extends Spatial

onready var inv_gravity = -ProjectSettings.get_setting("physics/3d/default_gravity_vector") * ProjectSettings.get_setting("physics/3d/default_gravity")

func _physics_process(_delta):
    var parent = get_parent()
    var water = get_node("/root/Main/Water/MeshInstance")
    var height = self.global_transform.origin.y
    var wave_height = water.height(self.global_transform.origin)
    if height < wave_height:
        var pos = self.global_transform.origin-parent.global_transform.origin
        #buoyancy force is weight of the displaced water
        #we can estimate it by how deep we are in the water
        var buoyancy = inv_gravity * clamp(wave_height-height,0.0,1.0)
        parent.add_force(buoyancy, pos)