Added a dampening (lowpass) spatial audio effect for obstacles between the player and the audio source

core/audio/spatial_audio_player.gd

@@ -1,7 +1,13 @@
 class_name SpatialAudioStreamPlayer2D
 extends AudioStreamPlayer2D
 
-# DETERMINE REVERB AMOUNT
+# EXPORTED VARS
+
+@export var lowpass_cutoff_mult: float = 1000
+@export var lowpass_cutoff_min: float = 100
+@export var dampening_distance_divisor_mult: float = 500
+
+# DETERMINE REVERB EFFECT PARAMETERS
 
 const RAYCAST_VECS: Array[Vector2] = [
 	Vector2(-1, 0),	 # 0 - left
@@ -43,10 +49,10 @@ const REVERB_PAIRS = [
 	[5, 7, REVERB_MULT_90DEG]
 ]
 const REVERB_PAIRS_SUM_DIVISOR = 2500.0 # i dunno
-
 var raycasts: Array[RayCast2D] = []
 
 func create_raycasts():
+	# raycasts used for reverb
 	for v in RAYCAST_VECS:
 		var r = RayCast2D.new()
 		r.target_position = v.normalized() * max_distance
@@ -78,18 +84,53 @@ func determine_reverb_params() -> Array[float]:
 	var wetness = n_coll / 8.0
 	return [room_size, wetness]
 
+# DETERMINE DAMPENING (LOWPASS) EFFECT PARAMETERS
+
+const N_POINTCASTS_TO_PLAYER: int = 25
+const POINTCAST_TO_PLAYER_COLL_MASK: int = 0b00000000_00000000_00000000_00000001
+const LOWPASS_CUTOFF_MAX: float = 20000
+
+func determine_distance_amount_blocked() -> float:
+	# returns how many points (in relation to the amount of points)
+	# between this and the player are intersecting
+	# and therefore an obstacle for the sound
+	var position_player = NodeRegistry.player.global_position
+	var distance_to_player = self.global_position.distance_to(position_player)
+	# get n collisions
+	var n_coll: int = 0
+	# cast points towards player
+	var space_state = get_world_2d().direct_space_state
+	for i in range(N_POINTCASTS_TO_PLAYER):
+		# linear interpolate between own position and player position
+		var point_pos = lerp(self.global_position, position_player, i/float(N_POINTCASTS_TO_PLAYER))
+		var query_params = PhysicsPointQueryParameters2D.new()
+		query_params.collision_mask = POINTCAST_TO_PLAYER_COLL_MASK
+		query_params.position = point_pos
+		var result = space_state.intersect_point(query_params)
+		if len(result) > 0:
+			n_coll += 1
+	return (n_coll*distance_to_player) / (float(N_POINTCASTS_TO_PLAYER)*dampening_distance_divisor_mult)
+
 # AUDIO EFFECTS
 
 var audio_effect_reverb = AudioEffectReverb.new()
+var audio_effect_dampen = AudioEffectLowPassFilter.new()
 
 func update_reverb(room_size: float, wetness: float):
 	audio_effect_reverb.room_size = room_size
 	audio_effect_reverb.wet = wetness
 
+func update_dampening(distance_blocked: float):
+	audio_effect_dampen.cutoff_hz = clamp(
+		lowpass_cutoff_mult / max(0.001, distance_blocked),
+		lowpass_cutoff_min, LOWPASS_CUTOFF_MAX
+	)
+
 # AUDIO BUS
 
 const BUS_NAME_PREFIX = "Spatial2DBus#"
 const BUS_EFFECT_POS_REVERB = 0
+const BUS_EFFECT_POS_LOWPASS = 1
 var bus_idx: int = -1
 var bus_name: String = ""
 
@@ -107,6 +148,8 @@ func create_audio_bus_effects():
 		return
 	# reverb
 	AudioServer.add_bus_effect(bus_idx, audio_effect_reverb, BUS_EFFECT_POS_REVERB)
+	# dampeing (lowpass)
+	AudioServer.add_bus_effect(bus_idx, audio_effect_dampen, BUS_EFFECT_POS_LOWPASS)
 
 #
 
@@ -117,4 +160,6 @@ func _ready() -> void:
 
 func _physics_process(_delta: float) -> void:
 	var reverb_params = determine_reverb_params()
+	var blocked_amount = determine_distance_amount_blocked()
 	update_reverb(reverb_params[0], reverb_params[1])
+	update_dampening(blocked_amount)

levels/intro.tscn

@@ -1,7 +1,9 @@
-[gd_scene load_steps=3 format=3 uid="uid://c6w7lrydi43ts"]
+[gd_scene load_steps=5 format=3 uid="uid://c6w7lrydi43ts"]
 
 [ext_resource type="PackedScene" uid="uid://cbynoofsjcl45" path="res://core/polygon/polygon.tscn" id="1_cup10"]
 [ext_resource type="Script" path="res://levels/intro.gd" id="1_pgj82"]
+[ext_resource type="Script" path="res://core/audio/spatial_audio_player.gd" id="3_3eqhh"]
+[ext_resource type="AudioStream" uid="uid://cs6l2t3jtags8" path="res://assets/sounds/clock-tick-76039.mp3" id="3_6yss2"]
 
 [node name="Intro" type="Node2D"]
 script = ExtResource("1_pgj82")
@@ -30,5 +32,12 @@ color = Color(1, 0.1, 0, 1)
 polygon = PackedVector2Array(416, 400, 416, 424, 440, 424, 440, 400)
 color = Color(0.484431, 0.687354, 1, 1)
 
+[node name="SpatialAudioStreamPlayer2D" type="AudioStreamPlayer2D" parent="."]
+position = Vector2(768, 328)
+stream = ExtResource("3_6yss2")
+volume_db = 15.0
+autoplay = true
+script = ExtResource("3_3eqhh")
+
 [connection signal="body_entered" from="Area2D" to="." method="_on_area_2d_body_entered"]
 [connection signal="body_entered" from="next_level" to="." method="_on_next_level_body_entered"]

player/player.tscn

@@ -1,8 +1,6 @@
-[gd_scene load_steps=6 format=3 uid="uid://ebb4pfxklatj"]
+[gd_scene load_steps=4 format=3 uid="uid://ebb4pfxklatj"]
 
 [ext_resource type="Script" path="res://player/player.gd" id="1_fob34"]
-[ext_resource type="AudioStream" uid="uid://cs6l2t3jtags8" path="res://assets/sounds/clock-tick-76039.mp3" id="2_p4pcw"]
-[ext_resource type="Script" path="res://core/audio/spatial_audio_player.gd" id="3_yaiah"]
 
 [sub_resource type="OccluderPolygon2D" id="OccluderPolygon2D_p33ik"]
 polygon = PackedVector2Array(-9, -9, -9, 9, 9, 9, 9, -9)
@@ -38,9 +36,3 @@ target_position = Vector2(0, -8.1)
 
 [node name="Polygon2D" type="Polygon2D" parent="."]
 polygon = PackedVector2Array(-9, -9, -9, 9, 9, 9, 9, -9)
-
-[node name="SpatialAudioStreamPlayer2D" type="AudioStreamPlayer2D" parent="."]
-stream = ExtResource("2_p4pcw")
-volume_db = 15.0
-autoplay = true
-script = ExtResource("3_yaiah")