Merge remote-tracking branch 'origin/dev' into claude/locked-phone-turn-issue-x9pvbv

README.md

@@ -173,7 +173,7 @@ production package instead.
 - `.github/workflows/ci.yml` — builds, tests and lints on `dev` and on pull
   requests into `dev` or `main`. Its APK artifact is a dev build, versioned
   `<series>.0-dev` — the series being whatever `plgVersionSeries` says in
-  `gradle.properties`, currently **1.1**.
+  `gradle.properties`, currently **1.3**.
 - `.github/workflows/release.yml` — on push to `main`, builds the APK and
   publishes it as a GitHub Release tagged `v<series>.<run-number>`. The in-app updater
   reads that tag, which is why the APK's `versionCode` is the same run number.
@@ -201,7 +201,7 @@ A version is **`<series>.<run number>`**. The series is set by hand, once, in
 `gradle.properties`:
 
 ```properties
-plgVersionSeries=1.1
+plgVersionSeries=1.3
 ```
 
 Both workflows read that same property when they name a release tag, and the

app/src/main/java/org/prolibertate/games/game/kaiser/KaiserModel.kt

@@ -92,6 +92,14 @@ data class KaiserState(
     val lastTrickWinner: Int?,
     /** Points taken this hand, per team. */
     val handPoints: List<Int>,
+    /**
+     * Tricks taken this hand, per seat. Kaiser scores in points rather than
+     * tricks, so nothing in the rules needs this — it is what the table draws
+     * in front of each player, and a player who has taken four tricks and no
+     * counters has still taken four tricks. Defaulted so a client on an older
+     * build can still read a state from the wire.
+     */
+    val tricksWon: List<Int> = List(4) { 0 },
     val scores: List<Int>,
     val log: List<String>,
 )

app/src/main/java/org/prolibertate/games/game/kaiser/KaiserRules.kt

@@ -62,6 +62,7 @@ object KaiserRules : GameRules<KaiserState, KaiserMove> {
             leader = (dealer + 1) % 4,
             lastTrickWinner = null,
             handPoints = listOf(0, 0),
+            tricksWon = List(4) { 0 },
             scores = scores,
             log = log,
         )
@@ -224,10 +225,14 @@ object KaiserRules : GameRules<KaiserState, KaiserMove> {
         val handPoints = played.handPoints.toMutableList()
         handPoints[teamOf(winner)] = handPoints[teamOf(winner)] + points
 
+        val tricksWon = played.tricksWon.toMutableList()
+        tricksWon[winner] = tricksWon[winner] + 1
+
         val afterTrick = played.copy(
             trick = emptyList(),
             completedTrick = trick,
             handPoints = handPoints,
+            tricksWon = tricksWon,
             leader = winner,
             turn = winner,
             lastTrickWinner = winner,

app/src/main/java/org/prolibertate/games/ui/AppRoot.kt

@@ -26,6 +26,7 @@ import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
@@ -45,6 +46,7 @@ import org.prolibertate.games.net.LobbyController
 import org.prolibertate.games.score.ScorekeeperRepository
 import org.prolibertate.games.settings.Settings
 import org.prolibertate.games.settings.SettingsRepository
+import org.prolibertate.games.ui.game.LocalCardSpeed
 import org.prolibertate.games.update.UpdateChannel
 import org.prolibertate.games.update.Updater
 
@@ -121,14 +123,19 @@ fun AppRoot(env: AppEnv) {
     var splashDone by remember { mutableStateOf(false) }
 
     Box(modifier = Modifier.fillMaxSize()) {
-        AppContent(
-            env = env,
-            settings = settings,
-            stack = stack,
-            showComingSoon = showComingSoon,
-            push = push,
-            pop = pop,
-        )
+        // Card motion reads its speed from here rather than from a parameter.
+        // Every card screen animates, most of them several layers deep, and the
+        // alternative was passing one unchanging number down through all of it.
+        CompositionLocalProvider(LocalCardSpeed provides settings.animationSpeed) {
+            AppContent(
+                env = env,
+                settings = settings,
+                stack = stack,
+                showComingSoon = showComingSoon,
+                push = push,
+                pop = pop,
+            )
+        }
 
         // Over the top, so the menu behind it is already composed when it fades.
         if (!splashDone) {

app/src/main/java/org/prolibertate/games/ui/common/Components.kt

@@ -18,6 +18,7 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.draw.clip
+import androidx.compose.ui.draw.shadow
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.Dp
@@ -41,6 +42,13 @@ fun PlayingCardView(
     width: Dp = 64.dp,
     selected: Boolean = false,
     enabled: Boolean = true,
+    /**
+     * How far off the surface the card is sitting. The default is the thickness
+     * of a card lying on a table, which is what separates a card *on* the felt
+     * from a card painted onto it; a card in flight is raised further by
+     * whatever is animating it.
+     */
+    elevation: Dp = CARD_RESTING_ELEVATION,
     /**
      * Short note printed on the face, for when the rank and suit alone do not
      * say what the card does — a Sequence jack being the obvious case, since
@@ -54,6 +62,7 @@ fun PlayingCardView(
         modifier = modifier
             .width(width)
             .aspectRatio(CARD_ASPECT)
+            .shadow(elevation, RoundedCornerShape(width * 0.12f))
             .clip(RoundedCornerShape(width * 0.12f))
             .background(Color.White)
             .border(
@@ -102,11 +111,13 @@ fun PlayingCardView(
 fun CardBackView(
     modifier: Modifier = Modifier,
     width: Dp = 64.dp,
+    elevation: Dp = CARD_RESTING_ELEVATION,
 ) {
     Box(
         modifier = modifier
             .width(width)
             .aspectRatio(CARD_ASPECT)
+            .shadow(elevation, RoundedCornerShape(width * 0.12f))
             .clip(RoundedCornerShape(width * 0.12f))
             .background(MaterialTheme.colorScheme.primary)
             .border(1.dp, Color(0x33000000), RoundedCornerShape(width * 0.12f)),
@@ -121,3 +132,11 @@ fun CardBackView(
 }
 
 const val CARD_ASPECT = 5f / 7f
+
+/**
+ * A card lying on a surface. Small enough to read as the thickness of a piece
+ * of card rather than as a floating tile — the miniature card backs used as
+ * hand counters are twelve dp wide, and anything heavier turns those into
+ * smudges.
+ */
+val CARD_RESTING_ELEVATION: Dp = 1.5.dp

app/src/main/java/org/prolibertate/games/ui/game/CardPhysics.kt

@@ -0,0 +1,708 @@
+package org.prolibertate.games.ui.game
+
+import androidx.compose.animation.core.Animatable
+import androidx.compose.animation.core.spring
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.BoxScope
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.offset
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.Immutable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.runtime.staticCompositionLocalOf
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.platform.LocalDensity
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.IntOffset
+import androidx.compose.ui.unit.dp
+import kotlin.math.PI
+import kotlin.math.abs
+import kotlin.math.cos
+import kotlin.math.roundToInt
+import kotlin.math.sin
+import kotlinx.coroutines.delay
+import org.prolibertate.games.game.cards.Card
+import org.prolibertate.games.settings.Settings
+import org.prolibertate.games.ui.common.CARD_ASPECT
+import org.prolibertate.games.ui.common.CARD_RESTING_ELEVATION
+import org.prolibertate.games.ui.common.CardBackView
+import org.prolibertate.games.ui.common.PlayingCardView
+
+/**
+ * How cards move.
+ *
+ * A card thrown onto a table does three things that a card faded into place
+ * does not: it arrives from the side of the person who threw it, it overshoots
+ * and rocks back rather than stopping dead, and it comes to rest a little
+ * crooked and a little off the spot it was aimed at. This file is those three
+ * things, and nothing else — no ragdolls, no collisions. Real cards played by
+ * a real hand are only slightly random, and the whole difficulty is in keeping
+ * the randomness *small*: a table where every card lands at a jaunty angle
+ * stops looking like cards and starts looking like a screensaver.
+ *
+ * The randomness is therefore bounded and deterministic. Bounded because every
+ * scatter is a fraction of a card width or a handful of degrees; deterministic
+ * because it is hashed out of the card's own identity rather than drawn from a
+ * generator, which is what stops a card twitching to a new angle every time
+ * something else on the screen recomposes. The same card in the same place
+ * always lies the same way, and two cards never lie the same way as each other.
+ */
+
+// ---------------------------------------------------------------------------
+// Bounds. Every one of these is deliberately smaller than it wants to be.
+// ---------------------------------------------------------------------------
+
+/** Most a settled card is left turned by, in degrees. */
+const val REST_TILT_DEGREES = 4.5f
+
+/** Most a settled card misses its spot by, as a fraction of its own width. */
+const val REST_DRIFT_FRACTION = 0.055f
+
+/**
+ * The same two bounds for a card thrown onto a heap rather than laid in front
+ * of a player, which is a good deal less tidy. They are also what makes a heap
+ * legible: with the tight bounds a discard pile of five cards looks like one
+ * card, because the four underneath are hidden to within a twentieth of a card
+ * width of the top one.
+ */
+const val HEAP_TILT_DEGREES = 8f
+const val HEAP_DRIFT_FRACTION = 0.15f
+
+/** Extra turn a card carries while it is still travelling. */
+const val THROW_SPIN_DEGREES = 15f
+
+/** Tilt of a card held in a hand, where the pack has been squared up. */
+const val HAND_TILT_DEGREES = 1.6f
+
+/** How far off the table a thrown card starts, in card widths. */
+const val THROW_DISTANCE = 2.2f
+
+/** How much bigger a card looks while it is above the table rather than on it. */
+private const val THROW_SCALE = 1.11f
+
+/**
+ * Shadow under a card in flight. What it settles to is the ordinary resting
+ * elevation every other card on the screen already has, read from there rather
+ * than repeated, so a card that has just landed is indistinguishable from one
+ * that has been lying there all along.
+ */
+private const val THROW_ELEVATION_DP = 9f
+private val REST_ELEVATION_DP = CARD_RESTING_ELEVATION.value
+
+/**
+ * Bounce in the settle. Below 1 is an underdamped spring, so the card carries
+ * past its resting place and comes back — which is the whole point. Much below
+ * this and it wobbles like rubber.
+ */
+private const val SETTLE_DAMPING = 0.62f
+
+/** Stiffness that gives [CARD_THROW_MILLIS] at normal speed. */
+private const val SETTLE_STIFFNESS = 420f
+
+/** Nominal flight time of a card, before the animation-speed setting. */
+const val CARD_THROW_MILLIS = 380
+
+/** Nominal time a finished trick takes to be gathered up. */
+const val CARD_SWEEP_MILLIS = 520
+
+/**
+ * How much of the sweep is spent letting the stragglers go. Cards do not all
+ * leave at once when a hand scoops them up, but they do all leave quickly.
+ */
+private const val SWEEP_SPREAD = 0.3f
+
+/**
+ * The last stretch of the sweep, over which a gathered card fades out. It has
+ * to be late: the cards vanish exactly as the winner's pile grows by one, and
+ * that swap is only invisible if they are still whole most of the way there.
+ */
+private const val SWEEP_FADE = 0.42f
+
+/** How small four cards squared into a bundle end up against one card face. */
+private const val GATHERED_SCALE = 0.62f
+
+// ---------------------------------------------------------------------------
+// The pure part: where a card lands, and how far through leaving it is.
+// ---------------------------------------------------------------------------
+
+/**
+ * A hash, not a random number.
+ *
+ * Two rounds of a linear congruential step with a shift between them, which is
+ * more than enough to stop neighbouring seeds producing neighbouring angles —
+ * the visible failure would be a whole suit landing at the same tilt.
+ */
+private fun scramble(seed: Int): Int {
+    var h = seed
+    repeat(2) {
+        h = h * 1_664_525 + 1_013_904_223
+        h = h xor (h ushr 15)
+    }
+    return h
+}
+
+/**
+ * A value in `[-1, 1)` for this [seed] and [salt], stable for the life of the
+ * program and identical between runs. [salt] separates the several independent
+ * numbers one card needs from a single seed.
+ */
+fun unitNoise(seed: Int, salt: Int): Float {
+    val bits = scramble(seed * 31 + salt * 0x5F5F) ushr 8
+    return bits / 8_388_608f - 1f
+}
+
+/** A seed for one card, optionally distinguished by where it is lying. */
+fun cardSeed(card: Card, place: Int = 0): Int =
+    (card.rank.ordinal * 4 + card.suit.ordinal) * 71 + place * 7919
+
+/**
+ * Where a card has come to rest, and how it got there.
+ *
+ * All four scatters come off one seed, so the same card always lies the same
+ * way: [tiltDegrees] and the two drifts are where it ended up, [spinDegrees] is
+ * the turn it was still carrying on the way in, and [lateness] is its place in
+ * the queue when a group of cards moves together.
+ */
+@Immutable
+data class CardRest(
+    val tiltDegrees: Float,
+    val driftX: Float,
+    val driftY: Float,
+    val spinDegrees: Float,
+    val lateness: Float,
+)
+
+/** The resting scatter for [seed], within the bounds set at the top of the file. */
+fun cardRest(
+    seed: Int,
+    tilt: Float = REST_TILT_DEGREES,
+    drift: Float = REST_DRIFT_FRACTION,
+): CardRest = CardRest(
+    tiltDegrees = unitNoise(seed, 1) * tilt,
+    driftX = unitNoise(seed, 2) * drift,
+    driftY = unitNoise(seed, 3) * drift,
+    spinDegrees = unitNoise(seed, 4) * THROW_SPIN_DEGREES,
+    lateness = (unitNoise(seed, 5) + 1f) / 2f,
+)
+
+/**
+ * The same, at the looser bounds a heap gets.
+ *
+ * A card keeps this scatter for as long as it is on the heap, including once
+ * something has been played on top of it. Switching a card to a wider scatter
+ * the moment it stopped being the top card would make it shuffle sideways on
+ * its own, which is the one thing on a table that never happens.
+ */
+fun heapRest(seed: Int): CardRest = cardRest(seed, HEAP_TILT_DEGREES, HEAP_DRIFT_FRACTION)
+
+/** The small tilt of a card sitting in a squared-up hand. */
+fun handTilt(seed: Int): Float = unitNoise(seed, 6) * HAND_TILT_DEGREES
+
+/**
+ * Where a card thrown by a seat comes in from, in card widths, for a four-seat
+ * table where relative seat 0 sits at the bottom and the rest run clockwise.
+ * A card arrives from beyond its own player's edge, which is the direction it
+ * would have been thrown from.
+ */
+fun seatOrigin(relative: Int, distance: Float = THROW_DISTANCE): Pair<Float, Float> =
+    when (relative) {
+        0 -> 0f to distance
+        1 -> -distance to 0f
+        2 -> 0f to -distance
+        else -> distance to 0f
+    }
+
+/**
+ * Where a card lands on a pile from, in card widths, when there is no seat to
+ * read a direction off — a discard pile takes cards from everyone. The angle is
+ * hashed rather than drawn, so a card always arrives from the same side.
+ */
+fun pileOrigin(seed: Int, distance: Float = THROW_DISTANCE): Pair<Float, Float> {
+    val angle = (unitNoise(seed, 7) + 1f) * PI.toFloat()
+    return cos(angle) * distance to sin(angle) * distance
+}
+
+/**
+ * Where a card that has been played *on* lies, given how much ground the cards
+ * now covering it take up — half the width and half the height of it, in
+ * pixels.
+ *
+ * Pushed out towards the edge of that ground rather than scattered evenly
+ * across it. A card buried dead centre under a set of four is a card nobody can
+ * see, and the entire point of still drawing it is that you can tell the heap
+ * has a history. Out at the edge a corner shows, which is what a real heap
+ * looks like from above.
+ */
+fun buriedOffset(seed: Int, halfWidth: Float, halfHeight: Float): Pair<Float, Float> {
+    val angle = (unitNoise(seed, 11) + 1f) * PI.toFloat()
+    // Never right at the rim and never far inside it.
+    val reach = 0.72f + 0.28f * abs(unitNoise(seed, 12))
+    return cos(angle) * halfWidth * reach to sin(angle) * halfHeight * reach
+}
+
+/**
+ * Acceleration curve for cards being dragged off a table: slow to break away,
+ * then gone. Written out rather than taken from an easing class so the sweep
+ * arithmetic stays plain Kotlin and can be tested without a composition.
+ */
+private fun accelerate(x: Float): Float = x * x * (0.35f + 0.65f * x)
+
+/**
+ * How far through leaving a single card is, given how far through the sweep as
+ * a whole is. Cards start over a window of [spread] rather than together, so a
+ * trick gathers up in one motion rather than four cards moving in lockstep.
+ */
+fun sweepProgress(sweep: Float, rest: CardRest, spread: Float = SWEEP_SPREAD): Float {
+    val start = rest.lateness.coerceIn(0f, 1f) * spread.coerceIn(0f, 0.9f)
+    val raw = ((sweep - start) / (1f - start)).coerceIn(0f, 1f)
+    return accelerate(raw)
+}
+
+/** Straight interpolation, [fraction] being free to overshoot past one. */
+fun blend(from: Float, to: Float, fraction: Float): Float =
+    from + (to - from) * fraction
+
+/**
+ * How solid a card being gathered up still is. Whole for most of the journey
+ * and gone at the end of it, so it disappears at the moment the winner's pile
+ * grows rather than dissolving on the way over.
+ */
+fun gatherAlpha(leaving: Float): Float = ((1f - leaving) / SWEEP_FADE).coerceIn(0f, 1f)
+
+/** And how far it has been squared down into the bundle it is joining. */
+fun gatherScale(leaving: Float): Float = blend(1f, GATHERED_SCALE, leaving.coerceIn(0f, 1f))
+
+// ---------------------------------------------------------------------------
+// The Compose part.
+// ---------------------------------------------------------------------------
+
+/**
+ * The animation-speed setting, so card motion follows the same slider as
+ * everything else. A composition local rather than a parameter because it would
+ * otherwise have to be threaded through every card screen and down into every
+ * pile inside them, to say one number that never changes mid-game.
+ */
+val LocalCardSpeed = staticCompositionLocalOf { 1f }
+
+/** A nominal duration, adjusted for the speed the player has chosen. */
+@Composable
+fun motionMillis(nominal: Int): Int {
+    val speed = LocalCardSpeed.current.coerceIn(Settings.MIN_SPEED, Settings.MAX_SPEED)
+    return (nominal / speed).toInt().coerceAtLeast(1)
+}
+
+/**
+ * Where a card is, and what it looks like, part way through being thrown.
+ *
+ * [alpha] is only ever 0 or 1, and only ever 0 for a card waiting its turn in a
+ * set that is being played together. Without it a delayed card would sit
+ * plainly visible two card widths off the table until its moment came, which
+ * reads as a card teleporting out and flying back rather than as one still in
+ * somebody's hand.
+ */
+@Immutable
+data class CardLanding(
+    val offsetX: Float,
+    val offsetY: Float,
+    val rotation: Float,
+    val scale: Float,
+    val elevation: Dp,
+    val alpha: Float = 1f,
+)
+
+/**
+ * Follows one card from the moment it is played until it has stopped moving.
+ *
+ * The whole flight is one underdamped spring on a single 0-to-1 value, and
+ * everything else is read off it. That is why the card overshoots its resting
+ * place and rocks back instead of easing to a halt: the spring passes 1 and
+ * returns, and the position, the angle and the height above the table all
+ * follow it there and back together. Driving them separately was tried and
+ * looked like three animations that happened to start at the same time.
+ *
+ * [key] is what counts as a new card arriving. It must change when the card in
+ * this place changes and at no other time, or the card either fails to animate
+ * or animates again every recomposition.
+ */
+@Composable
+fun rememberCardLanding(
+    key: Any?,
+    rest: CardRest,
+    facingDegrees: Float,
+    fromX: Float,
+    fromY: Float,
+    cardWidthPx: Float,
+    durationMillis: Int,
+    delayMillis: Int = 0,
+): CardLanding {
+    val settle = remember(key) { Animatable(0f) }
+    var launched by remember(key) { mutableStateOf(delayMillis <= 0) }
+    LaunchedEffect(key) {
+        if (delayMillis > 0) {
+            delay(delayMillis.toLong())
+            launched = true
+        }
+        settle.animateTo(
+            targetValue = 1f,
+            animationSpec = spring(
+                dampingRatio = SETTLE_DAMPING,
+                stiffness = SETTLE_STIFFNESS * CARD_THROW_MILLIS / durationMillis,
+            ),
+        )
+    }
+
+    val travelled = settle.value
+    // Height above the table is the one thing that must not overshoot: a card
+    // that has landed cannot rise again, whatever the spring is still doing.
+    val landed = travelled.coerceIn(0f, 1f)
+    return CardLanding(
+        offsetX = blend(fromX, rest.driftX * cardWidthPx, travelled),
+        offsetY = blend(fromY, rest.driftY * cardWidthPx, travelled),
+        rotation = blend(
+            facingDegrees + rest.spinDegrees,
+            facingDegrees + rest.tiltDegrees,
+            travelled,
+        ),
+        scale = blend(THROW_SCALE, 1f, landed),
+        elevation = blend(THROW_ELEVATION_DP, REST_ELEVATION_DP, landed).dp,
+        alpha = if (launched) 1f else 0f,
+    )
+}
+
+/** Puts a card where its [landing] says it is. For cards drawn on their own. */
+fun Modifier.landed(landing: CardLanding): Modifier = this
+    .offset { IntOffset(landing.offsetX.roundToInt(), landing.offsetY.roundToInt()) }
+    .graphicsLayer {
+        scaleX = landing.scale
+        scaleY = landing.scale
+        rotationZ = landing.rotation
+        alpha = landing.alpha
+    }
+
+/** How many cards of a pile are worth drawing. Below this it is not a heap. */
+private const val PILE_DEPTH = 5
+
+/**
+ * How many taken tricks are worth drawing separately. Past this the pile stops
+ * growing rather than climbing off the table — Wizard's last round is twenty
+ * tricks, and twenty bundles of stagger is not a pile, it is a staircase.
+ */
+private const val WON_STACK_DEPTH = 8
+
+/** How far each taken trick sits off the one under it, in card widths. */
+private const val WON_STACK_STEP = 0.045f
+
+/**
+ * The tricks a player has taken, squared up and turned face down in front of
+ * them.
+ *
+ * One card back per trick rather than four, which is what a real table looks
+ * like: a trick is gathered, squared and put down as a single bundle, and from
+ * above you see the top card of each bundle and the edges of the rest. The
+ * count is the pile — it is the thing a player actually glances at to see how
+ * the hand is going, and it is why cards are kept rather than binned.
+ */
+@Composable
+fun WonTrickStack(
+    tricks: Int,
+    width: Dp,
+    modifier: Modifier = Modifier,
+    facingDegrees: Float = 0f,
+    /** Where on the table these were gathered from, in pixels. */
+    fromX: Float = 0f,
+    fromY: Float = 0f,
+) {
+    if (tricks <= 0) return
+
+    val shown = tricks.coerceAtMost(WON_STACK_DEPTH)
+    val step = width * WON_STACK_STEP
+    val widthPx = with(LocalDensity.current) { width.toPx() }
+    val throwMillis = motionMillis(CARD_THROW_MILLIS)
+
+    Box(
+        modifier = modifier
+            .padding(end = step * shown, bottom = step * shown)
+            .width(width)
+            .height(width / CARD_ASPECT),
+    ) {
+        for (bundle in 0 until shown) {
+            key(bundle) {
+                // Each bundle is squared up, not thrown down, so it gets a
+                // fraction of the scatter a played card gets.
+                val rest = cardRest(bundle * 613, tilt = REST_TILT_DEGREES * 0.5f)
+                val top = bundle == shown - 1
+                val landing = if (!top) {
+                    CardLanding(
+                        offsetX = 0f,
+                        offsetY = 0f,
+                        rotation = facingDegrees + rest.tiltDegrees,
+                        scale = 1f,
+                        elevation = REST_ELEVATION_DP.dp,
+                    )
+                } else {
+                    // Only the newest bundle arrives; the ones under it have
+                    // been sitting there since earlier in the hand.
+                    rememberCardLanding(
+                        key = tricks,
+                        rest = rest.copy(driftX = 0f, driftY = 0f),
+                        facingDegrees = facingDegrees,
+                        fromX = fromX,
+                        fromY = fromY,
+                        cardWidthPx = widthPx,
+                        durationMillis = throwMillis,
+                    )
+                }
+                CardBackView(
+                    width = width,
+                    elevation = landing.elevation,
+                    modifier = Modifier
+                        .offset(x = step * bundle, y = step * bundle)
+                        .landed(landing),
+                )
+            }
+        }
+    }
+}
+
+/** How wide a taken-trick pile is drawn against a card on the table. */
+private const val WON_STACK_SCALE = 0.5f
+
+/**
+ * Everyone's taken tricks, at a table of four with partners opposite.
+ *
+ * Each pile sits beside its own player's card, one place clockwise along their
+ * edge, which is both where a real player would put them and the one spot on
+ * each edge that nothing else on the table is using.
+ */
+@Composable
+fun BoxScope.TakenTricks(tricksWon: List<Int>, localSeat: Int, cardWidth: Dp) {
+    val stackWidth = cardWidth * WON_STACK_SCALE
+    val stackWidthPx = with(LocalDensity.current) { stackWidth.toPx() }
+
+    for (seat in 0 until 4) {
+        val relative = ((seat - localSeat) % 4 + 4) % 4
+        val alignment = when (relative) {
+            0 -> Alignment.BottomCenter
+            1 -> Alignment.CenterStart
+            2 -> Alignment.TopCenter
+            else -> Alignment.CenterEnd
+        }
+        val (nudgeX, nudgeY) = when (relative) {
+            0 -> cardWidth * 1.6f to 0.dp
+            1 -> 0.dp to cardWidth * 1.4f
+            2 -> -(cardWidth * 1.6f) to 0.dp
+            else -> 0.dp to -(cardWidth * 1.4f)
+        }
+        // Gathered in from the middle of the table, which is the opposite way
+        // from the edge this player sits at.
+        val (outX, outY) = seatOrigin(relative, 2.5f)
+
+        WonTrickStack(
+            tricks = tricksWon.getOrElse(seat) { 0 },
+            width = stackWidth,
+            facingDegrees = relative * 90f,
+            fromX = -outX * stackWidthPx,
+            fromY = -outY * stackWidthPx,
+            modifier = Modifier.align(alignment).offset(x = nudgeX, y = nudgeY),
+        )
+    }
+}
+
+/**
+ * The same, round a table of any size: each pile sits half a seat clockwise
+ * from its player's card, just inside the ring the cards are played on.
+ */
+@Composable
+fun BoxScope.TakenTricksAround(
+    tricksWon: List<Int>,
+    localSeat: Int,
+    players: Int,
+    cardWidth: Dp,
+    radiusPx: Float,
+) {
+    val stackWidth = cardWidth * WON_STACK_SCALE
+    val stackWidthPx = with(LocalDensity.current) { stackWidth.toPx() }
+
+    for (seat in 0 until players) {
+        val relative = ((seat - localSeat) % players + players) % players
+        val angle = 2.0 * PI * relative / players + PI / players
+        val x = -sin(angle) * radiusPx
+        val y = cos(angle) * radiusPx
+
+        WonTrickStack(
+            tricks = tricksWon.getOrElse(seat) { 0 },
+            width = stackWidth,
+            facingDegrees = relative * 360f / players,
+            fromX = (sin(angle) * stackWidthPx * 2.5f).toFloat(),
+            fromY = (-cos(angle) * stackWidthPx * 2.5f).toFloat(),
+            modifier = Modifier
+                .align(Alignment.Center)
+                .offset { IntOffset(x.roundToInt(), y.roundToInt()) },
+        )
+    }
+}
+
+/**
+ * Trick counts, held back until the cards have actually got there.
+ *
+ * The rules count a trick the instant its last card is played, which is a beat
+ * before the cards are gathered and two before they arrive. Reading the count
+ * straight from the state would grow the winner's pile while the trick was
+ * still lying in the middle of the table, and the cards would then slide over
+ * and land on a pile that had already counted them.
+ */
+@Composable
+fun rememberArrivedTricks(
+    tricksWon: List<Int>,
+    sweeping: Boolean,
+    sweepStarted: Boolean,
+    sweepMillis: Int,
+): List<Int> {
+    var arrived by remember { mutableStateOf(tricksWon) }
+    LaunchedEffect(tricksWon, sweeping, sweepStarted) {
+        // Still on the table waiting to be read: the pile has not won it yet.
+        if (sweeping && !sweepStarted) return@LaunchedEffect
+        if (sweeping) delay(sweepMillis.toLong())
+        arrived = tricksWon
+    }
+    return arrived
+}
+
+/** Holder for [rememberPileWatermark]. Deliberately not snapshot state. */
+private class PileWatermark(var value: Int)
+
+/**
+ * How much of a pile was already lying there rather than played onto it.
+ *
+ * Cards above this line get thrown on; cards below it are simply drawn where
+ * they lie. Two things have to be true and only one of them is obvious. The
+ * obvious one is that a pile you have just opened the screen on was not built
+ * in front of you, so none of it should fly in. The other is that a pile gets
+ * *shorter* between rounds — a new deal replaces a twenty-card heap with a
+ * single turned card — and a mark left at twenty would then sit above every
+ * card of the new round and quietly switch the animation off for the rest of
+ * the game. So the mark follows the pile down, and only ever down.
+ *
+ * A plain holder rather than snapshot state on purpose: this is written and
+ * read within one composition, and it must not be the reason anything
+ * recomposes.
+ */
+@Composable
+private fun rememberPileWatermark(size: Int): Int {
+    val mark = remember { PileWatermark(size) }
+    if (size < mark.value) mark.value = size
+    return mark.value
+}
+
+/**
+ * A pile of cards seen from above.
+ *
+ * Only the top few are drawn, each lying where it fell, which is enough to read
+ * as a heap without painting fifty cards nobody can see. Cards already on the
+ * pile when the screen opens are drawn settled — the pile was built before you
+ * got here — and only cards played after that are thrown on.
+ */
+@Composable
+fun CardPile(
+    cards: List<Card>,
+    width: Dp,
+    modifier: Modifier = Modifier,
+    depth: Int = PILE_DEPTH,
+) {
+    if (cards.isEmpty()) return
+
+    // Position in the pile, not position in the window, so a card keeps its
+    // identity — and so its resting angle — as the window slides past it.
+    val bottom = (cards.size - depth).coerceAtLeast(0)
+    val alreadyDown = rememberPileWatermark(cards.size)
+    val cardWidthPx = with(LocalDensity.current) { width.toPx() }
+    val throwMillis = motionMillis(CARD_THROW_MILLIS)
+
+    // Room for the scatter, so the outermost card is not clipped by whatever
+    // this pile has been placed inside.
+    val margin = width * HEAP_DRIFT_FRACTION
+    Box(
+        modifier = modifier
+            .padding(horizontal = margin, vertical = margin)
+            .width(width)
+            .height(width / CARD_ASPECT),
+    ) {
+        for (index in bottom until cards.size) {
+            key(index) {
+                val card = cards[index]
+                val rest = heapRest(cardSeed(card, index))
+                val landing = if (index < alreadyDown) {
+                    CardLanding(
+                        offsetX = rest.driftX * cardWidthPx,
+                        offsetY = rest.driftY * cardWidthPx,
+                        rotation = rest.tiltDegrees,
+                        scale = 1f,
+                        elevation = REST_ELEVATION_DP.dp,
+                    )
+                } else {
+                    val (fromX, fromY) = pileOrigin(cardSeed(card, index))
+                    rememberCardLanding(
+                        key = index,
+                        rest = rest,
+                        facingDegrees = 0f,
+                        fromX = fromX * cardWidthPx,
+                        fromY = fromY * cardWidthPx,
+                        cardWidthPx = cardWidthPx,
+                        durationMillis = throwMillis,
+                    )
+                }
+                PlayingCardView(
+                    card = card,
+                    width = width,
+                    elevation = landing.elevation,
+                    modifier = Modifier.landed(landing),
+                )
+            }
+        }
+    }
+}
+
+/**
+ * A stock of face-down cards, drawn with enough of the pack under the top card
+ * to show there is something left in it. The offsets are a squared-up deck's
+ * worth — a couple of percent — rather than the scatter a played card gets.
+ */
+@Composable
+fun CardBackStack(
+    count: Int,
+    width: Dp,
+    modifier: Modifier = Modifier,
+    depth: Int = 3,
+) {
+    if (count <= 0) return
+
+    val shown = count.coerceAtMost(depth)
+    val step = width * 0.018f
+    Box(
+        modifier = modifier
+            .padding(end = step * shown, bottom = step * shown)
+            .width(width)
+            .height(width / CARD_ASPECT),
+    ) {
+        // Bottom of the pack first, so the top card is drawn last and sits on top.
+        for (below in (shown - 1) downTo 0) {
+            CardBackView(
+                width = width,
+                elevation = if (below == 0) REST_ELEVATION_DP.dp else 0.dp,
+                modifier = Modifier
+                    .offset(x = step * below, y = step * below)
+                    .rotate(unitNoise(below, 8) * 0.8f),
+            )
+        }
+    }
+}

app/src/main/java/org/prolibertate/games/ui/game/CrazyEightsScreen.kt

@@ -27,6 +27,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.rotate
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
@@ -181,7 +182,10 @@ private fun PileArea(state: CrazyEightsState, cardWidth: Dp) {
                         color = MaterialTheme.colorScheme.onPrimary,
                     )
                 } else {
-                    CardBackView(width = cardWidth)
+                    // A pack, not a single back: the stock is the one thing on
+                    // this screen that is visibly a stack of card, and drawing
+                    // it as one is most of what makes the table look real.
+                    CardBackStack(count = state.stock.size, width = cardWidth)
                 }
             }
             Column(horizontalAlignment = Alignment.CenterHorizontally) {
@@ -190,7 +194,9 @@ private fun PileArea(state: CrazyEightsState, cardWidth: Dp) {
                     style = MaterialTheme.typography.labelSmall,
                     color = MaterialTheme.colorScheme.onPrimary,
                 )
-                state.topCard?.let { PlayingCardView(card = it, width = cardWidth) }
+                // The discard heap rather than only its top card, so a card
+                // played onto it lands on something.
+                CardPile(cards = state.discard, width = cardWidth)
             }
         }
         // An eight on top says nothing about what may be played next, so the
@@ -331,6 +337,7 @@ private fun HandRow(
                     enabled = canPlay,
                     selected = card == pendingWild,
                     caption = if (isWild(card)) "WILD" else null,
+                    modifier = Modifier.rotate(handTilt(cardSeed(card))),
                     onClick = { onTap(card) },
                 )
             }

app/src/main/java/org/prolibertate/games/ui/game/CribbageScreen.kt

@@ -22,13 +22,16 @@ import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.rotate
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
@@ -280,8 +283,34 @@ private fun TableArea(state: CribbageState, localSeat: Int, cardWidth: Dp) {
                         color = ink,
                     )
                 }
-                state.series.forEach { pegged ->
-                    PlayingCardView(card = pegged.card, width = cardWidth * 0.7f)
+                // The series stays on the table until it is counted out, so each
+                // card is laid beside the last rather than replacing it. Keyed
+                // by its place in the series so only the card just pegged is
+                // thrown down.
+                val pegWidth = cardWidth * 0.7f
+                val pegWidthPx = with(LocalDensity.current) { pegWidth.toPx() }
+                val throwMillis = motionMillis(CARD_THROW_MILLIS)
+                state.series.forEachIndexed { place, pegged ->
+                    key(place) {
+                        val seed = cardSeed(pegged.card, place)
+                        val rest = cardRest(seed)
+                        val (fromX, fromY) = pileOrigin(seed)
+                        val landing = rememberCardLanding(
+                            key = place,
+                            rest = rest,
+                            facingDegrees = 0f,
+                            fromX = fromX * pegWidthPx,
+                            fromY = fromY * pegWidthPx,
+                            cardWidthPx = pegWidthPx,
+                            durationMillis = throwMillis,
+                        )
+                        PlayingCardView(
+                            card = pegged.card,
+                            width = pegWidth,
+                            elevation = landing.elevation,
+                            modifier = Modifier.landed(landing),
+                        )
+                    }
                 }
             }
         }
@@ -415,6 +444,7 @@ private fun HandRow(
                     width = cardWidth,
                     enabled = enabled,
                     selected = card in chosen,
+                    modifier = Modifier.rotate(handTilt(cardSeed(card))),
                     onClick = { onTap(card) },
                 )
             }

app/src/main/java/org/prolibertate/games/ui/game/EuchreScreen.kt

@@ -1,5 +1,6 @@
 package org.prolibertate.games.ui.game
 
+import androidx.compose.animation.core.LinearEasing
 import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.animation.core.tween
 import androidx.compose.foundation.background
@@ -25,6 +26,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
@@ -33,6 +35,7 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.IntOffset
@@ -184,9 +187,6 @@ private fun seatLabel(relative: Int): String = when (relative) {
 /** How long a completed trick rests on the table before being swept away. */
 const val TRICK_HOLD_MILLIS = 1_000L
 
-/** Duration of the sweep itself. */
-private const val TRICK_SWEEP_MILLIS = 450
-
 @Composable
 private fun TrickArea(
     state: EuchreState,
@@ -206,9 +206,12 @@ private fun TrickArea(
             sweepStarted = true
         }
     }
+    // Driven linearly, because the shape of the sweep belongs to each card
+    // rather than to the clock: sweepProgress gives them their own start and
+    // their own acceleration off this one value.
     val sweep by animateFloatAsState(
         targetValue = if (sweeping && sweepStarted) 1f else 0f,
-        animationSpec = tween(durationMillis = TRICK_SWEEP_MILLIS),
+        animationSpec = tween(durationMillis = motionMillis(CARD_SWEEP_MILLIS), easing = LinearEasing),
         label = "trickSweep",
     )
 
@@ -220,10 +223,25 @@ private fun TrickArea(
         2 -> 0f to -1f
         else -> 1f to 0f
     }
-    val travelPx = with(LocalDensity.current) { (cardWidth * 2.5f).toPx() }
+    val cardWidthPx = with(LocalDensity.current) { cardWidth.toPx() }
+    val travelPx = cardWidthPx * 2.5f
+    val throwMillis = motionMillis(CARD_THROW_MILLIS)
+
+    // The count follows the cards rather than the rules, so a pile grows as the
+    // trick reaches it and not the moment the last card was played.
+    val arrived = rememberArrivedTricks(
+        tricksWon = state.tricksWon,
+        sweeping = sweeping,
+        sweepStarted = sweepStarted,
+        sweepMillis = motionMillis(CARD_SWEEP_MILLIS),
+    )
 
     Box(modifier = Modifier.fillMaxSize().padding(4.dp)) {
 
+        // What each player has taken, face down in front of them. Drawn first
+        // so a trick still being gathered passes over the pile it is joining.
+        TakenTricks(arrived, localSeat, cardWidth)
+
         // The turn card sits in the middle of the table during bidding.
         state.upCard?.let { up ->
             Column(
@@ -249,45 +267,77 @@ private fun TrickArea(
             )
         }
 
+        // Keyed by seat: one card per seat per trick, so this holds a card's
+        // flight steady while the trick fills up and while the finished trick
+        // is swapped for the copy that gets swept away. Without it the list
+        // position would decide identity and every card would jump back into
+        // the air whenever another one landed.
         cardsOnTable.forEach { played ->
-            val relative = relativePosition(played.seat, localSeat)
-            val alignment = when (relative) {
-                0 -> Alignment.BottomCenter
-                1 -> Alignment.CenterStart
-                2 -> Alignment.TopCenter
-                else -> Alignment.CenterEnd
-            }
-            // Rotate to face the player who played it: the side seats end up
-            // landscape, the partner's card upside down from your side.
-            val rotation = when (relative) {
-                1 -> 90f
-                2 -> 180f
-                3 -> -90f
-                else -> 0f
-            }
+            key(played.seat) {
+                val relative = relativePosition(played.seat, localSeat)
+                val alignment = when (relative) {
+                    0 -> Alignment.BottomCenter
+                    1 -> Alignment.CenterStart
+                    2 -> Alignment.TopCenter
+                    else -> Alignment.CenterEnd
+                }
+                // Turned to face the player who played it: the side seats end
+                // up landscape, the partner's card upside down from your side.
+                val facing = when (relative) {
+                    1 -> 90f
+                    2 -> 180f
+                    3 -> -90f
+                    else -> 0f
+                }
 
-            Column(
-                modifier = Modifier
-                    .align(alignment)
-                    .offset {
-                        IntOffset(
-                            x = (dirX * travelPx * sweep).roundToInt(),
-                            y = (dirY * travelPx * sweep).roundToInt(),
-                        )
-                    }
-                    .alpha(1f - sweep),
-                horizontalAlignment = Alignment.CenterHorizontally,
-            ) {
-                PlayingCardView(
-                    card = played.card,
-                    width = cardWidth,
-                    modifier = Modifier.rotate(rotation),
-                )
-                Text(
-                    text = seatLabel(relative),
-                    style = MaterialTheme.typography.labelSmall,
-                    color = MaterialTheme.colorScheme.onPrimary,
+                val rest = cardRest(cardSeed(played.card, played.seat))
+                val (fromX, fromY) = seatOrigin(relative)
+                val landing = rememberCardLanding(
+                    key = played.card,
+                    rest = rest,
+                    facingDegrees = facing,
+                    fromX = fromX * cardWidthPx,
+                    fromY = fromY * cardWidthPx,
+                    cardWidthPx = cardWidthPx,
+                    durationMillis = throwMillis,
                 )
+                val leaving = sweepProgress(sweep, rest)
+
+                Column(
+                    modifier = Modifier
+                        .align(alignment)
+                        .offset {
+                            IntOffset(
+                                x = (landing.offsetX + dirX * travelPx * leaving).roundToInt(),
+                                y = (landing.offsetY + dirY * travelPx * leaving).roundToInt(),
+                            )
+                        }
+                        .graphicsLayer {
+                            // Squared down into the bundle it is joining, and
+                            // still whole until it gets there.
+                            val gathered = landing.scale * gatherScale(leaving)
+                            scaleX = gathered
+                            scaleY = gathered
+                            alpha = landing.alpha * gatherAlpha(leaving)
+                        },
+                    horizontalAlignment = Alignment.CenterHorizontally,
+                ) {
+                    PlayingCardView(
+                        card = played.card,
+                        width = cardWidth,
+                        elevation = landing.elevation,
+                        // The turn it picks up on the way out is the same turn
+                        // it carried on the way in, so a card leaves the table
+                        // the way it arrived.
+                        modifier = Modifier
+                            .rotate(landing.rotation + rest.spinDegrees * leaving),
+                    )
+                    Text(
+                        text = seatLabel(relative),
+                        style = MaterialTheme.typography.labelSmall,
+                        color = MaterialTheme.colorScheme.onPrimary,
+                    )
+                }
             }
         }
 
@@ -449,6 +499,11 @@ private fun HandRow(
                     card = card,
                     width = cardWidth,
                     enabled = canPlay || canDiscard,
+                    // A hand that has been squared up is still not square. Two
+                    // degrees is below the threshold at which anyone notices a
+                    // tilt and above the one at which a row of cards stops
+                    // looking printed.
+                    modifier = Modifier.rotate(handTilt(cardSeed(card))),
                     onClick = {
                         when {
                             canDiscard -> onPlay(Discard(card))

app/src/main/java/org/prolibertate/games/ui/game/GolfScreen.kt

@@ -252,7 +252,14 @@ private fun StockAndDiscard(
         Column(horizontalAlignment = Alignment.CenterHorizontally) {
             Text("Stock", style = MaterialTheme.typography.labelSmall,
                 color = MaterialTheme.colorScheme.onPrimary)
-            CardBackView(width = cardWidth)
+            // Drawing the pack rather than one back also means an empty stock
+            // now looks empty, where before it showed a card that was not there.
+            if (state.stock.isEmpty()) {
+                Text("empty", style = MaterialTheme.typography.labelSmall,
+                    color = MaterialTheme.colorScheme.onPrimary)
+            } else {
+                CardBackStack(count = state.stock.size, width = cardWidth)
+            }
             if (legal.contains(DrawFromStock)) {
                 Button(onClick = { onMove(DrawFromStock) }) { Text("Draw") }
             }
@@ -261,7 +268,7 @@ private fun StockAndDiscard(
         Column(horizontalAlignment = Alignment.CenterHorizontally) {
             Text("Discard", style = MaterialTheme.typography.labelSmall,
                 color = MaterialTheme.colorScheme.onPrimary)
-            state.discard.lastOrNull()?.let { PlayingCardView(card = it, width = cardWidth) }
+            CardPile(cards = state.discard, width = cardWidth)
             if (legal.contains(DrawFromDiscard)) {
                 Button(onClick = { onMove(DrawFromDiscard) }) { Text("Take") }
             }

app/src/main/java/org/prolibertate/games/ui/game/HeartsScreen.kt

@@ -18,6 +18,7 @@ import androidx.compose.material3.TextButton
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
@@ -25,6 +26,8 @@ import androidx.compose.runtime.snapshots.SnapshotStateList
 import androidx.compose.runtime.mutableStateListOf
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.dp
 import org.prolibertate.games.game.cards.Card
@@ -126,6 +129,7 @@ fun HeartsScreen(
                         selected = chosen.contains(card),
                         enabled = if (selectable) true else playable.contains(card),
                         caption = pointsOf(card).takeIf { it > 0 }?.let { "−$it" },
+                        modifier = Modifier.rotate(handTilt(cardSeed(card))),
                         onClick = {
                             if (selectable) {
                                 toggle(chosen, card)
@@ -188,13 +192,35 @@ private fun TrickView(state: HeartsState) {
         if (showing.isEmpty()) {
             Text("Nothing played yet.", style = MaterialTheme.typography.bodySmall)
         } else {
+            // Hearts lays its trick out in a row rather than round a table, so
+            // there is no seat direction to throw a card in from — each one
+            // comes in from its own side, which the seed decides and keeps.
+            val width = 46.dp
+            val widthPx = with(LocalDensity.current) { width.toPx() }
+            val throwMillis = motionMillis(CARD_THROW_MILLIS)
             FlowRow(horizontalArrangement = Arrangement.spacedBy(4.dp)) {
                 showing.forEach { played ->
-                    PlayingCardView(
-                        card = played.card,
-                        width = 46.dp,
-                        caption = "seat ${played.seat}",
-                    )
+                    key(played.seat) {
+                        val seed = cardSeed(played.card, played.seat)
+                        val rest = cardRest(seed)
+                        val (fromX, fromY) = pileOrigin(seed)
+                        val landing = rememberCardLanding(
+                            key = played.card,
+                            rest = rest,
+                            facingDegrees = 0f,
+                            fromX = fromX * widthPx,
+                            fromY = fromY * widthPx,
+                            cardWidthPx = widthPx,
+                            durationMillis = throwMillis,
+                        )
+                        PlayingCardView(
+                            card = played.card,
+                            width = width,
+                            caption = "seat ${played.seat}",
+                            elevation = landing.elevation,
+                            modifier = Modifier.landed(landing),
+                        )
+                    }
                 }
             }
         }
@@ -214,6 +240,16 @@ private fun ScoreRow(state: HeartsState, localSeat: Int) {
                     style = MaterialTheme.typography.labelSmall,
                     fontWeight = if (seat == localSeat) FontWeight.Bold else FontWeight.Normal,
                 )
+                // The tricks this player has taken, face down in front of them.
+                // Hearts keeps the cards themselves rather than a count, since
+                // it is the cards that are scored at the end of the round, so
+                // the number of tricks is however many players-worth of them
+                // there are.
+                WonTrickStack(
+                    tricks = state.taken.getOrElse(seat) { emptyList() }.size /
+                        state.options.playerCount,
+                    width = 26.dp,
+                )
                 Text("$score", fontWeight = FontWeight.Bold)
                 // What this round has cost so far, which is the number anybody
                 // actually watches while a hand is being played.

app/src/main/java/org/prolibertate/games/ui/game/KaiserScreen.kt

@@ -1,5 +1,6 @@
 package org.prolibertate.games.ui.game
 
+import androidx.compose.animation.core.LinearEasing
 import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.animation.core.tween
 import androidx.compose.foundation.background
@@ -25,6 +26,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
@@ -32,6 +34,7 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.Dp
@@ -181,9 +184,6 @@ private fun seatLabel(relative: Int): String = when (relative) {
     else -> "Right"
 }
 
-/** Duration of the sweep towards the winner. */
-private const val SWEEP_MILLIS = 450
-
 @Composable
 private fun TrickArea(
     state: KaiserState,
@@ -203,7 +203,7 @@ private fun TrickArea(
     }
     val sweep by animateFloatAsState(
         targetValue = if (sweeping && sweepStarted) 1f else 0f,
-        animationSpec = tween(durationMillis = SWEEP_MILLIS),
+        animationSpec = tween(durationMillis = motionMillis(CARD_SWEEP_MILLIS), easing = LinearEasing),
         label = "kaiserSweep",
     )
 
@@ -214,9 +214,25 @@ private fun TrickArea(
         2 -> 0f to -1f
         else -> 1f to 0f
     }
-    val travelPx = with(LocalDensity.current) { (cardWidth * 2.5f).toPx() }
+    val cardWidthPx = with(LocalDensity.current) { cardWidth.toPx() }
+    val travelPx = cardWidthPx * 2.5f
+    val throwMillis = motionMillis(CARD_THROW_MILLIS)
+
+    // Kaiser scores in points rather than tricks, but the cards are still won
+    // and still kept, and how many each player is sitting on is worth seeing.
+    val arrived = rememberArrivedTricks(
+        tricksWon = state.tricksWon,
+        sweeping = sweeping,
+        sweepStarted = sweepStarted,
+        sweepMillis = motionMillis(CARD_SWEEP_MILLIS),
+    )
 
     Box(modifier = Modifier.fillMaxSize().padding(4.dp)) {
+
+        // Drawn first, so a trick still being gathered passes over the pile it
+        // is on its way to joining.
+        TakenTricks(arrived, localSeat, cardWidth)
+
         if (cardsOnTable.isEmpty()) {
             Text(
                 text = when {
@@ -230,43 +246,65 @@ private fun TrickArea(
         }
 
         cardsOnTable.forEach { played ->
-            val relative = relativePosition(played.seat, localSeat)
-            val alignment = when (relative) {
-                0 -> Alignment.BottomCenter
-                1 -> Alignment.CenterStart
-                2 -> Alignment.TopCenter
-                else -> Alignment.CenterEnd
-            }
-            val rotation = when (relative) {
-                1 -> 90f
-                2 -> 180f
-                3 -> -90f
-                else -> 0f
-            }
+            key(played.seat) {
+                val relative = relativePosition(played.seat, localSeat)
+                val alignment = when (relative) {
+                    0 -> Alignment.BottomCenter
+                    1 -> Alignment.CenterStart
+                    2 -> Alignment.TopCenter
+                    else -> Alignment.CenterEnd
+                }
+                val facing = when (relative) {
+                    1 -> 90f
+                    2 -> 180f
+                    3 -> -90f
+                    else -> 0f
+                }
 
-            Column(
-                modifier = Modifier
-                    .align(alignment)
-                    .offset {
-                        IntOffset(
-                            x = (dirX * travelPx * sweep).roundToInt(),
-                            y = (dirY * travelPx * sweep).roundToInt(),
-                        )
-                    }
-                    .alpha(1f - sweep),
-                horizontalAlignment = Alignment.CenterHorizontally,
-            ) {
-                PlayingCardView(
-                    card = played.card,
-                    width = cardWidth,
-                    caption = counterCaption(played.card),
-                    modifier = Modifier.rotate(rotation),
-                )
-                Text(
-                    text = seatLabel(relative),
-                    style = MaterialTheme.typography.labelSmall,
-                    color = MaterialTheme.colorScheme.onPrimary,
+                val rest = cardRest(cardSeed(played.card, played.seat))
+                val (fromX, fromY) = seatOrigin(relative)
+                val landing = rememberCardLanding(
+                    key = played.card,
+                    rest = rest,
+                    facingDegrees = facing,
+                    fromX = fromX * cardWidthPx,
+                    fromY = fromY * cardWidthPx,
+                    cardWidthPx = cardWidthPx,
+                    durationMillis = throwMillis,
                 )
+                val leaving = sweepProgress(sweep, rest)
+
+                Column(
+                    modifier = Modifier
+                        .align(alignment)
+                        .offset {
+                            IntOffset(
+                                x = (landing.offsetX + dirX * travelPx * leaving).roundToInt(),
+                                y = (landing.offsetY + dirY * travelPx * leaving).roundToInt(),
+                            )
+                        }
+                        .graphicsLayer {
+                            val gathered = landing.scale * gatherScale(leaving)
+                            scaleX = gathered
+                            scaleY = gathered
+                            alpha = landing.alpha * gatherAlpha(leaving)
+                        },
+                    horizontalAlignment = Alignment.CenterHorizontally,
+                ) {
+                    PlayingCardView(
+                        card = played.card,
+                        width = cardWidth,
+                        caption = counterCaption(played.card),
+                        elevation = landing.elevation,
+                        modifier = Modifier
+                            .rotate(landing.rotation + rest.spinDegrees * leaving),
+                    )
+                    Text(
+                        text = seatLabel(relative),
+                        style = MaterialTheme.typography.labelSmall,
+                        color = MaterialTheme.colorScheme.onPrimary,
+                    )
+                }
             }
         }
 
@@ -406,6 +444,7 @@ private fun HandRow(
                     width = cardWidth,
                     enabled = canPlay,
                     caption = counterCaption(card),
+                    modifier = Modifier.rotate(handTilt(cardSeed(card))),
                     onClick = { if (canPlay) onPlay(PlayCard(card)) },
                 )
             }

app/src/main/java/org/prolibertate/games/ui/game/PresidentScreen.kt

@@ -1,5 +1,7 @@
 package org.prolibertate.games.ui.game
 
+import androidx.compose.animation.core.animateFloatAsState
+import androidx.compose.animation.core.tween
 import androidx.compose.foundation.background
 import androidx.compose.foundation.horizontalScroll
 import androidx.compose.foundation.layout.Arrangement
@@ -11,7 +13,9 @@ import androidx.compose.foundation.layout.FlowRow
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.offset
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.material3.Button
 import androidx.compose.material3.MaterialTheme
@@ -20,11 +24,17 @@ import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.graphics.graphicsLayer
+import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.IntOffset
 import androidx.compose.ui.unit.dp
+import kotlin.math.roundToInt
 import org.prolibertate.games.game.president.PassTurn
 import org.prolibertate.games.game.president.PlayCards
 import org.prolibertate.games.game.president.PresidentMove
@@ -34,6 +44,7 @@ import org.prolibertate.games.game.president.titleFor
 import org.prolibertate.games.net.MatchController
 import org.prolibertate.games.ui.PrimaryAction
 import org.prolibertate.games.ui.ScreenScaffold
+import org.prolibertate.games.ui.common.CARD_ASPECT
 import org.prolibertate.games.ui.common.CardBackView
 import org.prolibertate.games.ui.common.PlayingCardView
 import org.prolibertate.games.ui.theme.FeltGreenDark
@@ -155,11 +166,7 @@ private fun PileView(state: PresidentState, cardWidth: Dp) {
             style = MaterialTheme.typography.labelSmall,
             color = MaterialTheme.colorScheme.onPrimary,
         )
-        Row(horizontalArrangement = Arrangement.spacedBy(6.dp)) {
-            state.pile.takeLast(state.setSize).forEach { card ->
-                PlayingCardView(card = card, width = cardWidth)
-            }
-        }
+        PileHeap(state, cardWidth)
         Text(
             text = "Beat it with ${state.setSize} card(s)",
             style = MaterialTheme.typography.labelSmall,
@@ -168,6 +175,120 @@ private fun PileView(state: PresidentState, cardWidth: Dp) {
     }
 }
 
+/** How much of what is under the top set is worth drawing. */
+private const val BURIED_DEPTH = 5
+
+/**
+ * The pile, as a pile.
+ *
+ * Every card played since the pile was last cleared is still lying there, and a
+ * new set is played *onto* them rather than instead of them — which is what the
+ * pile is for. Only the top set has to be readable, since that is the one that
+ * has to be beaten, so it is laid out square and side by side; everything under
+ * it is pushed out towards the edge of the ground the top set covers, so a
+ * corner of it shows.
+ *
+ * The whole pile is drawn in one loop keyed by position, which is what lets a
+ * set slide out of the way as the next one lands on it instead of vanishing
+ * from the row and reappearing under the heap. Each card animates from wherever
+ * it actually is to wherever it now belongs, so being buried needs no
+ * bookkeeping about where it used to sit.
+ */
+@Composable
+private fun PileHeap(state: PresidentState, cardWidth: Dp) {
+    val density = LocalDensity.current
+    val cardWidthPx = with(density) { cardWidth.toPx() }
+    val cardHeightPx = cardWidthPx / CARD_ASPECT
+    val gapPx = with(density) { 6.dp.toPx() }
+    val throwMillis = motionMillis(CARD_THROW_MILLIS)
+
+    // Where the cards of the top set sit: centred, side by side.
+    val step = cardWidthPx + gapPx
+    val slotOffset = (state.setSize - 1) / 2f
+
+    // Half the ground the top set covers, which is what the cards underneath
+    // have to get out from under.
+    val halfWidth = (step * state.setSize) / 2f
+    val halfHeight = cardHeightPx * 0.34f
+
+    val lowest = (state.pile.size - state.setSize - BURIED_DEPTH).coerceAtLeast(0)
+
+    Box(
+        modifier = Modifier.size(
+            width = with(density) { (halfWidth * 2f + cardWidthPx * 0.9f).toDp() },
+            height = with(density) { (cardHeightPx + halfHeight * 2f).toDp() },
+        ),
+        contentAlignment = Alignment.Center,
+    ) {
+        for (place in lowest until state.pile.size) {
+            key(place) {
+                val card = state.pile[place]
+                val seed = cardSeed(card, place)
+                val depth = state.pile.size - 1 - place
+                val onTop = depth < state.setSize
+
+                val rest = heapRest(seed)
+                val (buriedX, buriedY) = buriedOffset(seed, halfWidth, halfHeight)
+                val (targetX, targetY) = if (onTop) {
+                    // Slot 0 is the leftmost card of the set, which is the
+                    // deepest of them — they were dealt onto the pile in order.
+                    val slot = state.setSize - 1 - depth
+                    (slot - slotOffset) * step to 0f
+                } else {
+                    buriedX to buriedY
+                }
+
+                val slideSpec = tween<Float>(durationMillis = throwMillis)
+                val x by animateFloatAsState(targetX, slideSpec, label = "pileX")
+                val y by animateFloatAsState(targetY, slideSpec, label = "pileY")
+                // Buried cards are knocked further askew than the tidy set on
+                // top of them, which is the other half of reading as a heap.
+                val tilt by animateFloatAsState(
+                    targetValue = if (onTop) rest.tiltDegrees * 0.4f else rest.tiltDegrees,
+                    animationSpec = slideSpec,
+                    label = "pileTilt",
+                )
+
+                // The throw is relative to wherever the card belongs, so the two
+                // compose: a card lands in its slot, and is later shoved aside
+                // from it without the landing having to know.
+                val (fromX, fromY) = pileOrigin(seed)
+                val landing = rememberCardLanding(
+                    key = place,
+                    rest = rest,
+                    facingDegrees = 0f,
+                    fromX = fromX * cardWidthPx,
+                    fromY = fromY * cardWidthPx,
+                    cardWidthPx = cardWidthPx,
+                    durationMillis = throwMillis,
+                    // A set leaves the hand together and lands one after
+                    // another rather than as a block.
+                    delayMillis = (rest.lateness * throwMillis * 0.3f).toInt(),
+                )
+
+                PlayingCardView(
+                    card = card,
+                    width = cardWidth,
+                    elevation = landing.elevation,
+                    modifier = Modifier
+                        .offset {
+                            IntOffset(
+                                (x + landing.offsetX).roundToInt(),
+                                (y + landing.offsetY).roundToInt(),
+                            )
+                        }
+                        .graphicsLayer {
+                            scaleX = landing.scale
+                            scaleY = landing.scale
+                            rotationZ = tilt + (landing.rotation - rest.tiltDegrees)
+                            alpha = landing.alpha
+                        },
+                )
+            }
+        }
+    }
+}
+
 /** Everyone else, as card counts — their hands are never sent to this device. */
 @Composable
 private fun OpponentRow(state: PresidentState, localSeat: Int) {
@@ -258,7 +379,11 @@ private fun HandView(state: PresidentState, localSeat: Int, cardWidth: Dp) {
                 Text("—", style = MaterialTheme.typography.bodySmall)
             }
             hand.forEach { card ->
-                PlayingCardView(card = card, width = cardWidth * 0.8f)
+                PlayingCardView(
+                    card = card,
+                    width = cardWidth * 0.8f,
+                    modifier = Modifier.rotate(handTilt(cardSeed(card))),
+                )
             }
         }
     }

app/src/main/java/org/prolibertate/games/ui/game/WizardScreen.kt

@@ -1,5 +1,6 @@
 package org.prolibertate.games.ui.game
 
+import androidx.compose.animation.core.LinearEasing
 import androidx.compose.animation.core.animateFloatAsState
 import androidx.compose.animation.core.tween
 import androidx.compose.foundation.background
@@ -26,6 +27,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.key
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
@@ -33,6 +35,7 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.alpha
 import androidx.compose.ui.draw.rotate
+import androidx.compose.ui.graphics.graphicsLayer
 import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.unit.Dp
@@ -190,9 +193,6 @@ private fun BidTally(state: WizardState, localSeat: Int) {
 private fun seatLabel(seat: Int, localSeat: Int): String =
     if (seat == localSeat) "You" else "Seat $seat"
 
-/** Duration of the sweep towards the winner. */
-private const val SWEEP_MILLIS = 450
-
 @Composable
 private fun TrickArea(
     state: WizardState,
@@ -213,7 +213,7 @@ private fun TrickArea(
     }
     val sweep by animateFloatAsState(
         targetValue = if (sweeping && sweepStarted) 1f else 0f,
-        animationSpec = tween(durationMillis = SWEEP_MILLIS),
+        animationSpec = tween(durationMillis = motionMillis(CARD_SWEEP_MILLIS), easing = LinearEasing),
         label = "wizardSweep",
     )
 
@@ -226,7 +226,26 @@ private fun TrickArea(
         // Cards sit on a circle that fits inside whatever space the table has.
         val radius = (minOf(maxWidth, maxHeight) / 2 - cardWidth * 0.7f).coerceAtLeast(0.dp)
         val radiusPx = with(LocalDensity.current) { radius.toPx() }
-        val travelPx = with(LocalDensity.current) { (cardWidth * 2f).toPx() }
+        val cardWidthPx = with(LocalDensity.current) { cardWidth.toPx() }
+        val travelPx = cardWidthPx * 2f
+        val throwMillis = motionMillis(CARD_THROW_MILLIS)
+
+        val arrived = rememberArrivedTricks(
+            tricksWon = state.tricksWon,
+            sweeping = sweeping,
+            sweepStarted = sweepStarted,
+            sweepMillis = motionMillis(CARD_SWEEP_MILLIS),
+        )
+
+        // What each player has taken, face down beside their own place at the
+        // ring. Drawn first so a trick being gathered passes over its pile.
+        TakenTricksAround(
+            tricksWon = arrived,
+            localSeat = localSeat,
+            players = players,
+            cardWidth = cardWidth,
+            radiusPx = radiusPx,
+        )
 
         if (cardsOnTable.isEmpty()) {
             Text(
@@ -241,37 +260,63 @@ private fun TrickArea(
         }
 
         cardsOnTable.forEach { played ->
-            val relative = ((played.seat - localSeat) % players + players) % players
-            val angle = 2.0 * PI * relative / players
-            // Relative seat 0 is you, at the bottom; the rest run clockwise.
-            val x = -sin(angle) * radiusPx
-            val y = cos(angle) * radiusPx
-            // Turn each card to face whoever played it.
-            val rotation = (relative * 360f / players)
+            key(played.seat) {
+                val relative = ((played.seat - localSeat) % players + players) % players
+                val angle = 2.0 * PI * relative / players
+                // Relative seat 0 is you, at the bottom; the rest run clockwise.
+                val x = -sin(angle) * radiusPx
+                val y = cos(angle) * radiusPx
+                // Turn each card to face whoever played it.
+                val facing = (relative * 360f / players)
 
-            Column(
-                modifier = Modifier
-                    .align(Alignment.Center)
-                    .offset {
-                        IntOffset(
-                            x = (x + -sin(winnerAngle) * travelPx * sweep).roundToInt(),
-                            y = (y + cos(winnerAngle) * travelPx * sweep).roundToInt(),
-                        )
-                    }
-                    .alpha(1f - sweep),
-                horizontalAlignment = Alignment.CenterHorizontally,
-            ) {
-                PlayingCardView(
-                    card = played.card,
-                    width = cardWidth,
-                    caption = specialCaption(played.card),
-                    modifier = Modifier.rotate(rotation),
-                )
-                Text(
-                    text = seatLabel(played.seat, localSeat),
-                    style = MaterialTheme.typography.labelSmall,
-                    color = MaterialTheme.colorScheme.onPrimary,
+                // A card comes in along the ray it sits on, from further out —
+                // which on a round table is the direction its player is in,
+                // however many of them there are.
+                val rest = cardRest(cardSeed(played.card, played.seat))
+                val landing = rememberCardLanding(
+                    key = played.card,
+                    rest = rest,
+                    facingDegrees = facing,
+                    fromX = (-sin(angle) * THROW_DISTANCE * cardWidthPx).toFloat(),
+                    fromY = (cos(angle) * THROW_DISTANCE * cardWidthPx).toFloat(),
+                    cardWidthPx = cardWidthPx,
+                    durationMillis = throwMillis,
                 )
+                val leaving = sweepProgress(sweep, rest)
+
+                Column(
+                    modifier = Modifier
+                        .align(Alignment.Center)
+                        .offset {
+                            IntOffset(
+                                x = (x + landing.offsetX +
+                                    -sin(winnerAngle) * travelPx * leaving).roundToInt(),
+                                y = (y + landing.offsetY +
+                                    cos(winnerAngle) * travelPx * leaving).roundToInt(),
+                            )
+                        }
+                        .graphicsLayer {
+                            val gathered = landing.scale * gatherScale(leaving)
+                            scaleX = gathered
+                            scaleY = gathered
+                            alpha = landing.alpha * gatherAlpha(leaving)
+                        },
+                    horizontalAlignment = Alignment.CenterHorizontally,
+                ) {
+                    PlayingCardView(
+                        card = played.card,
+                        width = cardWidth,
+                        caption = specialCaption(played.card),
+                        elevation = landing.elevation,
+                        modifier = Modifier
+                            .rotate(landing.rotation + rest.spinDegrees * leaving),
+                    )
+                    Text(
+                        text = seatLabel(played.seat, localSeat),
+                        style = MaterialTheme.typography.labelSmall,
+                        color = MaterialTheme.colorScheme.onPrimary,
+                    )
+                }
             }
         }
 
@@ -395,6 +440,7 @@ private fun HandRow(
                     width = cardWidth,
                     enabled = canPlay,
                     caption = specialCaption(card),
+                    modifier = Modifier.rotate(handTilt(cardSeed(card))),
                     onClick = { if (canPlay) onPlay(PlayCard(card)) },
                 )
             }

app/src/test/java/org/prolibertate/games/game/kaiser/KaiserRulesTest.kt

@@ -250,6 +250,39 @@ class KaiserRulesTest {
         assertEquals("all four held for display", 4, state.completedTrick.size)
     }
 
+    /**
+     * Kaiser scores in points, not tricks, so nothing in the rules reads this
+     * count — the table does, to draw the cards each player has taken. That is
+     * exactly why it is worth a test: a field no rule depends on is a field
+     * that can quietly stop being maintained.
+     */
+    @Test
+    fun `tricks are counted to the seat that took them`() {
+        // Everything is clubs and nothing is trump, so each trick simply goes
+        // to the highest card in it: the ace, then the king.
+        val hands = listOf(
+            listOf(Card(Rank.ACE, Suit.CLUBS), Card(Rank.SEVEN, Suit.CLUBS)),
+            listOf(Card(Rank.EIGHT, Suit.CLUBS), Card(Rank.NINE, Suit.CLUBS)),
+            listOf(Card(Rank.TEN, Suit.CLUBS), Card(Rank.JACK, Suit.CLUBS)),
+            listOf(Card(Rank.QUEEN, Suit.CLUBS), Card(Rank.KING, Suit.CLUBS)),
+        )
+        var state = playingState(hands, trump = Suit.SPADES)
+        assertEquals("nothing taken at the deal", listOf(0, 0, 0, 0), state.tricksWon)
+
+        repeat(4) {
+            val seat = KaiserRules.currentSeat(state)!!
+            state = KaiserRules.applyMove(state, seat, PlayCard(state.hands[seat].first()))
+        }
+        assertEquals("the ace takes the first", listOf(1, 0, 0, 0), state.tricksWon)
+
+        repeat(4) {
+            val seat = KaiserRules.currentSeat(state)!!
+            state = KaiserRules.applyMove(state, seat, PlayCard(state.hands[seat].first()))
+        }
+        assertEquals("the king takes the second", listOf(1, 0, 0, 1), state.tricksWon)
+        assertEquals("and they add up", 2, state.tricksWon.sum())
+    }
+
     // -- Scoring ------------------------------------------------------------
 
     @Test

app/src/test/java/org/prolibertate/games/ui/game/CardPhysicsTest.kt

@@ -0,0 +1,247 @@
+package org.prolibertate.games.ui.game
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import kotlin.math.abs
+import org.prolibertate.games.game.cards.Card
+import org.prolibertate.games.game.cards.Decks
+import org.prolibertate.games.game.cards.Rank
+import org.prolibertate.games.game.cards.Suit
+
+/**
+ * The scatter under the card animations.
+ *
+ * Two properties matter and neither is visible in a screenshot. It has to be
+ * *bounded*, because the whole difference between cards on a table and cards
+ * thrown down a flight of stairs is the size of the numbers; and it has to be
+ * *stable*, because a card that picks a new angle on every recomposition
+ * twitches, and a card whose angle depends on where it sits in a list jumps
+ * whenever a card is played next to it.
+ */
+class CardPhysicsTest {
+
+    private val deck = Decks.standard52()
+
+    @Test
+    fun `noise stays inside minus one to one`() {
+        for (seed in -500..500) {
+            for (salt in 0..8) {
+                val n = unitNoise(seed, salt)
+                assertTrue("$seed/$salt gave $n", n >= -1f && n < 1f)
+            }
+        }
+    }
+
+    @Test
+    fun `noise is the same every time it is asked`() {
+        assertEquals(unitNoise(12345, 3), unitNoise(12345, 3), 0f)
+        assertEquals(unitNoise(-7, 1), unitNoise(-7, 1), 0f)
+    }
+
+    /**
+     * The salt is what lets one seed produce a tilt, two drifts, a spin and a
+     * queue position that are not all the same number. If it stopped separating
+     * them, every card would drift exactly as far as it tilted.
+     */
+    @Test
+    fun `salts do not agree with each other`() {
+        val fromOneSeed = (0..8).map { unitNoise(4242, it) }
+        assertEquals(fromOneSeed.size, fromOneSeed.toSet().size)
+    }
+
+    /** Sequential seeds are the normal case: adjacent cards in a hand. */
+    @Test
+    fun `neighbouring seeds do not give neighbouring values`() {
+        val runs = (0 until 200).count { abs(unitNoise(it, 1) - unitNoise(it + 1, 1)) < 0.05f }
+        assertTrue("$runs of 200 neighbouring seeds landed together", runs < 30)
+    }
+
+    @Test
+    fun `every card in a deck rests within the stated bounds`() {
+        deck.forEach { card ->
+            val rest = cardRest(cardSeed(card))
+            assertTrue(abs(rest.tiltDegrees) <= REST_TILT_DEGREES)
+            assertTrue(abs(rest.driftX) <= REST_DRIFT_FRACTION)
+            assertTrue(abs(rest.driftY) <= REST_DRIFT_FRACTION)
+            assertTrue(abs(rest.spinDegrees) <= THROW_SPIN_DEGREES)
+            assertTrue(rest.lateness in 0f..1f)
+            assertTrue(abs(handTilt(cardSeed(card))) <= HAND_TILT_DEGREES)
+        }
+    }
+
+    @Test
+    fun `a card lies the same way however often it is asked`() {
+        val card = Card(Rank.QUEEN, Suit.SPADES)
+        assertEquals(cardRest(cardSeed(card)), cardRest(cardSeed(card)))
+        assertEquals(cardRest(cardSeed(card, 3)), cardRest(cardSeed(card, 3)))
+    }
+
+    /**
+     * Two cards lying at the same angle in the same place is the one thing that
+     * makes a scattered pile look printed rather than dealt.
+     */
+    @Test
+    fun `no two cards in a deck share a seed`() {
+        val seeds = deck.map { cardSeed(it) }
+        assertEquals(seeds.size, seeds.toSet().size)
+    }
+
+    /**
+     * A pile can hold the same card twice — Golf and Spider deal more than one
+     * deck — so where a card is lying has to be part of its seed.
+     */
+    @Test
+    fun `the same card in two places lies two ways`() {
+        val card = Card(Rank.SEVEN, Suit.HEARTS)
+        assertNotEquals(cardRest(cardSeed(card, 0)), cardRest(cardSeed(card, 1)))
+    }
+
+    /**
+     * A heap is untidier than a card laid in front of a player, and has to be:
+     * at the tight bounds five cards on a discard pile are hidden to within a
+     * twentieth of a card width of each other and the pile looks like one card.
+     */
+    @Test
+    fun `a heap lies looser than a table but still within bounds`() {
+        deck.forEach { card ->
+            val seed = cardSeed(card)
+            val heap = heapRest(seed)
+            val table = cardRest(seed)
+            assertTrue(abs(heap.tiltDegrees) <= HEAP_TILT_DEGREES)
+            assertTrue(abs(heap.driftX) <= HEAP_DRIFT_FRACTION)
+            assertTrue(abs(heap.driftY) <= HEAP_DRIFT_FRACTION)
+            assertTrue(abs(heap.tiltDegrees) >= abs(table.tiltDegrees))
+            assertTrue(abs(heap.driftX) >= abs(table.driftX))
+        }
+    }
+
+    /**
+     * The two have to agree about everything except how far the card strayed,
+     * or a card would jump when it was drawn one way rather than the other.
+     */
+    @Test
+    fun `a heap and a table agree about the throw`() {
+        deck.take(6).forEach { card ->
+            val seed = cardSeed(card)
+            assertEquals(cardRest(seed).spinDegrees, heapRest(seed).spinDegrees, 0f)
+            assertEquals(cardRest(seed).lateness, heapRest(seed).lateness, 0f)
+        }
+    }
+
+    /**
+     * A buried card has to end up near the rim of whatever is covering it. One
+     * left in the middle is one nobody can see, and then drawing the pile as a
+     * pile achieves nothing.
+     */
+    @Test
+    fun `a buried card ends up out where a corner of it shows`() {
+        deck.forEach { card ->
+            val (x, y) = buriedOffset(cardSeed(card), halfWidth = 100f, halfHeight = 40f)
+            val howFarOut = kotlin.math.hypot(x / 100f, y / 40f)
+            assertTrue("$card sat at $howFarOut of the way out", howFarOut >= 0.719f)
+            assertTrue(howFarOut <= 1.001f)
+        }
+    }
+
+    /** Two cards buried under the same set must not end up in the same place. */
+    @Test
+    fun `buried cards do not stack on each other`() {
+        val places = (0 until 6).map { buriedOffset(cardSeed(deck[it], it), 100f, 40f) }
+        assertEquals(places.size, places.toSet().size)
+    }
+
+    /** Every seat's card arrives from that seat, and from a card-width or two out. */
+    @Test
+    fun `a card comes in from its own player's side`() {
+        assertEquals(0f to THROW_DISTANCE, seatOrigin(0))
+        assertEquals(-THROW_DISTANCE to 0f, seatOrigin(1))
+        assertEquals(0f to -THROW_DISTANCE, seatOrigin(2))
+        assertEquals(THROW_DISTANCE to 0f, seatOrigin(3))
+    }
+
+    @Test
+    fun `a pile card comes in from somewhere off the pile`() {
+        deck.forEach { card ->
+            val (x, y) = pileOrigin(cardSeed(card))
+            val distance = kotlin.math.hypot(x, y)
+            assertEquals(THROW_DISTANCE, distance, 0.001f)
+        }
+    }
+
+    @Test
+    fun `nothing has left the table before the sweep starts`() {
+        deck.take(8).forEach { card ->
+            assertEquals(0f, sweepProgress(0f, cardRest(cardSeed(card))), 0f)
+        }
+    }
+
+    @Test
+    fun `everything has left the table by the end of the sweep`() {
+        deck.take(8).forEach { card ->
+            assertEquals(1f, sweepProgress(1f, cardRest(cardSeed(card))), 0.0001f)
+        }
+    }
+
+    @Test
+    fun `a card only ever gets further from the table`() {
+        val rest = cardRest(cardSeed(Card(Rank.ACE, Suit.CLUBS)))
+        var previous = 0f
+        for (step in 0..100) {
+            val now = sweepProgress(step / 100f, rest)
+            assertTrue("went backwards at $step", now >= previous - 0.0001f)
+            assertTrue(now in 0f..1f)
+            previous = now
+        }
+    }
+
+    /**
+     * The stagger: a trick gathers up as one motion, so the cards must not all
+     * be at the same point in it, and none of them may still be sitting there
+     * when the sweep is nearly over.
+     */
+    @Test
+    fun `cards leave at different moments but none is left behind`() {
+        val hand = deck.take(4).map { cardRest(cardSeed(it)) }
+        val halfway = hand.map { sweepProgress(0.5f, it) }
+        assertEquals(halfway.size, halfway.toSet().size)
+        hand.forEach { assertTrue(sweepProgress(0.95f, it) > 0.5f) }
+    }
+
+    /**
+     * A gathered card has to still be whole when it reaches the winner's pile,
+     * because it vanishes at the same moment the pile grows by one and that
+     * swap is only invisible if there was something there to swap.
+     */
+    @Test
+    fun `a gathered card is whole most of the way and gone at the end`() {
+        assertEquals(1f, gatherAlpha(0f), 0f)
+        assertEquals(1f, gatherAlpha(0.5f), 0f)
+        assertEquals(0f, gatherAlpha(1f), 0f)
+        var previous = 1f
+        for (step in 0..100) {
+            val now = gatherAlpha(step / 100f)
+            assertTrue("went back up at $step", now <= previous + 0.0001f)
+            assertTrue(now in 0f..1f)
+            previous = now
+        }
+    }
+
+    /** And is squared down into the bundle rather than arriving full size. */
+    @Test
+    fun `a gathered card is squared down on the way`() {
+        assertEquals(1f, gatherScale(0f), 0f)
+        assertTrue(gatherScale(1f) < 1f)
+        assertTrue(gatherScale(1f) > 0.5f)
+        assertTrue(gatherScale(0.5f) < gatherScale(0.25f))
+    }
+
+    /** A trick that never completes must not leave a card part way off the table. */
+    @Test
+    fun `a sweep that never starts moves nothing`() {
+        deck.take(4).forEach { card ->
+            assertEquals(0f, sweepProgress(0f, cardRest(cardSeed(card)), spread = 0f), 0f)
+        }
+    }
+}

gradle.properties

@@ -22,4 +22,4 @@ android.nonTransitiveRClass=true
 # Only the series is set by hand. The number after it is the CI run number, so
 # it keeps climbing on its own and an APK's versionCode never goes backwards
 # when this changes.
-plgVersionSeries=1.2
+plgVersionSeries=1.3