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(Owned<P> &p, Args &&... a): Owned(static_cast<Handle<P> &>(p), std::forward<Args>(a)...) { }
  26
  27         template<typename P, typename... Args>
  28                 requires(!std::is_const_v<P>)
  29         Owned(P &parent, Args &&... args): Owned(Handle<P>::from_object(&parent), std::forward<Args>(args)...) { }
  30
  31         Owned(Owned &&other): Handle<T>(other) { other.ptr = nullptr; }
  32         Owned &operator=(Owned &&other);
  33         ~Owned() { destroy(); }
  34
  35 private:
  36         template<typename O>
  37         static Stage &get_stage(O &);
  38
  39         void destroy();
  40 };
  41
  42
  43 template<typename T>
  44 template<typename P, typename... Args>
  45 Owned<T>::Owned(Handle<P> parent, Args &&... args)
  46 {
  47 #ifdef DEBUG
  48         AccessGuard::get_instance().check<AccessGuard::Create>();
  49 #endif
  50
  51         if(!parent)
  52                 throw std::invalid_argument("Owned::Owned");
  53
  54         Stage &stage = get_stage(*parent);
  55         Pool<T> &pool = stage.get_pools().get_pool<T>();
  56         bool first_created = !pool.get_capacity();
  57         this->ptr = pool.create(parent, std::forward<Args>(args)...);
  58         if constexpr(std::is_base_of_v<Component, T>)
  59         {
  60                 if(first_created)
  61                         stage.get_reflector().get_or_create_class<T>().template set_polymorphic_base<Component>(**this);
  62                 parent->add_component(*this);
  63                 stage.get_event_source().emit<Events::ComponentCreated>(*this);
  64         }
  65         else
  66         {
  67                 if(first_created)
  68                         stage.get_reflector().get_or_create_class<T>().template set_polymorphic_base<Entity>(**this);
  69                 parent->add_child(*this);
  70                 stage.get_event_source().emit<Events::EntityCreated>(*this);
  71         }
  72 }
  73
  74 template<typename T>
  75 Owned<T> &Owned<T>::operator=(Owned &&other)
  76 {
  77         destroy();
  78
  79         this->ptr = other.ptr;
  80         other.ptr = nullptr;
  81
  82         return *this;
  83 }
  84
  85 template<typename T>
  86 template<typename O>
  87 Stage &Owned<T>::get_stage(O &obj)
  88 {
  89         if constexpr(std::is_base_of_v<Component, O>)
  90                 return get_stage(*obj.get_entity());
  91         else
  92                 return obj.get_stage();
  93 }
  94
  95 template<typename T>
  96 void Owned<T>::destroy()
  97 {
  98         T *obj = this->get();
  99         if(!obj)
 100                 return;
 101
 102 #ifdef DEBUG
 103         AccessGuard::get_instance().check<AccessGuard::Destroy>();
 104 #endif
 105
 106         Stage &stage = get_stage(*obj);
 107
 108         if constexpr(std::is_base_of_v<Component, T>)
 109         {
 110                 stage.get_event_source().emit<Events::ComponentDestroyed>(*this);
 111                 obj->get_entity()->remove_component(*this);
 112         }
 113         else if(auto parent = obj->get_parent().get())
 114         {
 115                 stage.get_event_source().emit<Events::EntityDestroyed>(*this);
 116                 parent->remove_child(*this);
 117         }
 118
 119         Pool<T> &pool = stage.get_pools().get_pool<T>();
 120         pool.destroy(this->ptr);
 121 }
 122
 123 } // namespace Msp::Game
 124
 125 #endif