chore(release): 4.64.2 [skip ci]

## [4.64.2](https://github.com/antialias/soroban-abacus-flashcards/compare/v4.64.1...v4.64.2) (2025-10-22)

### Bug Fixes

* **complement-race:** use individual player positions for ghost trains ([00dc4b1](00dc4b1d06))

CHANGELOG.md

@@ -1,3 +1,31 @@
+## [4.64.2](https://github.com/antialias/soroban-abacus-flashcards/compare/v4.64.1...v4.64.2) (2025-10-22)
+
+
+### Bug Fixes
+
+* **complement-race:** use individual player positions for ghost trains ([00dc4b1](https://github.com/antialias/soroban-abacus-flashcards/commit/00dc4b1d06a4e1763deb16333a298145cafd9187))
+
+## [4.64.1](https://github.com/antialias/soroban-abacus-flashcards/compare/v4.64.0...v4.64.1) (2025-10-22)
+
+
+### Bug Fixes
+
+* **complement-race:** use local player instead of first player for train display ([915d8a5](https://github.com/antialias/soroban-abacus-flashcards/commit/915d8a5343e70a30c7a82bed645e6628fcc08a86))
+
+## [4.64.0](https://github.com/antialias/soroban-abacus-flashcards/compare/v4.63.11...v4.64.0) (2025-10-22)
+
+
+### Features
+
+* **complement-race:** add ghost trains for multiplayer visibility ([7668cc9](https://github.com/antialias/soroban-abacus-flashcards/commit/7668cc9b113b3eae2acb1b852b0ad48c979e6604))
+
+## [4.63.11](https://github.com/antialias/soroban-abacus-flashcards/compare/v4.63.10...v4.63.11) (2025-10-22)
+
+
+### Bug Fixes
+
+* **complement-race:** actually filter by isActive instead of just id ([ef4ca57](https://github.com/antialias/soroban-abacus-flashcards/commit/ef4ca57a6c3f35d1bddc6a70952f478058fbc6b5))
+
 ## [4.63.10](https://github.com/antialias/soroban-abacus-flashcards/compare/v4.63.9...v4.63.10) (2025-10-22)
 
 

apps/web/src/app/arcade/complement-race/components/RaceTrack/GhostTrain.tsx

@@ -0,0 +1,123 @@
+'use client'
+
+import { useEffect, useMemo, useRef } from 'react'
+import type { PlayerState } from '@/arcade-games/complement-race/types'
+import type { RailroadTrackGenerator } from '../../lib/RailroadTrackGenerator'
+
+interface GhostTrainProps {
+  player: PlayerState
+  trainPosition: number
+  trackGenerator: RailroadTrackGenerator
+  pathRef: React.RefObject<SVGPathElement>
+}
+
+/**
+ * GhostTrain - Renders a semi-transparent train for other players in multiplayer
+ * Shows opponent positions in real-time during steam sprint races
+ */
+export function GhostTrain({ player, trainPosition, trackGenerator, pathRef }: GhostTrainProps) {
+  const ghostRef = useRef<SVGGElement>(null)
+
+  // Calculate train transform using same logic as local player
+  const trainTransform = useMemo(() => {
+    if (!pathRef.current) {
+      return { x: 0, y: 0, rotation: 0, opacity: 0 }
+    }
+
+    const pathLength = pathRef.current.getTotalLength()
+    const targetDistance = (trainPosition / 100) * pathLength
+    const point = pathRef.current.getPointAtLength(targetDistance)
+
+    // Calculate tangent for rotation
+    const tangentDelta = 1
+    const tangentDistance = Math.min(targetDistance + tangentDelta, pathLength)
+    const tangentPoint = pathRef.current.getPointAtLength(tangentDistance)
+    const rotation =
+      (Math.atan2(tangentPoint.y - point.y, tangentPoint.x - point.x) * 180) / Math.PI
+
+    return {
+      x: point.x,
+      y: point.y,
+      rotation,
+      opacity: 0.35, // Ghost effect - 35% opacity
+    }
+  }, [trainPosition, pathRef])
+
+  // Log only once when this ghost train first renders
+  const hasLoggedRef = useRef(false)
+  useEffect(() => {
+    if (!hasLoggedRef.current && trainTransform.opacity > 0) {
+      console.log('[GhostTrain] rendering:', player.name, 'at position:', trainPosition.toFixed(1))
+      hasLoggedRef.current = true
+    }
+  }, [trainTransform.opacity, player.name, trainPosition])
+
+  // Don't render if position data isn't ready
+  if (trainTransform.opacity === 0) {
+    return null
+  }
+
+  return (
+    <g
+      ref={ghostRef}
+      data-component="ghost-train"
+      data-player-id={player.id}
+      transform={`translate(${trainTransform.x}, ${trainTransform.y}) rotate(${trainTransform.rotation}) scale(-1, 1)`}
+      opacity={trainTransform.opacity}
+      style={{
+        transition: 'opacity 0.3s ease-in',
+      }}
+    >
+      {/* Ghost locomotive */}
+      <text
+        data-element="ghost-locomotive"
+        x={0}
+        y={0}
+        textAnchor="middle"
+        style={{
+          fontSize: '100px',
+          filter: `drop-shadow(0 2px 8px ${player.color || 'rgba(100, 100, 255, 0.6)'})`,
+          pointerEvents: 'none',
+        }}
+      >
+        🚂
+      </text>
+
+      {/* Player name label - positioned above train */}
+      <text
+        data-element="ghost-label"
+        x={0}
+        y={-60}
+        textAnchor="middle"
+        style={{
+          fontSize: '18px',
+          fontWeight: 'bold',
+          fill: player.color || '#6366f1',
+          filter: 'drop-shadow(0 1px 2px rgba(0, 0, 0, 0.3))',
+          pointerEvents: 'none',
+          transform: 'scaleX(-1)', // Counter the parent's scaleX(-1)
+        }}
+      >
+        {player.name || `Player ${player.id.slice(0, 4)}`}
+      </text>
+
+      {/* Score indicator - positioned below train */}
+      <text
+        data-element="ghost-score"
+        x={0}
+        y={50}
+        textAnchor="middle"
+        style={{
+          fontSize: '14px',
+          fontWeight: 'bold',
+          fill: 'rgba(255, 255, 255, 0.9)',
+          filter: 'drop-shadow(0 1px 2px rgba(0, 0, 0, 0.5))',
+          pointerEvents: 'none',
+          transform: 'scaleX(-1)', // Counter the parent's scaleX(-1)
+        }}
+      >
+        {player.score}
+      </text>
+    </g>
+  )
+}

apps/web/src/app/arcade/complement-race/components/RaceTrack/SteamTrainJourney.tsx

@@ -1,7 +1,7 @@
 'use client'
 
 import { animated, useSpring } from '@react-spring/web'
-import { memo, useMemo, useRef, useState } from 'react'
+import { memo, useEffect, useMemo, useRef, useState } from 'react'
 import { useGameMode } from '@/contexts/GameModeContext'
 import { useUserProfile } from '@/contexts/UserProfileContext'
 import { useComplementRace } from '@/arcade-games/complement-race/Provider'
@@ -20,6 +20,7 @@ import { GameHUD } from './GameHUD'
 import { RailroadTrackPath } from './RailroadTrackPath'
 import { TrainAndCars } from './TrainAndCars'
 import { TrainTerrainBackground } from './TrainTerrainBackground'
+import { GhostTrain } from './GhostTrain'
 
 const BoardingPassengerAnimation = memo(({ animation }: { animation: BoardingAnimation }) => {
   const spring = useSpring({
@@ -92,7 +93,7 @@ export function SteamTrainJourney({
   currentQuestion,
   currentInput,
 }: SteamTrainJourneyProps) {
-  const { state } = useComplementRace()
+  const { state, multiplayerState, localPlayerId } = useComplementRace()
 
   const { getSkyGradient, getTimeOfDayPeriod } = useSteamJourney()
   const _skyGradient = getSkyGradient()
@@ -100,10 +101,20 @@ export function SteamTrainJourney({
   const { players } = useGameMode()
   const { profile: _profile } = useUserProfile()
 
-  // Get the first active player's emoji
-  const activePlayers = Array.from(players.values()).filter((p) => p.id)
-  const firstActivePlayer = activePlayers[0]
-  const playerEmoji = firstActivePlayer?.emoji ?? '👤'
+  // Get the LOCAL player's emoji (not just the first player!)
+  const activePlayers = Array.from(players.values()).filter((p) => p.isActive)
+  const localPlayer = activePlayers.find((p) => p.isLocal)
+  const playerEmoji = localPlayer?.emoji ?? '👤'
+
+  // Log only when localPlayer changes
+  useEffect(() => {
+    console.log(
+      '[SteamTrainJourney] localPlayer:',
+      localPlayer?.name,
+      'isLocal:',
+      localPlayer?.isLocal
+    )
+  }, [localPlayer?.id, localPlayer?.name, localPlayer?.isLocal])
 
   const svgRef = useRef<SVGSVGElement>(null)
   const pathRef = useRef<SVGPathElement>(null)
@@ -164,14 +175,13 @@ export function SteamTrainJourney({
 
   // Memoize filtered passenger lists to avoid recalculating on every render
   // Arcade room multiplayer uses claimedBy/deliveredBy instead of isBoarded/isDelivered
-  // Only show passengers claimed by the first active player
+  // Only show passengers claimed by the LOCAL player
   const boardedPassengers = useMemo(
     () =>
       displayPassengers.filter(
-        (p) =>
-          p.claimedBy === firstActivePlayer?.id && p.claimedBy !== null && p.deliveredBy === null
+        (p) => p.claimedBy === localPlayer?.id && p.claimedBy !== null && p.deliveredBy === null
       ),
-    [displayPassengers, firstActivePlayer?.id]
+    [displayPassengers, localPlayer?.id]
   )
 
   const nonDeliveredPassengers = useMemo(
@@ -191,6 +201,30 @@ export function SteamTrainJourney({
     []
   )
 
+  // Get other players for ghost trains (filter out local player)
+  const otherPlayers = useMemo(() => {
+    if (!multiplayerState?.players || !localPlayerId) {
+      return []
+    }
+
+    const filtered = Object.entries(multiplayerState.players)
+      .filter(([playerId, player]) => playerId !== localPlayerId && player.isActive)
+      .map(([_, player]) => player)
+
+    return filtered
+  }, [multiplayerState?.players, localPlayerId])
+
+  // Log only when otherPlayers count changes
+  useEffect(() => {
+    console.log('[SteamTrainJourney] otherPlayers count:', otherPlayers.length)
+    if (otherPlayers.length > 0) {
+      console.log(
+        '[SteamTrainJourney] ghost positions:',
+        otherPlayers.map((p) => `${p.name}: ${p.position.toFixed(1)}`).join(', ')
+      )
+    }
+  }, [otherPlayers.length, otherPlayers])
+
   if (!trackData) return null
 
   return (
@@ -252,7 +286,18 @@ export function SteamTrainJourney({
           disembarkingAnimations={disembarkingAnimations}
         />
 
-        {/* Train, cars, and passenger animations */}
+        {/* Ghost trains - other players in multiplayer */}
+        {otherPlayers.map((player) => (
+          <GhostTrain
+            key={player.id}
+            player={player}
+            trainPosition={player.position} // Use each player's individual position
+            trackGenerator={trackGenerator}
+            pathRef={pathRef}
+          />
+        ))}
+
+        {/* Train, cars, and passenger animations - local player */}
         <TrainAndCars
           boardingAnimations={boardingAnimations}
           disembarkingAnimations={disembarkingAnimations}

apps/web/src/arcade-games/complement-race/Provider.tsx

@@ -99,6 +99,8 @@ interface CompatibleGameState {
  */
 interface ComplementRaceContextValue {
   state: CompatibleGameState // Return adapted state
+  multiplayerState: ComplementRaceState // Raw multiplayer state for rendering other players
+  localPlayerId: string | undefined // Local player ID for filtering
   dispatch: (action: { type: string; [key: string]: any }) => void // Compatibility layer
   lastError: string | null
   startGame: () => void
@@ -304,12 +306,18 @@ export function ComplementRaceProvider({ children }: { children: ReactNode }) {
 
   // Get local player ID
   const localPlayerId = useMemo(() => {
-    return activePlayers.find((id) => {
+    const foundId = activePlayers.find((id) => {
       const player = players.get(id)
       return player?.isLocal
     })
+    return foundId
   }, [activePlayers, players])
 
+  // Log only when localPlayerId changes
+  useEffect(() => {
+    console.log('[Provider] localPlayerId:', localPlayerId)
+  }, [localPlayerId])
+
   // Debug logging ref (track last logged values)
   const lastLogRef = useState({ key: '', count: 0 })[0]
 
@@ -914,6 +922,8 @@ export function ComplementRaceProvider({ children }: { children: ReactNode }) {
 
   const contextValue: ComplementRaceContextValue = {
     state: compatibleState, // Use transformed state
+    multiplayerState, // Expose raw multiplayer state for ghost trains
+    localPlayerId, // Expose local player ID for filtering
     dispatch,
     lastError,
     startGame,

package.json

@@ -1,6 +1,6 @@
 {
   "name": "soroban-monorepo",
-  "version": "4.63.10",
+  "version": "4.64.2",
   "private": true,
   "description": "Beautiful Soroban Flashcard Generator - Monorepo",
   "workspaces": [