Video Game Design and Coding · PLECK lesson

PLECK lesson 55 · suggested week 11, day 5

Validate the puzzle graph

Objective. Test reachability, reset and alternate routes.

Godot Engine Standard desktop editor 4.7.2-stable, GDScript (Godot 4), Compatibility renderer. Headless Godot 4.7.2.stable.official.ed1daf0bf passed 106 assertions on the supplied scaffolds, including malformed JSON saves. Audio used the Dummy driver and a synthetic WAV, not a speaker. The visual editor, browser export, and signed-in submission were not tested. The desk still does not run a student's own upload.

About 55 minutes. The due date is chosen by a parent.

Booleans, truth tables, inventory flags and testable conditions

Suggested pace: Recall and predict 5 min; Read instruction and scaffold 12 min; Build or design the assigned artifact 25 min; Run acceptance tests 8 min; Explain and checkpoint 5 min.

Materials: Godot Standard 4.7.2 desktop editor (GDScript, Compatibility renderer), Local course folder and prior checkpoint, No paid assets or public account required.

Comes after VGC-L054.

A story can contain correct local conditions while its overall graph is broken. Walk every arrow and record the destination, then test whether each required item can be obtained before the gate needs it. Try the least helpful order of actions, not only the ideal route. Check restart after both endings. Use a small route table containing start state, action sequence and expected ending. This is a manual integration test of navigation, state and logic together.

Worked example

A separate practice door might require badge OR helper_present. Test each Boolean combination on paper before using the function to show an Open button. Scaffold C-DIALOGUE — Data-driven branching dialogue without personal data Setup: Create Control root Dialogue with VBoxContainer Box containing Label Line and Buttons A and B. Set Box anchors to full rect; Line autowrap if needed. Attach script to Dialogue. Data keys are fictional scene IDs. All three screens can fit in 640x360. This is a self-contained example; replace story text in the assignment. ```gdscript extends Control var page: String = "start" var story: Dictionary = { "start": {"text": "Two paths enter the archive.", "choices": [["Ask the keeper", "keeper"], ["Read a sign", "sign"]]}, "keeper": {"text": "The keeper offers a map.", "choices": [["Return", "start"]]}, "sign": {"text": "Quiet room to the east.", "choices": [["Return", "start"]]} } func _ready() -> void: $Box/A.pressed.connect(_choose.bind(0)) $Box/B.pressed.connect(_choose.bind(1)) _show() func _show() -> void: var entry: Dictionary = story[page] $Box/Line.text = entry["text"] var buttons: Array[Button] = [$Box/A, $Box/B] for i in range(buttons.size()): buttons[i].visible = i < entry["choices"].size() if buttons[i].visible: buttons[i].text = entry["choices"][i][0] $Box/A.grab_focus() func _choose(index: int) -> void: var choices: Array = story[page]["choices"] if index < 0 or index >= choices.size(): return page = str(choices[index][1]) _show() ``` Scaffold C-PUZZLE — A testable gate rule Setup: Create Node root GateLab and attach this script. The pure gate_open function does not read input or change a scene. A level can call it with its inventory and lever state. Assertions run on start. For the assignment write additional tests before changing the rule. ```gdscript extends Node func gate_open(has_key: bool, lever_on: bool, alarm_on: bool) -> bool: return has_key and lever_on and not alarm_on func _ready() -> void: assert(gate_open(true, true, false)) assert(not gate_open(false, true, false)) assert(not gate_open(true, false, false)) assert(not gate_open(true, true, true)) print("Gate checks passed") ```

Data-driven branching dialogue without personal data

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

Scene and node setup

Create Control root Dialogue with VBoxContainer Box containing Label Line and Buttons A and B. Set Box anchors to full rect; Line autowrap if needed. Attach script to Dialogue. Data keys are fictional scene IDs. All three screens can fit in 640x360. This is a self-contained example; replace story text in the assignment.

extends Control
var page: String = "start"
var story: Dictionary = {
    "start": {"text": "Two paths enter the archive.", "choices": [["Ask the keeper", "keeper"], ["Read a sign", "sign"]]},
    "keeper": {"text": "The keeper offers a map.", "choices": [["Return", "start"]]},
    "sign": {"text": "Quiet room to the east.", "choices": [["Return", "start"]]}
}
func _ready() -> void:
    $Box/A.pressed.connect(_choose.bind(0))
    $Box/B.pressed.connect(_choose.bind(1))
    _show()
func _show() -> void:
    var entry: Dictionary = story[page]
    $Box/Line.text = entry["text"]
    var buttons: Array[Button] = [$Box/A, $Box/B]
    for i in range(buttons.size()):
        buttons[i].visible = i < entry["choices"].size()
        if buttons[i].visible:
            buttons[i].text = entry["choices"][i][0]
    $Box/A.grab_focus()
func _choose(index: int) -> void:
    var choices: Array = story[page]["choices"]
    if index < 0 or index >= choices.size():
        return
    page = str(choices[index][1])
    _show()

Checks to run in the editor

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.

A testable gate rule

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

Scene and node setup

Create Node root GateLab and attach this script. The pure gate_open function does not read input or change a scene. A level can call it with its inventory and lever state. Assertions run on start. For the assignment write additional tests before changing the rule.

extends Node
func gate_open(has_key: bool, lever_on: bool, alarm_on: bool) -> bool:
    return has_key and lever_on and not alarm_on
func _ready() -> void:
    assert(gate_open(true, true, false))
    assert(not gate_open(false, true, false))
    assert(not gate_open(true, false, false))
    assert(not gate_open(true, true, true))
    print("Gate checks passed")

Checks to run in the editor

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.

Validate the puzzle graph — evidence task

  1. 1. Test every story arrow and at least three action orders.
  2. 2. Repair one discovered issue or document a deliberately injected link fault and fix.

Deliverable. Complete graph audit and repaired Archive Lantern checkpoint.

Acceptance checks

Understanding question. Can a correct gate function guarantee the story is completable?

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. Use the C-PUZZLE pure function and a paper truth table before attaching conditions to UI. Start with the first assigned task and re-run its acceptance test before adding the remaining feature.

Optional extra. Find a logically equivalent expression and verify all eight truth-table rows. Document one changed parameter, your prediction, and the observed effect; optional, not required for completion.

Name ____________________ Date ____________________