feat(scene): per-lap variety, the occasional face-plant, and a sky per tab

Every tab was running the identical eight seconds forever. Three changes:

- Each lap rolls its own timing: 3-5s of empty field, and the money now enters
  on its own delay at its own pace instead of shadowing the doge every time.
- Roughly one lap in six the doge eats it partway down the field: he tips
  nose-first onto the grass, GAME OVER comes up, and the coins he never reached
  are still sitting there. Costs no new art — it is the running sprite pivoted
  on its own feet.
- A `variant` on SceneWidget picks the sky: dusk (History, lock screen), dawn
  (Receive), night (Send, with stars and a moon instead of the sun).

The cycle is now a timer-driven state machine rather than one SequentialAnimation.
That is not stylistic: a lap that rolls its own durations has to assign them
somewhere, and assigning a duration to a child of a *running* SequentialAnimation
makes the group recompute and re-enter its own ScriptAction until the JS stack
blows. Qt flags the binding form of the same mistake as a binding loop.

Verified by headless qml6 render: a forced trip lap, and a clean run with no QML
warnings.

src/ReceiveWidget.cpp

@@ -23,7 +23,7 @@ ReceiveWidget::ReceiveWidget(Wallet *wallet, QWidget *parent)
 
     // wowlet: ambient scene as a short banner under the address table. A layout
     // item, never an overlay over the table.
-    auto *scene = new SceneWidget(this);
+    auto *scene = new SceneWidget(this, SceneWidget::Dawn);
     scene->setMinimumHeight(110);
     scene->setMaximumHeight(130);
     ui->verticalLayout->addWidget(scene);

src/SendWidget.cpp

@@ -29,7 +29,7 @@ SendWidget::SendWidget(Wallet *wallet, QWidget *parent)
     // wowlet: the form only needs the top of the tab — give the rest of it to
     // the ambient scene. A layout item under the form, never an overlay: the
     // send form itself stays untouched.
-    auto *scene = new SceneWidget(this);
+    auto *scene = new SceneWidget(this, SceneWidget::Night);
     scene->setMinimumHeight(160);
     scene->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
     ui->verticalLayoutOuter->addWidget(scene, 1);

src/assets/qml/scene.qml

@@ -1,14 +1,20 @@
 import QtQuick
 
-// wowlet ambient scene — dusk sky, tiled grass, and a doge that runs the field
-// collecting WOW coins. All motion gates on `scene.reducedMotion` (exposed by
-// the host SceneBackend); frozen it is the reduced-motion still.
+// wowlet ambient scene — a doge running a field of WOW coins under a big sky.
+// All motion gates on `scene.reducedMotion` (exposed by the host SceneBackend);
+// frozen it is the reduced-motion still.
 //
 // One cycle is three beats, so the scene breathes instead of running flat out:
 //
-//   1. empty field for a few seconds  (nothing but sky and grass)
+//   1. an empty field for 3-5s (nothing but sky and grass)
 //   2. the coins pop in, one at a time
-//   3. the doge and the money go by; the doge collects the coins
+//   3. the doge and the money go by, and the doge collects the coins
+//
+// Every lap re-rolls its own timing — how long the field stays empty, when the
+// money enters relative to the doge and how fast it crosses — so the loop does
+// not read as the same eight seconds forever. Roughly one lap in six, the doge
+// eats it halfway down the field and the lap ends in GAME OVER with the rest of
+// the coins uncollected.
 //
 // Motion is driven by a unitless 0..1 `runProgress` rather than by animating
 // straight to `scene.width`: an animation whose `to:` is bound to the width
@@ -18,12 +24,29 @@ Rectangle {
     id: scene
 
     property bool reducedMotion: (typeof sceneCtx !== 'undefined' && sceneCtx) ? sceneCtx.reducedMotion : false
+    // 0 dusk · 1 dawn · 2 night — so the tabs are not all the same field.
+    property int  variant:       (typeof sceneCtx !== 'undefined' && sceneCtx) ? sceneCtx.variant : 0
 
-    // --- cycle timing -------------------------------------------------------
-    readonly property int emptyBeat:  4000   // just background, between laps
+    // --- sky ----------------------------------------------------------------
+    readonly property var skies: [
+        ["#160d2b", "#5b2f6e", "#c96aa0", "#f2adc9"],   // dusk
+        ["#123a63", "#2f6fa8", "#e8a06a", "#ffd9a8"],   // dawn
+        ["#04060f", "#0d1330", "#1d2450", "#39406e"]    // night
+    ]
+    readonly property var sky: skies[Math.max(0, Math.min(skies.length - 1, variant))]
+    readonly property bool night: variant === 2
+
+    // --- cycle timing (re-rolled every lap) ---------------------------------
+    // emptyBeat / moneyDelay / moneyBeat are rolled onto the animations directly
+    // (see the ScriptAction at the foot of the file).
     readonly property int revealStep:  320   // per coin, popping in one by one
-    readonly property int settleBeat:   500   // coins all out, before the run
-    readonly property int runBeat:     8000   // doge + money crossing
+    readonly property int settleBeat:  500   // coins all out, before the run
+    readonly property int runBeat:     8000  // the doge crossing
+
+    // --- the trip -----------------------------------------------------------
+    property bool tripLap: false     // does the doge eat it this lap?
+    property real tripAt:  0.55      // ...and how far along
+    readonly property bool tripped: tripLap && runProgress >= tripAt
 
     // --- ground plane and the doge's run ------------------------------------
     readonly property int  grassHeight: 46
@@ -34,7 +57,10 @@ Rectangle {
     readonly property real runEnd:      scene.width + 10
 
     property real runProgress: 0.0
-    readonly property real dogX: runStart + runProgress * (runEnd - runStart)
+    property real moneyProgress: 0.0
+    // A tripped doge stops where he fell instead of sliding on to the far edge.
+    readonly property real dogProgress: tripped ? tripAt : runProgress
+    readonly property real dogX: runStart + dogProgress * (runEnd - runStart)
     // The doge collects a coin once its snout reaches the coin's centre.
     readonly property real snoutX: dogX + dogWidth * 0.78
 
@@ -46,27 +72,46 @@ Rectangle {
     property real coinReveal: 0.0
 
     gradient: Gradient {
-        GradientStop { position: 0.0;  color: "#160d2b" }
-        GradientStop { position: 0.5;  color: "#5b2f6e" }
-        GradientStop { position: 0.82; color: "#c96aa0" }
-        GradientStop { position: 1.0;  color: "#f2adc9" }
+        GradientStop { position: 0.0;  color: scene.sky[0] }
+        GradientStop { position: 0.5;  color: scene.sky[1] }
+        GradientStop { position: 0.82; color: scene.sky[2] }
+        GradientStop { position: 1.0;  color: scene.sky[3] }
     }
 
-    // Sun, low in the dusk sky.
+    // Stars, night only. Positions are a fixed hash of the index so they do not
+    // jump around on every repaint.
+    Repeater {
+        model: scene.night ? 26 : 0
+        Rectangle {
+            width: (index % 4 === 0) ? 3 : 2
+            height: width
+            radius: 1
+            color: "#fdf6d8"
+            opacity: 0.45 + ((index * 37) % 50) / 100
+            x: scene.width  * (((index * 73) % 100) / 100)
+            y: scene.height * 0.06 + scene.height * 0.42 * (((index * 41) % 100) / 100)
+        }
+    }
+
+    // Sun, or a paler moon at night.
     Rectangle {
-        x: scene.width * 0.74; y: scene.height * 0.14
-        width: 62; height: 62; radius: 31
-        color: "#ffe9b0"; opacity: 0.9
+        x: scene.width * 0.74
+        y: scene.height * (scene.night ? 0.10 : 0.14)
+        width: scene.night ? 46 : 62
+        height: width
+        radius: width / 2
+        color: scene.night ? "#e8ecff" : "#ffe9b0"
+        opacity: scene.night ? 0.85 : 0.9
     }
 
-    // Money crosses with the doge, a little quicker, so it leads him off screen.
+    // Money crosses on its own roll, so it does not shadow the doge every lap.
     AnimatedImage {
         source: "qrc:/scene/flyingmoney.gif"
         playing: !scene.reducedMotion
         width: 60; height: 55
         y: Math.max(4, Math.min(scene.height * 0.10, 60))
         x: scene.reducedMotion ? scene.width * 0.30
-                               : -80 + scene.runProgress * (scene.width + 240)
+                               : -80 + scene.moneyProgress * (scene.width + 240)
         opacity: 0.9
     }
 
@@ -90,7 +135,8 @@ Rectangle {
 
             // Both states are derived from the cycle, so a lap needs no reset
             // bookkeeping: `coinReveal` dropping to 0 hides them, and the doge
-            // returning to the left edge un-collects them.
+            // returning to the left edge un-collects them. A tripped doge never
+            // reaches the rest, so they are still sitting there at GAME OVER.
             readonly property bool revealed:  scene.reducedMotion || scene.coinReveal >= index + 1
             readonly property bool collected: revealed && !scene.reducedMotion
                                               && scene.snoutX >= x + width / 2
@@ -115,7 +161,6 @@ Rectangle {
 
             // Pickup pop.
             Text {
-                id: popText
                 anchors.horizontalCenter: parent.horizontalCenter
                 text: "+1"
                 color: "#ffd257"
@@ -137,36 +182,109 @@ Rectangle {
     }
 
     AnimatedImage {
+        id: doge
         source: "qrc:/scene/dog.gif"
-        playing: !scene.reducedMotion
+        playing: !scene.reducedMotion && !scene.tripped
         width: scene.dogWidth; height: scene.dogHeight
         y: scene.groundY - scene.dogHeight + 21
         x: scene.reducedMotion ? 8 : scene.dogX
+        // Face-plant: tips forward over his own feet rather than sinking
+        // through the grass, so he ends up nose-down on the ground.
+        transformOrigin: Item.Bottom
+        rotation: scene.tripped ? 58 : 0
+        Behavior on rotation { NumberAnimation { duration: 260; easing.type: Easing.OutQuad } }
     }
 
-    // The three beats, on a loop.
-    SequentialAnimation {
-        running: !scene.reducedMotion
-        loops: Animation.Infinite
+    Text {
+        anchors.centerIn: parent
+        text: "GAME OVER"
+        color: "#ff6b6b"
+        style: Text.Outline
+        styleColor: "#1a0b1f"
+        font.bold: true
+        font.pixelSize: Math.max(20, Math.min(scene.height * 0.20, 34))
+        opacity: scene.tripped ? 1.0 : 0.0
+        Behavior on opacity { NumberAnimation { duration: 320 } }
+    }
 
-        // 1. empty field — doge and money are parked off the left edge by
-        //    runProgress 0, and every coin is hidden.
-        ScriptAction { script: { scene.runProgress = 0.0; scene.coinReveal = 0.0; } }
-        PauseAnimation { duration: scene.emptyBeat }
+    // The three beats, on a loop, re-rolled each time round.
+    //
+    // This is a timer-driven state machine rather than one big
+    // SequentialAnimation on purpose: each lap rolls its own durations, and
+    // assigning a duration to a child of a *running* SequentialAnimation makes
+    // the group recompute and re-enter its own ScriptAction, which recurses
+    // until the JS stack blows.
+    property int beat: 0
 
-        // 2. coins pop in, one at a time
-        NumberAnimation {
-            target: scene; property: "coinReveal"
-            from: 0.0; to: scene.coinCount
-            duration: scene.coinCount * scene.revealStep
+    NumberAnimation {
+        id: revealAnim
+        target: scene; property: "coinReveal"
+        from: 0.0; to: scene.coinCount
+        duration: scene.coinCount * scene.revealStep
+    }
+    NumberAnimation {
+        id: runAnim
+        target: scene; property: "runProgress"
+        from: 0.0; to: 1.0
+        duration: scene.runBeat
+    }
+    NumberAnimation {
+        id: moneyAnim
+        target: scene; property: "moneyProgress"
+        from: 0.0; to: 1.0
+        duration: 6000
+    }
+
+    Timer { id: beatTimer;  repeat: false; onTriggered: scene.advance() }
+    Timer { id: moneyTimer; repeat: false; onTriggered: moneyAnim.start() }
+
+    // Beat 0 is the empty field, 1 is the coins coming out, 2 is the run.
+    function startLap() {
+        beatTimer.stop(); moneyTimer.stop();
+        revealAnim.stop(); runAnim.stop(); moneyAnim.stop();
+
+        scene.beat = 0;
+        scene.runProgress = 0.0;
+        scene.moneyProgress = 0.0;
+        scene.coinReveal = 0.0;
+
+        moneyAnim.duration  = 5000 + Math.floor(Math.random() * 2000);
+        moneyTimer.interval = Math.floor(Math.random() * Math.max(1, scene.runBeat - moneyAnim.duration));
+        scene.tripLap = Math.random() < 0.17;
+        scene.tripAt  = 0.34 + Math.random() * 0.34;
+
+        beatTimer.interval = 3000 + Math.floor(Math.random() * 2000);   // 3-5s of empty field
+        beatTimer.start();
+    }
+
+    function advance() {
+        if (scene.reducedMotion)
+            return;
+        if (scene.beat === 0) {
+            scene.beat = 1;
+            revealAnim.start();
+            beatTimer.interval = scene.coinCount * scene.revealStep + scene.settleBeat;
+            beatTimer.start();
+        } else if (scene.beat === 1) {
+            scene.beat = 2;
+            runAnim.start();
+            moneyTimer.start();
+            beatTimer.interval = scene.runBeat + 900;   // 900 holds on GAME OVER
+            beatTimer.start();
+        } else {
+            scene.startLap();
         }
-        PauseAnimation { duration: scene.settleBeat }
+    }
 
-        // 3. the run
-        NumberAnimation {
-            target: scene; property: "runProgress"
-            from: 0.0; to: 1.0
-            duration: scene.runBeat
+    Component.onCompleted: if (!scene.reducedMotion) scene.startLap();
+
+    onReducedMotionChanged: {
+        if (scene.reducedMotion) {
+            beatTimer.stop(); moneyTimer.stop();
+            revealAnim.stop(); runAnim.stop(); moneyAnim.stop();
+            scene.tripLap = false;
+        } else {
+            scene.startLap();
         }
     }
 }

src/widgets/SceneWidget.cpp

@@ -7,11 +7,12 @@
 
 #include "utils/config.h"
 
-SceneWidget::SceneWidget(QWidget *parent)
+SceneWidget::SceneWidget(QWidget *parent, Variant variant)
     : QQuickWidget(parent)
     , m_backend(new SceneBackend(this))
 {
     m_backend->setReducedMotion(conf()->get(Config::reducedMotion).toBool());
+    m_backend->setVariant(static_cast<int>(variant));
     this->rootContext()->setContextProperty("sceneCtx", m_backend);
     this->setResizeMode(QQuickWidget::SizeRootObjectToView);
     this->setSource(QUrl("qrc:/qml/scene.qml"));

src/widgets/SceneWidget.h

@@ -8,18 +8,24 @@
 #include <QQuickWidget>
 
 // Context object exposed to scene.qml as `sceneCtx`. Carries the reduced-motion
-// setting so the scene freezes into its still (reduced-motion) form.
+// setting so the scene freezes into its still (reduced-motion) form, and the
+// sky variant so the tabs are not all showing the same field.
 class SceneBackend : public QObject {
 Q_OBJECT
     Q_PROPERTY(bool reducedMotion READ reducedMotion NOTIFY reducedMotionChanged)
+    Q_PROPERTY(int variant READ variant NOTIFY variantChanged)
 public:
     explicit SceneBackend(QObject *parent = nullptr) : QObject(parent) {}
     bool reducedMotion() const { return m_reducedMotion; }
     void setReducedMotion(bool r) { if (m_reducedMotion != r) { m_reducedMotion = r; emit reducedMotionChanged(); } }
+    int variant() const { return m_variant; }
+    void setVariant(int v) { if (m_variant != v) { m_variant = v; emit variantChanged(); } }
 signals:
     void reducedMotionChanged();
+    void variantChanged();
 private:
     bool m_reducedMotion = false;
+    int  m_variant = 0;
 };
 
 // wowlet: reusable ambient-scene surface. Hosts scene.qml and reads the
@@ -28,7 +34,11 @@ private:
 class SceneWidget : public QQuickWidget {
 Q_OBJECT
 public:
-    explicit SceneWidget(QWidget *parent = nullptr);
+    // Sky variants, one per host, so History/Send/Receive do not all show the
+    // same field. Must match the `skies` table in scene.qml.
+    enum Variant { Dusk = 0, Dawn = 1, Night = 2 };
+
+    explicit SceneWidget(QWidget *parent = nullptr, Variant variant = Dusk);
     void refreshReducedMotion();
 private:
     SceneBackend *m_backend;