road simplification via Ramer–Douglas–Peucker

5 files changed, 92 insertions, 4 deletions

diff --git a/Assets/road.png b/Assets/road.png
new file mode 100644
index 0000000..5acc2e9
--- /dev/null
+++ b/Assets/road.png
diff --git a/Assets/road.png.import b/Assets/road.png.import
new file mode 100644
index 0000000..59a81a8
--- /dev/null
+++ b/Assets/road.png.import
@@ -0,0 +1,34 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://bcn7tgs6a4fm7"
+path="res://.godot/imported/road.png-c3c47e2cc8c90beae2ad5c8a3bb2c3ca.ctex"
+metadata={
+"vram_texture": false
+}
+
+[deps]
+
+source_file="res://Assets/road.png"
+dest_files=["res://.godot/imported/road.png-c3c47e2cc8c90beae2ad5c8a3bb2c3ca.ctex"]
+
+[params]
+
+compress/mode=0
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/hdr_compression=1
+compress/normal_map=0
+compress/channel_pack=0
+mipmaps/generate=false
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=1
diff --git a/Nodes/Level_test.tscn b/Nodes/Level_test.tscn
index f082198..0703906 100644
--- a/Nodes/Level_test.tscn
+++ b/Nodes/Level_test.tscn
@@ -1,4 +1,4 @@
-[gd_scene load_steps=11 format=3 uid="uid://dliou1u4o6bib"]
+[gd_scene load_steps=12 format=3 uid="uid://dliou1u4o6bib"]
 
 [ext_resource type="Script" path="res://Scripts/scene_control.gd" id="1_0esj3"]
 [ext_resource type="Texture2D" uid="uid://5xqahgawme4m" path="res://Assets/start.png" id="1_wenkl"]
@@ -6,7 +6,8 @@
 [ext_resource type="Texture2D" uid="uid://dg3v488vx0oj6" path="res://Assets/checkpoint.png" id="3_cgigr"]
 [ext_resource type="PackedScene" uid="uid://c1mvbh2fwqtkb" path="res://Nodes/car.tscn" id="4_xvobs"]
 [ext_resource type="Script" path="res://Scripts/drawing.gd" id="5_x7h3g"]
-[ext_resource type="PackedScene" uid="uid://wkfai2lvnp7n" path="res://Nodes/checkpoint.tscn" id="7_52mhf"]
+[ext_resource type="PackedScene" path="res://Nodes/checkpoint.tscn" id="7_52mhf"]
+[ext_resource type="Script" path="res://Scripts/Road.gd" id="7_nyjk7"]
 [ext_resource type="PackedScene" uid="uid://c8r6i3bu37ogu" path="res://Nodes/ui.tscn" id="8_8u1ba"]
 
 [sub_resource type="CircleShape2D" id="CircleShape2D_6g88q"]
@@ -42,7 +43,11 @@ acceleration = 0.05
 [node name="DrawNode" type="Node2D" parent="."]
 script = ExtResource("5_x7h3g")
 
-[node name="TrackLine" type="Line2D" parent="DrawNode"]
+[node name="Road" type="Line2D" parent="DrawNode"]
+width = 100.0
+default_color = Color(0.133333, 0.133333, 0.133333, 1)
+joint_mode = 2
+script = ExtResource("7_nyjk7")
 
 [node name="TrackPath" type="Path2D" parent="DrawNode"]
 curve = SubResource("Curve2D_0exre")
diff --git a/Scripts/Road.gd b/Scripts/Road.gd
new file mode 100644
index 0000000..e0b69a1
--- /dev/null
+++ b/Scripts/Road.gd
@@ -0,0 +1,48 @@
+extends Line2D
+
+var epsilon = 20
+
+# Called when the node enters the scene tree for the first time.
+func _ready():
+	pass # Replace with function body.
+
+
+# Called every frame. 'delta' is the elapsed time since the previous frame.
+func _process(delta):
+	pass
+
+func simplify():
+	points = simplify_rec(points, 5)
+
+func simplify_rec(pointArray: PackedVector2Array, epsilon: float):
+	var dmax = 0
+	var index = -1
+	if pointArray.size() < 3:
+		return pointArray
+	var end = pointArray.size() - 1
+	for i in range(1, end-1):
+		var d = find_perpendicular_distance(pointArray[i], pointArray[0], pointArray[end])
+		if d > dmax:
+			index = i
+			dmax = d
+	
+	if dmax > epsilon:
+		var recResults1 = simplify_rec(pointArray.slice(0, index), epsilon)
+		var recResults2 = simplify_rec(pointArray.slice(index, end), epsilon)
+		recResults1.append_array(recResults2)
+		return recResults1
+	else:
+		return [pointArray[0], pointArray[end]]
+
+func find_perpendicular_distance(p: Vector2, p1: Vector2, p2: Vector2):
+	var result
+	var slope
+	var intercept
+	if p1.x == p2.x:
+		result = p.x - p1.x
+	else:
+		slope = (p2.y - p1.y) / (p2.x - p1.x)
+		intercept = p1.y - (slope * p1.x)
+		result = abs(slope * p.x - p.y + intercept) / sqrt(pow(slope, 2) + 1)
+	
+	return result
diff --git a/Scripts/drawing.gd b/Scripts/drawing.gd
index 61896f9..c45196b 100644
--- a/Scripts/drawing.gd
+++ b/Scripts/drawing.gd
@@ -2,7 +2,7 @@ extends Node
 
 var drawing = false
 
-@onready var line: Line2D = $TrackLine
+@onready var line = $Road
 @onready var path: Path2D = $TrackPath
 
 func _ready():
@@ -16,6 +16,7 @@ func start_drawing():
 
 func _end_drawing():
 	drawing = false
+	line.simplify()
 	owner.set_driving(true)