Ferrous-Solitaire/docs/superpowers/plans/2026-04-23-phase3-bevy-rendering.md

Phase 3 — Bevy Rendering & Interaction

Status: In progress (started 2026-04-23) Crate: solitaire_engine Depends on: solitaire_core (complete), bevy = 0.15, bevy_egui = 0.30

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Scope

Make the game playable with a graphical interface. This phase takes solitaire_engine from an empty stub to a full Bevy rendering + input layer wired to solitaire_core::GameState.

Out of scope (later phases):

• Persistence (StatsSnapshot, file I/O) — Phase 4
• Achievements toast content — Phase 5
• Audio — Phase 7
• Sync — Phase 8

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Sub-phases

3A — Plumbing & event wiring

Modules under solitaire_engine/src/:

• lib.rs — re-exports plugins, types
• resources.rs
  • GameStateResource(pub GameState) — wraps solitaire_core::GameState directly (no solitaire_data layer yet)
  • DragState { cards: Vec<u32>, origin_pile: PileType, cursor_offset: Vec2, origin_z: f32 } (starts empty)
  • SyncStatusResource(pub SyncStatus) where SyncStatus is Idle|Syncing|LastSynced(DateTime<Utc>)|Error(String)
• events.rs
  • MoveRequestEvent { from: PileType, to: PileType, count: usize }
  • DrawRequestEvent
  • UndoRequestEvent
  • NewGameRequestEvent { seed: Option<u64> }
  • StateChangedEvent
  • GameWonEvent { score: i32, time_seconds: u64 }
  • CardFlippedEvent(pub u32)
  • AchievementUnlockedEvent(pub AchievementRecord) — placeholder, unused until Phase 5
• game_plugin.rs — GamePlugin:
  • On Startup: init GameStateResource::new(system_time_seed, DrawMode::DrawOne)
  • Systems: handle_draw, handle_move, handle_undo, handle_new_game
  • Each fires StateChangedEvent on success; GameWonEvent when check_win() flips to true
  • Errors: log via tracing, do not panic
• Register in solitaire_app/src/main.rs

Tests: event-routing unit tests that drive GamePlugin in a headless App::new() and verify resource mutations.

Exit: cargo test --workspace green, cargo clippy --workspace -- -D warnings clean. Running the app still shows a blank window (no rendering yet), but pressing nothing crashes anything.

Commit: feat(engine): add resources, events, and GamePlugin event routing

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3B — Layout + TablePlugin

Modules:

• layout.rs — pure function compute_layout(window: Vec2) -> Layout
  • Layout { card_size: Vec2, pile_positions: HashMap<PileType, Vec2> }
  • card_width = window.x / 9.0
  • card_height = card_width * 1.4
  • Row 1: stock, waste, [gap], 4 foundations
  • Row 2: 7 tableau columns below
• LayoutResource(pub Layout) — a Bevy resource
• table_plugin.rs — TablePlugin:
  • Spawns background rectangle (dark green #0f5132)
  • Spawns 13 PileMarker sprite entities for empty-pile placeholders
  • System on_window_resized: recompute LayoutResource, reposition pile markers

Tests: compute_layout at 800×600, 1280×800, 1920×1080 — all 13 piles within bounds, non-overlapping.

Exit: Window shows a green table with 13 translucent pile outlines that resize with the window.

Commit: feat(engine): add layout, LayoutResource, and TablePlugin

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3C — CardPlugin rendering (procedural)

Decision: Phase 3 uses procedural cards (rounded white rectangle + rank/suit text). Real PNG assets can be slotted in later by replacing the sprite setup; API shape stays stable.

Modules:

• card_plugin.rs — CardPlugin:
  • Component CardEntity { card_id: u32 }
  • StateChangedEvent handler: sync entities with GameStateResource — spawn missing, despawn removed, reposition all
  • Position: LayoutResource.pile_positions[pile] + Vec3::Z * stack_index
  • Face-up: white rect + text of rank+suit glyph (red for hearts/diamonds, black for clubs/spades)
  • Face-down: blue rect with a subtle pattern overlay
  • No assets loaded — text uses Bevy's default font (or shipped system font if needed)

Exit: A freshly dealt game renders — stock (24 cards face-down), 7 tableau columns in standard 1/2/3/.../7 face-down + 1 face-up, empty foundations.

Commit: feat(engine): add CardPlugin with procedural card rendering

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3D — Keyboard input & click-to-draw

Modules:

• input_plugin.rs — InputPlugin:
  • Keyboard system: KeyCode::KeyU → UndoRequestEvent, KeyN → NewGameRequestEvent{seed: None}, KeyD → DrawRequestEvent, Escape → pause-stub event
  • Mouse system: on left-click, if cursor over stock pile → DrawRequestEvent

Exit: Pressing D cycles stock↔waste on-screen; N deals a new game; U undoes.

Commit: feat(engine): add InputPlugin with keyboard and stock-click

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3E — Drag & drop

Modules:

• Extend input_plugin.rs with drag systems:
  • start_drag: on left mouse-down, ray-hit the top card (or run of face-up cards) of a pile; populate DragState; elevate z
  • follow_cursor: while DragState.cards non-empty, move those entities to cursor position + per-card stack offset
  • end_drag: on mouse-up, determine target pile; early-validate with can_place_on_tableau / can_place_on_foundation; fire MoveRequestEvent (backend also validates)
  • On MoveError via StateChangedEvent non-emission: snap cards back with a short lerp (uses CardAnim from 3F)
• Multi-card tableau drag: grabbing card N pulls N..=top if all face-up

Exit: Full game playable with mouse. GameWonEvent fires on a win. No animations yet on invalid drop (just snap back instantly in 3E, smooth in 3F).

Commit: feat(engine): add drag-and-drop input with multi-card tableau support

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3F — AnimationPlugin (polish)

Modules:

• animation_plugin.rs — AnimationPlugin:
  • Component CardAnim { start: Vec3, target: Vec3, elapsed: f32, duration: f32 } — linear lerp 0.15s for moves
  • Flip: CardFlip { elapsed: f32, duration: f32, flips_to_face_up: bool } — scale-X 1→0→1 over 0.2s, toggle face_up at midpoint, fire CardFlippedEvent
  • Win cascade: on GameWonEvent, iterate foundation cards and schedule CardAnim to random off-screen targets with staggered 0.05s starts
  • Toast component scaffold: egui popup placeholder, wired to AchievementUnlockedEvent (no content yet)

Exit: Valid moves animate smoothly; flipping a tableau card shows a flip; winning plays a cascade.

Commit: feat(engine): add AnimationPlugin with slide, flip, and win cascade

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Cross-cutting rules

• solitaire_core and solitaire_sync gain NO new dependencies.
• No unwrap() / panic!() in new Bevy systems — log errors via tracing::warn! and continue.
• cargo test --workspace and cargo clippy --workspace -- -D warnings green after EVERY sub-phase.
• Every commit follows type(scope): description convention.
• One Plugin per responsibility; cross-system communication is Events only.

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Open questions resolved

• Procedural vs. sourced card art: procedural for Phase 3.
• GameStateResource layer: wraps solitaire_core::GameState directly.
• Phases 4–8 plugins (Audio/UI/Achievement/Sync): not in Phase 3.
• New-game seed: system time when None, explicit when Some(u64).
• Commit cadence: one per sub-phase.

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Risks

• Bevy 0.15 API drift from older tutorials — verify each API call as written.
• bevy_egui 0.30 may require slightly different system ordering than earlier versions — pin to workspace versions, don't downgrade.
• Procedural card text depends on Bevy's default font; if rendering is unreadable, drop in a .ttf to assets/fonts/main.ttf as a follow-up (still Phase 3, not 3F).