89 lines
3.0 KiB
GDScript
89 lines
3.0 KiB
GDScript
class_name Droplet extends RigidBody2D
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# default mode: a bit sluggish, tendency to pile
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# bounce mode: doesn't settle down at all, but keeps flat surface
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# bounce_wip: wonky AF, probably due to extra compute
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# stick mode: piles tightly, very calm
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# wip mode: interesting, the base stays together, and the new one jumps into place
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enum Mode { DEFAULT, BOUNCE, BOUNCE_WIP, STICK, WIP }
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const MODE: Mode = Mode.WIP
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class DropletConfig:
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var bounce
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var friction
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var linear_damp
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var angular_damp
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func _init(mode):
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linear_damp = ProjectSettings.get_setting("physics/2d/default_linear_damp")
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angular_damp = ProjectSettings.get_setting("physics/2d/default_angular_damp")
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if mode == Mode.DEFAULT:
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bounce = 0
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friction = 0.1
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elif mode == Mode.BOUNCE:
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bounce = 0.5
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friction = 0.1
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elif mode == Mode.BOUNCE_WIP:
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bounce = 0.5
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friction = 0.1
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elif mode == Mode.STICK:
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bounce = 0.1
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friction = 0.3
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else: # WIP
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bounce = 0.1
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friction = 1
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func _ready():
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var config = DropletConfig.new(MODE)
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var mat = PhysicsMaterial.new()
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mat.bounce = config.bounce
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mat.friction = config.friction
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physics_material_override = mat
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linear_damp = config.linear_damp
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angular_damp = config.angular_damp
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# setup body entered signal, seems to also matter for STICK mode
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if not MODE == Mode.DEFAULT:
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contact_monitor = true
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max_contacts_reported = 10
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body_entered.connect(_on_body_entered)
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func _physics_process(delta):
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if MODE == Mode.WIP:
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for body in get_colliding_bodies():
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if body is RigidBody2D:
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var dir = global_position - body.global_position
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var dist = dir.length()
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if dist < 64:
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## IIUC: should act to keep close droplets together
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var force = -dir.normalized() * (1.0 - dist / 64.0)
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body.apply_central_force(force * 100)
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func _integrate_forces(state):
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# this is probably overkill since we are overriding the default physics engine
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if MODE == Mode.STICK:
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var v = state.linear_velocity
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var contacts = state.get_contact_count()
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for i in range(contacts):
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var body = state.get_contact_collider_object(i)
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var normal = state.get_contact_local_normal(i)
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var self_damp = .9
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var other_damp = 1 - self_damp
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v = v.bounce(normal) * self_damp
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state.linear_velocity = v # self bounce
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if body is RigidBody2D: # other body
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body.apply_central_impulse(normal * v.length() * (other_damp/contacts))
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func _on_body_entered(body):
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if MODE == Mode.BOUNCE_WIP:
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# trying to elicit stronger response from rigidBody that was struck
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# ends up being kind of erratic
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# at damp_factor .75: settles laterally, but erratic past half-full
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# at damp_factor of .5, it's pretty calm, but then can't overfill (expected?)
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var vel = get_linear_velocity()
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const damp_factor = 0.7
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var normal = (body.global_position - global_position).normalized()
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# reflect velocity across collision direction
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var bounced = vel.bounce(normal) # reflection
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set_linear_velocity(bounced * damp_factor)
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if body is RigidBody2D:
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body.apply_central_impulse(-bounced * damp_factor)
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