornerHelper.getArcDirection(root.trMultX, root.trMultY)
+  }
+
+  PathLine {
+    x: root.isRenderable ? (root.isFramed ? root.screenWidth : (root.barMappedPos.x + root.barWidth + root.rightEdgeOvs)) : 0
+    y: root.isRenderable ? (root.isFramed ? (root.screenHeight - root._minR) : (root.barMappedPos.y + root.barHeight + root.bottomEdgeOvs - root.brRadius * root.brMultY)) : 0
+  }
+
+  // Bottom-right corner
+  PathArc {
+    x: root.isRenderable ? (root.isFramed ? (root.screenWidth - root._minR) : (root.barMappedPos.x + root.barWidth + root.rightEdgeOvs - root.brRadius * root.brMultX)) : -0.25
+    y: root.isRenderable ? (root.isFramed ? root.screenHeight : (root.barMappedPos.y + root.barHeight + root.bottomEdgeOvs)) : 0
+    radiusX: root.isRenderable ? (root.isFramed ? root._minR : root.brRadius) : 0
+    radiusY: root.isRenderable ? (root.isFramed ? root._minR : root.brRadius) : 0
+    direction: ShapeCornerHelper.getArcDirection(root.brMultX, root.brMultY)
+  }
+
+  PathLine {
+    x: root.isRenderable ? (root.isFramed ? root._minR : (root.barMappedPos.x + root.leftEdgeOvs + root.blRadius * root.blMultX)) : -1
+    y: root.isRenderable ? (root.isFramed ? root.screenHeight : (root.barMappedPos.y + root.barHeight + root.bottomEdgeOvs)) : 0
+  }
+
+  // Bottom-left corner
+  PathArc {
+    x: root.isRenderable ? (root.isFramed ? 0 : (root.barMappedPos.x + root.leftEdgeOvs)) : -1
+    y: root.isRenderable ? (root.isFramed ? (root.screenHeight - root._minR) : (root.barMappedPos.y + root.barHeight + root.bottomEdgeOvs - root.blRadius * root.blMultY)) : -0.25
+    radiusX: root.isRenderable ? (root.isFramed ? root._minR : root.blRadius) : 0
+    radiusY: root.isRenderable ? (root.isFramed ? root._minR : root.blRadius) : 0
+    direction: ShapeCornerHelper.getArcDirection(root.blMultX, root.blMultY)
+  }
+
+  PathLine {
+    x: root.isRenderable ? (root.isFramed ? 0 : (root.barMappedPos.x + root.leftEdgeOvs)) : -1
+    y: root.isRenderable ? (root.isFramed ? root._minR : (root.barMappedPos.y + root.topEdgeOvs + root.tlRadius * root.tlMultY)) : -1
+  }
+
+  // Top-left corner (back to start)
+  PathArc {
+    x: root.isRenderable ? (root.isFramed ? root._minR : (root.barMappedPos.x + root.leftEdgeOvs + root.tlRadius * root.tlMultX)) : -0.75
+    y: root.isRenderable ? (root.isFramed ? 0 : (root.barMappedPos.y + root.topEdgeOvs)) : -1
+    radiusX: root.isRenderable ? (root.isFramed ? root._minR : root.tlRadius) : 0
+    radiusY: root.isRenderable ? (root.isFramed ? root._minR : root.tlRadius) : 0
+    direction: ShapeCornerHelper.getArcDirection(root.tlMultX, root.tlMultY)
+  }
+
+  // 2. Inner Hole for Framed Mode (Clockwise)
+  // When !isFramed, draws a tiny 1x1 rectangle inside the bar as a non-degenerate WindingFill
+  // no-op to prevent a zero-area degenerate subpath crashing qTriangulate.
+  // Note: an exact duplicate of the outer path cannot be used here because Qt's CurveRenderer
+  // has issues with exactly coincident subpaths, causing the fill to not render on some systems.
+  // When !isRenderable, falls back to a valid 1×1 off-screen square at (-3,-3)→(-2,-2).
+  readonly property real _nhX: barMappedPos.x + barWidth / 2
+  readonly property real _nhY: barMappedPos.y + barHeight / 2
+  PathMove {
+    x: root.isRenderable ? (root.isFramed ? (root.holeX + root.frameRadius) : (root._nhX + 0.25)) : -2.75
+    y: root.isRenderable ? (root.isFramed ? root.holeY : root._nhY) : -3
+  }
+
+  // Top edge
+  PathLine {
+    x: root.isRenderable ? (root.isFramed ? (root.holeX + root.holeWidth - root.frameRadius) : (root._nhX + 1)) : -2
+    y: root.isRenderable ? (root.isFramed ? root.holeY : root._nhY) : -3
+  }
+
+  // Top-right corner
+  PathArc {
+    x: root.isRenderable ? (root.isFramed ? (root.holeX + root.holeWidth) : (root._nhX + 1)) : -2
+    y: root.isRenderable ? (root.isFramed ? (root.holeY + root.frameRadius) : (root._nhY + 0.25)) : -2.75
+    radiusX: root.isRenderable ? (root.isFramed ? root.frameRadius : 0) : 0
+    radiusY: root.isRenderable ? (root.isFramed ? root.frameRadius : 0) : 0
+    direction: PathArc.Clockwise
+  }
+
+  // Right edge
+  PathLine {
+    x: root.isRenderable ? (root.isFramed ? (root.holeX + root.holeWidth) : (root._nhX + 1)) : -2
+    y: root.isRenderable ? (root.isFramed ? (root.holeY + root.holeHeight - root.frameRadius) : (root._nhY + 1)) : -2
+  }
+
+  // Bottom-right corner
+  PathArc {
+    x: root.isRenderable ? (root.isFramed ? (root.holeX + root.holeWidth - root.frameRadius) : (root._nhX + 0.75)) : -2.25
+    y: root.isRenderable ? (root.isFramed ? (root.holeY + root.holeHeight) : (root._nhY + 1)) : -2
+    radiusX: root.isRenderable ? (root.isFramed ? root.frameRadius : 0) : 0
+    radiusY: root.isRenderable ? (root.isFramed ? root.frameRadius : 0) : 0
+    direction: PathArc.Clockwise
+  }
+
+  // Bottom edge
+  PathLine {
+    x: root.isRenderable ? (root.isFramed ? (root.holeX + root.frameRadius) : root._nhX) : -3
+    y: root.isRenderable ? (root.isFramed ? (root.holeY + root.holeHeight) : (root._nhY + 1)) : -2
+  }
+
+  // Bottom-left corner
+  PathArc {
+    x: root.isRenderable ? (root.isFramed ? root.holeX : root._nhX) : -3
+    y: root.isRenderable ? (root.isFramed ? (root.holeY + root.holeHeight - root.frameRadius) : (root._nhY + 0.75)) : -2.25
+    radiusX: root.isRenderable ? (root.isFramed ? root.frameRadius : 0) : 0
+    radiusY: root.isRenderable ? (root.isFramed ? root.frameRadius : 0) : 0
+    direction: PathArc.Clockwise
+  }
+
+  // Left edge
+  PathLine {
+    x: root.isRenderable ? (root.isFramed ? root.holeX : root._nhX) : -3
+    y: root.isRenderable ? (root.isFramed ? (root.holeY + root.frameRadius) : root._nhY) : -3
+  }
+
+  // Top-left corner (back to start)
+  PathArc {
+    x: root.isRenderable ? (root.isFramed ? (root.holeX + root.frameRadius) : (root._nhX + 0.25)) : -2.75
+    y: root.isRenderable ? (root.isFramed ? root.holeY : root._nhY) : -3
+    radiusX: root.isRenderable ? (root.isFramed ? root.frameRadius : 0) : 0
+    radiusY: root.isRenderable ? (root.isFramed ? root.frameRadius : 0) : 0
+    direction: PathArc.Clockwise
+  }
+}

fedora/.config/quickshell/noctalia-shell/Modules/MainScreen/Backgrounds/PanelBackground.qml

@@ -0,0 +1,167 @@
+import QtQuick
+import QtQuick.Shapes
+import qs.Commons
+import qs.Modules.MainScreen.Backgrounds
+
+/**
+* PanelBackground - Dynamic ShapePath for rendering panel backgrounds
+*
+* Dynamically switches between panels based on which panel is currently
+* assigned by PanelService. Only 2 instances are needed: one for the
+* currently open panel and one for a closing panel during transitions.
+*
+* Uses 4-state per-corner system for flexible corner rendering:
+* - State -1: No radius (flat/square corner)
+* - State 0: Normal (inner curve)
+* - State 1: Horizontal inversion (outer curve on X-axis)
+* - State 2: Vertical inversion (outer curve on Y-axis)
+*/
+ShapePath {
+  id: root
+
+  // Dynamically assigned panel (null if slot is unused)
+  property var assignedPanel: null
+
+  // Required reference to AllBackgrounds shapeContainer
+  required property var shapeContainer
+
+  // Default background color (used if panel doesn't specify one)
+  property color defaultBackgroundColor: Color.mSurface
+
+  // Corner radius (from Style)
+  readonly property real radius: Style.radiusL
+
+  // Get panel's panelRegion (geometry placeholder)
+  readonly property var panelRegion: assignedPanel?.panelRegion ?? null
+
+  // Get the actual panelBackground Item from panelRegion
+  // Only access panelItem if panelRegion exists and is visible
+  readonly property var panelBg: (panelRegion && panelRegion.visible) ? panelRegion.panelItem : null
+
+  // Effective background color: use panel's if defined, else default
+  readonly property color effectiveBackgroundColor: {
+    if (!assignedPanel)
+      return "transparent";
+    if (assignedPanel.panelBackgroundColor !== undefined) {
+      return assignedPanel.panelBackgroundColor;
+    }
+    return defaultBackgroundColor;
+  }
+
+  // Panel position - panelBg is in screen coordinates already
+  readonly property real panelX: panelBg ? panelBg.x : 0
+  readonly property real panelY: panelBg ? panelBg.y : 0
+  readonly property real panelWidth: panelBg ? panelBg.width : 0
+  readonly property real panelHeight: panelBg ? panelBg.height : 0
+  readonly property bool isRenderable: assignedPanel && panelBg && panelWidth > 0 && panelHeight > 0
+
+  // Flatten corners if panel is too small
+  readonly property bool shouldFlatten: panelBg ? ShapeCornerHelper.shouldFlatten(panelWidth, panelHeight, radius) : false
+  readonly property real effectiveRadius: shouldFlatten ? ShapeCornerHelper.getFlattenedRadius(Math.min(panelWidth, panelHeight), radius) : radius
+
+  // Minimum safe arc radius — prevents zero-displacement zero-radius PathArcs
+  // that crash qTriangulate in CurveRenderer. 0.01px is sub-pixel and invisible.
+  readonly property real _minR: 0.01
+
+  // Helper function for getting corner radius based on state
+  function getCornerRadius(cornerState) {
+    // State -1 = flat corner — use minimum safe radius instead of 0
+    // to prevent degenerate PathArc (zero displacement + zero radius)
+    if (cornerState === -1)
+      return _minR;
+    // All other states use effectiveRadius (clamped to safe minimum)
+    return Math.max(_minR, effectiveRadius);
+  }
+
+  // Per-corner multipliers and radii based on panelBg's corner states
+  readonly property real tlMultX: panelBg ? ShapeCornerHelper.getMultX(panelBg.topLeftCornerState) : 1
+  readonly property real tlMultY: panelBg ? ShapeCornerHelper.getMultY(panelBg.topLeftCornerState) : 1
+  readonly property real tlRadius: panelBg ? getCornerRadius(panelBg.topLeftCornerState) : 0
+
+  readonly property real trMultX: panelBg ? ShapeCornerHelper.getMultX(panelBg.topRightCornerState) : 1
+  readonly property real trMultY: panelBg ? ShapeCornerHelper.getMultY(panelBg.topRightCornerState) : 1
+  readonly property real trRadius: panelBg ? getCornerRadius(panelBg.topRightCornerState) : 0
+
+  readonly property real brMultX: panelBg ? ShapeCornerHelper.getMultX(panelBg.bottomRightCornerState) : 1
+  readonly property real brMultY: panelBg ? ShapeCornerHelper.getMultY(panelBg.bottomRightCornerState) : 1
+  readonly property real brRadius: panelBg ? getCornerRadius(panelBg.bottomRightCornerState) : 0
+
+  readonly property real blMultX: panelBg ? ShapeCornerHelper.getMultX(panelBg.bottomLeftCornerState) : 1
+  readonly property real blMultY: panelBg ? ShapeCornerHelper.getMultY(panelBg.bottomLeftCornerState) : 1
+  readonly property real blRadius: panelBg ? getCornerRadius(panelBg.bottomLeftCornerState) : 0
+
+  // ShapePath configuration
+  strokeWidth: -1 // No stroke, fill only
+
+  // Start point - use tiny off-screen non-degenerate fallback when not renderable.
+  // Fallback forms a 1×1 off-screen square where each edge is split between a PathLine
+  // and a PathArc, ensuring no arc has zero displacement (which can crash qTriangulate).
+  startX: isRenderable ? (panelX + tlRadius * tlMultX) : -0.75
+  startY: isRenderable ? panelY : -1
+
+  fillColor: isRenderable ? effectiveBackgroundColor : "transparent"
+
+  // ========== PATH DEFINITION ==========
+  // Draws a rectangle with potentially inverted corners
+  // All coordinates are relative to startX/startY
+
+  // Top edge (moving right)
+  PathLine {
+    relativeX: root.isRenderable ? (root.panelWidth - root.tlRadius * root.tlMultX - root.trRadius * root.trMultX) : 0.75
+    relativeY: 0
+  }
+
+  // Top-right corner arc
+  PathArc {
+    relativeX: root.isRenderable ? (root.trRadius * root.trMultX) : 0
+    relativeY: root.isRenderable ? (root.trRadius * root.trMultY) : 0.25
+    radiusX: root.isRenderable ? root.trRadius : 0
+    radiusY: root.isRenderable ? root.trRadius : 0
+    direction: ShapeCornerHelper.getArcDirection(root.trMultX, root.trMultY)
+  }
+
+  // Right edge (moving down)
+  PathLine {
+    relativeX: 0
+    relativeY: root.isRenderable ? (root.panelHeight - root.trRadius * root.trMultY - root.brRadius * root.brMultY) : 0.75
+  }
+
+  // Bottom-right corner arc
+  PathArc {
+    relativeX: root.isRenderable ? (-root.brRadius * root.brMultX) : -0.25
+    relativeY: root.isRenderable ? (root.brRadius * root.brMultY) : 0
+    radiusX: root.isRenderable ? root.brRadius : 0
+    radiusY: root.isRenderable ? root.brRadius : 0
+    direction: ShapeCornerHelper.getArcDirection(root.brMultX, root.brMultY)
+  }
+
+  // Bottom edge (moving left)
+  PathLine {
+    relativeX: root.isRenderable ? (-(root.panelWidth - root.brRadius * root.brMultX - root.blRadius * root.blMultX)) : -0.75
+    relativeY: 0
+  }
+
+  // Bottom-left corner arc
+  PathArc {
+    relativeX: root.isRenderable ? (-root.blRadius * root.blMultX) : 0
+    relativeY: root.isRenderable ? (-root.blRadius * root.blMultY) : -0.25
+    radiusX: root.isRenderable ? root.blRadius : 0
+    radiusY: root.isRenderable ? root.blRadius : 0
+    direction: ShapeCornerHelper.getArcDirection(root.blMultX, root.blMultY)
+  }
+
+  // Left edge (moving up) - closes the path back to start
+  PathLine {
+    relativeX: 0
+    relativeY: root.isRenderable ? (-(root.panelHeight - root.blRadius * root.blMultY - root.tlRadius * root.tlMultY)) : -0.75
+  }
+
+  // Top-left corner arc (back to start)
+  PathArc {
+    relativeX: root.isRenderable ? (root.tlRadius * root.tlMultX) : 0.25
+    relativeY: root.isRenderable ? (-root.tlRadius * root.tlMultY) : 0
+    radiusX: root.isRenderable ? root.tlRadius : 0
+    radiusY: root.isRenderable ? root.tlRadius : 0
+    direction: ShapeCornerHelper.getArcDirection(root.tlMultX, root.tlMultY)
+  }
+}

fedora/.config/quickshell/noctalia-shell/Modules/MainScreen/Backgrounds/ShapeCornerHelper.qml

@@ -0,0 +1,74 @@
+pragma Singleton
+
+import QtQuick
+import QtQuick.Shapes
+import Quickshell
+
+/**
+* ShapeCornerHelper - Utility singleton for shape corner calculations
+*
+* Uses 4-state per-corner system for flexible corner rendering:
+* - State -1: No radius (flat/square corner)
+* - State 0: Normal (inner curve)
+* - State 1: Horizontal inversion (outer curve on X-axis)
+* - State 2: Vertical inversion (outer curve on Y-axis)
+*
+* The key technique: Using PathArc direction control (Clockwise vs Counterclockwise)
+* combined with multipliers to create both inner and outer corner curves.
+*/
+Singleton {
+  id: root
+
+  /**
+  * Get X-axis multiplier for a corner state
+  * State 1 (horizontal invert) returns -1, others return 1
+  */
+  function getMultX(cornerState) {
+    return cornerState === 1 ? -1 : 1;
+  }
+
+  /**
+  * Get Y-axis multiplier for a corner state
+  * State 2 (vertical invert) returns -1, others return 1
+  */
+  function getMultY(cornerState) {
+    return cornerState === 2 ? -1 : 1;
+  }
+
+  /**
+  * Get PathArc direction for a corner based on its multipliers
+  * Uses XOR logic: if X inverted differs from Y inverted, use Counterclockwise
+  * This creates the outer curve effect for inverted corners
+  */
+  function getArcDirection(multX, multY) {
+    return ((multX < 0) !== (multY < 0)) ? PathArc.Counterclockwise : PathArc.Clockwise;
+  }
+
+  /**
+  * Convenience function to get arc direction directly from corner state
+  */
+  function getArcDirectionFromState(cornerState) {
+    const multX = getMultX(cornerState);
+    const multY = getMultY(cornerState);
+    return getArcDirection(multX, multY);
+  }
+
+  /**
+  * Get the "flattening" radius when shape dimensions are too small
+  * Prevents visual artifacts when radius exceeds dimensions
+  */
+  function getFlattenedRadius(dimension, requestedRadius) {
+    if (dimension < requestedRadius * 2) {
+      return dimension / 2;
+    }
+    return requestedRadius;
+  }
+
+  /**
+  * Check if a shape should use flattened corners
+  * Returns true if width or height is too small for the requested radius
+  */
+  function shouldFlatten(width, height, radius) {
+    return width < radius * 2 || height < radius * 2;
+  }
+}