01 Prototype 01 Hud Pass

Implementation notes

VolleyTracker not extracted. The design specified extracting volley logic into scripts/volley_tracker.gd for unit testability. This was skipped, game.gd emits signals (volley_count_changed, personal_best_changed) which the scene wires to the HUD directly. Integration tests cover the same behaviour through signals, making the extra class unnecessary indirection.

Goal

Complete the volley tracking system and display it properly in the HUD. This is the foundation that Progression System and Ball Scaling build on.

Points: 2 Dependencies: Pong Prototype (done) Unlocks: Ball Scaling, Progression System (friendship display, high score persistence)

Current state

• Ball emits paddle_hit on paddle contact, working
• game.gd counts volleys inline and writes directly to a CanvasLayer/Label, bypasses hud.gd
• hud.gd exists with update_volley_count() but is not wired up
• No miss detection, no volley reset, no high score tracking
• No VolleyTracker class

Scope

In scope

1. Volley reset on miss
2. High score tracking (session only, persistence comes with Progression System)
3. VolleyTracker refactor
4. HUD wiring and high score display

Out of scope

• Friendship display (Progression System)
• Streak-based visual feedback or animations (UI Polish in v0.5)
• Ball speed changes during streak (Ball Scaling)
• Save/load of high score (Progression System)

Features

1. Volley reset on miss

Design: Define what counts as a miss, ball contacts the left or right wall. Tech: Add ball_missed signal to ball.gd, emitted on left/right wall contact. game.gd connects this to reset the volley count.

2. High score tracking

Design: High score is the best volley streak in the current session. Resets when the game closes (persistence deferred to Progression System). Tech: Track best streak, update when current streak exceeds it.

3. VolleyTracker refactor

Tech: Extract volley logic from game.gd into scripts/volley_tracker.gd. Pure logic class (no node dependencies), unit-testable.

• hit(), increment current streak
• reset(), save high score if beaten, reset streak to 0
• current_streak: int, current volley count
• high_score: int, best streak

game.gd owns a VolleyTracker instance, connects ball signals to it, and updates HUD on changes.

4. HUD wiring and high score display

Design: Layout, volley count top center, high score below it. Tech:

• Add high score label to hud.tscn
• Wire game.gd to call hud.gd methods instead of writing to the label directly
• hud.gd exposes update_volley(count: int) and update_high_score(score: int)

Architecture

VolleyTracker (scripts/volley_tracker.gd)
  - current_streak: int
  - high_score: int
  - hit() -> void
  - reset() -> void

Ball (scripts/ball.gd)
  - signal paddle_hit      (existing)
  - signal ball_missed      (new)

HUD (scripts/hud/hud.gd)
  - update_volley(count: int)
  - update_high_score(score: int)

game.gd
  - Owns VolleyTracker instance
  - Connects ball signals to tracker
  - Updates HUD on changes

Test plan

• Unit: VolleyTracker, hit increments, reset clears streak, high score persists across resets, high score only updates when beaten
• In-game: volley count increments on paddle hit, resets on wall miss, high score updates and survives streak resets
• Integration: game.gd no longer writes to labels directly, all HUD updates go through hud.gd