fix(player): refine immersive lyrics and seekbars

Reuse the split lyrics renderer for full-screen timed fill, add a contrast shadow and expose the immersive song card there. Render the compact seekbar as a stable three-sine motif and make the larger waveform use normalized rounded capsules with stronger peaks.

cx

crates/qbz-qt/cxx/seek_waveform_item.cpp

@@ -97,6 +97,70 @@ void setQuad(QSGGeometry::ColoredPoint2D *vertices,
     setVertex(vertices[5], right, bottom, color, bottomAlpha);
 }
 
+constexpr int capsuleCapSegments = 4;
+constexpr int capsuleVertexCount = 12 + capsuleCapSegments * 6;
+
+void setTriangle(QSGGeometry::ColoredPoint2D *vertices,
+                 const QPointF &first,
+                 const QPointF &second,
+                 const QPointF &third,
+                 const QColor &color,
+                 float firstAlpha,
+                 float secondAlpha,
+                 float thirdAlpha)
+{
+    setVertex(vertices[0], static_cast<float>(first.x()), static_cast<float>(first.y()),
+              color, firstAlpha);
+    setVertex(vertices[1], static_cast<float>(second.x()), static_cast<float>(second.y()),
+              color, secondAlpha);
+    setVertex(vertices[2], static_cast<float>(third.x()), static_cast<float>(third.y()),
+              color, thirdAlpha);
+}
+
+void setVerticalCapsule(QSGGeometry::ColoredPoint2D *vertices,
+                        float left,
+                        float top,
+                        float right,
+                        float bottom,
+                        const QColor &color)
+{
+    constexpr qreal pi = 3.14159265358979323846;
+    const float centreX = (left + right) * 0.5f;
+    const float centreY = (top + bottom) * 0.5f;
+    const float radius = std::min((right - left) * 0.5f, (bottom - top) * 0.5f);
+    const float topCentre = top + radius;
+    const float bottomCentre = bottom - radius;
+
+    setQuad(vertices, left, topCentre, right, centreY, color, 0.62f, 1.0f);
+    setQuad(vertices + 6, left, centreY, right, bottomCentre, color, 1.0f, 0.58f);
+
+    int vertex = 12;
+    for (int segment = 0; segment < capsuleCapSegments; ++segment) {
+        const qreal firstAngle = pi + pi * segment / capsuleCapSegments;
+        const qreal secondAngle = pi + pi * (segment + 1) / capsuleCapSegments;
+        setTriangle(vertices + vertex,
+                    QPointF(centreX, topCentre),
+                    QPointF(centreX + std::cos(firstAngle) * radius,
+                            topCentre + std::sin(firstAngle) * radius),
+                    QPointF(centreX + std::cos(secondAngle) * radius,
+                            topCentre + std::sin(secondAngle) * radius),
+                    color, 0.62f, 0.42f, 0.42f);
+        vertex += 3;
+    }
+    for (int segment = 0; segment < capsuleCapSegments; ++segment) {
+        const qreal firstAngle = pi * segment / capsuleCapSegments;
+        const qreal secondAngle = pi * (segment + 1) / capsuleCapSegments;
+        setTriangle(vertices + vertex,
+                    QPointF(centreX, bottomCentre),
+                    QPointF(centreX + std::cos(firstAngle) * radius,
+                            bottomCentre + std::sin(firstAngle) * radius),
+                    QPointF(centreX + std::cos(secondAngle) * radius,
+                            bottomCentre + std::sin(secondAngle) * radius),
+                    color, 0.58f, 0.38f, 0.38f);
+        vertex += 3;
+    }
+}
+
 void setLayerGeometry(QSGGeometryNode *node,
                       const std::vector<float> &values,
                       qreal width,
@@ -110,10 +174,10 @@ void setLayerGeometry(QSGGeometryNode *node,
     const float halfHeight = std::max(1.0f, static_cast<float>(height * 0.47));
 
     if (renderMode == 1) {
-        // Small NPB: the RMS document has no signed samples, so present its
-        // loudness contour as one continuous, centre-crossing curve. A few
-        // dozen well-spaced segments read as a waveform at 11 px; hundreds
-        // of sub-pixel bars only read as a rough blue rail.
+        // Small NPB: this is a stable three-sine motif rather than decoded
+        // RMS. At thirteen pixels the real envelope cannot communicate track
+        // structure, while a smooth repeated contour remains readable and
+        // still carries played/cache clipping as a seek affordance.
         geometry->allocate(6 + std::max(0, count - 1) * 6);
         geometry->setDrawingMode(QSGGeometry::DrawTriangles);
         auto *vertices = geometry->vertexDataAsColoredPoint2D();
@@ -162,7 +226,7 @@ void setLayerGeometry(QSGGeometryNode *node,
 
     const int visibleBars = static_cast<int>(std::count_if(values.begin(), values.end(),
         [](float value) { return value > 0.0005f; }));
-    geometry->allocate(6 + visibleBars * 12);
+    geometry->allocate(6 + visibleBars * capsuleVertexCount);
     geometry->setDrawingMode(QSGGeometry::DrawTriangles);
     auto *vertices = geometry->vertexDataAsColoredPoint2D();
 
@@ -178,13 +242,13 @@ void setLayerGeometry(QSGGeometryNode *node,
         return;
     }
 
-    constexpr int groupSize = 8;
+    constexpr int groupSize = 12;
     const int groupBreaks = (count - 1) / groupSize;
     const float nominalSlot = static_cast<float>(width) / count;
-    const float groupGap = std::min(2.8f, std::max(1.1f, nominalSlot * 0.52f));
+    const float groupGap = std::min(2.4f, std::max(0.9f, nominalSlot * 0.34f));
     const float usableWidth = std::max(1.0f, static_cast<float>(width) - groupBreaks * groupGap);
     const float slot = usableWidth / count;
-    const float barWidth = std::max(1.2f, std::min(slot * 0.74f, slot - 0.35f));
+    const float barWidth = std::clamp(slot * 0.56f, 1.8f, 3.6f);
     int vertex = 6;
 
     for (int index = 0; index < count; ++index) {
@@ -196,12 +260,9 @@ void setLayerGeometry(QSGGeometryNode *node,
         const float left = slot * index + groupGap * (index / groupSize)
             + (slot - barWidth) * 0.5f;
         const float right = left + barWidth;
-        setQuad(vertices + vertex, left, centre - amplitude, right, centre,
-                color, 0.48f, 0.98f);
-        vertex += 6;
-        setQuad(vertices + vertex, left, centre, right, centre + amplitude,
-                color, 0.98f, 0.42f);
-        vertex += 6;
+        setVerticalCapsule(vertices + vertex, left, centre - amplitude,
+                           right, centre + amplitude, color);
+        vertex += capsuleVertexCount;
     }
     node->markDirty(QSGNode::DirtyGeometry);
 }
@@ -233,6 +294,30 @@ std::vector<float> renderValues(const QVariantList &source, int columns, float g
         }
         values.swap(scratch);
     }
+    const float maximum = *std::max_element(values.begin(), values.end());
+    if (maximum > 0.0005f) {
+        for (float &value : values)
+            value = std::clamp(value / maximum, 0.0f, 1.0f);
+    }
+    return values;
+}
+
+std::vector<float> decorativeWaveValues(int columns, qreal width)
+{
+    std::vector<float> values(columns, 0.5f);
+    if (columns < 2)
+        return values;
+
+    constexpr qreal twoPi = 6.28318530717958647692;
+    const qreal repeats = std::max<qreal>(3.0, width / 210.0);
+    for (int index = 0; index < columns; ++index) {
+        const qreal progress = static_cast<qreal>(index) / (columns - 1);
+        const qreal phase = twoPi * repeats * progress;
+        const qreal composite = 0.55 * std::sin(phase)
+            + 0.28 * std::sin(phase * 2.0 + 0.85)
+            + 0.17 * std::sin(phase * 3.0 + 2.1);
+        values[index] = static_cast<float>(0.5 + composite * 0.46);
+    }
     return values;
 }
 
@@ -307,7 +392,7 @@ void SeekWaveformItem::setRenderMode(int mode)
 
 QSGNode *SeekWaveformItem::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
 {
-    if (m_values.isEmpty() || width() <= 0.0 || height() <= 0.0) {
+    if ((m_values.isEmpty() && m_renderMode == 0) || width() <= 0.0 || height() <= 0.0) {
         delete oldNode;
         return nullptr;
     }
@@ -327,9 +412,11 @@ QSGNode *SeekWaveformItem::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData
     if (root->geometryRevision != m_valuesRevision || root->geometrySize != size()
         || colorsChanged || root->geometryRenderMode != m_renderMode) {
         const int columns = m_renderMode == 1
-            ? qBound(32, static_cast<int>(std::ceil(width() / 9.0)), 192)
-            : qBound(40, static_cast<int>(std::ceil(width() / 5.5)), 256);
-        const auto values = renderValues(m_values, columns, m_renderMode == 1 ? 0.9f : 0.78f);
+            ? qBound(64, static_cast<int>(std::ceil(width() / 3.0)), 512)
+            : qBound(48, static_cast<int>(std::ceil(width() / 7.5)), 240);
+        const auto values = m_renderMode == 1
+            ? decorativeWaveValues(columns, width())
+            : renderValues(m_values, columns, 0.72f);
         setLayerGeometry(root->baseLayer, values, width(), height(), m_baseColor, m_renderMode);
         setLayerGeometry(root->cacheLayer, values, width(), height(), m_cacheColor, m_renderMode);
         setLayerGeometry(root->playedLayer, values, width(), height(), m_playedColor, m_renderMode);

crates/qbz-qt/qml/immersive/ImmersiveSongCard.qml

@@ -4,10 +4,9 @@
 // built fresh — shell/SongCard.qml is the bar's INTERACTIVE meta-link card
 // with AudioStamp; this twin is NON-interactive with the E chip).
 //
-// Mounted by ImmersiveView as layer 4: visible ONLY
-// `viewMode==0 && mode==6 && npHasTrack` (trap 19), bottom-right 24px
-// insets, and it does NOT fade with the auto-hide chrome
-// (ImmersiveView.slint:1602-1605). Content-sized: the card hugs its content
+// Mounted by ImmersiveView as layer 4 over Wave Bed, full Lyrics and every
+// shader scene, bottom-right with 24px insets. It does NOT fade with the
+// auto-hide chrome. Content-sized: the card hugs its content
 // and the mount pins it bottom-right, so a wider card grows LEFTWARD.
 //
 //   meta column (right-aligned): title 15px semibold capped 420px + elide

crates/qbz-qt/qml/immersive/ImmersiveView.qml

@@ -29,8 +29,8 @@
 //      spectrum band and the viz eye toggle; port of the Slint root
 //      TouchArea :1283-1286). Stacked BELOW panels + chrome.
 //   3. FOCUS panels (viewMode==0 && mode==N) / the SPLIT layout (viewMode==1)
-//   4. ImmersiveSongCard (viewMode==0 && mode==6 && npHasTrack — trap 19;
-//      does NOT fade with the chrome, :1602-1605)
+//   4. ImmersiveSongCard (Wave Bed, full Lyrics and shader scenes;
+//      does NOT fade with the chrome)
 //   5. ImmersivePlayerBar (B5, :1607-1616) — centered, y = height-90-24,
 //      fades with the chrome like the header
 //   6. ImmersiveHeader band
@@ -356,7 +356,7 @@ Item {
             }
         }
     }
-    // FOCUS Lyrics (mode 4, B4 §6.6): the giant-line variant. It shares the
+    // FOCUS Lyrics (mode 4, B4 §6.6): the one-line variant. It shares the
     // immersive LyricsSyncEngine with the split lyrics mount (trap 22 — the
     // gate covers BOTH lyric surfaces and nothing else). No entry load: Qt
     // fetches lyrics automatically per track (§5.5).
@@ -638,9 +638,10 @@ Item {
     }
 
     // --- Layer 4: ImmersiveSongCard (§5.1, :1602-1605) ----------------------
-    // Slint shows it bottom-right ONLY over the shader backgrounds OR in
-    // WaveBed (shader-mode > 0 || (view-mode == 0 && mode == 6)) &&
-    // has-track — the focus panels render their own metadata. In v1
+    // Keep the compact bottom-right metadata over shader backgrounds,
+    // Wave Bed and full-screen Lyrics. The lyrics surface deliberately keeps
+    // one line at a time, so the card supplies the otherwise absent track
+    // context without competing with the active line.
     // shader-mode was constant 0 so the first arm was dead (trap 19); A1
     // makes it real. NON-interactive; does NOT fade with the auto-hide
     // chrome (no opacity binding here — that is deliberate).
@@ -651,7 +652,8 @@ Item {
         anchors.rightMargin: 24
         anchors.bottomMargin: 24
         visible: (QbzShaderScene.scene > 0
-                  || (QbzImmersive.viewMode === 0 && QbzImmersive.mode === 6))
+                  || (QbzImmersive.viewMode === 0
+                      && (QbzImmersive.mode === 4 || QbzImmersive.mode === 6)))
             && QbzPlayer.npHasTrack
     }
 

crates/qbz-qt/qml/immersive/LyricsFocusPanel.qml

@@ -1,10 +1,10 @@
-// LyricsFocusPanel — FOCUS mode 4, the giant-line lyrics variant (§6.6 of
+// LyricsFocusPanel — FOCUS mode 4, the one-line lyrics variant (§6.6 of
 // the 2026-08-02 immersive-port contract), port of
 // crates/qbz-ui/ui/immersive/ImmersiveLyricsFocusPanel.slint:50-151.
 //
-// One giant centered CURRENT line, cross-faded on every line change; NO
-// karaoke fill (whole-line swap only, exactly like the Slint/Svelte source
-// which omits activeProgress). Data: the QbzLyrics doc (lines/status/synced,
+// One centered CURRENT line, cross-faded on every line change. The host still
+// advances one line at a time, but the active line now reuses the split-view
+// typography and per-line time fill. Data: the QbzLyrics doc (lines/status/synced,
 // passed in by the mount) + the SHARED immersive LyricsSyncEngine instance
 // from ImmersiveView (`sync`) — the Slint reads the one global LyricsState
 // active-index; Qt has one engine per surface group, and the focus panel +
@@ -18,12 +18,12 @@
 // does not animate), a 16ms one-shot releases it and the 500ms
 // cubic-bezier(0.22,1,0.36,1) runs forward.
 //
-// The line takes QbzShell.ambientAccent — the album-art accent that is the
-// COMPLEMENT of the cover's dominant hue (ImmersiveState.lyrics-accent),
-// NOT the UI lyrics color, NOT plain white (:102-107).
+// The line uses split-lyrics white plus a restrained native shadow so the
+// timed fill remains legible over every immersive background.
 
 import QtQuick
 import com.blitzfc.qbz
+import "../shell"
 
 Item {
     id: root
@@ -51,9 +51,23 @@ Item {
     readonly property bool noLyrics: root.status === 3
         || (root.status === 2 && root.lines.length === 0)
 
-    // Responsive font size (clamp(28px, 5vw, 56px), :50-51) — vw = the
-    // panel's own width (full-viewport in the focus placement).
-    readonly property real lineSize: Math.max(28, Math.min(root.width * 0.05, 56))
+    // Same responsive active size as immersive split lyrics. Keeping this
+    // scale identical prevents a jarring type jump between full and split.
+    readonly property real lineSize: Math.round(Math.max(28,
+        Math.min(root.width * 0.022, 42)))
+
+    readonly property string fontDir: "qrc:/qt/qml/com/blitzfc/qbz/qml/assets/fonts/"
+    FontLoader { id: fLineSeed; source: QbzLyrics.fontIndex === 1 ? root.fontDir + "LINESeedJP-Regular.ttf" : "" }
+    FontLoader { id: fMontserrat; source: QbzLyrics.fontIndex === 2 ? root.fontDir + "Montserrat-VariableFont_wght.ttf" : "" }
+    FontLoader { id: fNoto; source: QbzLyrics.fontIndex === 3 ? root.fontDir + "NotoSans-VariableFont_wdth,wght.ttf" : "" }
+    FontLoader { id: fSource; source: QbzLyrics.fontIndex === 4 ? root.fontDir + "SourceSans3-VariableFont_wght.ttf" : "" }
+    readonly property string fontFamily: {
+        if (QbzLyrics.fontIndex === 1) return fLineSeed.status === FontLoader.Ready ? fLineSeed.name : ""
+        if (QbzLyrics.fontIndex === 2) return fMontserrat.status === FontLoader.Ready ? fMontserrat.name : ""
+        if (QbzLyrics.fontIndex === 3) return fNoto.status === FontLoader.Ready ? fNoto.name : ""
+        if (QbzLyrics.fontIndex === 4) return fSource.status === FontLoader.Ready ? fSource.name : ""
+        return ""
+    }
 
     // --- Entry-animation retrigger (:57-74) --------------------------------
     readonly property int watchedIndex: root.activeIndex
@@ -82,19 +96,24 @@ Item {
         anchors.rightMargin: 60
         anchors.bottomMargin: 140
 
-        // Current line — fadeInUp-lite (:100-126). Centered in the block.
-        Text {
+        // Current line — one line at a time, with the exact split-view
+        // karaoke renderer and a restrained native shadow.
+        LyricsLineRow {
             visible: root.hasCurrent
             anchors.centerIn: parent
-            // width min(parent, vw*0.9) (:114).
-            width: Math.min(parent.width, root.width * 0.9)
-            text: root.currentLine
-            color: QbzShell.ambientAccent
-            font.pixelSize: root.lineSize
-            font.weight: Font.Bold // 700
-            font.letterSpacing: 0.2
-            horizontalAlignment: Text.AlignHCenter
-            wrapMode: Text.WordWrap
+            contentWidth: Math.min(parent.width, root.width * 0.9)
+            lineText: root.currentLine
+            lineIndex: root.activeIndex
+            sync: root.sync
+            synced: root.synced
+            activeIndex: root.activeIndex
+            sizeInactive: root.lineSize
+            sizeActive: root.lineSize
+            uppercase: QbzLyrics.uppercase
+            fontFamily: root.fontFamily
+            activeColor: "#ffffff"
+            liteFill: false
+            textShadow: true
             // The translate-up is applied via anchors.verticalCenterOffset so
             // the centering anchor survives the offset.
             anchors.verticalCenterOffset: root.entering ? 24 : 0

crates/qbz-qt/qml/shell/LyricsLineRow.qml

@@ -57,6 +57,11 @@ Column {
     // Lite fill: light the active line whole, no per-frame clip sweep.
     property bool liteFill: false
     property bool showTranslation: false
+    // The full-screen one-line host enables this lightweight native text
+    // shadow. It avoids an extra blurred layer while keeping every glyph
+    // readable over arbitrary album artwork.
+    property bool textShadow: false
+    property color textShadowColor: "#b0000000"
 
     QbzTheme { id: theme }
 
@@ -115,6 +120,8 @@ Column {
         font.pixelSize: row.sizeInactive
         font.weight: theme.weightMedium
         font.letterSpacing: 0.2
+        style: row.textShadow ? Text.Raised : Text.Normal
+        styleColor: row.textShadowColor
     }
 
     // ---- ACTIVE: per-visual-line karaoke -------------------------------
@@ -209,6 +216,8 @@ Column {
                     font.pixelSize: row.sizeActive
                     font.weight: theme.weightBold
                     font.letterSpacing: 0.2
+                    style: row.textShadow ? Text.Raised : Text.Normal
+                    styleColor: row.textShadowColor
                 }
 
                 // Bright (sung) overlay, clipped to this segment's LOCAL fill:
@@ -246,6 +255,8 @@ Column {
                         font.pixelSize: row.sizeActive
                         font.weight: theme.weightBold
                         font.letterSpacing: 0.2
+                        style: row.textShadow ? Text.Raised : Text.Normal
+                        styleColor: row.textShadowColor
                     }
                 }
             }
@@ -269,5 +280,7 @@ Column {
         font.pixelSize: Math.round((row.isActive ? row.sizeActive : row.sizeInactive) * 0.72)
         font.weight: theme.weightRegular
         font.letterSpacing: 0.2
+        style: row.textShadow ? Text.Raised : Text.Normal
+        styleColor: row.textShadowColor
     }
 }

crates/qbz-qt/qml/shell/NowPlayingBarSmall.qml

@@ -45,8 +45,7 @@ Rectangle {
     color: ambientOn ? theme.surfaceCardA50 : theme.surfaceCard
     readonly property bool ambientOn: theme.ambientOn
     readonly property bool waveformVisible: QbzShell.seekbarWaveform
-        && QbzPlayer.npSeekWaveformAnalyzed > 0
-        && QbzPlayer.npSeekWaveform.length > 0
+        && QbzPlayer.npHasTrack
 
 
     QbzTheme { id: theme }
@@ -219,7 +218,7 @@ Rectangle {
             Rectangle {
                 id: seekTrack
                 width: parent.width
-                height: root.waveformVisible ? 11 : 3
+                height: root.waveformVisible ? 13 : 3
                 anchors.verticalCenter: parent.verticalCenter
                 radius: 2
                 color: root.waveformVisible ? "transparent" : theme.surfaceElevated