add tire trails

scenes/car.tscn

@@ -1,10 +1,10 @@
-[gd_scene load_steps=48 format=3 uid="uid://0g7qqh7naniv"]
+[gd_scene load_steps=49 format=3 uid="uid://0g7qqh7naniv"]
 
 [ext_resource type="Script" path="res://scripts/car_node.gd" id="1_0tin3"]
 [ext_resource type="Script" path="res://scripts/car.gd" id="1_i5tet"]
 [ext_resource type="Texture2D" uid="uid://mqdujngircok" path="res://sprites/car_features.png" id="3_ts6mm"]
 [ext_resource type="Texture2D" uid="uid://e5aeyl47wi8p" path="res://sprites/car_body.png" id="4_lps13"]
-[ext_resource type="PackedScene" uid="uid://c3fdxjrpcgnnp" path="res://scenes/tire_trail.tscn" id="5_2bgdv"]
+[ext_resource type="Script" path="res://scripts/tiretrails.gd" id="5_4geqi"]
 [ext_resource type="Script" path="res://scripts/label_round.gd" id="5_vheit"]
 [ext_resource type="PackedScene" uid="uid://dl7r8s5sxyvlw" path="res://scenes/enginesound.tscn" id="6_v21se"]
 [ext_resource type="AudioStream" uid="uid://dq5rei2w1isu4" path="res://sounds/crash/Car_Crash_01.mp3" id="7_7erwn"]
@@ -45,6 +45,10 @@
 radius = 8.0
 height = 34.0
 
+[sub_resource type="Curve" id="Curve_qs34t"]
+_data = [Vector2(0, 0), 0.0, 5.0, 0, 0, Vector2(0.5, 1), 0.0, 0.0, 0, 0, Vector2(1, 0), -5.0, 0.0, 0, 0]
+point_count = 3
+
 [sub_resource type="Animation" id="Animation_3soig"]
 length = 0.001
 tracks/0/type = "value"
@@ -151,13 +155,14 @@ shape = SubResource("CapsuleShape2D_bj1hp")
 
 [node name="PositionFrontLeftTire" type="Node2D" parent="CharacterBody_Car"]
 position = Vector2(10, -7)
-
+script = ExtResource("5_4geqi")
-[node name="Trail" parent="CharacterBody_Car/PositionFrontLeftTire" instance=ExtResource("5_2bgdv")]
 
 [node name="PositionFrontRightTire" type="Node2D" parent="CharacterBody_Car"]
 position = Vector2(10, 7)
+script = ExtResource("5_4geqi")
 
-[node name="Trail" parent="CharacterBody_Car/PositionFrontRightTire" instance=ExtResource("5_2bgdv")]
+[node name="Line2D" type="Line2D" parent="CharacterBody_Car"]
+width_curve = SubResource("Curve_qs34t")
 
 [node name="RayCast_FL" type="RayCast2D" parent="CharacterBody_Car"]
 target_position = Vector2(256, -128)

scenes/tire_trail.tscn

@@ -1,14 +1,38 @@
 [gd_scene load_steps=3 format=3 uid="uid://c3fdxjrpcgnnp"]
 
-[ext_resource type="Script" path="res://scripts/tiretrail.gd" id="1_cvwoe"]
-
 [sub_resource type="Curve" id="Curve_ckg0w"]
 _data = [Vector2(0, 0), 0.0, 3.77363, 0, 0, Vector2(1, 0), -4.04783, 0.0, 0, 0]
 point_count = 2
 
+[sub_resource type="GDScript" id="GDScript_6pryv"]
+script/source = "extends Line2D
+
+var point
+var isSliding=false
+# Called when the node enters the scene tree for the first time.
+func _ready() -> void:
+	set_as_top_level(true)
+
+
+# Called every frame. 'delta' is the elapsed time since the previous frame.
+func _physics_process(delta):
+	pass
+func _process(delta: float) -> void:
+	if isSliding:
+		point = get_parent().global_position
+		add_point(point)
+		if points.size()>100:
+			remove_point(0)
+
+func setSliding(psliding:bool):
+	#if not isSliding and psliding: #just started sliding
+		#clear_points()
+	isSliding=psliding
+"
+
 [node name="Trail" type="Line2D"]
 z_index = 9
 width = 4.0
 width_curve = SubResource("Curve_ckg0w")
 default_color = Color(0, 0, 0, 1)
-script = ExtResource("1_cvwoe")
+script = SubResource("GDScript_6pryv")

scripts/car.gd

@@ -219,13 +219,13 @@ func calculate_steering(delta:float):
 	
 	if d > 0:
 		velocity = velocity.lerp(new_heading * velocity.length(), traction)
-		if d<0.82 and velocity.length()>slip_speed and applied_engine_power>engine_power/2:
+		if d<0.85 and velocity.length()>slip_speed and applied_engine_power>engine_power/2:
 			sfx.sliding(velocity.length())
-			$PositionFrontLeftTire/Trail.setSliding(true)
+			$PositionFrontLeftTire.setSliding(true)
-			$PositionFrontRightTire/Trail.setSliding(true)
+			$PositionFrontRightTire.setSliding(true)
 		elif d>0.98: #keep trails a bit longer
-			$PositionFrontLeftTire/Trail.setSliding(false)
+			$PositionFrontLeftTire.setSliding(false)
-			$PositionFrontRightTire/Trail.setSliding(false)
+			$PositionFrontRightTire.setSliding(false)
 			
 	elif d<0:
 		velocity = - new_heading * min(velocity.length(),max_speed_reverse)

scripts/time_display.gd

@@ -1,12 +0,0 @@
-extends Node2D
-@onready var label: Label = $Label
-
-
-# Called when the node enters the scene tree for the first time.
-func _ready() -> void:
-	pass # Replace with function body.
-
-
-# Called every frame. 'delta' is the elapsed time since the previous frame.
-func _process(delta: float) -> void:
-	pass

scripts/tiretrail.gd

@@ -1,23 +0,0 @@
-extends Line2D
-
-var point
-var isSliding=false
-# Called when the node enters the scene tree for the first time.
-func _ready() -> void:
-	set_as_top_level(true)
-
-
-# Called every frame. 'delta' is the elapsed time since the previous frame.
-func _physics_process(delta):
-	pass
-func _process(delta: float) -> void:
-	if isSliding:
-		point = get_parent().global_position
-		add_point(point)
-		if points.size()>100:
-			remove_point(0)
-
-func setSliding(psliding:bool):
-	if not isSliding and psliding: #just started sliding
-		clear_points()
-	isSliding=psliding

scripts/tiretrails.gd

@@ -0,0 +1,49 @@
+extends Node2D
+
+
+var point
+var isSliding=false
+
+var currentTrail:Line2D
+#TODO: queue_free(), #clear_points()
+
+const STARTALPHA=0.8
+const MAXIMUM_POINTS=100 #maximum points per trail
+const FADETIME=120 #in seconds. how long a trail should last (if alpha would start at 1.0)
+
+func _ready() -> void:
+	pass
+
+func _physics_process(delta: float) -> void:
+	if isSliding:
+		point = global_position
+		currentTrail.add_point(point)
+		if currentTrail.points.size()>MAXIMUM_POINTS:
+			currentTrail.remove_point(0) #remove points from start
+			
+	for c:Line2D in get_children():
+		c.default_color.a=max(c.default_color.a-1.0/FADETIME*delta,0.0)
+		if c.default_color.a<=0: #not visible anymore
+			c.queue_free()
+
+func setSliding(psliding:bool):
+	if not isSliding and psliding: #just started sliding
+		#Reduce old lines
+		const KEEP_LINES=3
+		#if get_child_count()>KEEP_LINES:
+		#	var trails=get_children()
+			
+		#Create new Line
+		currentTrail=Line2D.new()
+		add_child(currentTrail)
+		currentTrail.width=4
+		currentTrail.default_color=Color(0,0,0,STARTALPHA)
+		var curve=Curve.new()
+		curve.add_point(Vector2(0,0),0,5,Curve.TANGENT_FREE,Curve.TANGENT_FREE)
+		curve.add_point(Vector2(0.5,1),0,0,Curve.TANGENT_FREE,Curve.TANGENT_FREE)
+		curve.add_point(Vector2(1,0),-5,0,Curve.TANGENT_FREE,Curve.TANGENT_FREE)
+		currentTrail.width_curve=curve
+		currentTrail.set_as_top_level(true)
+		currentTrail.z_index=9 #above road, behind car
+		
+	isSliding=psliding