eel waving animation capability

objects/enemy/eel.gd

@@ -1,5 +1,6 @@
 extends "res://objects/enemy/enemy.gd"
 
+
 # distance between segments
 const SEGMENT_LENGTH: float = 4.0
 
@@ -7,12 +8,17 @@ const SEGMENT_LENGTH: float = 4.0
 export var segments: int = 8
 # speed eel travels
 export var speed: float = 32.0
+# how far eel travels along path for complete wave
+export var wave_length: float = 0.0
+# intensity in pixels of eel wave animation
+export var wave_amplitude: float = 0.0
 
 var _segments: Array
 
 onready var head: PathFollow2D = $Head
 onready var tail: PathFollow2D = $Tail
 
+
 func _ready() -> void:
 	# get nodes
 	var first_segment: PathFollow2D = $Segment
@@ -36,11 +42,15 @@ func _ready() -> void:
 	first_segment.queue_free()
 	first_segment_shape.queue_free()
 
+
 func _physics_process(delta: float) -> void:
 	# move along path
 	head.offset += speed * delta
 	# position segments accordingly
 	_offset_segments()
+	# waving animation
+	_wave_segments()
+
 
 func _offset_segments() -> void:
 	# put tail at end
@@ -50,6 +60,19 @@ func _offset_segments() -> void:
 		# set segment position based on index and length
 		_segments[i].offset = head.offset - SEGMENT_LENGTH * float(i + 1)
 
+
+func _wave_segments() -> void:
+	# save the effort of looping if nothing will come of it
+	if wave_length == 0.0 and wave_amplitude == 0.0:
+		return
+	for child in get_children():
+		# only affect childent that are pathfollows
+		var segment = child as PathFollow2D
+		if segment:
+			# multiply by tau to use pixels as unit
+			segment.v_offset = sin(segment.offset * TAU / wave_length) * wave_amplitude
+
+
 func die() -> void:
 	# instance death particles for every segment
 	for segment in _segments: