Make it possible to retrieve components and systems of a particular type

[libs/game.git] / source / game / stage.h

diff --git a/source/game/stage.h b/source/game/stage.h
index dbffc9960bedb4fd89c55a232dd6dd91f0fb68c5..d7793e22f60ec21fd52acab1b8af9aafbe2f4d94 100644 (file)
--- a/source/game/stage.h
+++ b/source/game/stage.h
@@ -4,6 +4,8 @@
 #include <memory>
 #include <msp/time/timedelta.h>
 #include "eventbus.h"
+#include "events.h"
+#include "eventsource.h"
 #include "handle.h"
 
 namespace Msp::Game {
@@ -13,9 +15,14 @@ class System;
 
 class Stage
 {
+public:
+       using EventSource = Game::EventSource<Events::EntityCreated, Events::EntityDestroyed,
+               Events::ComponentCreated, Events::ComponentDestroyed>;
+
 private:
        PoolPool pools;
        EventBus event_bus;
+       EventSource event_source;
        /* Use unique_ptr because there's only one root per stage so it's pointless
        to put it in a pool. */
        std::unique_ptr<Root> root;
@@ -27,6 +34,7 @@ public:
 
        PoolPool &get_pools() { return pools; }
        EventBus &get_event_bus() { return event_bus; }
+       EventSource &get_event_source() { return event_source; }
        Handle<Root> get_root() { return Handle<Root>::from_object(root.get()); }
 
        template<typename T, typename F>
@@ -37,22 +45,34 @@ public:
 
        const std::vector<std::unique_ptr<System>> &get_systems() const { return systems; }
 
+       template<typename T>
+       T *get_system() const;
+
        void tick(Time::TimeDelta);
 };
 
 template<typename T, typename F>
-void Stage::iterate_objects(const F &func)
+inline void Stage::iterate_objects(const F &func)
 {
        pools.get_pool<T>().iterate_objects(func);
 }
 
 template<typename T, typename... Args>
-T &Stage::add_system(Args &&... args)
+inline T &Stage::add_system(Args &&... args)
 {
        systems.emplace_back(std::make_unique<T>(*this, std::forward<Args>(args)...));
        return static_cast<T &>(*systems.back());
 }
 
+template<typename T>
+inline T *Stage::get_system() const
+{
+       for(const auto &s: systems)
+               if(T *ts = dynamic_cast<T *>(s.get()))
+                       return ts;
+       return nullptr;
+}
+
 } // namespace Msp::Game
 
 #endif