3d游戏引擎的Utilities模块实现
1.Vector.h
#pragma once
#include "CommonHeaders.h"
namespace primal::utl
{
template
class vector
{
public:
vector() = default;
constexpr vector(u64 count)
{
resize(count);
}
constexpr explicit vector(u64 count, const T& value)
{
resize(count,value);
}
/*
template
constexpr explicit vector(it first, it last)
{
for (; first != last; ++first)
{
emplace_back(*first);
}
}
*/
constexpr vector(const vector& o)
{
*this = o;
}
constexpr vector(vector&& o)
: _capacity{ o._capacity }, _size{ o.size }, _data{o.data}
{
o.reset();
}
constexpr vector& operator=(const vector& o)
{
assert(this != std::addressof(o));
if (this != std::addressof(o))
{
clear();
reserve(o._size);
for (auto& item : o)
{
emplace_back(item);
}
assert(_size == o._size);
}
return *this;
}
constexpr vector& operator=(vector&& o)
{
assert(this != std::addressof(o));
if (this != std::addressof(o))
{
destroy();
move(o);
}
return *this;
}
~vector() { destroy(); }
constexpr void push_back(const T& value)
{
emplace_back(value);
}
constexpr void push_back(T&& value)
{
emplace_back(std::move(value));
}
template
constexpr decltype(auto) emplace_back(params&&... p)
{
if (_size == _capacity)
{
reserve(((_capacity + 1) * 3) >> 1);
}
assert(_size < _capacity);
T* const item{ new(std::addressof(_data[_size])) T(std::forward
++_size;
return *item;
}
constexpr void resize(u64 new_size)
{
static_assert(std::is_default_constructible_v
"Type must be default-constructable."
);
if (new_size > _size)
{
reserve(new_size);
while (_size < new_size)
{
emplace_back();
}
}
else
{
if constexpr (destruct)
{
destruct_range(new_size, _size);
}
_size = new_size;
}
assert(new_size == _size);
}
constexpr void resize(u64 new_size,const T& value)
{
static_assert(std::is_copy_constructible_v
"Type must be copy-constructable."
);
if (new_size > _size)
{
reserve(new_size);
while (_size < new_size)
{
emplace_back(value);
}
}
else
{
if constexpr (destruct)
{
destruct_range(new_size, _size);
}
_size = new_size;
}
assert(new_size == _size);
}
constexpr void reserve(u64 new_capacity)
{
if (new_capacity > _capacity)
{
void* new_buffer{ realloc(_data,new_capacity * sizeof(T)) };
if (new_buffer)
{
_data = static_cast
_capacity = new_capacity;
}
}
}
constexpr T* const erase(u64 index)
{
assert(_data && index < _size);
return erase(std::addressof(_data[index]));
}
constexpr T* const erase(T* const item)
{
assert(_data && item >= std::addressof(_data[0]) &&
item < std::addressof(_data[_size])
);
if constexpr (destruct) item->~T();
--_size;
if (item < std::addressof(_data[_size]))
{
memcpy(item, item + 1, (std::addressof(_data[_size]) - item) * sizeof(T));
}
return item;
}
constexpr T* const erase_unordered(u64 index)
{
assert(_data && index < _size);
return erase_unordered(std::addressof(_data[index]));
}
constexpr T* const erase_unordered(T* const item)
{
assert(_data && item >= std::addressof(_data[0]) &&
item < std::addressof(_data[_size])
);
if constexpr (destruct) item->~T();
--_size;
if (item < std::addressof(_data[_size]))
{
memcpy(item, std::addressof(_data[_size]), sizeof(T));
}
return item;
}
constexpr void clear()
{
if constexpr (destruct)
{
destruct_range(0, _size);
}
_size = 0;
}
constexpr void swap(vector& o)
{
if (this != std::addressof(o))
{
auto temp(std::move(o));
o.move(*this);
move(temp);
}
}
[[nodiscard]] constexpr T* data()
{
return _data;
}
[[nodiscard]] constexpr T* const data() const
{
return _data;
}
[[nodiscard]] constexpr bool empty() const
{
return _size == 0;
}
[[nodiscard]] constexpr u64 size() const
{
return _size;
}
[[nodiscard]] constexpr u64 capacity() const
{
return _capacity;
}
[[nodiscard]] constexpr T& operator[](u64 index)
{
assert(_data && index < _size);
return _data[index];
}
[[nodiscard]] constexpr const T& operator[](u64 index) const
{
assert(_data && index < _size);
return _data[index];
}
[[nodiscard]] constexpr T& front()
{
assert(_data && _size);
return _data[0];
}
[[nodiscard]] constexpr const T& front() const
{
assert(_data && _size);
return _data[0];
}
[[nodiscard]] constexpr T& back()
{
assert(_data && _size);
return _data[_size - 1];
}
[[nodiscard]] constexpr const T& back() const
{
assert(_data && _size);
return _data[_size - 1];
}
[[nodiscard]] constexpr T* begin()
{
assert(_data);
return std::addressof(_data[0]);
}
[[nodiscard]] constexpr const T* begin() const
{
assert(_data);
return std::addressof(_data[0]);
}
[[nodiscard]] constexpr T* end()
{
assert(_data);
return std::addressof(_data[_size]);
}
[[nodiscard]] constexpr const T* end() const
{
assert(_data);
return std::addressof(_data[_size]);
}
private:
constexpr void move(vector& o)
{
_capacity = o._capacity;
_size = o._size;
_data = o._data;
o.reset();
}
constexpr void reset()
{
_capacity = 0;
_size = 0;
_data = nullptr;
}
constexpr void destruct_range(u64 first, u64 last)
{
assert(destruct);
assert(first <= _size && last <= _size && first <= last);
if (_data)
{
for (; first != last; ++first)
{
_data[first].~T();
}
}
}
constexpr void destroy()
{
assert([&] {return _capacity ? _data != nullptr : _data == nullptr; }());
clear();
_capacity = 0;
if (_data) free(_data);
_data = nullptr;
}
u64 _capacity{ 0 };
u64 _size{ 0 };
T* _data{ nullptr };
};
}