Track lives with a minimum

Worked example

If phase is TITLE, a scoring event returns immediately. After start_round sets phase PLAY, the same event may add points. One exclusive phase prevents simultaneous WIN and LOSE flags. Scaffold C-STATES — Explicit game states and gated scoring Setup: Attach to Node root StateLab with child Label Status. This is a standalone demonstrator; call start_round, add_points, finish_round from buttons or Remote Inspector. In a real game the manager owns this state. Additional Player and spawner scripts must also honor the manager’s state, or be disabled when finishing. ```gdscript extends Node enum Phase { TITLE, PLAY, WIN, LOSE } var phase: Phase = Phase.TITLE var score: int = 0 func _ready() -> void: _show() func start_round() -> void: score = 0 phase = Phase.PLAY _show() func add_points(amount: int) -> void: if phase != Phase.PLAY: return score += maxi(amount, 0) _show() func finish_round(won: bool) -> void: if phase != Phase.PLAY: return phase = Phase.WIN if won else Phase.LOSE _show() func _show() -> void: $Status.text = "State: %s | Score: %d" % [Phase.keys()[phase], score] ``` Scaffold C-HAZARD — Falling hazard with player notification and cleanup Setup: Area2D Hazard root on layer 4 (bit 8), mask layer 1 only, child CollisionShape2D circle radius 12. Attach this script. Player in group player. A Player damage method is deliberately not hardcoded: connect hit_player to a manager’s damage handler when instantiating. Parent Hazards must be unscaled and unrotated. ```gdscript extends Area2D signal hit_player @export var fall_speed: float = 110.0 var hit: bool = false func _ready() -> void: body_entered.connect(_on_body_entered) func _draw() -> void: draw_rect(Rect2(-12, -12, 24, 24), Color.TOMATO) draw_line(Vector2(-8,-8),Vector2(8,8),Color.BLACK,2.0) func _physics_process(delta: float) -> void: position.y += fall_speed * delta if position.y > 390.0: queue_free() func _on_body_entered(body: Node2D) -> void: if hit or not body.is_in_group("player"): return hit = true hit_player.emit() queue_free() ```

Explicit game states and gated scoring

GDScript (Godot 4, not Scratch, Python, JavaScript or C#). Scaffold C-STATES. Copy starts from this text. The desk does not run it.

Scene and node setup

Attach to Node root StateLab with child Label Status. This is a standalone demonstrator; call start_round, add_points, finish_round from buttons or Remote Inspector. In a real game the manager owns this state. Additional Player and spawner scripts must also honor the manager’s state, or be disabled when finishing.

extends Node
enum Phase { TITLE, PLAY, WIN, LOSE }
var phase: Phase = Phase.TITLE
var score: int = 0
func _ready() -> void:
    _show()
func start_round() -> void:
    score = 0
    phase = Phase.PLAY
    _show()
func add_points(amount: int) -> void:
    if phase != Phase.PLAY:
        return
    score += maxi(amount, 0)
    _show()
func finish_round(won: bool) -> void:
    if phase != Phase.PLAY:
        return
    phase = Phase.WIN if won else Phase.LOSE
    _show()
func _show() -> void:
    $Status.text = "State: %s | Score: %d" % [Phase.keys()[phase], score]

Checks to run in the editor

• Calling add_points before start does not change score.
• After finish_round, extra score events do nothing.

Native Godot 4.7.2.stable.official.ed1daf0bf headless compile and representative node-tree/runtime tests passed; see native-qa-results.json. Visual UI, audible output, exports and website submission still need separate checks.

Falling hazard with player notification and cleanup

GDScript (Godot 4, not Scratch, Python, JavaScript or C#). Scaffold C-HAZARD. Copy starts from this text. The desk does not run it.

Scene and node setup

Area2D Hazard root on layer 4 (bit 8), mask layer 1 only, child CollisionShape2D circle radius 12. Attach this script. Player in group player. A Player damage method is deliberately not hardcoded: connect hit_player to a manager’s damage handler when instantiating. Parent Hazards must be unscaled and unrotated.

extends Area2D
signal hit_player
@export var fall_speed: float = 110.0
var hit: bool = false
func _ready() -> void:
    body_entered.connect(_on_body_entered)
func _draw() -> void:
    draw_rect(Rect2(-12, -12, 24, 24), Color.TOMATO)
    draw_line(Vector2(-8,-8),Vector2(8,8),Color.BLACK,2.0)
func _physics_process(delta: float) -> void:
    position.y += fall_speed * delta
    if position.y > 390.0:
        queue_free()
func _on_body_entered(body: Node2D) -> void:
    if hit or not body.is_in_group("player"):
        return
    hit = true
    hit_player.emit()
    queue_free()

Checks to run in the editor

• Hazard moves downward and disappears beyond y390.
• One overlap emits one damage event.

Native Godot 4.7.2.stable.official.ed1daf0bf headless compile and representative node-tree/runtime tests passed; see native-qa-results.json. Visual UI, audible output, exports and website submission still need separate checks.

Track lives with a minimum — evidence task

1. 1. Add lives=3 and a damage handler with Play-state guard and clampi.
2. 2. Test one hit, three hits and an extra hit after zero.

Deliverable. Lives implementation and boundary-test log.

Acceptance checks

• VGC-L036-T1. Lives follow 3,2,1,0 and never become negative.
• VGC-L036-T2. Damage outside Play leaves lives unchanged.

Understanding question. Is changing the Label text to zero enough to end the game?

Include a downloadable project ZIP with project.godot, .tscn, .gd and original asset files when code changes. A private, teacher-accessible download link to that ZIP is equivalent. Screenshots or a playthrough do not replace editable source.

If this is still shaky. Print lives and phase in one Label before adding effects. Restrict every gameplay handler to the Play state. Start with the first assigned task and re-run its acceptance test before adding the remaining feature.

Optional extra. Test simultaneous end conditions and write a deliberate tie policy. Document one changed parameter, your prediction, and the observed effect; optional, not required for completion.

Turn in typed notes and a JPEG, PNG, or WebP screenshot. One https address is stored as text and is not opened, extracted, or run. An MP3, WAV, M4A, MP4, or WebM file up to 4 MB can show a demo. The demo does not replace editable source. Zip and code files are refused. If there is no private link, keep the project on the family computer and review the code in person.

• Your first 2D game

  Free public tutorial; no account; external asset download is optional, not used by this course.

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