source/game/entity.h

   1 #ifndef MSP_GAME_ENTITY_H_
   2 #define MSP_GAME_ENTITY_H_
   3
   4 #include "handle.h"
   5 #include "mspgame_api.h"
   6 #include "owned.h"
   7
   8 namespace Msp::Game {
   9
  10 class Component;
  11 class Stage;
  12 class Transform;
  13 struct TransformValues;
  14
  15 class MSPGAME_API hierarchy_error: public std::logic_error
  16 {
  17 public:
  18         hierarchy_error(): std::logic_error("hierarchy error") { }
  19 };
  20
  21 class MSPGAME_API Entity
  22 {
  23 public:
  24         enum TransformTag { NO_TRANSFORM };
  25
  26 private:
  27         Handle<Entity> parent;
  28         std::vector<Handle<Component>> components;
  29         std::vector<Handle<Entity>> children;
  30         Owned<Transform> transform;
  31
  32 public:
  33         Entity(Handle<Entity>, TransformTag);
  34         Entity(Handle<Entity>, const TransformValues &);
  35         virtual ~Entity();
  36
  37         void add_component(Handle<Component>);
  38         void remove_component(Handle<Component>);
  39         const std::vector<Handle<Component>> &get_components() const { return components; }
  40
  41         template<typename T>
  42         Handle<T> get_component();
  43
  44         Handle<Transform> get_transform() const { return transform; }
  45
  46         void add_child(Handle<Entity>);
  47         void remove_child(Handle<Entity>);
  48
  49         Handle<Entity> get_parent() const { return parent; }
  50         Handle<Entity> get_root();
  51         const std::vector<Handle<Entity>> &get_children() const { return children; }
  52         Stage &get_stage();
  53 };
  54
  55
  56 template<typename T>
  57 inline Handle<T> Entity::get_component()
  58 {
  59         for(Handle<Component> c: components)
  60                 if(Handle<T> tc = dynamic_handle_cast<T>(c))
  61                         return tc;
  62         return nullptr;
  63 }
  64
  65 inline Handle<Entity> Entity::get_root()
  66 {
  67         Handle<Entity> e = Handle<Entity>::from_object(this);
  68         while(Handle<Entity> p = e->get_parent())
  69                 e = p;
  70         return e;
  71 }
  72
  73 } // namespace Msp::Game
  74
  75 #endif