8 files changed, 128 insertions, 44 deletions
diff --git a/sim/CMakeLists.txt b/sim/CMakeLists.txt
index 27f312b..55dcc60 100644
--- a/sim/CMakeLists.txt
+++ b/sim/CMakeLists.txt
@@ -7,6 +7,8 @@ add_library(
 	src/FloatingMovement.cpp
 	src/HitPoints.cpp
 	src/RandomSpawner.cpp
+	src/sim.cpp
+	src/State.cpp
 	src/systems.cpp
 	src/TeamManager.cpp
 	src/TurretControl.cpp
diff --git a/sim/include/kurator/sim.h b/sim/include/kurator/sim.h
new file mode 100644
index 0000000..3c4364c
--- /dev/null
+++ b/sim/include/kurator/sim.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include <kurator/campaign/Scenario.h>
+
+#include "sim/State.h"
+
+
+namespace kurator
+{
+namespace sim
+{
+
+
+void load_scenario(State& ctx, const campaign::Scenario& scenario);
+
+
+}  // namespace sim
+}  // namespace kurator
diff --git a/sim/include/kurator/sim/Battle.h b/sim/include/kurator/sim/Battle.h
index 6874b39..1692c0c 100644
--- a/sim/include/kurator/sim/Battle.h
+++ b/sim/include/kurator/sim/Battle.h
@@ -2,9 +2,6 @@
 
 #include <memory>
 
-#include <entt/entity/registry.hpp>
-#include <entt/signal/dispatcher.hpp>
-
 #include <kurator/engine/Context.h>
 #include <kurator/campaign/Scenario.h>
 
@@ -19,8 +16,8 @@ class Battle
 {
 public:
 	virtual ~Battle() = default;
-	virtual entt::registry& registry() = 0;
-	virtual entt::dispatcher& dispatcher() = 0;
+	virtual engine::Context context() = 0;
+	virtual engine::ConstContext const_context() const = 0;
 	virtual void update(engine::Context& ctx) = 0;
 };
 
diff --git a/sim/include/kurator/sim/State.h b/sim/include/kurator/sim/State.h
new file mode 100644
index 0000000..8449ad2
--- /dev/null
+++ b/sim/include/kurator/sim/State.h
@@ -0,0 +1,29 @@
+#pragma once
+
+#include <entt/entity/registry.hpp>
+#include <entt/signal/dispatcher.hpp>
+
+#include <kurator/engine/Camera.h>
+#include <kurator/engine/Clock.h>
+#include <kurator/engine/Context.h>
+
+
+namespace kurator
+{
+namespace sim
+{
+
+
+struct State
+{
+	entt::registry registry;
+	entt::dispatcher dispatcher;
+	engine::Clock clock;
+	engine::Camera camera;  // does not fit in here really
+	operator engine::Context();
+	operator engine::ConstContext() const;
+};
+
+
+}  // namespace sim
+}  // namespace kurator
diff --git a/sim/src/BaseBattle.cpp b/sim/src/BaseBattle.cpp
index 888379e..916a9f8 100644
--- a/sim/src/BaseBattle.cpp
+++ b/sim/src/BaseBattle.cpp
@@ -7,6 +7,7 @@
 
 #include <kurator/engine/Context.h>
 #include <kurator/campaign/Scenario.h>
+#include <kurator/sim.h>
 #include <kurator/sim/components.h>
 #include <kurator/sim/FloatingMovement.h>
 #include <kurator/sim/systems.h>
@@ -23,45 +24,24 @@ namespace sim
 {
 
 
-static void setup_scenario(entt::registry& registry, const campaign::Scenario& scenario);
-
-
-BaseBattle::BaseBattle(const campaign::Scenario& scenario) :
-	_registry {}
-{
-	setup_scenario(_registry, scenario);
-	manager.extend(_registry);
-}
-
-
-void
-setup_scenario(entt::registry& registry, const campaign::Scenario& scenario)
+BaseBattle::BaseBattle(const campaign::Scenario& scenario)
 {
-	RandomSpawner spawner {scenario.last_team(), scenario.radius, 0.1};
-	Builder build {registry, spawner};
-	for (const auto& ship : scenario.ships) {
-		const auto entity = build(ship.loadout.type, ship.team);
-		registry.emplace<universe::UniqueIdentifier>(entity, ship.identifier);
-		auto& state = registry.get<AIState>(entity);
-		for (const auto& turret_type : ship.loadout.turrets) {
-			build(turret_type, entity);
-			state.keep_at_range = std::min(state.keep_at_range, turret_type.optimal_range);
-		}
-	}
+	load_scenario(state, scenario);
+	manager.extend(state.registry);
 }
 
 
-entt::registry&
-BaseBattle::registry()
+engine::Context
+BaseBattle::context()
 {
-	return _registry;
+	return state;
 }
 
 
-entt::dispatcher&
-BaseBattle::dispatcher()
+engine::ConstContext
+BaseBattle::const_context() const
 {
-	return _dispatcher;
+	return state;
 }
 
 
@@ -80,9 +60,9 @@ BaseBattle::update(engine::Context& ctx)
 void
 BaseBattle::pick_random_targets()
 {
-	auto view = _registry.view<Team, AIState>();
+	auto view = state.registry.view<Team, AIState>();
 	for (auto&& [entity, team, ai] : view.each()) {
-		if (!_registry.valid(ai.target))
+		if (!state.registry.valid(ai.target))
 			ai.target = manager.random(team.id);
 	}
 }
diff --git a/sim/src/BaseBattle.h b/sim/src/BaseBattle.h
index 77e1d10..6f59457 100644
--- a/sim/src/BaseBattle.h
+++ b/sim/src/BaseBattle.h
@@ -1,11 +1,9 @@
 #pragma once
 
-#include <entt/entity/registry.hpp>
-#include <entt/signal/dispatcher.hpp>
-
 #include <kurator/engine/Context.h>
 #include <kurator/campaign/Scenario.h>
 #include <kurator/sim/Battle.h>
+#include <kurator/sim/State.h>
 
 #include "TeamManager.h"
 
@@ -20,12 +18,11 @@ class BaseBattle : public Battle
 {
 public:
 	BaseBattle(const campaign::Scenario& scenario);
-	entt::registry& registry() override;
-	entt::dispatcher& dispatcher() override;
+	engine::Context context() override;
+	engine::ConstContext const_context() const override;
 	void update(engine::Context& ctx) override;
 private:
-	entt::registry _registry;
-	entt::dispatcher _dispatcher;
+	State state;
 	TeamManager manager;
 	void pick_random_targets();
 };
diff --git a/sim/src/State.cpp b/sim/src/State.cpp
new file mode 100644
index 0000000..3c8a709
--- /dev/null
+++ b/sim/src/State.cpp
@@ -0,0 +1,25 @@
+#include <kurator/sim/State.h>
+
+#include <kurator/engine/Context.h>
+
+
+namespace kurator
+{
+namespace sim
+{
+
+
+State::operator engine::Context()
+{
+	return {registry, dispatcher, clock, camera};
+}
+
+
+State::operator engine::ConstContext() const
+{
+	return {registry, dispatcher, clock, camera};
+}
+
+
+}  // namespace sim
+}  // namespace kurator
diff --git a/sim/src/sim.cpp b/sim/src/sim.cpp
new file mode 100644
index 0000000..f915d20
--- /dev/null
+++ b/sim/src/sim.cpp
@@ -0,0 +1,36 @@
+#include <kurator/sim.h>
+
+#include <kurator/campaign/Scenario.h>
+#include <kurator/sim/components.h>
+#include <kurator/sim/State.h>
+#include <kurator/universe/UniqueIdentifier.h>
+
+#include "Builder.h"
+#include "RandomSpawner.h"
+
+
+namespace kurator
+{
+namespace sim
+{
+
+
+void
+load_scenario(State& ctx, const campaign::Scenario& scenario)
+{
+	RandomSpawner spawner {scenario.last_team(), scenario.radius, 0.1};
+	Builder build {ctx.registry, spawner};
+	for (const auto& ship : scenario.ships) {
+		const auto entity = build(ship.loadout.type, ship.team);
+		ctx.registry.emplace<universe::UniqueIdentifier>(entity, ship.identifier);
+		auto& state = ctx.registry.get<AIState>(entity);
+		for (const auto& turret_type : ship.loadout.turrets) {
+			build(turret_type, entity);
+			state.keep_at_range = std::min(state.keep_at_range, turret_type.optimal_range);
+		}
+	}
+}
+
+
+}  // namespace sim
+}  // namespace kurator