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
  29         template<typename U>
  30                 requires std::is_base_of_v<T, U>
  31         Owned(Owned<U> &&other): Handle<T>(other) { other.ptr = nullptr; }
  32
  33         Owned &operator=(Owned &&other) { assign(std::move(other)); return *this; }
  34
  35         template<typename U>
  36                 requires std::is_base_of_v<T, U>
  37         Owned &operator=(Owned<U> &&other) { assign(std::move(other)); return *this; }
  38
  39         ~Owned() { destroy(); }
  40
  41 private:
  42         template<typename U>
  43         void assign(Owned<U> &&);
  44
  45         template<typename O>
  46         static Stage &get_stage(O &);
  47
  48         void destroy();
  49 };
  50
  51
  52 template<typename T>
  53 template<typename P, typename... Args>
  54 Owned<T>::Owned(Handle<P> parent, Args &&... args)
  55 {
  56 #ifdef DEBUG
  57         AccessGuard::get_instance().check<AccessGuard::Create>();
  58 #endif
  59
  60         if(!parent)
  61                 throw std::invalid_argument("Owned::Owned");
  62
  63         Stage &stage = get_stage(*parent);
  64         Pool<T> &pool = stage.get_pools().get_pool<T>();
  65         bool first_created = !pool.get_capacity();
  66         this->ptr = pool.create(parent, std::forward<Args>(args)...);
  67         if constexpr(std::is_base_of_v<Component, T>)
  68         {
  69                 if(first_created)
  70                         stage.get_reflector().get_or_create_class<T>().template set_polymorphic_base<Component>(**this);
  71                 parent->add_component(*this);
  72                 stage.get_event_source().emit<Events::ComponentCreated>(*this);
  73         }
  74         else
  75         {
  76                 if(first_created)
  77                         stage.get_reflector().get_or_create_class<T>().template set_polymorphic_base<Entity>(**this);
  78                 parent->add_child(*this);
  79                 stage.get_event_source().emit<Events::EntityCreated>(*this);
  80         }
  81 }
  82
  83 template<typename T>
  84 template<typename U>
  85 void Owned<T>::assign(Owned<U> &&other)
  86 {
  87         destroy();
  88
  89         this->ptr = other.ptr;
  90         other.ptr = nullptr;
  91 }
  92
  93 template<typename T>
  94 template<typename O>
  95 Stage &Owned<T>::get_stage(O &obj)
  96 {
  97         if constexpr(std::is_base_of_v<Component, O>)
  98                 return get_stage(*obj.get_entity());
  99         else
 100                 return obj.get_stage();
 101 }
 102
 103 template<typename T>
 104 void Owned<T>::destroy()
 105 {
 106         T *obj = this->get();
 107         if(!obj)
 108                 return;
 109
 110 #ifdef DEBUG
 111         AccessGuard::get_instance().check<AccessGuard::Destroy>();
 112 #endif
 113
 114         Stage &stage = get_stage(*obj);
 115
 116         if constexpr(std::is_base_of_v<Component, T>)
 117         {
 118                 stage.get_event_source().emit<Events::ComponentDestroyed>(*this);
 119                 obj->get_entity()->remove_component(*this);
 120         }
 121         else if(auto parent = obj->get_parent().get())
 122         {
 123                 stage.get_event_source().emit<Events::EntityDestroyed>(*this);
 124                 parent->remove_child(*this);
 125         }
 126
 127         Pool<T> &pool = stage.get_pools().get_pool<T>();
 128         pool.destroy(this->ptr);
 129 }
 130
 131 } // namespace Msp::Game
 132
 133 #endif