voitures: freinage en fonction du time delta

le freinage dure un certain temps et ce temps dépends du delta des
frames. Sinon les voitures freinent plus ou moins vite en fonction de ce
que les pc cibles sont capable d'arriver à faire tourner.

vehicules/car.gd

@@ -3,14 +3,14 @@ extends CharacterBody2D
 
 @export var debugLabel: Label
 @export var speed = 750 # How fast the car will move (pixels/sec).
-@export var acceleration = speed / 100
-@export var slowZoneSpeed = 300
+@export var timeToChangeVelocity = 0.5 # How long to break to a full stop
+
+var targetedVelocity = 0
 var current_speed = speed;
 @onready var animation_tree := $AnimationTree
 @onready var state_machine := animation_tree.get("parameters/driving/playback") as AnimationNodeStateMachinePlayback
 
 var brakePedal = false;
-var fullStop = false;
 
 var last_facing_direction = Vector2(0,-1) # facing north
 
@@ -27,14 +27,12 @@ func updateFacingDirectionInAnimationTree():
 # Called every frame. 'delta' is the elapsed time since the previous frame.
 func _process(delta: float) -> void:
 	$ZIndexControler/ShapeCast2D.enabled = !$CollisionHorizontal.disabled
-	
+	var accelerationStep = (speed * delta / timeToChangeVelocity)
+
 	if brakePedal:
-		if fullStop:
-			current_speed = max(0, current_speed - acceleration)
-		else:
-			current_speed = max(slowZoneSpeed, current_speed - acceleration)
+		current_speed = max(targetedVelocity, current_speed - accelerationStep)
 	else:
-		current_speed = min(current_speed + acceleration, speed)
+		current_speed = min(current_speed + accelerationStep, speed)
 
 	if (targetGlobalPosition != null):
 		direction = (targetGlobalPosition - global_position).normalized()
@@ -45,9 +43,9 @@ func _process(delta: float) -> void:
 		last_facing_direction = velocity.normalized()
 	updateFacingDirectionInAnimationTree()
 	
-func brake(needsToStop : bool):
+func brake(wantedVelocity : int):
 	brakePedal = true;
-	fullStop = needsToStop;
+	targetedVelocity = wantedVelocity;
 
 func accelerate():
 	brakePedal = false;