Hiding away implementation details of battle simulation

4 files changed, 49 insertions, 16 deletions

diff --git a/battles/include/kurator/battles/Battle.h b/battles/include/kurator/battles/Battle.h
index 468a972..82a5da5 100644
--- a/battles/include/kurator/battles/Battle.h
+++ b/battles/include/kurator/battles/Battle.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <memory>
+
 #include <entt/entity/registry.hpp>
 
 #include "Scenario.h"
@@ -11,13 +13,17 @@ namespace battles
 {
 
 
-struct Battle
+class Battle
 {
-	explicit Battle(Scenario scenario);
-	void update(float dt);
-	entt::registry registry;
+public:
+	virtual ~Battle() = default;
+	virtual entt::registry& registry() = 0;
+	virtual void update(float dt) = 0;
 };
 
 
+auto prepare(const Scenario& scenario) -> std::unique_ptr<Battle>;
+
+
 }  // namespace battles
 }  // namespace kurator
diff --git a/battles/src/Battle.cpp b/battles/src/Battle.cpp
index 454cbfd..99ed076 100644
--- a/battles/src/Battle.cpp
+++ b/battles/src/Battle.cpp
@@ -1,7 +1,10 @@
 #include <kurator/battles/Battle.h>
 
+#include <memory>
 #include <random>
 
+#include <entt/entity/registry.hpp>
+
 #include <kurator/battles/components.h>
 #include <kurator/battles/Scenario.h>
 #include <kurator/universe/ShipType.h>
@@ -13,27 +16,52 @@ namespace battles
 {
 
 
-Battle::Battle(Scenario scenario)
+class BaseBattle : public Battle
+{
+public:
+	BaseBattle(const Scenario& scenario);
+	entt::registry& registry() override;
+	void update(float dt) override;
+private:
+	entt::registry _registry;
+};
+
+
+BaseBattle::BaseBattle(const Scenario& scenario)
 {
 	std::random_device dev;
 	std::uniform_real_distribution<> pos{-2.5, 2.5};
 	for (const auto& ship : scenario.ships) {
-		const auto entity = registry.create();
-		registry.emplace<universe::ShipType>(entity, ship.type);
-		registry.emplace<Team>(entity, ship.team);
-		registry.emplace<Transform>(entity, Point{pos(dev), pos(dev)}, Point{0.0, 0.0});
+		const auto entity = _registry.create();
+		_registry.emplace<universe::ShipType>(entity, ship.type);
+		_registry.emplace<Team>(entity, ship.team);
+		_registry.emplace<Transform>(entity, Point{pos(dev), pos(dev)}, Point{0.0, 0.0});
 	}
 }
 
 
+entt::registry&
+BaseBattle::registry()
+{
+	return _registry;
+}
+
+
 void
-Battle::update(const float dt)
+BaseBattle::update(const float dt)
 {
-	auto view = registry.view<Transform, Team>();
+	auto view = _registry.view<Transform, Team>();
 	for (auto&& [entity, transform, team] : view.each())
 		transform.position.x += 0.1 * dt * (team.id * 2 - 1);
 }
 
 
+std::unique_ptr<Battle>
+prepare(const Scenario& scenario)
+{
+	return std::make_unique<BaseBattle>(scenario);
+}
+
+
 }  // namespace battles
 }  // namespace kurator
diff --git a/kurator/src/Battle.cpp b/kurator/src/Battle.cpp
index 5aa18fe..7320c19 100644
--- a/kurator/src/Battle.cpp
+++ b/kurator/src/Battle.cpp
@@ -8,7 +8,6 @@
 
 #include <kurator/battles/components.h>
 #include <kurator/battles/Battle.h>
-#include <kurator/battles/Scenario.h>
 #include <kurator/battles/scenarios.h>
 #include <kurator/universe/ShipType.h>
 
@@ -22,7 +21,7 @@ namespace kurator
 
 Battle::Battle(std::shared_ptr<Session> _session) :
 	session {std::move(_session)},
-	battle {battles::scenarios::example()}
+	battle {battles::prepare(battles::scenarios::example())}
 {
 }
 
@@ -30,7 +29,7 @@ Battle::Battle(std::shared_ptr<Session> _session) :
 void
 Battle::update(const float dt)
 {
-	battle.update(dt);
+	battle->update(dt);
 	if (IsKeyPressed(KEY_SPACE))
 		session->set(std::make_shared<Title>(session));
 }
@@ -43,7 +42,7 @@ Battle::draw() const
 	const int width = GetScreenWidth();
 	const int height = GetScreenHeight();
 	const double scale = std::min(width/10.0, height/10.0);
-	auto view = battle.registry.view<const universe::ShipType, const battles::Team, const battles::Transform>();
+	auto view = battle->registry().view<const universe::ShipType, const battles::Team, const battles::Transform>();
 	for (auto [entity, ship_type, team, transform] : view.each()) {
 		(void) entity;
 		const auto color = team.id == 1 ? RED : GREEN;
diff --git a/kurator/src/Battle.h b/kurator/src/Battle.h
index 476381b..64cdb47 100644
--- a/kurator/src/Battle.h
+++ b/kurator/src/Battle.h
@@ -20,7 +20,7 @@ public:
 	void draw() const override;
 private:
 	std::shared_ptr<Session> session;
-	battles::Battle battle;
+	std::unique_ptr<battles::Battle> battle;
 };