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Diffstat (limited to 'libs')
| -rw-r--r-- | libs/shake_pivot.gd | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/libs/shake_pivot.gd b/libs/shake_pivot.gd new file mode 100644 index 0000000..5794ca0 --- /dev/null +++ b/libs/shake_pivot.gd @@ -0,0 +1,55 @@ +class_name ShakePivot +extends Node2D +## Shakes on command. Use this node as the parent of a sprite or a camera to make it shake! +## Adapted from https://shaggydev.com/2022/02/23/screen-shake-godot/. + +## How quickly to move through the noise. +@export var NOISE_SHAKE_SPEED: float = 20.0 +## How much to multiply the noise values (which are in the range (-1, 1)) by. +@export var NOISE_SHAKE_STRENGTH: float = 15.0 +## Multiplier for lerping the shake strength to zero. +@export var SHAKE_DECAY_RATE: float = 10.0 + +## Object that creates random noise to make for a nice shaking motion. +@onready var _noise := FastNoiseLite.new() + +## Used to keep track of where we are in the noise so we can smoothly move through it. +var noise_i: float = 0.0 +## Value taken from the noise to calculate the shaking node's position. +var shake_strength: float = 0.0 + + +# Called when the node enters the scene tree for the first time. +func _ready() -> void: + # Set noise type to simplex, since the tutorial I'm copying (uh I mean taking inspiration from) + # is for an older version of Godot that had a dedicated simplex noise class + _noise.noise_type = FastNoiseLite.TYPE_SIMPLEX + # Randomize the generated noise + _noise.seed = randi() + # Period affects how quickly the noise changes values + _noise.frequency = 0.5 + + +# Called every frame. 'delta' is the elapsed time since the previous frame. +func _process(delta: float) -> void: + # Fade out the intensity over time + shake_strength = lerp(shake_strength, 0.0, SHAKE_DECAY_RATE * delta) + + # Shake by adjusting position so we can move the object around + position = get_noise_offset(delta) + + +## Uses noise to generate a random 2D vector +func get_noise_offset(delta: float) -> Vector2: + noise_i += delta * NOISE_SHAKE_SPEED + # Set the x values of each call to 'get_noise_2d' to a different value so that our x and y + # vectors will read from unrelated areas of noise + return Vector2( + _noise.get_noise_2d(1, noise_i) * shake_strength, + _noise.get_noise_2d(100, noise_i) * shake_strength + ) + + +## Sets the strength to its initial value. +func shake() -> void: + shake_strength = NOISE_SHAKE_STRENGTH |