attack_time += delta;
while(attack_time >= attack_delay)
{
    attack_time -= attack_delay;

    attack_anim_active = true;
}

if(attack_anim_active)
{
    float percent = attack_time / attack_delay;
    int index_from_percent = (int)roundf(percent, attack_sprites.count);
    sprite = attack_sprites[index_from_percent];
    if(sprite == attack_sprites[attack_sprites.count - 1]) { attack_anim_active = false; }
}
else
{
    sprite = default_sprite_or_whatever;
}