4 files changed, 99 insertions, 8 deletions

diff --git a/src/crepe/manager/ComponentManager.h b/src/crepe/manager/ComponentManager.h
index 457a196..c3a5b4a 100644
--- a/src/crepe/manager/ComponentManager.h
+++ b/src/crepe/manager/ComponentManager.h
@@ -142,19 +142,39 @@ public:
 	template <typename T>
 	RefVector<T> get_components_by_tag(const std::string & tag) const;
 
+	//! Snapshot of single component (including path in \c components)
 	struct SnapshotComponent {
+		//! \c components path
 		std::type_index type;
+		//! \c components path
 		game_object_id_t id;
+		//! \c components path
 		size_t index;
+		//! Actual component snapshot
 		std::unique_ptr<Component> component;
 	};
+	//! Snapshot of the entire component manager state
 	struct Snapshot {
+		//! All components
+		std::vector<SnapshotComponent> components;
 		// TODO: some kind of hash code that ensures components exist in all the same places as
 		// this snapshot
-		std::vector<SnapshotComponent> components;
 	};
+	/**
+	 * \name ReplayManager (Memento) functions
+	 * \{
+	 */
+	/**
+	 * \brief Save a snapshot of the component manager state
+	 * \returns Deep copy of the component manager's internal state
+	 */
 	Snapshot save();
-	void restore(const Snapshot &);
+	/**
+	 * \brief Restore component manager from a snapshot
+	 * \param snapshot Snapshot to restore from (as returned by \c save())
+	 */
+	void restore(const Snapshot & snapshot);
+	//! \}
 
 private:
 	/**
diff --git a/src/crepe/manager/ReplayManager.cpp b/src/crepe/manager/ReplayManager.cpp
index ab8a5a0..db6acb0 100644
--- a/src/crepe/manager/ReplayManager.cpp
+++ b/src/crepe/manager/ReplayManager.cpp
@@ -38,6 +38,9 @@ void ReplayManager::release(recording_t handle) {
 }
 
 void ReplayManager::frame_record() {
+	if (this->state != RECORDING)
+		throw runtime_error("ReplayManager: frame_step called while not playing");
+
 	ComponentManager & components = this->mediator.component_manager;
 	Recording & recording = this->recording;
 
@@ -46,6 +49,9 @@ void ReplayManager::frame_record() {
 }
 
 bool ReplayManager::frame_step() {
+	if (this->state != PLAYING)
+		throw runtime_error("ReplayManager: frame_step called while not playing");
+
 	ComponentManager & components = this->mediator.component_manager;
 	Recording & recording = this->recording;
 
@@ -58,6 +64,7 @@ bool ReplayManager::frame_step() {
 	// end of recording
 	recording.frame = 0;
 	this->state = IDLE;
+	this->recording.clear();
 	return true;
 }
 
diff --git a/src/crepe/manager/ReplayManager.h b/src/crepe/manager/ReplayManager.h
index 7be18f3..d3af879 100644
--- a/src/crepe/manager/ReplayManager.h
+++ b/src/crepe/manager/ReplayManager.h
@@ -8,13 +8,14 @@
 
 namespace crepe {
 
-class ReplaySystem;
-
 typedef size_t recording_t;
 
 /**
  * \brief Replay manager
  *
+ * The replay manager is responsible for creating, storing and restoring ComponentManager
+ * snapshots. Sequential snapshots can be recorded and replayed in combination with
+ * ReplaySystem.
  */
 class ReplayManager : public Manager {
 	// TODO: Delete recordings at end of scene
@@ -22,31 +23,70 @@ public:
 	ReplayManager(Mediator & mediator);
 
 public:
+	//! Start a new recording
 	void record_start();
+	/**
+	 * \brief End the latest recording started by \c record_start()
+	 * \returns Handle to recording
+	 */
 	recording_t record_end();
+	/**
+	 * \brief Play a recording
+	 * \param handle Handle to recording (as returned by \c record_end())
+	 */
 	void play(recording_t handle);
+	/**
+	 * \brief Delete a recording from memory
+	 * \param handle Handle to recording (as returned by \c record_end())
+	 */
 	void release(recording_t handle);
 	
 public:
+	//! Internal state
 	enum State {
-		IDLE,
-		RECORDING,
-		PLAYING,
+		IDLE, //!< Not doing anything
+		RECORDING, //!< Currently recording
+		PLAYING, //!< Currently playing back a recording
 	};
+	//! Get current internal state
 	State get_state() const;
 
 public:
+	/**
+	 * \brief Record a single frame to the current recording
+	 *
+	 * This function is called by ReplaySystem after the game programmer has called \c
+	 * record_start()
+	 */
 	void frame_record();
+	/**
+	 * \brief Play the next frame of the current recording
+	 *
+	 * \returns `true` if the recording is finished playing
+	 * \returns `false` if there are more frames
+	 *
+	 * This function also automatically resets the internal state from PLAYING to IDLE at the end
+	 * of a recording.
+	 */
 	bool frame_step();
 
 private:
+	/**
+	 * \brief Recording data
+	 */
 	struct Recording {
+		//! Current frame being shown
 		size_t frame = 0;
+		//! All frames in recording
 		std::vector<ComponentManager::Snapshot> frames;
 	};
+	//! Internal state
 	State state = IDLE;
-	OptionalRef<Recording> recording;
+	//! Current recording handle
 	recording_t id = -1;
+	//! Current recording data
+	OptionalRef<Recording> recording;
+	//! Recording storage
 	std::unordered_map<recording_t, std::unique_ptr<Recording>> memory;
 };
 
diff --git a/src/crepe/manager/SystemManager.h b/src/crepe/manager/SystemManager.h
index 6cf7f2b..a47961b 100644
--- a/src/crepe/manager/SystemManager.h
+++ b/src/crepe/manager/SystemManager.h
@@ -1,11 +1,21 @@
 #pragma once
 
+#include <typeindex>
+#include <unordered_map>
+#include <memory>
+
 #include "../system/System.h"
 
 #include "Manager.h"
 
 namespace crepe {
 
+/**
+ * \brief Collection of all systems
+ *
+ * This manager aggregates all systems and provides utility functions to retrieve references to
+ * and update systems.
+ */
 class SystemManager : public Manager {
 public:
 	SystemManager(Mediator &);
@@ -50,9 +60,23 @@ public:
 	T & get_system();
 
 public:
+	/**
+	 * \brief SystemManager snapshot
+	 *
+	 * The SystemManager snapshot only stores which systems are active
+	 */
 	typedef std::unordered_map<std::type_index, bool> Snapshot;
+	/**
+	 * \brief Save a snapshot of the systems' state
+	 * \returns Copy of each system's active property
+	 */
 	Snapshot save();
+	/**
+	 * \brief Restore system active state from a snapshot
+	 * \param snapshot Snapshot to restore from (as returned by \c save())
+	 */
 	void restore(const Snapshot & snapshot);
+	//! Disable all systems
 	void disable_all();
 };