Implement ecs::entity_container::attach/detach

libs/ecs/include/psemek/ecs/detail/column.hpp

@@ -10,15 +10,16 @@ namespace psemek::ecs::detail
 
 	struct column
 	{
-		column(util::uuid const & uuid)
-			: uuid_(uuid)
-		{}
-
 		std::uint8_t * data()
 		{
 			return data_;
 		}
 
+		std::size_t stride() const
+		{
+			return stride_;
+		}
+
 		util::uuid const & uuid() const
 		{
 			return uuid_;
@@ -36,7 +37,13 @@ namespace psemek::ecs::detail
 
 	protected:
 		std::uint8_t * data_ = nullptr;
+		std::size_t stride_;
 		util::uuid uuid_;
+
+		column(std::size_t stride, util::uuid const & uuid)
+			: stride_(stride)
+			, uuid_(uuid)
+		{}
 	};
 
 	template <typename Component, bool Empty = detail::is_empty_v<Component>>
@@ -81,7 +88,7 @@ namespace psemek::ecs::detail
 
 	template <typename Component, bool Empty>
 	column_impl<Component, Empty>::column_impl()
-		: column(Component::uuid())
+		: column(detail::stride<Component>(), Component::uuid())
 	{}
 
 	template <typename Component, bool Empty>
@@ -177,7 +184,7 @@ namespace psemek::ecs::detail
 
 	template <typename Component>
 	column_impl<Component, true>::column_impl()
-		: column(Component::uuid())
+		: column(detail::stride<Component>(), Component::uuid())
 	{
 		data_ = reinterpret_cast<std::uint8_t *>(new Component[1]);
 	}

libs/ecs/include/psemek/ecs/detail/table.hpp

@@ -33,6 +33,11 @@ namespace psemek::ecs::detail
 			return entity_handles_;
 		}
 
+		util::span<std::unique_ptr<detail::column> const> columns() const
+		{
+			return columns_;
+		}
+
 		std::size_t column_count() const
 		{
 			return component_uuid_to_column_.size();
@@ -44,6 +49,7 @@ namespace psemek::ecs::detail
 		}
 
 		std::size_t push_row(entity_handle handle);
+		std::size_t move_row(entity_handle handle, table * from, std::size_t from_row);
 		void swap_rows(std::size_t row1, std::size_t row2);
 		void pop_row();
 		void clear();
@@ -68,7 +74,8 @@ namespace psemek::ecs::detail
 
 	protected:
 		std::size_t hash_;
-		util::hash_map<util::uuid, std::unique_ptr<detail::column>> component_uuid_to_column_;
+		std::vector<std::unique_ptr<detail::column>> columns_;
+		util::hash_map<util::uuid, detail::column *> component_uuid_to_column_;
 
 		std::vector<entity_handle> entity_handles_;
 

libs/ecs/include/psemek/ecs/detail/table_container.hpp

@@ -43,8 +43,8 @@ namespace psemek::ecs::detail
 	// TODO: store tables in a bitmask trie balanced by subtree size
 	struct table_container
 	{
-		template <typename ... Components>
-		std::pair<table *, bool> insert(util::span<util::uuid const> component_uuids);
+		table * get(util::span<util::uuid const> component_uuids);
+		table * insert(std::unique_ptr<table> table);
 
 		template <typename Function>
 		void apply(Function && function, util::span<util::uuid const> component_uuids);
@@ -53,20 +53,19 @@ namespace psemek::ecs::detail
 		util::hash_set<std::unique_ptr<table>, table_hashset_hash, table_hashset_equal> tables_;
 	};
 
-	template <typename ... Components>
-	std::pair<table *, bool> table_container::insert(util::span<util::uuid const> component_uuids)
+	inline table * table_container::get(util::span<util::uuid const> component_uuids)
 	{
 		auto it = tables_.find(component_uuids);
 		if (it != tables_.end())
-			return {it->get(), false};
+			return it->get();
+		return nullptr;
+	}
 
-		std::vector<std::unique_ptr<column>> columns;
-		(columns.push_back(std::make_unique<column_impl<Components>>()), ...);
-
-		auto table = std::make_unique<detail::table>(std::move(columns));
+	inline table * table_container::insert(std::unique_ptr<table> table)
+	{
 		auto result = table.get();
 		tables_.insert(std::move(table));
-		return {result, true};
+		return result;
 	}
 
 	template <typename Function>

libs/ecs/include/psemek/ecs/entity_container.hpp

@@ -122,23 +122,29 @@ namespace psemek::ecs
 		entity_accessor get(entity_handle const & entity);
 
 		/** Attach new components to an existing entity, or update existing
-		 *    components with new values.
+		 *    components with new values. Other components of this entity
+		 *    are left untouched.
+		 *  Attaching components invalidates all previously created entity accessors.
+		 *  For the purposes of `apply()` semantics, attaching behaves as if the
+		 *    entity was destroyed and then recreated with the same handle.
 		 *  If any two of the passed component types are equal, the call fails with
 		 *    a compilation error.
-		 *  Attaching components invalidates all previously created entity accessors.
 		 *  If the handle wasn't previously obtained by a `create()` call, or
 		 *    the refered entity was already destroyed, the behavior is undefined.
 		 */
-		// TODO: implement
 		template <typename ... Components>
 		void attach(entity_handle const & entity, Components && ... components);
 
-		/** Detach (remove) components from an existing entity.
+		/** Detach (remove) components from an existing entity. Other components of this entity
+		 *    are left untouched. Detaching a component that doesn't exist does nothing.
 		 *  Detaching components invalidates all previously created entity accessors.
+		 *  For the purposes of `apply()` semantics, detaching behaves as if the
+		 *    entity was destroyed and then recreated with the same handle.
+		 *  If any two of the passed component types are equal, the call fails with
+		 *    a compilation error.
 		 *  If the handle wasn't previously obtained by a `create()` call, or
 		 *    the refered entity was already destroyed, the behavior is undefined.
 		 */
-		// TODO: implement
 		template <typename ... Components>
 		void detach(entity_handle const & entity);
 
@@ -155,10 +161,11 @@ namespace psemek::ecs
 		 *      void(entity_handle, components...)
 		 *      void(entity_container, components...)
 		 *      void(entity_container, entity_handle, components...)
-		 *  The function can freely create or destroy entities. It is unspecified
-		 *    whether the function will or will not visit newly created entities
-		 *    during this `apply()` call. The function is guaranteed not to visit
-		 *    destroyed entities (unless it did so before the entity was destroyed).
+		 *  The function can freely create or destroy entities, and or attach/detach
+		 *    components to existing entities. It is unspecified whether the function
+		 *    will or will not visit newly created entities during this `apply()` call.
+		 *    The function is guaranteed not to visit destroyed entities (unless it did
+		 *    so before the entity was destroyed).
 		 *  An optional query cache can be supplied to speed up iteration.
 		 *  If the query cache wasn't created with the exact sequence of component
 		 *    types, the behavior is undefined.
@@ -193,7 +200,10 @@ namespace psemek::ecs
 		detail::query_cache_container query_cache_container_;
 
 		std::vector<util::uuid> uuid_helper_;
+		util::hash_set<util::uuid> uuid_set_helper_;
 
+		detail::table * insert_table(std::vector<std::unique_ptr<detail::column>> columns);
+		void do_destroy(entity_handle const & entity);
 		void remove_row(detail::table & table, std::uint32_t row, util::span<detail::entity_data> entities);
 	};
 
@@ -204,15 +214,14 @@ namespace psemek::ecs
 
 		detail::component_uuid_helper<Components...> uuids;
 
-		auto insert_result = table_container_.insert<Components...>(uuids.get());
-		auto table = insert_result.first;
-		bool created = insert_result.second;
+		auto table = table_container_.get(uuids.get());
 
-		if (created)
+		if (!table)
 		{
-			query_cache_container_.apply([table](detail::query_cache & cache){
-				cache.add(table);
-			}, [table](util::uuid const & uuid){ return table->column(uuid) != nullptr; });
+			std::vector<std::unique_ptr<detail::column>> columns;
+			(columns.push_back(std::make_unique<detail::column_impl<Components>>()), ...);
+
+			table = insert_table(std::move(columns));
 		}
 
 		if (table->get_iteration_data())
@@ -228,6 +237,88 @@ namespace psemek::ecs
 		return handle;
 	}
 
+	template <typename ... Components>
+	void entity_container::attach(entity_handle const & entity, Components && ... components)
+	{
+		static_assert(detail::all_different_types_v<Components...>, "all component types must be different");
+
+		auto & data = entity_list_.get_entities()[entity.id];
+		for (auto const & column : data.table->columns())
+			uuid_helper_.push_back(column->uuid());
+
+		((data.table->column(Components::uuid()) ? 0 : (uuid_helper_.push_back(Components::uuid()), 0)), ...);
+
+		auto table = table_container_.get(uuid_helper_);
+
+		if (!table)
+		{
+			std::vector<std::unique_ptr<detail::column>> columns;
+			for (auto const & column : data.table->columns())
+				columns.push_back(column->clone());
+
+			((data.table->column(Components::uuid()) ? 0 : (columns.push_back(std::make_unique<detail::column_impl<Components>>()), 0)), ...);
+
+			table = insert_table(std::move(columns));
+		}
+
+		if (table != data.table)
+		{
+			if (table->get_iteration_data())
+				table = table->get_delayed_table();
+
+			auto new_row = table->move_row(entity, data.table, data.row);
+			do_destroy(entity);
+
+			data.table = table;
+			data.row = new_row;
+		}
+
+		auto accessor = get(entity);
+		((accessor.get<Components>() = std::move(components)), ...);
+
+		uuid_helper_.clear();
+	}
+
+	template <typename ... Components>
+	void entity_container::detach(entity_handle const & entity)
+	{
+		static_assert(detail::all_different_types_v<Components...>, "all component types must be different");
+
+		(uuid_set_helper_.insert(Components::uuid()), ...);
+
+		auto & data = entity_list_.get_entities()[entity.id];
+		for (auto const & column : data.table->columns())
+			if (!uuid_set_helper_.contains(column->uuid()))
+				uuid_helper_.push_back(column->uuid());
+
+		auto table = table_container_.get(uuid_helper_);
+
+		if (!table)
+		{
+			std::vector<std::unique_ptr<detail::column>> columns;
+			for (auto const & column : data.table->columns())
+				if (!uuid_set_helper_.contains(column->uuid()))
+					columns.push_back(column->clone());
+
+			table = insert_table(std::move(columns));
+		}
+
+		if (table != data.table)
+		{
+			if (table->get_iteration_data())
+				table = table->get_delayed_table();
+
+			auto new_row = table->move_row(entity, data.table, data.row);
+			do_destroy(entity);
+
+			data.table = table;
+			data.row = new_row;
+		}
+
+		uuid_set_helper_.clear();
+		uuid_helper_.clear();
+	}
+
 	template <typename ... Components>
 	query_cache entity_container::cache()
 	{

libs/ecs/source/detail/table.cpp

@@ -11,44 +11,59 @@ namespace psemek::ecs::detail
 		{
 			auto uuid = column->uuid();
 			hasher(uuid);
-			component_uuid_to_column_.insert({uuid, std::move(column)});
+			component_uuid_to_column_.insert({uuid, column.get()});
 		}
 		hash_ = hasher.result;
+
+		columns_ = std::move(columns);
 	}
 
 	detail::column * table::column(util::uuid const & uuid) const
 	{
 		if (auto it = component_uuid_to_column_.find(uuid); it != component_uuid_to_column_.end())
-			return it->second.get();
+			return it->second;
 		return nullptr;
 	}
 
 	std::size_t table::push_row(entity_handle handle)
 	{
-		for (auto & pair : component_uuid_to_column_)
-			pair.second->push_row();
+		for (auto & column : columns_)
+			column->push_row();
+		entity_handles_.push_back(handle);
+		return entity_handles_.size() - 1;
+	}
+
+	std::size_t table::move_row(entity_handle handle, table * from, std::size_t from_row)
+	{
+		for (auto & column : columns_)
+		{
+			if (auto other_column = from->column(column->uuid()))
+				column->emplace_rows(other_column->data() + other_column->stride() * from_row, 1);
+			else
+				column->push_row();
+		}
 		entity_handles_.push_back(handle);
 		return entity_handles_.size() - 1;
 	}
 
 	void table::swap_rows(std::size_t row1, std::size_t row2)
 	{
-		for (auto & pair : component_uuid_to_column_)
-			pair.second->swap_rows(row1, row2);
+		for (auto & column : columns_)
+			column->swap_rows(row1, row2);
 		std::swap(entity_handles_[row1], entity_handles_[row2]);
 	}
 
 	void table::pop_row()
 	{
-		for (auto & pair : component_uuid_to_column_)
-			pair.second->pop_row();
+		for (auto & column : columns_)
+			column->pop_row();
 		entity_handles_.pop_back();
 	}
 
 	void table::clear()
 	{
-		for (auto & pair : component_uuid_to_column_)
-			pair.second->clear();
+		for (auto & column : columns_)
+			column->clear();
 		entity_handles_.clear();
 	}
 
@@ -65,8 +80,8 @@ namespace psemek::ecs::detail
 	std::unique_ptr<table> table::clone() const
 	{
 		std::vector<std::unique_ptr<detail::column>> columns;
-		for (auto const & pair : component_uuid_to_column_)
-			columns.push_back(pair.second->clone());
+		for (auto const & column : columns_)
+			columns.push_back(column->clone());
 		return std::make_unique<table>(std::move(columns));
 	}
 
@@ -83,10 +98,10 @@ namespace psemek::ecs::detail
 			return {};
 
 		std::size_t count = delayed_table_->row_count();
-		for (auto & pair : component_uuid_to_column_)
+		for (std::size_t i = 0; i < columns_.size(); ++i)
 		{
-			auto * src_column = delayed_table_->column(pair.second->uuid());
-			pair.second->emplace_rows(src_column->data(), count);
+			auto * src_column = delayed_table_->columns_[i].get();
+			columns_[i]->emplace_rows(src_column->data(), count);
 		}
 		entity_handles_.insert(entity_handles_.end(), delayed_table_->entity_handles_.begin(), delayed_table_->entity_handles_.end());
 

libs/ecs/source/entity_container.cpp

@@ -10,20 +10,8 @@ namespace psemek::ecs
 
 	void entity_container::destroy(entity_handle const & entity)
 	{
-		auto entities = entity_list_.get_entities();
-		auto & data = entities[entity.id];
-		auto & iteration_data = data.table->get_iteration_data();
-
-		if (!iteration_data || iteration_data->current_row < data.row)
-		{
-			remove_row(*data.table, data.row, entities);
-			entity_list_.destroy(entity.id);
-		}
-		else
-		{
-			data.table->push_remove(data.row);
-			entity_list_.destroy(entity.id);
-		}
+		do_destroy(entity);
+		entity_list_.destroy(entity.id);
 	}
 
 	entity_accessor entity_container::get(entity_handle const & entity)
@@ -32,6 +20,29 @@ namespace psemek::ecs
 		return {data.table, data.row};
 	}
 
+	detail::table * entity_container::insert_table(std::vector<std::unique_ptr<detail::column>> columns)
+	{
+		auto table = table_container_.insert(std::make_unique<detail::table>(std::move(columns)));
+
+		query_cache_container_.apply([table](detail::query_cache & cache){
+			cache.add(table);
+		}, [table](util::uuid const & uuid){ return table->column(uuid) != nullptr; });
+
+		return table;
+	}
+
+	void entity_container::do_destroy(entity_handle const & entity)
+	{
+		auto entities = entity_list_.get_entities();
+		auto & data = entities[entity.id];
+		auto & iteration_data = data.table->get_iteration_data();
+
+		if (!iteration_data || iteration_data->current_row < data.row)
+			remove_row(*data.table, data.row, entities);
+		else
+			data.table->push_remove(data.row);
+	}
+
 	void entity_container::remove_row(detail::table & table, std::uint32_t row, util::span<detail::entity_data> entities)
 	{
 		// Swap with the last row in that table

libs/ecs/tests/attach.cpp

@@ -0,0 +1,242 @@
+#include <psemek/test/test.hpp>
+
+#include <psemek/ecs/entity_container.hpp>
+#include <psemek/ecs/declare_uuid.hpp>
+#include <psemek/random/generator.hpp>
+#include <psemek/random/uniform.hpp>
+
+using namespace psemek;
+using namespace psemek::ecs;
+
+namespace
+{
+
+	struct component_1
+	{
+		int value;
+
+		psemek_declare_uuid("component_1")
+	};
+
+	struct component_2
+	{
+		int value;
+
+		psemek_declare_uuid("component_2")
+	};
+
+	void check_impl(entity_container & container, int count0, int count1, int count2, int count12)
+	{
+		int call_count = 0;
+		container.apply<>([&]{ ++call_count; });
+		expect_equal(call_count, count0 + count1 + count2 + count12);
+
+		call_count = 0;
+		container.apply<component_1>([&](component_1 const &){ ++call_count; });
+		expect_equal(call_count, count1 + count12);
+
+		call_count = 0;
+		container.apply<component_2>([&](component_2 const &){ ++call_count; });
+		expect_equal(call_count, count2 + count12);
+
+		call_count = 0;
+		container.apply<component_1, component_2>([&](component_1 const &, component_2 const &){ ++call_count; });
+		expect_equal(call_count, count12);
+	}
+
+}
+
+test_case(ecs_attach_empty)
+{
+	entity_container container;
+
+	auto h = container.create();
+
+	expect(container.get(h).get_if<component_1>() == nullptr);
+	expect(container.get(h).get_if<component_2>() == nullptr);
+
+	check_impl(container, 1, 0, 0, 0);
+}
+
+test_case(ecs_attach_one)
+{
+	entity_container container;
+
+	auto h = container.create();
+
+	container.attach(h, component_1{10});
+
+	expect_equal(container.get(h).get<component_1>().value, 10);
+	expect(container.get(h).get_if<component_2>() == nullptr);
+
+	check_impl(container, 0, 1, 0, 0);
+}
+
+test_case(ecs_attach_twice)
+{
+	entity_container container;
+
+	auto h = container.create();
+
+	container.attach(h, component_1{10});
+	container.attach(h, component_1{11});
+
+	expect_equal(container.get(h).get<component_1>().value, 11);
+	expect(container.get(h).get_if<component_2>() == nullptr);
+
+	check_impl(container, 0, 1, 0, 0);
+}
+
+test_case(ecs_attach_two)
+{
+	entity_container container;
+
+	auto h = container.create();
+
+	container.attach(h, component_1{10});
+	container.attach(h, component_2{20});
+
+	expect_equal(container.get(h).get<component_1>().value, 10);
+	expect_equal(container.get(h).get<component_2>().value, 20);
+
+	check_impl(container, 0, 0, 0, 1);
+}
+
+test_case(ecs_detach_empty)
+{
+	entity_container container;
+
+	auto h = container.create();
+
+	container.detach<component_1>(h);
+
+	expect(container.get(h).get_if<component_1>() == nullptr);
+	expect(container.get(h).get_if<component_2>() == nullptr);
+
+	check_impl(container, 1, 0, 0, 0);
+}
+
+test_case(ecs_detach_nonexistent)
+{
+	entity_container container;
+
+	auto h = container.create(component_1{10});
+
+	container.detach<component_2>(h);
+
+	expect_equal(container.get(h).get<component_1>().value, 10);
+	expect(container.get(h).get_if<component_2>() == nullptr);
+
+	check_impl(container, 0, 1, 0, 0);
+}
+
+test_case(ecs_detach_one)
+{
+	entity_container container;
+
+	auto h = container.create(component_1{10}, component_2{20});
+
+	container.detach<component_2>(h);
+
+	expect_equal(container.get(h).get<component_1>().value, 10);
+	expect(container.get(h).get_if<component_2>() == nullptr);
+
+	check_impl(container, 0, 1, 0, 0);
+}
+
+test_case(ecs_detach_two)
+{
+	entity_container container;
+
+	auto h = container.create(component_1{10}, component_2{20});
+
+	container.detach<component_1>(h);
+	container.detach<component_2>(h);
+
+	expect(container.get(h).get_if<component_1>() == nullptr);
+	expect(container.get(h).get_if<component_2>() == nullptr);
+
+	check_impl(container, 1, 0, 0, 0);
+}
+
+test_case(ecs_attach_random)
+{
+	random::generator rng;
+	entity_container container;
+
+	int count0 = 0;
+	int count1 = 0;
+	int count2 = 0;
+	int count12 = 0;
+
+	for (int i = 0; i < 1024 * 1024; ++i)
+	{
+		auto h = container.create();
+
+		bool has1 = random::uniform<bool>(rng);
+		bool has2 = random::uniform<bool>(rng);
+
+		if (has1 && has2)
+		{
+			container.attach(h, component_1{i}, component_2{2 * i});
+			++count12;
+		}
+		else if (has1 && !has2)
+		{
+			container.attach(h, component_1{i});
+			++count1;
+		}
+		else if (!has1 && has2)
+		{
+			container.attach(h, component_2{2 * i});
+			++count2;
+		}
+		else
+		{
+			++count0;
+		}
+	}
+
+	check_impl(container, count0, count1, count2, count12);
+}
+
+test_case(ecs_detach_random)
+{
+	random::generator rng;
+	entity_container container;
+
+	int count0 = 0;
+	int count1 = 0;
+	int count2 = 0;
+	int count12 = 0;
+
+	for (int i = 0; i < 1024 * 1024; ++i)
+	{
+		auto h = container.create(component_1{i}, component_2{2 * i});
+
+		bool has1 = random::uniform<bool>(rng);
+		bool has2 = random::uniform<bool>(rng);
+
+		if (has1 && has2)
+		{
+			++count12;
+		}
+		else if (has1 && !has2)
+		{
+			container.detach<component_2>(h);
+			++count1;
+		}
+		else if (!has1 && has2)
+		{
+			container.detach<component_1>(h);
+			++count2;
+		}
+		else
+		{
+			container.detach<component_1, component_2>(h);
+			++count0;
+		}
+	}
+
+	check_impl(container, count0, count1, count2, count12);
+}