compsci_godot_albert/_subsections/sec03/lesson-30.org

Section 03 - Lesson 30 | Section Review

• Links
• Notes
  • paddle scene
    • node composition
    • script view: paddle.gd
      • use @export to create speed variable
      • override _process function
  • gem scene
    • node composition
    • script view: gem.gd
      • set class name
      • set a signal property
      • set export property
    • modify _process
      • determine if the gem has gone out of bounds
      • if gem went out of bounds
        • emit signal
        • stop the gem and remove it from the node tree
  • Game scene

Links

• TOC - Godot Notes
• S03:L42.30 - Section Review

Notes

paddle scene

node composition

• root: Area2D
• Sprite2D
• CollisionShape2D

script view: paddle.gd

• extends Area2D

use @export to create speed variable

• can be modified in Inspector
• give default value

override _process function

• check if Input.is_action_pressed

  • is 'left'
  • is 'right'

• move paddle

  • get the Node2D.position property

    • multiply speed by delta and add or subtract it from position.x
    • delta is number of seconds that elapsed since the previous frame

gem scene

node composition

• root: Area2D
• Sprite2D
• CollisionShape2D

script view: gem.gd

• extends Area2D

set class name

• class_name Gem
• this allows us to instantiate Gem objects in scripts

set a signal property

• signal on_gem_off_screen
• allows us to attach listeners who will be notified when we emit a signal

set export property

• @export var speed
• lets us set the speed in the Inspector

modify _process

determine if the gem has gone out of bounds

• this is going to be the edge of the viewport

• check position property against the viewport rect property

  if position.y > get_viewport_rect().size.y

if gem went out of bounds

emit signal

on_gem_off_screen.emit()

stop the gem and remove it from the node tree

• stop going through the process function
• delete node at the end of the current frame

set_process(false)
queue_free()

Game scene