source/game/entity.h

   1 #ifndef MSP_GAME_ENTITY_H_
   2 #define MSP_GAME_ENTITY_H_
   3
   4 #include "handle.h"
   5 #include "owned.h"
   6
   7 namespace Msp::Game {
   8
   9 class Component;
  10 class Stage;
  11 class Transform;
  12 struct TransformValues;
  13
  14 class hierarchy_error: public std::logic_error
  15 {
  16 public:
  17         hierarchy_error(): std::logic_error("hierarchy error") { }
  18 };
  19
  20 class Entity
  21 {
  22 public:
  23         enum TransformTag { NO_TRANSFORM };
  24
  25 private:
  26         Handle<Entity> parent;
  27         std::vector<Handle<Component>> components;
  28         std::vector<Handle<Entity>> children;
  29         Owned<Transform> transform;
  30
  31 public:
  32         Entity(Handle<Entity>, TransformTag);
  33         Entity(Handle<Entity>, const TransformValues &);
  34         virtual ~Entity();
  35
  36         void add_component(Handle<Component>);
  37         void remove_component(Handle<Component>);
  38
  39         template<typename T>
  40         Handle<T> get_component();
  41
  42         Handle<Transform> get_transform() const { return transform; }
  43
  44         void add_child(Handle<Entity>);
  45         void remove_child(Handle<Entity>);
  46
  47         Handle<Entity> get_parent() const { return parent; }
  48         Handle<Entity> get_root();
  49         const std::vector<Handle<Entity>> &get_children() const { return children; }
  50         Stage &get_stage();
  51 };
  52
  53
  54 template<typename T>
  55 inline Handle<T> Entity::get_component()
  56 {
  57         for(Handle<Component> c: components)
  58                 if(Handle<T> tc = dynamic_handle_cast<T>(c))
  59                         return tc;
  60         return nullptr;
  61 }
  62
  63 inline Handle<Entity> Entity::get_root()
  64 {
  65         Handle<Entity> e = Handle<Entity>::from_object(this);
  66         while(Handle<Entity> p = e->get_parent())
  67                 e = p;
  68         return e;
  69 }
  70
  71 } // namespace Msp::Game
  72
  73 #endif