giants-godot/addons/Trail/trail_2d.gd

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2021-09-08 18:36:41 +02:00
"""
Author: Oussama BOUKHELF
License: MIT
Version: 0.1
Email: o.boukhelf@gmail.com
Description: Advanced 2D/3D Trail system.
Note: This is a simple implementation, I will update it later on.
"""
extends Line2D
export(bool) var emit := true
export(float) var lifetime := 0.5
export(float) var distance := 20.0
export(int) var segments := 20
var target
var trail_points := []
var offset := Vector2()
class Point:
var position := Vector2()
var age := 0.0
func _init(position :Vector2, age :float) -> void:
self.position = position
self.age = age
func update(delta :float, points :Array) -> void:
self.age -= delta
if self.age <= 0:
points.erase(self)
func _ready():
offset = position
show_behind_parent = true
target = get_parent()
clear_points()
set_as_toplevel(true)
position = Vector2()
func _emit():
var _rotated_offset :Vector2 = offset.rotated(target.rotation)
var _position :Vector2 = target.global_transform.origin + _rotated_offset
var point = Point.new(_position, lifetime)
if trail_points.size() < 1:
trail_points.push_back(point)
return
if trail_points[-1].position.distance_squared_to(_position) > distance*distance:
trail_points.push_back(point)
update_points()
func update_points() -> void:
var delta = get_process_delta_time()
if trail_points.size() > segments:
trail_points.invert()
trail_points.resize(segments)
trail_points.invert()
clear_points()
for point in trail_points:
point.update(delta, trail_points)
# if point:
add_point(point.position)
func _process(delta):
if emit:
_emit()