extends EffectBase
class_name Particle

@export var is_billboard: bool

var sub_particle_list: Array[Particle]          = []
var particle_list: Array[GPUParticles3D]        = []
var speed_scale_list: Array[float]              = []
var decal_list: Array[ParticleDecal]            = []
var sub_emitter_list: Array[ParticleSubEmitter] = []


func on_ready():
    for child in get_children():
        if child is Particle:
            sub_particle_list.append(child)
        elif child is GPUParticles3D:
            var particle: GPUParticles3D = child as GPUParticles3D
            particle_list.append(particle)
            speed_scale_list.append(particle.speed_scale)
            particle.restart()
        elif child is ParticleDecal:
            child.on_ready()
            decal_list.append(child)
        elif child is ParticleSubEmitter:
            sub_emitter_list.append(child)
        else:
            continue
        if child.lifetime > lifetime_now:
            lifetime_now = child.lifetime

    for particle: GPUParticles3D in particle_list:
        if particle.lifetime > lifetime_now:
            lifetime_now = particle.lifetime


func on_process(delta: float):
    for decal: ParticleDecal in decal_list:
        decal.on_process(delta)


func on_set_pause(is_pause_set: bool):
    for i in range(len(particle_list)):
        var particle: GPUParticles3D = particle_list[i]
        var speed_scale: float       = speed_scale_list[i]
        particle.speed_scale = 0 if is_pause else speed_scale
    for sub_particle: Particle in sub_particle_list:
        sub_particle.set_pause(is_pause_set)