TouhouGD/script/effect/fragment.gd

extends CharacterBody3D
class_name Fragment

@export var sub: PackedScene
@export var gravity_scale: float = 1.0
@export var velocity_min: Vector2 = Vector2.ONE
@export var velocity_max: Vector2 = Vector2.ONE

@onready var sprite3D: Sprite3D = %Sprite3D as Sprite3D

var gravity           = ProjectSettings.get_setting("physics/3d/default_gravity")
var frame_rate: float = 0.1
var frame_time: float = 0


func _ready():
    var dir: Vector2 = Util.angle_dir(randf_range(0, 360)) * randf_range(velocity_min.x, velocity_max.x)
    velocity.x = dir.x
    velocity.z = dir.y
    velocity.y = randf_range(velocity_min.y, velocity_max.y)


func _process(delta: float) -> void:
    velocity.y -= gravity * gravity_scale * delta
    var frame_count: int      = sprite3D.hframes * sprite3D.vframes
    var frame_time_all: float = frame_rate * frame_count
    frame_time += delta
    sprite3D.frame = int(frame_time / frame_rate) % frame_count
    frame_time = fmod(frame_time, frame_time_all)
    move_and_slide()
    var collision_count: int = get_slide_collision_count()
    if collision_count > 0:
        if sub:
            var normal: Vector3 = Vector3.ZERO
            for i in collision_count:
                var collision: KinematicCollision3D = get_slide_collision(i)
                normal += collision.get_normal()
            normal = normal.normalized()
            Global.effect_mgr.cast_particle(sub, global_position, normal)
        queue_free()