refactored droplet mode-ing

scripts/droplet.gd

@@ -1,26 +1,65 @@
 class_name Droplet extends RigidBody2D
 
-# bounce mode seems to settle with a consistent surface, but is erratic
-# stick mode seems to make sand castles, but is very calm
-enum Mode { BOUNCE, STICK }
-const mode: Mode = Mode.BOUNCE
+# default mode: a bit sluggish, tendency to pile
+# bounce mode: doesn't settle down at all, but keeps flat surface
+# bounce_wip: wonky AF, probably due to extra compute
+# stick mode: piles tightly, very calm
+# wip mode: interesting, the base stays together, and the new one jumps into place
+enum Mode { DEFAULT, BOUNCE, BOUNCE_WIP, STICK, WIP }
+const MODE: Mode = Mode.WIP
+
+class DropletConfig:
+	var bounce
+	var friction
+	var linear_damp
+	var angular_damp
+	func _init(mode):
+		linear_damp = ProjectSettings.get_setting("physics/2d/default_linear_damp")
+		angular_damp = ProjectSettings.get_setting("physics/2d/default_angular_damp")
+		if mode == Mode.DEFAULT:
+			bounce = 0
+			friction = 0.1
+		elif mode == Mode.BOUNCE:
+			bounce = 0.5
+			friction = 0.1
+		elif mode == Mode.BOUNCE_WIP:
+			bounce = 0.5
+			friction = 0.1
+		elif mode == Mode.STICK:
+			bounce = 0.1
+			friction = 0.3
+		else: # WIP
+			bounce = 0.1
+			friction = 1
 
 func _ready():
+	var config = DropletConfig.new(MODE)
 	var mat = PhysicsMaterial.new()
-	mat.bounce = .1 if mode == Mode.BOUNCE else 0
-	mat.friction = 0.0
+	mat.bounce = config.bounce
+	mat.friction = config.friction
 	physics_material_override = mat
-	
+	linear_damp = config.linear_damp
+	angular_damp = config.angular_damp
 	# setup body entered signal, seems to also matter for STICK mode
-	contact_monitor = true
-	max_contacts_reported = 10
-	body_entered.connect(_on_body_entered)
+	if not MODE == Mode.DEFAULT:
+		contact_monitor = true
+		max_contacts_reported = 10
+		body_entered.connect(_on_body_entered)
 
 func _physics_process(delta):
-	pass
-	
+	if MODE == Mode.WIP:
+		for body in get_colliding_bodies():
+			if body is RigidBody2D:
+				var dir = global_position - body.global_position
+				var dist = dir.length()
+				if dist < 64:
+					## IIUC: should act to keep close droplets together
+					var force = -dir.normalized() * (1.0 - dist / 64.0)
+					body.apply_central_force(force * 100)
+
 func _integrate_forces(state):
-	if mode == Mode.STICK:
+	# this is probably overkill since we are overriding the default physics engine
+	if MODE == Mode.STICK:
 		var v = state.linear_velocity
 		var contacts = state.get_contact_count()
 		for i in range(contacts):
@@ -34,7 +73,7 @@ func _integrate_forces(state):
 				body.apply_central_impulse(normal * v.length() * (other_damp/contacts))
 
 func _on_body_entered(body):
-	if mode == Mode.BOUNCE:
+	if MODE == Mode.BOUNCE_WIP:
 		# trying to elicit stronger response from rigidBody that was struck
 		# ends up being kind of erratic
 		# at damp_factor .75: settles laterally, but erratic past half-full

scripts/model.gd

@@ -3,17 +3,18 @@ class_name Model extends Node2D
 const PERIOD: int = 20 # smaller makes droplets faster
 var CURRENT_TIME: int = 0
 var last_droplet: int = 0
+const DROP_PT_X = 450
 
 func _ready():
 	pass # Replace with function body.
 
 func _process(delta: float):
-	CURRENT_TIME += delta * 100 	
+	CURRENT_TIME += delta * 100
 	if CURRENT_TIME - last_droplet > PERIOD:
 		last_droplet = CURRENT_TIME
 		# print("new droplet at time: ", str(CURRENT_TIME))
 		var droplet = preload("res://scenes/droplet.tscn").instantiate()
 		var shape = droplet.get_node("CollisionShape2D")
 		shape.shape.radius = 5
-		droplet.global_position = Vector2(450, 100)		
+		droplet.global_position = Vector2(DROP_PT_X, 100)
 		add_child(droplet)