21 files changed, 865 insertions, 0 deletions

diff --git a/sim/CMakeLists.txt b/sim/CMakeLists.txt
new file mode 100644
index 0000000..f7478e3
--- /dev/null
+++ b/sim/CMakeLists.txt
@@ -0,0 +1,21 @@
+project(battles)
+add_library(
+	${PROJECT_NAME}
+	src/BaseBattle.cpp
+	src/Battle.cpp
+	src/Builder.cpp
+	src/Point.cpp
+	src/RandomSpawner.cpp
+	src/Scenario.cpp
+	src/scenarios.cpp
+	src/TeamManager.cpp
+)
+target_include_directories(
+	${PROJECT_NAME}
+	PUBLIC include
+)
+target_link_libraries(
+	${PROJECT_NAME}
+	PUBLIC EnTT::EnTT
+	PUBLIC universe
+)
diff --git a/sim/include/kurator/sim/Battle.h b/sim/include/kurator/sim/Battle.h
new file mode 100644
index 0000000..1542597
--- /dev/null
+++ b/sim/include/kurator/sim/Battle.h
@@ -0,0 +1,31 @@
+#pragma once
+
+#include <memory>
+
+#include <entt/entity/registry.hpp>
+#include <entt/signal/dispatcher.hpp>
+
+#include "Scenario.h"
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+class Battle
+{
+public:
+	virtual ~Battle() = default;
+	virtual entt::registry& registry() = 0;
+	virtual entt::dispatcher& dispatcher() = 0;
+	virtual void update(float dt) = 0;
+};
+
+
+auto prepare(const Scenario& scenario) -> std::unique_ptr<Battle>;
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/include/kurator/sim/Point.h b/sim/include/kurator/sim/Point.h
new file mode 100644
index 0000000..ba9ab63
--- /dev/null
+++ b/sim/include/kurator/sim/Point.h
@@ -0,0 +1,26 @@
+#pragma once
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+struct Point
+{
+	double x;
+	double y;
+	double magnitude() const;
+	double distance(const Point& other) const;
+	double angle() const;
+	Point rotate(double angle) const;
+	Point scale(double _scale) const;
+	Point normalized() const;
+	Point operator-(const Point& other) const;
+	Point operator+(const Point& other) const;
+};
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/include/kurator/sim/Scenario.h b/sim/include/kurator/sim/Scenario.h
new file mode 100644
index 0000000..afbb74c
--- /dev/null
+++ b/sim/include/kurator/sim/Scenario.h
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "ShipConfig.h"
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+struct Scenario
+{
+	std::string name;
+	std::vector<ShipConfig> ships;
+	int total_teams() const;
+};
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/include/kurator/sim/ShipConfig.h b/sim/include/kurator/sim/ShipConfig.h
new file mode 100644
index 0000000..2066430
--- /dev/null
+++ b/sim/include/kurator/sim/ShipConfig.h
@@ -0,0 +1,22 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+struct ShipConfig
+{
+	int team;
+	std::string type;
+	std::vector<std::string> turrets;
+};
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/include/kurator/sim/components.h b/sim/include/kurator/sim/components.h
new file mode 100644
index 0000000..d4363c4
--- /dev/null
+++ b/sim/include/kurator/sim/components.h
@@ -0,0 +1,59 @@
+#pragma once
+
+#include <entt/entity/entity.hpp>
+
+#include "Point.h"
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+struct Transform
+{
+	Point position;
+	double angle;
+	entt::entity reference_frame = entt::null;
+};
+
+
+struct Team
+{
+	int id;
+};
+
+
+struct AIState
+{
+	Point destination;
+	entt::entity target = entt::null;
+};
+
+
+struct FloatingMovement
+{
+	double max_speed;
+	double acceleration;
+	double deceleration;
+	double destination_boundary;
+	Point speed = {0.0, 0.0};
+};
+
+
+struct HitPoints
+{
+	double health;
+};
+
+
+struct TurretControl
+{
+	double reload;
+	entt::entity owner;
+};
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/include/kurator/sim/events.h b/sim/include/kurator/sim/events.h
new file mode 100644
index 0000000..0e4af14
--- /dev/null
+++ b/sim/include/kurator/sim/events.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#include <entt/entity/entity.hpp>
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+struct Hit
+{
+	double damage;
+	entt::entity source;
+	entt::entity victim;
+};
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/include/kurator/sim/scenarios.h b/sim/include/kurator/sim/scenarios.h
new file mode 100644
index 0000000..3d7e697
--- /dev/null
+++ b/sim/include/kurator/sim/scenarios.h
@@ -0,0 +1,19 @@
+#pragma once
+
+#include "Scenario.h"
+
+
+namespace kurator
+{
+namespace battles
+{
+namespace scenarios
+{
+
+
+Scenario example();
+
+
+}  // namespace scenarios
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/BaseBattle.cpp b/sim/src/BaseBattle.cpp
new file mode 100644
index 0000000..33e0957
--- /dev/null
+++ b/sim/src/BaseBattle.cpp
@@ -0,0 +1,162 @@
+#include "BaseBattle.h"
+
+#include <algorithm>
+#include <cmath>
+
+#include <entt/entity/registry.hpp>
+#include <entt/signal/dispatcher.hpp>
+
+#include <kurator/battles/components.h>
+#include <kurator/battles/events.h>
+#include <kurator/battles/Scenario.h>
+#include <kurator/universe.h>
+
+#include "Builder.h"
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+BaseBattle::BaseBattle(const Scenario& scenario) :
+	_registry {},
+	spawner {scenario.total_teams(), 12000, 0.1}
+{
+	const auto repo = universe::load_sample();
+	Builder build {_registry, spawner};
+	for (const auto& ship : scenario.ships) {
+		const auto entity = build(repo->ship_type(ship.type), ship.team);
+		for (const auto& turret_type : ship.turrets)
+			build(repo->turret_type(turret_type), entity);
+		manager.add(ship.team, entity);  // registry supports on construction events
+	}
+}
+
+
+entt::registry&
+BaseBattle::registry()
+{
+	return _registry;
+}
+
+
+entt::dispatcher&
+BaseBattle::dispatcher()
+{
+	return _dispatcher;
+}
+
+
+void
+BaseBattle::update(const float dt)
+{
+	pick_random_targets();
+	keep_at_range();
+	floating_movement(dt);
+	turrets(dt);
+	kill_off_dead();
+	manager.clear(_registry);  // registry supports on destructions events
+}
+
+
+void
+BaseBattle::pick_random_targets()
+{
+	auto view = _registry.view<Team, AIState>();
+	for (auto&& [entity, team, ai] : view.each()) {
+		if (!_registry.valid(ai.target))
+			ai.target = manager.random((team.id + 1) % 2);  // FIXME
+	}
+}
+
+
+void
+BaseBattle::keep_at_range()
+{
+	auto view = _registry.view<Transform, AIState>();
+	for (auto&& [entity, self, ai] : view.each()) {
+		if (!_registry.valid(ai.target))
+			continue;
+		const auto target = _registry.get<Transform>(ai.target);
+		const Point offset = target.position - self.position;
+		ai.destination = target.position - offset.normalized().scale(6000.0);
+	}
+}
+
+
+void
+BaseBattle::floating_movement(const float dt)
+{
+	auto view = _registry.view<Transform, FloatingMovement, AIState>();
+	for (auto&& [entity, transform, movement, ai] : view.each()) {
+		const auto offset = ai.destination - transform.position;
+		const auto at_destination = offset.magnitude() > movement.destination_boundary;
+		const auto acceleration =
+			at_destination ?
+			offset.normalized().scale(movement.acceleration * dt) :
+			offset.normalized().scale(-1 * movement.deceleration * dt);
+		movement.speed.x += acceleration.x;
+		movement.speed.y += acceleration.y;
+		if (movement.speed.magnitude() > movement.max_speed)
+			movement.speed = movement.speed.normalized().scale(movement.max_speed);
+		const auto speed = movement.speed.scale(dt);
+		transform.position.x += speed.x;
+		transform.position.y += speed.y;
+		transform.angle = speed.angle();
+	}
+}
+
+
+double
+effective_damage(const universe::TurretType& def, const double distance)
+{
+	const auto overflow = distance - def.optimal_range;
+	const auto falloff = std::max(0.0, overflow / def.optimal_range / def.falloff_modifier);
+	return def.base_damage * std::round(std::pow(def.falloff_intensity, std::pow(falloff, 2)) * 1000) / 1000;
+}
+
+
+void
+BaseBattle::turrets(const float dt)
+{
+	auto view = _registry.view<TurretControl, universe::TurretType>();
+	for (auto&& [entity, control, def] : view.each()) {
+		if (!_registry.valid(control.owner)) {
+			_registry.destroy(entity);
+			continue;
+		}
+		const auto& [state, transform] = _registry.get<AIState, Transform>(control.owner);  // no checks
+		if (!_registry.valid(state.target))
+			continue;
+		if (control.reload > 0.0)
+			control.reload -= dt;
+		if (control.reload <= 0.0) {
+			auto& target_points = _registry.get<HitPoints>(state.target);
+			const auto& target = _registry.get<Transform>(state.target);
+			const auto distance = transform.position - target.position;
+			const auto damage = effective_damage(def, distance.magnitude());
+			if (damage > 0.0) {
+				target_points.health -= damage;
+				_dispatcher.trigger(Hit{damage, entity, state.target});
+			}
+			control.reload = def.rate_of_fire;
+		}
+	}
+}
+
+
+void
+BaseBattle::kill_off_dead()
+{
+	auto view = _registry.view<HitPoints>();
+	for (auto&& [entity, points] : view.each()) {
+		if (points.health <= 0.0)
+			_registry.destroy(entity);
+	}
+}
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/BaseBattle.h b/sim/src/BaseBattle.h
new file mode 100644
index 0000000..8240fd2
--- /dev/null
+++ b/sim/src/BaseBattle.h
@@ -0,0 +1,40 @@
+#pragma once
+
+#include <entt/entity/registry.hpp>
+#include <entt/signal/dispatcher.hpp>
+
+#include <kurator/battles/Battle.h>
+#include <kurator/battles/Scenario.h>
+
+#include "RandomSpawner.h"
+#include "TeamManager.h"
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+class BaseBattle : public Battle
+{
+public:
+	BaseBattle(const Scenario& scenario);
+	entt::registry& registry() override;
+	entt::dispatcher& dispatcher() override;
+	void update(float dt) override;
+private:
+	entt::registry _registry;
+	entt::dispatcher _dispatcher;
+	RandomSpawner spawner;
+	TeamManager manager;
+	void pick_random_targets();
+	void keep_at_range();
+	void floating_movement(float dt);
+	void turrets(float dt);
+	void kill_off_dead();
+};
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/Battle.cpp b/sim/src/Battle.cpp
new file mode 100644
index 0000000..f44a88e
--- /dev/null
+++ b/sim/src/Battle.cpp
@@ -0,0 +1,24 @@
+#include <kurator/battles/Battle.h>
+
+#include <memory>
+
+#include <kurator/battles/Scenario.h>
+
+#include "BaseBattle.h"
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+std::unique_ptr<Battle>
+prepare(const Scenario& scenario)
+{
+	return std::make_unique<BaseBattle>(scenario);
+}
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/Builder.cpp b/sim/src/Builder.cpp
new file mode 100644
index 0000000..d7cc893
--- /dev/null
+++ b/sim/src/Builder.cpp
@@ -0,0 +1,57 @@
+#include "Builder.h"
+
+#include <entt/entity/registry.hpp>
+
+#include <kurator/battles/components.h>
+#include <kurator/battles/Point.h>
+#include <kurator/universe/ShipType.h>
+#include <kurator/universe/TurretType.h>
+
+#include "Spawner.h"
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+Builder::Builder(entt::registry& _registry, Spawner& _spawner) :
+	registry {_registry},
+	spawner {_spawner}
+{
+}
+
+
+entt::entity
+Builder::operator()(const universe::ShipType& ship_type, const int team) const
+{
+	const auto entity = registry.create();
+	registry.emplace<universe::ShipType>(entity, ship_type);
+	registry.emplace<Team>(entity, team);
+	registry.emplace<Transform>(entity, spawner.get(team));
+	registry.emplace<FloatingMovement>(
+		entity,
+		ship_type.max_speed,
+		ship_type.max_speed * 2.0,
+		ship_type.max_speed * 3.0,
+		100.0);
+	registry.emplace<AIState>(entity, Point{0.0, 0.0});
+	registry.emplace<HitPoints>(entity, ship_type.base_health_points);
+	return entity;
+}
+
+
+entt::entity
+Builder::operator()(const universe::TurretType& turret_type, const entt::entity& owner) const
+{
+	const auto entity = registry.create();
+	registry.emplace<universe::TurretType>(entity, turret_type);
+	registry.emplace<TurretControl>(entity, 0.0, owner);
+	registry.emplace<Transform>(entity, Point{0.0, 0.0}, 0.0, owner);
+	return entity;
+}
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/Builder.h b/sim/src/Builder.h
new file mode 100644
index 0000000..df50c4e
--- /dev/null
+++ b/sim/src/Builder.h
@@ -0,0 +1,35 @@
+#pragma once
+
+#include <entt/entity/registry.hpp>
+
+#include <kurator/universe/ShipType.h>
+#include <kurator/universe/TurretType.h>
+
+#include "Spawner.h"
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+class Builder
+{
+public:
+	Builder(entt::registry& _registry, Spawner& _spawner);
+	~Builder() = default;
+	Builder(Builder&&) = delete;
+	Builder(const Builder&) = delete;
+	Builder& operator=(Builder&&) = delete;
+	Builder& operator=(const Builder&) = delete;
+	entt::entity operator()(const universe::ShipType& ship_type, int team) const;
+	entt::entity operator()(const universe::TurretType& turret_type, const entt::entity& owner) const;
+private:
+	entt::registry& registry;
+	Spawner& spawner;
+};
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/Point.cpp b/sim/src/Point.cpp
new file mode 100644
index 0000000..31aecae
--- /dev/null
+++ b/sim/src/Point.cpp
@@ -0,0 +1,72 @@
+#include <kurator/battles/Point.h>
+
+#include <cmath>
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+double
+Point::magnitude() const
+{
+	return std::sqrt(std::pow(x, 2) + std::pow(y, 2));
+}
+
+
+double
+Point::distance(const Point& other) const
+{
+	return std::sqrt(std::pow(other.x - x, 2) + std::pow(other.y - y, 2));
+}
+
+
+double
+Point::angle() const
+{
+	return std::atan2(y, x);  // (+x, _) is 0
+}
+
+
+Point
+Point::rotate(const double angle) const
+{
+	return {
+		x * std::cos(angle) - y * std::sin(angle),
+		x * std::sin(angle) + y * std::cos(angle),
+	};
+}
+
+
+Point
+Point::scale(const double _scale) const
+{
+	return {x * _scale, y * _scale};
+}
+
+
+Point
+Point::normalized() const
+{
+	return scale(1.0 / magnitude());
+}
+
+
+Point
+Point::operator-(const Point& other) const
+{
+	return {x - other.x, y - other.y};
+}
+
+
+Point
+Point::operator+(const Point& other) const
+{
+	return {x + other.x, y + other.y};
+}
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/RandomSpawner.cpp b/sim/src/RandomSpawner.cpp
new file mode 100644
index 0000000..b85d140
--- /dev/null
+++ b/sim/src/RandomSpawner.cpp
@@ -0,0 +1,42 @@
+#include "RandomSpawner.h"
+
+#include <cmath>
+
+#include <kurator/battles/components.h>
+#include <kurator/battles/Point.h>
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+RandomSpawner::RandomSpawner(const int total_teams, const double distance, const double variation) :
+	angle_step {2.0 * M_PI / total_teams},
+	device {},
+	distribution_d {distance - distance * variation, distance + distance * variation},
+	distribution_a {-variation * M_PI, variation * M_PI}
+{
+}
+
+
+Transform
+RandomSpawner::get(const int team)
+{
+	const double distance = distribution_d(device);
+	const double clean_angle = angle_step * team;
+	const double angle = clean_angle + distribution_a(device);
+	double facing = clean_angle + M_PI;
+	if (facing > 2 * M_PI)
+		facing -= 2 * M_PI;
+	const Point position {
+		distance * std::cos(angle),
+		distance * std::sin(angle),
+	};
+	return {position, facing};
+}
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/RandomSpawner.h b/sim/src/RandomSpawner.h
new file mode 100644
index 0000000..1ef2f20
--- /dev/null
+++ b/sim/src/RandomSpawner.h
@@ -0,0 +1,30 @@
+#pragma once
+
+#include <random>
+
+#include <kurator/battles/components.h>
+
+#include "Spawner.h"
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+class RandomSpawner : public Spawner
+{
+public:
+	RandomSpawner(int total_teams, double distance, double variation);
+	Transform get(int team) override;
+private:
+	const double angle_step;
+	std::random_device device;
+	std::uniform_real_distribution<double> distribution_d;
+	std::uniform_real_distribution<double> distribution_a;
+};
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/Scenario.cpp b/sim/src/Scenario.cpp
new file mode 100644
index 0000000..49a9c7c
--- /dev/null
+++ b/sim/src/Scenario.cpp
@@ -0,0 +1,23 @@
+#include <kurator/battles/Scenario.h>
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+int
+Scenario::total_teams() const
+{
+	int last_team = 0;
+	for (const auto& ship : ships) {
+		if (ship.team > last_team)
+			last_team = ship.team;
+	}
+	return last_team + 1;
+}
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/Spawner.h b/sim/src/Spawner.h
new file mode 100644
index 0000000..ebae699
--- /dev/null
+++ b/sim/src/Spawner.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#include <kurator/battles/components.h>
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+class Spawner
+{
+public:
+	virtual ~Spawner() = default;
+	virtual Transform get(int team) = 0;
+};
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/TeamManager.cpp b/sim/src/TeamManager.cpp
new file mode 100644
index 0000000..9dc90e3
--- /dev/null
+++ b/sim/src/TeamManager.cpp
@@ -0,0 +1,62 @@
+#include "TeamManager.h"
+
+#include <algorithm>
+#include <random>
+#include <utility>
+#include <vector>
+
+#include <entt/entity/registry.hpp>
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+TeamManager::TeamManager() :
+	teams {},
+	generator {std::random_device{}()}
+{
+}
+
+
+void
+TeamManager::add(int team, entt::entity entity)
+{
+	for (int i = teams.size(); i < team + 1; ++i)
+		teams.emplace_back();
+	teams.at(team).push_back(std::move(entity));
+}
+
+
+TeamManager::Team
+TeamManager::get(int team) const
+{
+	return teams.at(team);
+}
+
+
+entt::entity
+TeamManager::random(int team)
+{
+	auto& members = teams.at(team);
+	if (members.size() == 0)
+		return entt::null;
+	std::uniform_int_distribution<Team::size_type> uniform{0, members.size() - 1};
+	return members.at(uniform(generator));
+}
+
+
+void
+TeamManager::clear(entt::registry& registry)
+{
+	for (auto& members : teams) {
+		auto is_valid = [&registry](entt::entity entity){ return !registry.valid(entity); };
+		members.erase(std::remove_if(members.begin(), members.end(), is_valid), members.end());
+	}
+}
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/TeamManager.h b/sim/src/TeamManager.h
new file mode 100644
index 0000000..384d9ee
--- /dev/null
+++ b/sim/src/TeamManager.h
@@ -0,0 +1,31 @@
+#pragma once
+
+#include <random>
+#include <vector>
+
+#include <entt/entity/registry.hpp>
+
+
+namespace kurator
+{
+namespace battles
+{
+
+
+class TeamManager
+{
+public:
+	using Team = std::vector<entt::entity>;
+	TeamManager();
+	void add(int team, entt::entity entity);
+	Team get(int team) const;
+	entt::entity random(int team);
+	void clear(entt::registry& registry);
+private:
+	std::vector<Team> teams;
+	std::mt19937 generator;
+};
+
+
+}  // namespace battles
+}  // namespace kurator
diff --git a/sim/src/scenarios.cpp b/sim/src/scenarios.cpp
new file mode 100644
index 0000000..34b4a24
--- /dev/null
+++ b/sim/src/scenarios.cpp
@@ -0,0 +1,43 @@
+#include <kurator/battles/scenarios.h>
+
+#include <kurator/battles/Scenario.h>
+
+
+namespace kurator
+{
+namespace battles
+{
+namespace scenarios
+{
+
+
+Scenario
+example()
+{
+	return {
+		"Example",
+		{
+			{0, "Anvil", {"ChargeLaser", "ChargeLaser"}},
+			{0, "Anvil", {"ChargeLaser", "ChargeLaser"}},
+			{0, "Anvil", {"ChargeLaser", "ChargeLaser"}},
+			{0, "Warbringer", {"ChargeLaser"}},
+			{0, "Warbringer", {"ChargeLaser"}},
+			{0, "Eclipse", {"ChargeLaser"}},
+			{0, "Eclipse", {"ChargeLaser"}},
+			{0, "Eclipse", {"ChargeLaser"}},
+			{1, "Anvil", {"ChargeLaser", "ChargeLaser"}},
+			{1, "Anvil", {"ChargeLaser", "ChargeLaser"}},
+			{1, "Anvil", {"ChargeLaser", "ChargeLaser"}},
+			{1, "Warbringer", {"ChargeLaser"}},
+			{1, "Warbringer", {"ChargeLaser"}},
+			{1, "Eclipse", {"ChargeLaser"}},
+			{1, "Eclipse", {"ChargeLaser"}},
+			{1, "Eclipse", {"ChargeLaser"}},
+		},
+	};
+}
+
+
+}  // namespace scenarios
+}  // namespace battles
+}  // namespace kurator