From b3920b897516674611f4b9eab43156a1de1a096d Mon Sep 17 00:00:00 2001
From: Martin Felis <martin@fysx.org>
Date: Fri, 19 Aug 2022 19:13:39 +0200
Subject: [PATCH] Allow clamping of movable speed

---
 Components/MovableComponent.gd | 10 ++++++----
 Entities/PlayerEntity.gd       | 15 ++++++++++-----
 Entities/PlayerEntity.tscn     |  1 +
 Game.gd                        |  9 +--------
 Utils/SpringDamper.gd          | 13 +++++++++++++
 5 files changed, 31 insertions(+), 17 deletions(-)

diff --git a/Components/MovableComponent.gd b/Components/MovableComponent.gd
index bf5b9ea..3c8cc17 100644
--- a/Components/MovableComponent.gd
+++ b/Components/MovableComponent.gd
@@ -5,9 +5,7 @@ var SpringDamper = preload("res://Utils/SpringDamper.gd")
 export var target = Vector2 (0, 0)
 export var pos = Vector2 (0, 0)
 export var vel = Vector2 (0, 0)
-export var max_speed = 50
-export var spring_k = 10
-export var spring_b = 0.5
+export var max_speed = 100000
 
 onready var spring_damper = SpringDamper.new(4, .99, 0.5)
 
@@ -24,9 +22,13 @@ func _ready():
 # Called every frame. 'delta' is the elapsed time since the previous frame.
 func _process(delta):
 	if (target - pos).length_squared() > pos_error_eps * pos_error_eps:
-		var spring_res = spring_damper.calc(pos, vel, target, delta)
+		var spring_res = spring_damper.calc_clamped_speed(pos, vel, target, delta, max_speed)
 		
 		pos = spring_res[0]
 		vel = spring_res[1]
 		
+		var speed = vel.length()
+		if speed > max_speed:
+			vel = vel * max_speed / speed
+		
 		emit_signal("position_updated", pos)
diff --git a/Entities/PlayerEntity.gd b/Entities/PlayerEntity.gd
index ba8b09a..c1c90ae 100644
--- a/Entities/PlayerEntity.gd
+++ b/Entities/PlayerEntity.gd
@@ -21,6 +21,7 @@ func _ready():
 		movable_component.target = self.transform.origin
 		movable_component.pos = self.transform.origin
 
+
 func _process(delta):
 	if is_active and color_component:
 		var color = Color(
@@ -30,15 +31,19 @@ func _process(delta):
 		)
 		color_component.set_color(color)
 		pass
-		
+
+
 func _on_entity_clicked():
 	is_active = not is_active
 
+
 func _on_position_updated(new_position):
 	transform.origin = new_position
 	update()
 
-func on_world_location_clicked(position):
-	assert(movable_component)
-	
-	movable_component.target = position
+
+func _unhandled_input(event):
+	if event is InputEventMouseButton and event.pressed:
+		assert(movable_component)
+		
+		movable_component.target = event.position
diff --git a/Entities/PlayerEntity.tscn b/Entities/PlayerEntity.tscn
index d6a7fa3..b090e86 100644
--- a/Entities/PlayerEntity.tscn
+++ b/Entities/PlayerEntity.tscn
@@ -14,6 +14,7 @@ script = ExtResource( 1 )
 
 [node name="Movable" type="Node2D" parent="Components"]
 script = ExtResource( 5 )
+max_speed = 1000
 
 [node name="Clickable" parent="Components" instance=ExtResource( 4 )]
 
diff --git a/Game.gd b/Game.gd
index 92970ae..c783a22 100644
--- a/Game.gd
+++ b/Game.gd
@@ -3,14 +3,13 @@ extends Node2D
 
 onready var SimpleEntity = preload("res://Entities/SimpleEntity.tscn")
 onready var WanderingEntity = preload("res://Entities/WanderingEntity.tscn")
-onready var player = $PlayerEntity
 onready var entities = $Entities
 
 signal world_location_clicked
 
 # Called when the node enters the scene tree for the first time.
 func _ready():
-	self.connect("world_location_clicked", player, "on_world_location_clicked")
+	pass
 
 func _on_AddEntityButton_pressed():
 	var entity_instance = SimpleEntity.instance()
@@ -24,9 +23,3 @@ func _on_AddWanderingEntity_pressed():
 	entity_instance.transform.origin = Vector2(randf() * viewport_rect.size[0], randf() * viewport_rect.size[1])
 	entities.add_child(entity_instance)
 	entity_instance.set_target(Vector2(randf() * viewport_rect.size[0], randf() * viewport_rect.size[1]))
-
-func _unhandled_input(event):
-	if event is InputEventMouseButton and event.pressed:
-		#get_tree().get_root().set_input_as_handled()
-		emit_signal("world_location_clicked", event.position)
-		pass
diff --git a/Utils/SpringDamper.gd b/Utils/SpringDamper.gd
index 9362c22..8455d84 100644
--- a/Utils/SpringDamper.gd
+++ b/Utils/SpringDamper.gd
@@ -26,3 +26,16 @@ func calc(x, v, xt, h:float):
 	var det_x = f * x + h * v + hhoo * xt
 	var det_v = v + hoo * (xt - x)
 	return [det_x * det_inv, det_v * det_inv]
+
+func calc_clamped_speed(x, v, xt, h:float, s_max:float):
+	var res = calc(x, v, xt, h)
+	
+	var x_new = res[0]
+	var vel_new = (x_new - x) / h
+	var speed_new = vel_new.length()
+	if speed_new > s_max:
+		vel_new = (vel_new / speed_new) * s_max
+		x_new = x + vel_new * h
+		return [x_new, vel_new]
+	
+	return res