(wip) Food now moves with a world flow (which is updated using a manual timer in the GameManager

evolve-die-repeat/game_manager.gd

@@ -4,8 +4,37 @@ var screen_size = Vector2(1920.0, 1080.0)  # Default screen size (this is a floa
 var viewport_size
 @onready var extent: Rect2 = get_viewport().get_visible_rect()
 
+# utils.
+var rng = RandomNumberGenerator.new()
+var eps: float = 1e-4
+
+# A world "current"
+# polar
+var flow_dir: float  # [0, 2pi)
+var flow_mag: float  # [0, 1]
+# cartesian
+var flow_x: float
+var flow_y: float
+# Swap period
+var flowT: float = 10
+
+# A game timer
+var t: float = 0.0
+
+
 func _ready() -> void:
 	viewport_size = get_viewport().get_visible_rect().size
+	
+	# initial world current
+	get_new_flow()
+
+func _physics_process(delta: float) -> void:
+	t += delta
+	
+	# Flow current change
+	if abs(fmod(t, flowT)) < eps:
+		get_new_flow()
+	
 
 # TODO: This needs to be called from a script inheriting a CharacterBody2D (e.g. the player)
 # Alternative would be to pass the player reference to this script (which might be better?)
@@ -22,3 +51,12 @@ func get_boundaried_position(position):
 	position.x = wrapf(position.x, 0, screen_size.x)
 	position.y = wrapf(position.y, 0, screen_size.y)
 	return position
+	
+func get_new_flow():
+	flow_dir = rng.randf()*2*PI
+	flow_mag = rng.randf()
+	
+	flow_x = flow_mag * cos(flow_dir)
+	flow_y = flow_mag * sin(flow_dir)
+	
+