extends MeshInstance3D

var godrays_material: ShaderMaterial

func _ready() -> void:
	var quad := QuadMesh.new()
	quad.size = Vector2(20.0, 40.0)
	mesh = quad

	godrays_material = ShaderMaterial.new()
	var shader := load("res://shaders/godrays.gdshader")
	if shader:
		godrays_material.shader = shader

	var mat_override := godrays_material
	material_override = mat_override

	# Position in front of camera, slightly above center
	position = Vector3(0.0, 5.0, -10.0)

func _process(_delta: float) -> void:
	if not godrays_material:
		return

	# Get player/camera world Y to drive fade_bottom
	var cam := get_viewport().get_camera_3d()
	if cam:
		var world_y := cam.global_position.y
		# Deeper = fade bottom rises, reducing godray reach
		var dynamic_fade := clamp(world_y - 20.0, -100.0, 0.0)
		godrays_material.set_shader_parameter("fade_bottom", dynamic_fade)