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galaxy-game/ui/docs/game-state.md
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Ilia Denisov ce7a66b3e6 ui/phase-11: map wired to live game state
Replaces the Phase 10 map stub with live planet rendering driven by
`user.games.report`, and wires the header turn counter to the same
data. Phase 11's frontend sits on a per-game `GameStateStore` that
lives in `lib/game-state.svelte.ts`: the in-game shell layout
instantiates one per game, exposes it through Svelte context, and
disposes it on remount. The store discovers the game's current turn
through `lobby.my.games.list`, fetches the matching report, and
exposes a TS-friendly snapshot to the header turn counter, the map
view, and the inspector / order / calculator tabs that later phases
will plug onto the same instance.

The pipeline forced one cross-stage decision: the user surface needs
the current turn number to know which report to fetch, but
`GameSummary` did not expose it. Phase 11 extends the lobby
catalogue (FB schema, transcoder, Go model, backend
gameSummaryWire, gateway decoders, openapi, TS bindings,
api/lobby.ts) with `current_turn:int32`. The data was already
tracked in backend's `RuntimeSnapshot.CurrentTurn`; surfacing it is
a wire change only. Two alternatives were rejected: a brand-new
`user.games.state` message (full wire-flow for one field) and
hard-coding `turn=0` (works for the dev sandbox, which never
advances past zero, but renders the initial state for any real
game). The change crosses Phase 8's already-shipped catalogue per
the project's "decisions baked back into the live plan" rule —
existing tests and fixtures are updated in the same patch.

The state binding lives in `map/state-binding.ts::reportToWorld`:
one Point primitive per planet across all four kinds (local /
other / uninhabited / unidentified) with distinct fill colours,
fill alphas, and point radii so the user can tell them apart at a
glance. The planet engine number is reused as the primitive id so
a hit-test result resolves directly to a planet without an extra
lookup table. Zero-planet reports yield a well-formed empty world;
malformed dimensions fall back to 1×1 so a bad report cannot crash
the renderer.

The map view's mount effect creates the renderer once and skips
re-mount on no-op refreshes (same turn, same wrap mode); a turn
change or wrap-mode flip disposes and recreates it. The renderer's
external API does not yet expose `setWorld`; Phase 24 / 34 will
extract it once high-frequency updates land. The store installs a
`visibilitychange` listener that calls `refresh()` when the tab
regains focus.

Wrap-mode preference uses `Cache` namespace `game-prefs`, key
`<gameId>/wrap-mode`, default `torus`. Phase 11 reads through
`store.wrapMode`; Phase 29 wires the toggle UI on top of
`setWrapMode`.

Tests: Vitest unit coverage for `reportToWorld` (every kind,
ids, styling, empty / zero-dimension edges, priority order) and
for the store lifecycle (init success, missing-membership error,
forbidden-result error, `setTurn`, wrap-mode persistence across
instances, `failBootstrap`). Playwright e2e mocks the gateway for
`lobby.my.games.list` and `user.games.report` and asserts the
live data path: turn counter shows the reported turn,
`active-view-map` flips to `data-status="ready"`, and
`data-planet-count` matches the fixture count. The zero-planet
regression and the missing-membership error path are covered.

Phase 11 status stays `pending` in `ui/PLAN.md` until the local-ci
run lands green; flipping to `done` follows in the next commit per
the per-stage CI gate in `CLAUDE.md`.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-08 21:17:17 +02:00

4.9 KiB

Per-game state store

This document describes the per-game state owned by the in-game shell layout. Phase 11 introduces the store and uses it for two consumers (the header turn counter and the map view); later phases plug inspector tabs, the order composer, and the calculator on top of the same instance.

Lifecycle

routes/games/[id]/+layout.svelte instantiates one GameStateStore per game (the layout remounts when the user navigates to a different game id, so each game gets a fresh store). The layout exposes the instance through Svelte context under GAME_STATE_CONTEXT_KEY; descendants read it via getContext(GAME_STATE_CONTEXT_KEY).

The layout's onMount builds the GalaxyClient, loads Cache through loadStore(), then calls gameState.init({ client, cache, gameId }). init:

  1. installs a visibilitychange listener on document so the report is refreshed when the tab regains focus;
  2. calls setGame(gameId), which:
    • reads the per-game wrap-mode preference from Cache (game-prefs / <gameId>/wrap-mode, default torus);
    • calls lobby.my.games.list and finds the game record (the Phase 11 wire schema extension on GameSummary adds current_turn); if the user is not a member, the store flips to error;
    • calls user.games.report for the discovered turn and decodes the FlatBuffers response into a TS-friendly GameReport shape.

The store exposes:

field type meaning
gameId string active game id
status idle / loading / ready / error current lifecycle state
report GameReport | null latest decoded report, null until first fetch
wrapMode torus / no-wrap per-game preference, persisted via Cache
error string | null localised error message when status === "error"

Phase boundaries

  • Phase 11 surfaces only the planet subset of the report. Later phases extend GameReport and decodeReport as their slice of the wire lands (ships, fleets, sciences, routes, battles, mail).
  • Phase 26 wires history mode through setTurn(turn). The store already supports it; the navigator UI is what is missing.
  • Phase 24 replaces the tab-focus refresh with push-event-driven refreshes; the visibility listener stays as a fallback for background tabs that miss a push.
  • Phase 29 wires the wrap-mode toggle UI on top of setWrapMode.

Why current_turn lives on GameSummary

The user-facing surface needs the current turn number to know which report to fetch. Two alternatives were rejected:

  • a brand-new user.games.state message — adds a full wire-flow (fbs schema, transcoder, gateway routing, backend handler) for a one-field response;
  • hard-coding turn=0 for all games — works for the dev sandbox (which never advances past turn zero) but renders the initial state for any real game past turn zero.

Extending GameSummary reuses the existing lobby pipeline; the backend already tracks current_turn in its runtime projection (backend/internal/server/handlers_user_lobby_helpers.go gameSummaryToWire reads it from g.RuntimeSnapshot.CurrentTurn).

The wire change touches Phase 8's already-shipped catalogue, but the current_turn field defaults to zero on the FB side, so existing tests and the dev sandbox flow continue to work unchanged.

State binding

map/state-binding.ts::reportToWorld(report) translates a GameReport into a renderer-ready World. Phase 11 emits one Point primitive per planet across all four kinds (local / other / uninhabited / unidentified). Each kind gets a distinct fill colour, fill alpha, and point radius so the four classes are visually-distinguishable at a glance; later phases will refine the colour palette as the visual language stabilises (Phase 35 polish).

The planet engine number is reused as the primitive id so a hit-test result can resolve back to a planet without an extra lookup table.

Refresh discipline

refresh() re-fetches the same turn snapshot. It is called by the visibilitychange handler when document.visibilityState === "visible" and the store is already in ready state. The map view's mount effect skips a re-render when the new snapshot's turn matches the previously-mounted turn (and the wrap mode is unchanged), so a no-op refresh does not flicker the canvas.

setTurn(turn) is the entry point for Phase 26 history mode: calling it on a different turn loads that snapshot and the same mount effect re-creates the renderer with the new world.

setWrapMode(mode) writes to Cache and updates the rune; the map view's effect picks the change up and re-mounts the renderer with the new mode.