Video Game Design and Coding · PLECK lesson

PLECK lesson 49 · suggested week 10, day 4

Connect choices without duplicate handlers

Objective. Bind button indexes and update a view from state.

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.

Branch diagrams, dialogue data, containers and keyboard focus

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-L048.

A button’s pressed signal does not say which story choice it represents. C-DIALOGUE binds index zero or one when connecting each button. _choose looks up the current page’s choices, validates the index, changes page and refreshes the view. _show hides an unused second button on one-choice pages. Connect buttons once in _ready; repeatedly connecting every time a passage is shown can trigger multiple transitions from one press. The page variable is state and the label is only its view.

Worked example

A passage with key entrance can display any original sentence. Its choice ["Read the note", "note"] links to a stable note key even if the sentence is later edited. 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() ```

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.

Connect choices without duplicate handlers — evidence task

  1. 1. Implement the story with C-DIALOGUE’s connection pattern.
  2. 2. Visit both branches and return repeatedly.

Deliverable. Runnable branching-story project and repeat-navigation log.

Acceptance checks

Understanding question. Why connect once rather than inside _show?

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 three screens and two buttons with C-DIALOGUE. Draw every link before writing dialogue. Start with the first assigned task and re-run its acceptance test before adding the remaining feature.

Optional extra. Create a branch that rejoins the main path while preserving a meaningful choice. Document one changed parameter, your prediction, and the observed effect; optional, not required for completion.

Name ____________________ Date ____________________