- Binary Tree (Partial)

- Sequence (Partial)

CMakeLists.txt

@@ -105,6 +105,7 @@ add_library(fennec STATIC
         include/fennec/containers/containers.h
 
         include/fennec/containers/array.h
+        include/fennec/containers/bintree.h
         include/fennec/containers/deque.h
         include/fennec/containers/dynarray.h
         include/fennec/containers/graph.h
@@ -114,6 +115,7 @@ add_library(fennec STATIC
         include/fennec/containers/optional.h
         include/fennec/containers/pair.h
         include/fennec/containers/rdtree.h
+        include/fennec/containers/sequence.h
         include/fennec/containers/set.h
         include/fennec/containers/traversal.h
         include/fennec/containers/tuple.h
@@ -235,7 +237,7 @@ add_library(fennec STATIC
 # EXTRA SOURCES ========================================================================================================
 
         ${FENNEC_EXTRA_SOURCES}
-        include/fennec/containers/bintree.h
+        include/fennec/renderers/interface/gfxresourcepool.h
 )
 
 add_dependencies(fennec metaprogramming fennec-dependencies)

include/fennec/containers/bintree.h

@@ -34,28 +34,36 @@
 #include <fennec/containers/dynarray.h>
 #include <fennec/containers/list.h>
 #include <fennec/containers/optional.h>
+#include <fennec/containers/traversal.h>
 #include <fennec/math/exponential.h>
 #include <fennec/memory/allocator.h>
 
 namespace fennec
 {
 
-template<typename TypeT, class AllocT>
+///
+/// \brief Structure defining a binary tree
+/// \tparam TypeT The data type
+/// \tparam AllocT An allocator class
+template<typename TypeT, class AllocT = allocator<TypeT>>
 struct bintree {
 
-	// Definitions =========================================================================================================
+// Definitions =========================================================================================================
 protected:
 	struct node;
 
 public:
 	using value_t = TypeT;
 	using alloc_t = allocator_traits<AllocT>::template rebind<node>;
-	static constexpr size_t root = 0;
 	static constexpr size_t npos = -1;
+	inline static size_t sink = npos;
+
+	friend class iterator;
+	friend class const_iterator;
 
 protected:
 	struct node {
-		optional<value_t> value;
+		value_t value;
 		size_t  parent, left, right;
 		size_t  depth;
 
@@ -83,18 +91,103 @@ protected:
 	using table_t = allocation<node, alloc_t>;
 	using freed_t = list<size_t, alloc_t>;
 
+// Constructors & Destructor ===========================================================================================
+public:
+
+	/// \name Constructors & Destructor
+	/// @{
+
+	///
+	/// \brief Default Constructor, initializes an empty tree
+	constexpr bintree()
+		: _table()
+		, _freed()
+		, _root(npos)
+		, _size(0) {
+	}
+
+	///
+	/// \brief Move Constructor, takes ownership of a tree
+	/// \param tree The tree to take ownership of
+	constexpr bintree(bintree&& tree) noexcept
+		: _table(fennec::move(tree._table))
+		, _freed(fennec::move(tree._freed))
+		, _root(tree._root)
+		, _size(tree._size) {
+	}
+
+	///
+	/// \brief Copy Constructor, copies a tree
+	/// \param tree The tree to copy
+	constexpr bintree(const bintree& tree)
+		: _table(tree._table)
+		, _freed(tree._freed)
+		, _root(tree._root)
+		, _size(tree._size) {
+	}
+
+	///
+	/// \brief Destructor, clears the tree
+	constexpr ~bintree() {
+		clear();
+	}
+
+	/// @}
+
+
+// Properties ==========================================================================================================
+public:
+
+	///
+	/// \returns The number of elements in the tree
+	constexpr size_t size() const {
+		return _size;
+	}
+
+	///
+	/// \returns The capacity of the underlying allocation
+	constexpr size_t capacity() const {
+		return _table.capacity();
+	}
+
+	///
+	/// \returns The next id to be returned by `insert` or `emplace`.
+	constexpr size_t next_id() const {
+		size_t i = _size;
+		if (not _freed.empty()) {
+			i = _freed.front();
+		}
+		return i;
+	}
+
+	///
+	/// \returns The next id to be returned by `insert` or `emplace`.
+	constexpr size_t root() const {
+		return _root;
+	}
+
+
+
 // Navigation ==========================================================================================================
 public:
 
+	/// \name Navigation
+	/// @{
+
 	///
 	/// \details \f$O(1)\f$
 	/// \param i The node id
 	/// \returns The parent of node `i`
 	constexpr size_t parent(size_t i) const {
-		if (i >= _table.size()) {
+		return i >= _table.size() ? npos : _table[i].parent;
-			return false;
 	}
-		return _table[i].parent;
+
+	///
+	/// \details \f$O(1)\f$
+	/// \param i The node id
+	/// \returns The grandparent of node `i`
+	constexpr size_t grandparent(size_t i) const {
+		return parent(parent(i));
 	}
 
 	///
@@ -102,10 +195,7 @@ public:
 	/// \param i The node id
 	/// \returns The left child of node `i`
 	constexpr size_t left(size_t i) const {
-		if (i >= _table.size()) {
+		return i >= _table.size() ? npos : _table[i].left;
-			return false;
-		}
-		return _table[i].left;
 	}
 
 	///
@@ -113,10 +203,26 @@ public:
 	/// \param i The node id
 	/// \returns The right child of node `i`
 	constexpr size_t right(size_t i) const {
-		if (i >= _table.size()) {
+		return i >= _table.size() ? npos : _table[i].right;
-			return false;
 	}
-		return _table[i].right;
+
+	///
+	/// \brief \f$O(1)\f$
+	/// \param i The id of the node
+	/// \returns The id of the sibling of `i`
+	constexpr size_t sibling(size_t i) const {
+		size_t p = parent(i);
+		size_t l = left(p);
+		size_t r = right(p);
+		return i == l ? l : r;
+	}
+
+	///
+	/// \brief Short for "Parent Sibling," \f$O(1)\f$
+	/// \param i The id of the node
+	/// \returns The id of the parents' sibling of `i`
+	constexpr size_t parsib(size_t i) const {
+		return sibling(parent(i));
 	}
 
 	///
@@ -124,14 +230,45 @@ public:
 	/// \param i The node id
 	/// \returns The depth of node `i`
 	constexpr size_t depth(size_t i) const {
+		return i >= _table.size() ? npos : _table[i].depth;
+	}
+
+	///
+	/// \brief \f$O(\log n)\f$
+	/// \param i The node id
+	/// \returns The id of the left-most node of `i`
+	constexpr size_t left_most(size_t i) const {
 		if (i >= _table.size()) {
 			return npos;
 		}
-		return _table[i].depth;
+		while (_table[i].left != npos) {
+			i = _table[i].left;
 		}
+		return i;
+	}
+
+	///
+	/// \brief \f$O(\log n)\f$
+	/// \param i The node id
+	/// \returns The id of the right-most node of `i`
+	constexpr size_t right_most(size_t i) const {
+		if (i >= _table.size()) {
+			return npos;
+		}
+		while (_table[i].right != npos) {
+			i = _table[i].right;
+		}
+		return i;
+	}
+
+	/// @}
 
 
 // Access ==============================================================================================================
+public:
+
+	/// \name Access
+	/// @{
 
 	///
 	/// \details \f$O(1)\f$
@@ -155,8 +292,13 @@ public:
 		return _table[i] ? &*_table[i] : nullptr;
 	}
 
+	/// @}
+
 // Modifiers ===========================================================================================================
 
+	/// \name Modifiers
+	/// @{
+
 	///
 	/// \brief Move Left Insertion, constructs a new node as the left child of `p`
 	/// \details If the left node of `p` already exists, the move assignment operator is used instead
@@ -174,11 +316,11 @@ public:
 	/// \param val The object to copy to the new node
 	/// \returns The id of the new node
 	constexpr size_t insert_left(size_t p, const value_t& val) {
-		return this->_insert_left(p,, val);
+		return this->_insert_left(p, val);
 	}
 
 	///
-	/// \brief Move Left Insertion, constructs a new node as the left child of `p`
+	/// \brief Emplace Left Insertion, constructs a new node as the left child of `p`
 	/// \details If the left node of `p` already exists, the move assignment operator is used instead
 	/// \param p The parent node
 	/// \param args The arguments to construct the new node with
@@ -188,6 +330,37 @@ public:
 		return this->_insert_left(p, fennec::forward<ArgsT>(args)...);
 	}
 
+	///
+	/// \brief Move Right Insertion, constructs a new node as the right child of `p`
+	/// \details If the right node of `p` already exists, the move assignment operator is used instead
+	/// \param p The parent node
+	/// \param val The object to move into the new node
+	/// \returns The id of the new node
+	constexpr size_t insert_right(size_t p, value_t&& val) {
+		return this->_insert_right(p, fennec::forward<value_t>(val));
+	}
+
+	///
+	/// \brief Copy Right Insertion, constructs a new node as the right child of `p`
+	/// \details If the right node of `p` already exists, the copy assignment operator is used instead
+	/// \param p The parent node
+	/// \param val The object to copy to the new node
+	/// \returns The id of the new node
+	constexpr size_t insert_right(size_t p, const value_t& val) {
+		return this->_insert_right(p, val);
+	}
+
+	///
+	/// \brief Emplace Right Insertion, constructs a new node as the right child of `p`
+	/// \details If the right node of `p` already exists, the move assignment operator is used instead
+	/// \param p The parent node
+	/// \param args The arguments to construct the new node with
+	/// \returns The id of the new node
+	template<typename...ArgsT>
+	constexpr size_t emplace_right(size_t p, ArgsT&&...args) {
+		return this->_insert_right(p, fennec::forward<ArgsT>(args)...);
+	}
+
 	///
 	/// \brief Perform a Left Tree Rotation at `i`
 	/// \param i The root node for the rotation
@@ -242,55 +415,345 @@ public:
 		_table[l].right  = r;
 	}
 
+	///
+	/// \brief Clears the tree, destroying all elements
+	constexpr void clear() {
+		list<size_t> queue;
+
+		if (_root != npos) {
+			queue.push_back(_root);
+		}
+
+		while (not queue.empty()) {
+			size_t i = queue.front();
+			queue.pop_front();
+
+			if (_table[i].left  != npos) {
+				queue.push_front(_table[i].left);
+			}
+			if (_table[i].right != npos) {
+				queue.push_front(_table[i].right);
+			}
+
+			fennec::destruct(&_table[i]);
+		}
+
+		_size = 0;
+		_root = npos;
+	}
+
+	/// @}
+
+
+// Traversal ===========================================================================================================
+
+	///
+	/// \brief Traverse the tree using a specified order and visiting functor
+	///
+	/// \details
+	/// The visitor should accept a reference to a value of type `TypeT` and a `size_t` which contains the node's id.
+	/// The visitor should return one of the following values in the `fennec::traversal_control_` enum
+	///
+	/// \tparam OrderT The order with which to traverse the tree.
+	/// \tparam VisitorT The visitor, should fulfill the signature `uint8_t visit(TypeT&, size_t)`
+	/// \param visit The visiting object
+	/// \param i The node to start at
+	template<typename OrderT, typename VisitorT>
+	constexpr void traverse(VisitorT&& visit, size_t i = root) {
+		OrderT order;
+		i = order(*this, i);
+		while (i != npos) {
+			uint8_t mode = traversal_control_continue;
+			if (_table[i].value) {
+				mode = visit(*_table[i].value, i);
+			}
+			if (mode == traversal_control_break) {
+				break;
+			}
+			i = order[*this, i, mode];
+		}
+	}
+
+	struct breadth_first {
+		list<size_t> visit;
+		size_t       head;
+
+		size_t operator()(const bintree&, size_t start) {
+			return head = start;
+		}
+
+		size_t operator[](const bintree& tree, size_t node, uint8_t mode) {
+			if (node == npos) {
+				return npos;
+			}
+
+			size_t lft = tree.left(tree.parent(node));
+			size_t nxt = lft == node ? tree.right(tree.parent(node)) : npos;
+			size_t chd = tree.left(node);
+
+			if (nxt != npos && node != head) {
+				visit.push_front(nxt);
+			}
+
+			if (chd != npos && mode != traversal_control_jump_over) {
+				visit.push_back(chd);
+			}
+
+			if (not visit.empty()) {
+				node = visit.front();
+				visit.pop_front();
+			} else {
+				node = npos;
+			}
+
+			return node;
+		}
+	};
+
+	struct pre_order {
+		list<size_t> visit;
+		size_t       head;
+
+		constexpr size_t operator()(const bintree&, size_t start) {
+			head = start;
+			return start;
+		}
+
+		constexpr size_t operator[](const bintree& tree, size_t node, uint8_t mode) {
+			if (node == npos) {
+				return npos;
+			}
+
+			size_t nxt = tree.sibling(node);
+			size_t chd = tree.left(node);
+			nxt = node == nxt ? npos : nxt;
+
+			if (nxt != npos && node != head) {
+				visit.push_front(nxt);
+			}
+
+			if (chd != npos && mode != traversal_control_jump_over) {
+				visit.push_front(chd);
+			}
+
+			if (not visit.empty()) {
+				node = visit.front();
+				visit.pop_front();
+			} else {
+				node = npos;
+			}
+
+			return node;
+		}
+	};
+
+	struct in_order {
+		list<size_t> visit;
+		size_t       head;
+
+		constexpr size_t operator()(const bintree& tree, size_t start) {
+			head = start;
+			return tree.left_most(start);
+		}
+
+		constexpr size_t operator[](const bintree& tree, size_t node, uint8_t) {
+			if (node == npos) {
+				return npos;
+			}
+
+			size_t prnt = tree.parent(node);
+			size_t next = tree.sibling(node);
+			next = node == next ? npos : next;
+
+			if (node != head) {
+				if (tree.left(prnt) == node) {
+					visit.push_back(prnt);
+					if (next != npos) {
+						visit.push_back(tree.left_most(next));
+					}
+				} else if (next != npos) {
+					visit.push_front(tree.left_most(next));
+				}
+			}
+
+			if (not visit.empty()) {
+				node = visit.front();
+				visit.pop_front();
+			} else {
+				node = npos;
+			}
+
+			return node;
+		}
+	};
+
+	struct post_order {
+		list<size_t> visit;
+		size_t       head;
+
+		constexpr size_t operator()(const bintree& tree, size_t start) {
+			head = start;
+			return tree.left_most(start);
+		}
+
+		constexpr size_t operator[](const bintree& tree, size_t node, uint8_t) {
+			if (node == npos) {
+				return npos;
+			}
+
+			size_t prnt = tree.parent(node);
+			size_t next = tree.sibling(node);
+			next = node == next ? npos : next;
+
+			if (node != head) {
+				if (next != npos) {
+					visit.push_front(tree.left_most(next));
+				} else {
+					visit.push_front(prnt);
+				}
+			}
+
+			if (not visit.empty()) {
+				node = visit.front();
+				visit.pop_front();
+			} else {
+				node = npos;
+			}
+
+			return node;
+		}
+	};
+
+// Iterator ============================================================================================================
+
+	class iterator {
+	protected:
+		bintree* _tree;
+		in_order _order;
+		size_t   _n;
+
+	public:
+		constexpr iterator(bintree* tree, size_t root, size_t node)
+			: _tree(tree)
+			, _order()
+			, _n(node) {
+			_order(*tree, root);
+		}
+
+		iterator& operator++() {
+			return _n = _order[*_tree, _n, traversal_control_continue], *this;
+		}
+
+		value_t& operator*() {
+			return _tree[_n];
+		}
+
+		value_t* operator->() {
+			return &_tree[_n];
+		}
+
+		const value_t& operator*() const {
+			return _tree[_n];
+		}
+
+		const value_t* operator->() const {
+			return &_tree[_n];
+		}
+
+		constexpr bool operator==(const iterator& it) {
+			return _tree == it._tree and _n == it._n;
+		}
+
+		constexpr bool operator!=(const iterator& it) {
+			return _tree != it._tree or _n != it._n;
+		}
+
+	};
+
+// Fields ==============================================================================================================
 protected:
 	table_t _table;
 	freed_t _freed;
 	size_t  _root, _size;
 
-	constexpr void _next_free() {
+// Helpers =============================================================================================================
+
+	constexpr size_t _next_free() {
 		size_t i = _size;
 		if (not _freed.empty()) {
 			i = _freed.front();
 			_freed.pop_front();
 		}
-		if (i >= _table.size()) {
+		if (i >= _table.capacity()) {
-			_table.reallocate(2 * fennec::max(_table.size(), 4));
+			_table.creallocate(2 * fennec::max(_table.capacity(), size_t(4)));
 		}
+		++_size;
+		return i;
 	}
 
 	template<typename...ArgsT>
 	constexpr size_t _insert_left(size_t p, ArgsT&&...args) {
-		size_t i = left(p);
+		size_t i = p == npos ? _root : left(p);
-		if (i == npos) {
+		if (i != npos) {
-			i = _next_free();
+			_table[i].value = value_t(fennec::forward<ArgsT>(args)...);
-			_table[i].value.emplace(fennec::forward<ArgsT>(args)...);
 		} else {
 			size_t d = 1;
+			i = _next_free();
 			if (p != npos) {
 				d = depth(p) + 1;
 				_table[p].left = i;
 			}
-			fennec::construct(&_table[i], p, npos, npos, d);
+			fennec::construct(&_table[i], p, npos, npos, d, fennec::forward<ArgsT>(args)...);
 		}
+		return i;
 	}
 
 	template<typename...ArgsT>
 	constexpr size_t _insert_right(size_t p, ArgsT&&...args) {
-		size_t i = right(p);
+		size_t i = p == npos ? _root : right(p);
-		if (i == npos) {
+		if (i != npos) {
-			i = _next_free();
+			_table[i].value = value_t(fennec::forward<ArgsT>(args)...);
-			_table[i].value.emplace(fennec::forward<ArgsT>(args)...);
 			if (p == npos || _root == npos) {
 				_root = i;
 			}
 		} else {
 			size_t d = 1;
+			i = _next_free();
 			if (p != npos) {
 				d = depth(p) + 1;
 				_table[p].right = i;
 			}
-			fennec::construct(&_table[i], p, npos, npos, d);
+			fennec::construct(&_table[i], p, npos, npos, d, fennec::forward<ArgsT>(args)...);
 		}
+		return i;
+	}
+
+
+	constexpr size_t& parent(size_t i) {
+		return i >= _table.size() ? sink : _table[i].parent;
+	}
+
+	constexpr size_t& grandparent(size_t i) {
+		return parent(parent(i));
+	}
+
+	constexpr size_t& left(size_t i) {
+		return i >= _table.size() ? sink : _table[i].left;
+	}
+
+	constexpr size_t& right(size_t i) {
+		return i >= _table.size() ? sink : _table[i].right;
+	}
+
+	constexpr size_t& sibling(size_t i) {
+		size_t  p = parent(i);
+		size_t& l = left(p);
+		size_t& r = right(p);
+		return i == l ? l : r;
+	}
+
+	constexpr size_t& parsib(size_t i) {
+		return sibling(parent(i));
 	}
 };
 

include/fennec/containers/detail/_tuple.h

@@ -25,7 +25,7 @@ namespace fennec::detail
 {
 
 
-template <std::size_t I, typename T>
+template <size_t I, typename T>
 struct _tuple_leaf
 {
     template <typename ArgT>

include/fennec/containers/list.h

@@ -140,6 +140,7 @@ public:
 		for (const value_t& it : l) {
 			this->push_back(it);
 		}
+		return *this;
 	}
 
 	///
@@ -152,6 +153,7 @@ public:
 		_freed = fennec::move(l._freed);
 		_root  = l._root; _last = l._last;
 		_size  = l._size;
+		return *this;
 	}
 
 	/// @}
@@ -164,15 +166,21 @@ public:
 
 	///
 	/// \returns The size of the list in elements.
-	constexpr size_t size() const { return _size; }
+	constexpr size_t size() const {
+		return _size;
+	}
 
 	///
 	/// \returns The capacity of the list in elements.
-	constexpr size_t capacity() const { return _table.capacity(); }
+	constexpr size_t capacity() const {
+		return _table.capacity();
+	}
 
 	///
 	/// \returns `true` when the list is empty, `false` otherwise.
-	constexpr bool empty() const { return _root == npos; }
+	constexpr bool empty() const {
+		return _root == npos;
+	}
 
 	/// @}
 

include/fennec/containers/pair.h

@@ -95,19 +95,33 @@ struct pair {
 
 	///
 	/// \brief Copy Constructor, copies both elements
-	constexpr pair(const pair&) = default;
+	constexpr pair(const pair& pair)
+		: first(fennec::copy(pair.first))
+		, second(fennec::copy(pair.second)) {
+	}
 
 	///
 	/// \brief Move Constructor, moves both elements
-	constexpr pair(pair&&) noexcept = default;
+	constexpr pair(pair&& pair) noexcept
+		: first(fennec::move(pair.first))
+		, second(fennec::move(pair.second)) {
+	}
 
 	///
 	/// \brief Copy Assignment, copies both elements
-	constexpr pair& operator=(const pair&) = default;
+	constexpr pair& operator=(const pair& pair) {
+		first  = fennec::copy(pair.first);
+		second = fennec::copy(pair.second);
+		return *this;
+	}
 
 	///
 	/// \brief Move Assignment, moves both elements
-	constexpr pair& operator=(pair&&) noexcept = default;
+	constexpr pair& operator=(pair&& pair) {
+		first  = fennec::move(pair.first);
+		second = fennec::move(pair.second);
+		return *this;
+	}
 
 	/// @}
 

include/fennec/containers/rdtree.h

@@ -414,7 +414,7 @@ public:
 	/// \param visit The visiting object
 	/// \param i The node to start at
 	template<typename OrderT, typename VisitorT>
-	void traverse(VisitorT&& visit, size_t i = root) {
+	constexpr void traverse(VisitorT&& visit, size_t i = root) {
 		OrderT order;
 		i = order(*this, i);
 		while (i != npos) {
@@ -429,16 +429,52 @@ public:
 		}
 	}
 
-	struct pre_order {
+	struct breadth_first {
 		list<size_t> visit;
 		size_t head;
 
-		size_t operator()(const rdtree&, size_t start) {
+		constexpr size_t operator()(const rdtree&, size_t start) {
 			head = start;
 			return start;
 		}
 
-		size_t operator[](const rdtree& tree, size_t node, uint8_t mode) {
+		constexpr size_t operator[](const rdtree& tree, size_t node, uint8_t mode) {
+			if (node == npos) {
+				return npos;
+			}
+
+			size_t nxt = tree.next(node);
+			size_t chd = tree.next(node);
+
+			if (nxt != npos && node != head) {
+				visit.push_front(nxt);
+			}
+
+			if (chd != npos && mode != traversal_control_jump_over) {
+				visit.push_back(chd);
+			}
+
+			if (not visit.empty()) {
+				node = visit.front();
+				visit.pop_front();
+			} else {
+				node = npos;
+			}
+
+			return node;
+		}
+	};
+
+	struct pre_order {
+		list<size_t> visit;
+		size_t       head;
+
+		constexpr size_t operator()(const rdtree&, size_t start) {
+			head = start;
+			return start;
+		}
+
+		constexpr size_t operator[](const rdtree& tree, size_t node, uint8_t mode) {
 			if (node == npos) {
 				return npos;
 			}
@@ -469,12 +505,12 @@ public:
 		list<size_t> visit;
 		size_t       head;
 
-		size_t operator()(const rdtree& tree, size_t start) {
+		constexpr size_t operator()(const rdtree& tree, size_t start) {
 			head = start;
 			return tree.left_most(start);
 		}
 
-		size_t operator[](const rdtree& tree, size_t node, uint8_t) {
+		constexpr size_t operator[](const rdtree& tree, size_t node, uint8_t) {
 			if (node == npos) {
 				return npos;
 			}
@@ -507,12 +543,12 @@ public:
 		list<size_t> visit;
 		size_t       head;
 
-		size_t operator()(const rdtree& tree, size_t start) {
+		constexpr size_t operator()(const rdtree& tree, size_t start) {
 			head = start;
 			return tree.left_most(start);
 		}
 
-		size_t operator[](const rdtree& tree, size_t node, uint8_t) {
+		constexpr size_t operator[](const rdtree& tree, size_t node, uint8_t) {
 			if (node == npos) {
 				return npos;
 			}

include/fennec/containers/sequence.h

@@ -0,0 +1,359 @@
+// =====================================================================================================================
+//  fennec, a free and open source game engine
+//  Copyright © 2025  Medusa Slockbower
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+// =====================================================================================================================
+
+///
+/// \file sequence.h
+/// \brief
+///
+///
+/// \details
+/// \author Medusa Slockbower
+///
+/// \copyright Copyright © 2025 Medusa Slockbower ([GPLv3](https://www.gnu.org/licenses/gpl-3.0.en.html))
+///
+///
+
+#ifndef FENNEC_CONTAINERS_SEQUENCE_H
+#define FENNEC_CONTAINERS_SEQUENCE_H
+#include <fennec/containers/bintree.h>
+#include <fennec/containers/bintree.h>
+#include <fennec/containers/pair.h>
+#include <fennec/containers/sequence.h>
+#include <fennec/containers/sequence.h>
+#include <fennec/containers/sequence.h>
+#include <fennec/lang/compare.h>
+#include <fennec/memory/allocator.h>
+
+namespace fennec
+{
+
+///
+///
+/// \brief wrapper for ordered sets of elements, called sequences in mathematics
+/// \details
+/// This data-structure behaves like an ordered-set, but does not use pointers, instead storing the table in-array
+///
+/// | Property   | Value           |
+/// |:----------:|:---------------:|
+/// | stable     |        ⛔        |
+/// | dynamic    |        ✅        |
+/// | homogenous |        ✅        |
+/// | distinct   |        ✅        |
+/// | ordered    |        ✅        |
+/// | space      |   \f$O(N)\f$    |
+/// | linear     |        ✅        |
+/// | access     | \f$O(\log N)\f$ |
+/// | find       | \f$O(\log N)\f$ |
+/// | insertion  | \f$O(\log N)\f$ |
+/// | deletion   | \f$O(\log N)\f$ |
+///
+/// \tparam TypeT The type to contain
+/// \tparam CompareT Function for comparing two values
+/// \tparam AllocT An allocator class
+template<typename TypeT, typename CompareT = less<TypeT>, class AllocT = allocator<pair<TypeT, bool>>>
+struct sequence : protected bintree<pair<TypeT, bool>, AllocT> {
+
+// Definitions =========================================================================================================
+protected:
+	struct node;
+
+public:
+	using value_t   = TypeT;
+	using node_t    = pair<TypeT, bool>;
+	using alloc_t   = allocator_traits<AllocT>::template rebind<node>;
+	using base_t    = bintree<pair<TypeT, bool>, AllocT>;
+	using compare_t = CompareT;
+	static constexpr size_t npos = -1;
+
+	enum color_ : bool {
+		black = false,
+		red   = true,
+	};
+
+	class iterator;
+
+protected:
+	using typename base_t::in_order;
+
+	using base_t::left;
+	using base_t::right;
+	using base_t::parent;
+	using base_t::grandparent;
+	using base_t::sibling;
+	using base_t::parsib;
+
+	using base_t::insert_left;
+	using base_t::insert_right;
+
+	using base_t::rotate_left;
+	using base_t::rotate_right;
+
+	using base_t::_table;
+	using base_t::_root;
+	using base_t::_size;
+
+// Constructors & Destructors ==========================================================================================
+public:
+	/// \name Constructors & Destructor
+	/// @{
+
+	///
+	/// \brief Default Constructor, initializes an empty sequence
+	constexpr sequence() = default;
+
+	///
+	/// \brief Move Constructor, takes ownership of a sequence
+	constexpr sequence(sequence&&) noexcept = default;
+
+	///
+	/// \brief Copy Constructor, copies a sequence
+	constexpr sequence(const sequence&) = default;
+
+	///
+	/// \brief Default Destructor, destructs elements *in-order*
+	constexpr ~sequence() {
+		this->clear();
+	}
+
+	/// @}
+
+// Search ==============================================================================================================
+public:
+	/// \name Search
+	/// @{
+
+	///
+	/// \brief Value Find Function, finds the iterator position for `val`, otherwise returns `end()`
+	/// \param val The value to find
+	/// \returns An iterator at the value
+	constexpr iterator find(const value_t& val) {
+		size_t node = _root;
+		while (node != npos) {
+			if (_compare(val, _value(node))) {
+				node = left(node);
+			} else if (_compare(_value(node), val)) {
+				node = right(node);
+			} else {
+				return sequence::iterator(this, _root, node);
+			}
+		}
+		return sequence::iterator(this, _root, node);
+	}
+
+	///
+	/// \brief Value Contains Function, checks if the sequence contains a value
+	/// \param val The value to find
+	/// \returns `true` if `val` is in the sequence, `false` otherwise
+	bool contains(const value_t& val) {
+		return find(val) != end();
+	}
+
+	/// @}
+
+
+// Properties ==========================================================================================================
+public:
+	/// \name Properties
+	/// @{
+
+	///
+	/// \returns The number of elements in the sequence
+	using base_t::size;
+
+	///
+	/// \returns The capacity of the underlying allocation
+	using base_t::capacity;
+
+	/// @}
+
+// Modifiers ===========================================================================================================
+public:
+	/// \name Modifiers
+	/// @{
+
+	///
+	/// \brief Move Insertion, moves `val` into the sequence
+	/// \param val The value to insert
+	constexpr void insert(value_t&& val) {
+		size_t i = _insert_bst(fennec::forward<value_t>(val));
+		_fix_insert(i);
+	}
+
+	///
+	/// \brief Copy Insertion, inserts a copy of `val` into the sequence
+	/// \param val The value to insert
+	constexpr void insert(const value_t& val) {
+		size_t i = _insert_bst(val);
+		_fix_insert(i);
+	}
+
+	///
+	/// \brief Emplacement, constructs and adds a value into the sequence
+	/// \tparam ArgsT The argument types
+	/// \param args The arguments to construct with
+	template<typename...ArgsT>
+	constexpr void emplace(ArgsT&&...args) {
+		size_t i = _insert_bst(fennec::forward<ArgsT>(args)...);
+		_fix_insert(i);
+	}
+
+	constexpr void erase(const value_t& val) {
+		size_t i = find(val)._n;
+
+	}
+
+	///
+	/// \brief Destructs all elements, *in-order*, contained in the sequence
+	constexpr void clear() {
+		in_order order;
+		size_t node = order(*this, _root);
+		while (node != npos) {
+			size_t erase = node;
+			node = order[*this, node, traversal_control_continue];
+			fennec::destruct(&_table[erase]);
+		}
+		_size = 0;
+	}
+
+	/// @}
+
+// Iterator ============================================================================================================
+
+	///
+	/// \returns An iterator at the smallest element in the sequence
+	constexpr sequence::iterator begin() {
+		return sequence::iterator(this, _root, _root);
+	}
+
+	///
+	/// \returns An iterator after the largest element in the sequence
+	constexpr sequence::iterator end() {
+		return sequence::iterator(this, _root, npos);
+	}
+
+	class iterator : public base_t::iterator {
+	protected:
+		using base_t::iterator::_n;
+
+
+	public:
+		using base_t::iterator::iterator;
+
+		value_t& operator*() {
+			return _table[_n].value.second;
+		}
+
+		const value_t& operator*() const {
+			return _table[_n].value.second;
+		}
+
+		value_t* operator->() {
+			return &_table[_n].value.second;
+		}
+
+		const value_t* operator->() const {
+			return &_table[_n].value.second;
+		}
+	};
+
+
+// Fields ==============================================================================================================
+protected:
+	compare_t _compare;
+	inline static bool    color_sink = red;
+	inline static value_t value_sink;
+
+// Helpers =============================================================================================================
+protected:
+	constexpr value_t& _value(size_t i) {
+		return i >= _table.capacity() ? value_sink : _table[i].value.first;
+	}
+
+	constexpr const value_t& _value(size_t i) const {
+		return i >= _table.capacity() ? value_sink : _table[i].value.first;
+	}
+
+	constexpr bool& _color(size_t i) {
+		return i >= _table.capacity() ? color_sink : _table[i].value.second;
+	}
+
+	constexpr bool _color(size_t i) const {
+		return i >= _table.capacity() ? color_sink : _table[i].value.second;
+	}
+
+	template<typename...ArgsT>
+	constexpr size_t _insert_bst(ArgsT&&...args) {
+		value_t val(fennec::forward<ArgsT>(args)...);
+
+		size_t i = _root;
+		size_t p = npos;
+		while (i != npos) {
+			p = i;
+
+			if (_compare(val, _value(i))) {
+				i = left(i);
+			} else if (_compare(_value(i), val)) {
+				i = right(i);
+			} else {
+				return i;
+			}
+		}
+
+		if (_root == npos) {
+			return _root = insert_left(npos, node_t(fennec::move(val), red));
+		}
+
+		if (_compare(val, _value(p))) {
+			return insert_left(p, node_t(fennec::move(val), red));
+		} else {
+			return insert_right(p, node_t(fennec::move(val), red));
+		}
+	}
+
+	constexpr void _fix_insert(size_t x) {
+		while (x != _root && _color(parent(x)) == red) {
+			if (_color(parsib(x)) == red) {
+				_color(parent(x))      = black;
+				_color(parsib(x))      = black;
+				_color(grandparent(x)) = red;
+				x = grandparent(x);
+			} else if (parent(x) == left(grandparent(x))) {
+				if (x == right(parent(x))) {
+					x = parent(x);
+					rotate_left(x);
+				}
+				_color(parent(x))      = black;
+				_color(grandparent(x)) = red;
+				rotate_right(grandparent(x));
+			} else {
+				if (x == left(parent(x))) {
+					x = parent(x);
+					rotate_right(x);
+				}
+				_color(parent(x))      = black;
+				_color(grandparent(x)) = red;
+				rotate_left(grandparent(x));
+			}
+		}
+		_color(_root) = black;
+	}
+};
+
+}
+
+#endif // FENNEC_CONTAINERS_SEQUENCE_H

include/fennec/platform/interface/platform.h

@@ -20,6 +20,7 @@
 #define FENNEC_PLATFORM_INTERFACE_PLATFORM_H
 
 #include <fennec/containers/list.h>
+#include <fennec/containers/sequence.h>
 #include <fennec/langproc/strings/cstring.h>
 #include <fennec/langproc/strings/string.h>
 #include <fennec/lang/typed.h>
@@ -69,11 +70,48 @@ public:
 	struct driver {
 		int  priority;
 		ctor constructor;
+
+		driver()
+			: priority(0)
+			, constructor(nullptr) {
+		}
+
+		driver(int priority, ctor constructor)
+			: priority(priority)
+			, constructor(constructor) {
+		}
+
+		driver(const driver& d)
+			: priority(d.priority)
+			, constructor(d.constructor) {
+		}
+
+		driver(driver&& d) noexcept
+			: priority(d.priority)
+			, constructor(d.constructor) {
+		}
+
+		driver& operator=(const driver& d) {
+			priority = d.priority;
+			constructor = d.constructor;
+			return *this;
+		}
+
+		driver& operator=(driver&& d) noexcept {
+			priority = fennec::move(d.priority);
+			constructor = fennec::move(d.constructor);
+			return *this;
+		}
+
+		bool operator<(const driver& d) const {
+			return priority > d.priority;
+		}
 	};
 
 	const string name;
 
 	virtual ~platform() = default;
+	platform(const platform&) = delete;
 
 	// Dynamically linked objects
 	virtual shared_object* load_object(const cstring& file)  = 0;
@@ -96,22 +134,27 @@ protected:
 	explicit platform(const cstring& name, PlatformT* type)
 		: typed(type)
 		, name(name) {
-		assertf(singleton == nullptr, "Conflicting platform implementations!");
+		assertf(globals.singleton == nullptr, "Conflicting platform implementations!");
-		singleton = this;
+		globals.singleton = this;
 	}
 
-private:
-	platform(const platform&) = delete;
-
 // Static Stuff ========================================================================================================
 
 public:
 	static platform* instance() {
-		return singleton;
+		return globals.singleton;
 	}
 
 private:
-	static platform* singleton;
+	inline static struct global {
+		platform*               singleton;
+		sequence<window_driver> windows;
+
+		global()
+			: singleton(nullptr)
+			, windows() {
+		}
+	} globals = global();
 };
 
 }

include/fennec/platform/unix/platform.h

@@ -27,8 +27,8 @@ namespace fennec
 class unix_platform : public platform {
 public:
 	template<typename PlatformT>
-	explicit unix_platform(const cstring& name, PlatformT*)
+	explicit unix_platform(const cstring& name, PlatformT* type)
-		: platform(name, (PlatformT*)(nullptr)) {
+		: platform(name, type) {
 	}
 
 	shared_object* load_object(const cstring& file) override;

include/fennec/renderers/interface/forward.h

@@ -34,7 +34,7 @@
 namespace fennec
 {
 
-class renderer;        // Overarching rendering scheme
+class gfxpass;        // Overarching rendering scheme
 class gfxcontext;      // Globals for an API's context
 class gfxresourcepool; // Handles resource creation, allocation, and mapping
 class gfxsubpass;      // A subpass of the renderer, implements, for example, the steps of composing and lighting a deferred renderer

include/fennec/renderers/interface/gfxcontext.h

@@ -30,25 +30,45 @@
 
 #ifndef FENNEC_RENDERERS_INTERFACE_GFXCONTEXT_H
 #define FENNEC_RENDERERS_INTERFACE_GFXCONTEXT_H
-#include <fennec/renderers/interface/renderer.h>
+
+#include <fennec/lang/types.h>
+#include <fennec/langproc/strings/string.h>
+#include <fennec/renderers/interface/forward.h>
+#include <fennec/renderers/interface/gfxresourcepool.h>
 
 namespace fennec
 {
 
 class gfxcontext {
 public:
+	enum texture_ : uint8_t {
+		texture_1d = 0,
+		texture_1d_array,
+		texture_2d,
+		texture_2d_array,
+		texture_multisample,
+		texture_multisample_array,
+		texture_cubemap,
+		texture_cubemap_array,
+		texture_3d,
+	};
+
+	using handle_t = uint32_t;
+
+	struct version_t {
+		uint8_t major, minor, patch;
+		string str;
+	};
+
+	const version_t version;
+	gfxresourcepool resources;
 
 	gfxcontext& operator=(const gfxcontext&) = delete;
 	gfxcontext& operator=(gfxcontext&&)      = delete;
 
-	renderer* get_renderer() {
+	virtual gfxpass* create_pass() = 0;
-		return _renderer;
-	}
 
 protected:
-	renderer* _renderer;
-
-	gfxcontext(renderer* renderer);
 
 private:
 };

include/fennec/renderers/interface/gfxpass.h

@@ -43,33 +43,8 @@ namespace fennec
 /// \details This represents the overarching renderer, and not any platform specific behaviour.
 ///          I.E. This acts as a proxy for creating API objects, but the behaviour of those objects
 ///          is defined elsewhere.
-class renderer {
+class gfxpass {
 public:
-	enum texture_ : uint8_t {
-		texture_1d = 0,
-		texture_1d_array,
-		texture_2d,
-		texture_2d_array,
-		texture_multisample,
-		texture_multisample_array,
-		texture_cubemap,
-		texture_cubemap_array,
-		texture_3d,
-	};
-
-	using handle_t = uint32_t;
-
-	struct version_t {
-		uint8_t major, minor, patch;
-		string str;
-	};
-
-	const version_t version;
-
-	gfxcontext      context;
-	gfxresourcepool resources;
-
-	handle_t add_subpass();
 
 private:
 

include/fennec/renderers/interface/gfxresourcepool.h

@@ -0,0 +1,43 @@
+// =====================================================================================================================
+//  fennec, a free and open source game engine
+//  Copyright © 2025  Medusa Slockbower
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+// =====================================================================================================================
+
+///
+/// \file gfxresourcepool.h
+/// \brief
+///
+///
+/// \details
+/// \author Medusa Slockbower
+///
+/// \copyright Copyright © 2025 Medusa Slockbower ([GPLv3](https://www.gnu.org/licenses/gpl-3.0.en.html))
+///
+///
+
+#ifndef FENNEC_RENDERERS_INTERFACE_GFXRESOURCEPOOL_H
+#define FENNEC_RENDERERS_INTERFACE_GFXRESOURCEPOOL_H
+
+namespace fennec
+{
+
+class gfxresourcepool {
+
+};
+
+}
+
+#endif // FENNEC_RENDERERS_INTERFACE_GFXRESOURCEPOOL_H

source/platform/interface/platform.cpp

@@ -41,8 +41,12 @@ void platform::initialize() {
 void platform::shutdown() {
 }
 
-window* platform::create_window(const window::config& config) {
+window* platform::create_window(const window::config&) {
+	return nullptr;
+}
 
+void platform::register_window_driver(window_driver&& driver) {
+	globals.windows.insert(fennec::forward<window_driver>(driver));
 }
 
 }

test/CMakeLists.txt

@@ -7,6 +7,7 @@ set(CMAKE_C_STANDARD 23)
 add_executable(fennec-test
         main.cpp
         tests/containers/performance/test_iterator_visitor.h
+        tests/containers/test_sequence.h
 )
 
 target_compile_definitions(fennec-test PUBLIC FENNEC_TEST_CWD="${CMAKE_SOURCE_DIR}/bin/${FENNEC_BUILD_NAME}"

test/tests/containers/test_sequence.h

@@ -0,0 +1,61 @@
+// =====================================================================================================================
+//  fennec, a free and open source game engine
+//  Copyright © 2025  Medusa Slockbower
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+// =====================================================================================================================
+
+///
+/// \file test_sequence.h
+/// \brief
+///
+///
+/// \details
+/// \author Medusa Slockbower
+///
+/// \copyright Copyright © 2025 Medusa Slockbower ([GPLv3](https://www.gnu.org/licenses/gpl-3.0.en.html))
+///
+///
+
+#ifndef FENNEC_TEST_CONTAINERS_SEQUENCE_H
+#define FENNEC_TEST_CONTAINERS_SEQUENCE_H
+#include <fennec/containers/sequence.h>
+
+namespace fennec
+{
+
+namespace test
+{
+
+inline void fennec_test_containers_sequence() {
+	dynarray<size_t> ref;
+	sequence<size_t> test;
+	const size_t n = 50;
+
+	for (size_t i = 0; i < n; ++i) {
+		size_t v = rand();
+		ref.push_back(v);
+		test.insert(v);
+	}
+
+	for (size_t v : ref) {
+		assertf(test.contains(v), "Failed Sequence Test!");
+	}
+}
+
+}
+
+}
+
+#endif // FENNEC_TEST_CONTAINERS_SEQUENCE_H

test/tests/test_containers.h

@@ -28,6 +28,7 @@
 #include "containers/test_object_pool.h"
 #include "containers/test_optional.h"
 #include "containers/test_rdtree.h"
+#include "containers/test_sequence.h"
 #include "containers/test_set.h"
 #include "containers/test_tuple.h"
 
@@ -71,6 +72,11 @@ namespace fennec::test
 		fennec_test_containers_set();
 		fennec_test_spacer(3);
 
+		fennec_test_subheader("sequence tests");
+		fennec_test_spacer(2);
+		fennec_test_containers_sequence();
+		fennec_test_spacer(3);
+
 		fennec_test_subheader("map tests");
 		fennec_test_spacer(2);
 		fennec_test_containers_map();