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         const std::vector<Handle<Component>> &get_components() const { return components; }
  39
  40         template<typename T>
  41         Handle<T> get_component();
  42
  43         Handle<Transform> get_transform() const { return transform; }
  44
  45         void add_child(Handle<Entity>);
  46         void remove_child(Handle<Entity>);
  47
  48         Handle<Entity> get_parent() const { return parent; }
  49         Handle<Entity> get_root();
  50         const std::vector<Handle<Entity>> &get_children() const { return children; }
  51         Stage &get_stage();
  52 };
  53
  54
  55 template<typename T>
  56 inline Handle<T> Entity::get_component()
  57 {
  58         for(Handle<Component> c: components)
  59                 if(Handle<T> tc = dynamic_handle_cast<T>(c))
  60                         return tc;
  61         return nullptr;
  62 }
  63
  64 inline Handle<Entity> Entity::get_root()
  65 {
  66         Handle<Entity> e = Handle<Entity>::from_object(this);
  67         while(Handle<Entity> p = e->get_parent())
  68                 e = p;
  69         return e;
  70 }
  71
  72 } // namespace Msp::Game
  73
  74 #endif