source/game/owned.h

   1 #ifndef MSP_GAME_OWNED_H_
   2 #define MSP_GAME_OWNED_H_
   3
   4 #include <stdexcept>
   5 #include "accessguard.h"
   6 #include "events.h"
   7 #include "handle.h"
   8 #include "stage.h"
   9
  10 namespace Msp::Game {
  11
  12 class Component;
  13 class Entity;
  14
  15 template<typename T>
  16 class Owned: public Handle<T>
  17 {
  18 public:
  19         Owned() = default;
  20
  21         template<typename P, typename... Args>
  22         Owned(Handle<P>, Args &&...);
  23
  24         template<typename P, typename... Args>
  25         Owned(P *parent, Args &&... args): Owned(Handle<P>::from_object(parent), std::forward<Args>(args)...) { }
  26
  27         Owned(Owned &&other): Handle<T>(other) { other.ptr = nullptr; }
  28         Owned &operator=(Owned &&other);
  29         ~Owned() { destroy(); }
  30
  31 private:
  32         template<typename O>
  33         static Stage &get_stage(O &);
  34
  35         void destroy();
  36 };
  37
  38
  39 template<typename T>
  40 template<typename P, typename... Args>
  41 Owned<T>::Owned(Handle<P> parent, Args &&... args)
  42 {
  43 #ifdef DEBUG
  44         AccessGuard::get_instance().check<AccessGuard::Create>();
  45 #endif
  46
  47         if(!parent)
  48                 throw std::invalid_argument("Owned::Owned");
  49
  50         Stage &stage = get_stage(*parent);
  51         Pool<T> &pool = stage.get_pools().get_pool<T>();
  52         bool first_created = !pool.get_capacity();
  53         this->ptr = pool.create(parent, std::forward<Args>(args)...);
  54         if constexpr(std::is_base_of_v<Component, T>)
  55         {
  56                 if(first_created)
  57                         stage.get_reflector().get_or_create_class<T>().template set_polymorphic_base<Component>(**this);
  58                 parent->add_component(*this);
  59                 stage.get_event_source().emit<Events::ComponentCreated>(*this);
  60         }
  61         else
  62         {
  63                 if(first_created)
  64                         stage.get_reflector().get_or_create_class<T>().template set_polymorphic_base<Entity>(**this);
  65                 parent->add_child(*this);
  66                 stage.get_event_source().emit<Events::EntityCreated>(*this);
  67         }
  68 }
  69
  70 template<typename T>
  71 Owned<T> &Owned<T>::operator=(Owned &&other)
  72 {
  73         destroy();
  74
  75         this->ptr = other.ptr;
  76         other.ptr = nullptr;
  77
  78         return *this;
  79 }
  80
  81 template<typename T>
  82 template<typename O>
  83 Stage &Owned<T>::get_stage(O &obj)
  84 {
  85         if constexpr(std::is_base_of_v<Component, O>)
  86                 return get_stage(*obj.get_entity());
  87         else
  88                 return obj.get_stage();
  89 }
  90
  91 template<typename T>
  92 void Owned<T>::destroy()
  93 {
  94         T *obj = this->get();
  95         if(!obj)
  96                 return;
  97
  98 #ifdef DEBUG
  99         AccessGuard::get_instance().check<AccessGuard::Destroy>();
 100 #endif
 101
 102         Stage &stage = get_stage(*obj);
 103
 104         if constexpr(std::is_base_of_v<Component, T>)
 105         {
 106                 stage.get_event_source().emit<Events::ComponentDestroyed>(*this);
 107                 obj->get_entity()->remove_component(*this);
 108         }
 109         else if(auto parent = obj->get_parent().get())
 110         {
 111                 stage.get_event_source().emit<Events::EntityDestroyed>(*this);
 112                 parent->remove_child(*this);
 113         }
 114
 115         Pool<T> &pool = stage.get_pools().get_pool<T>();
 116         pool.destroy(this->ptr);
 117 }
 118
 119 } // namespace Msp::Game
 120
 121 #endif