From 71489dcca4f2278a517a6f6ae784aa0913f1cdfe Mon Sep 17 00:00:00 2001
From: rexy712 <rexerton.rexy@tutamail.com>
Date: Sat, 15 Aug 2020 13:56:43 -0700
Subject: [PATCH] Add basic matrix stuff

---
 include/detail/math.hpp   |  19 ++++
 include/detail/matrix.hpp | 190 +++++++++++++++++++++++++++++++
 include/mat.hpp           | 227 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 436 insertions(+)
 create mode 100644 include/detail/math.hpp
 create mode 100644 include/detail/matrix.hpp
 create mode 100644 include/mat.hpp

diff --git a/include/detail/math.hpp b/include/detail/math.hpp
new file mode 100644
index 0000000..5423df9
--- /dev/null
+++ b/include/detail/math.hpp
@@ -0,0 +1,19 @@
+#ifndef REXY_DETAIL_MATH_HPP
+#define REXY_DETAIL_MATH_HPP
+
+namespace math{
+
+	namespace detail{
+		struct zero_initialize_t{};
+		struct no_initialize_t{};
+		struct id_initialize_t{};
+
+	}
+
+	static inline constexpr detail::zero_initialize_t zero_initialize;
+	static inline constexpr detail::no_initialize_t no_initialize;
+	static inline constexpr detail::id_initialize_t id_initialize;
+
+}
+
+#endif
diff --git a/include/detail/matrix.hpp b/include/detail/matrix.hpp
new file mode 100644
index 0000000..ec7e492
--- /dev/null
+++ b/include/detail/matrix.hpp
@@ -0,0 +1,190 @@
+#ifndef REXY_DETAIL_MATRIX_HPP
+#define REXY_DETAIL_MATRIX_HPP
+
+#include <cstdlib> //size_t
+#include <utility> //integer_sequence
+
+namespace math::detail{
+
+	template<size_t SW, size_t W = SW, size_t H = SW-1, size_t... Args>
+	struct gen_id_tup{
+		using tup = typename gen_id_tup<SW, W-1, H, Args..., 0>::tup;
+	};
+	template<size_t SW, size_t H, size_t... Args>
+	struct gen_id_tup<SW,SW,H,Args...>{
+		using tup = typename gen_id_tup<SW, SW-1, H, Args..., 1>::tup;
+	};
+	template<size_t SW, size_t H, size_t... Args>
+	struct gen_id_tup<SW,0,H,Args...>{
+		using tup = typename gen_id_tup<SW, SW, H-1, Args..., 0>::tup;
+	};
+	template<size_t SW, size_t... Args>
+	struct gen_id_tup<SW,SW,0,Args...>{
+		using tup = std::integer_sequence<size_t,Args...,1>;
+	};
+
+
+	template<size_t N, size_t... Args>
+	struct gen_zero_tup{
+		using tup = typename gen_zero_tup<N-1,Args...,0>::tup;
+	};
+	template<size_t... Args>
+	struct gen_zero_tup<0,Args...>{
+		using tup = std::integer_sequence<size_t,Args...>;
+	};
+
+	template<size_t W>
+	struct id_initialization_matrix{
+		using tuple = typename gen_id_tup<W>::tup;
+	};
+
+
+	template<size_t W, size_t H>
+	struct default_initialization_matrix{
+		using tuple = typename gen_zero_tup<W>::tup;
+	};
+	template<size_t W>
+	struct default_initialization_matrix<W,W>{
+		using tuple = typename id_initialization_matrix<W>::tuple;
+	};
+
+	template<class T, size_t R>
+	class mat_ref_obj
+	{
+	public:
+		using size_type = size_t;
+
+	protected:
+		T* m_data = nullptr;
+	public:
+		constexpr mat_ref_obj(T* d, size_type i):
+			m_data(d+i){}
+
+		constexpr T& operator[](size_type i){
+			return m_data[i*R];
+		}
+		constexpr const T& operator[](size_type i)const{
+			return m_data[i*R];
+		}
+	};
+
+	template<class T, size_t W, size_t H>
+	class matrix_base
+	{
+		static_assert(W > 0, "Cannot have 0 columns matrix");
+		static_assert(H > 0, "Cannot have 0 rows matrix");
+	public:
+		using value_type = T;
+		using size_type = size_t;
+		using pointer = value_type*;
+		using const_pointer = const value_type*;
+		using reference = value_type&;
+		using const_reference = const value_type&;
+
+		static constexpr size_type Columns = W;
+		static constexpr size_type Rows = H;
+
+	protected:
+		value_type m_data[W*H];
+
+	protected:
+		template<size_type... Ss>
+		constexpr matrix_base(std::integer_sequence<size_type,Ss...>):
+			m_data{Ss...}{}
+
+	public:
+		//Default construct as identity when square, zero otherwise
+		constexpr matrix_base(void):
+			matrix_base(typename detail::default_initialization_matrix<Columns,Rows>::tuple{}){}
+
+		//Range initializing constructors
+		constexpr explicit matrix_base(zero_initialize_t):
+			m_data{}{}
+		constexpr explicit matrix_base(no_initialize_t){}
+		template<class U = void>
+		constexpr explicit matrix_base(id_initialize_t):
+			matrix_base()
+		{
+			static_assert(Columns == Rows, "Identity initialization only supported on square matrices");
+		}
+
+		//Value initializing constructors
+		constexpr explicit matrix_base(value_type v){
+			for(size_type i = 0;i < Columns*Rows;++i)
+				m_data[i] = v;
+		}
+		template<class... Args>
+		constexpr explicit matrix_base(Args&&... args):
+			m_data{std::forward<Args>(args)...}{}
+
+		//Copying constructors
+		constexpr matrix_base(const matrix_base&) = default;
+		constexpr matrix_base(matrix_base&&) = default;
+		template<class U>
+		constexpr matrix_base(const matrix_base<U,Columns,Rows>& m){
+			using mat = decltype(m);
+			for(typename mat::size_type i = 0;i < mat::Columns*mat::Rows;++i)
+				m_data[i] = m.get(i);
+		}
+		~matrix_base(void) = default;
+
+		//Assignement
+		template<class U>
+		constexpr matrix_base& operator=(const matrix_base<U,Columns,Rows>& m){
+			using mat = decltype(m);
+			for(typename mat::size_type i = 0;i < mat::Columns*mat::Rows;++i)
+				m_data[i] = m.get(i);
+			return *this;
+		}
+		constexpr matrix_base& operator=(const matrix_base&) = default;
+		constexpr matrix_base& operator=(matrix_base&&) = default;
+
+
+		//Getters/Setters
+		constexpr auto operator[](size_type x){
+			return detail::mat_ref_obj<value_type,Rows>{m_data, x};
+		}
+		constexpr auto operator[](size_type x)const{
+			return detail::mat_ref_obj<const value_type,Rows>{m_data, x};
+		}
+		constexpr reference get(size_type x, size_type y){
+			return m_data[x+(y*Rows)];
+		}
+		constexpr const_reference get(size_type x, size_type y)const{
+			return m_data[x+(y*Rows)];
+		}
+		constexpr reference get(size_type i){
+			return m_data[i];
+		}
+		constexpr const_reference get(size_type i)const{
+			return m_data[i];
+		}
+
+		constexpr size_type columns(void)const{
+			return Columns;
+		}
+		constexpr size_type rows(void)const{
+			return Rows;
+		}
+		constexpr size_type size(void)const{
+			return Columns*Rows;
+		}
+
+		constexpr pointer raw(void){
+			return m_data;
+		}
+		constexpr const_pointer raw(void)const{
+			return m_data;
+		}
+		constexpr operator pointer(void){
+			return m_data;
+		}
+		constexpr operator const_pointer(void)const{
+			return m_data;
+		}
+
+	};
+
+}
+
+#endif
diff --git a/include/mat.hpp b/include/mat.hpp
new file mode 100644
index 0000000..1446265
--- /dev/null
+++ b/include/mat.hpp
@@ -0,0 +1,227 @@
+/**
+	This file is a part of the rexy/r0nk/atlas project
+	Copyright (C) 2020 rexy712
+
+	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 <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef REXY_MAT_HPP
+#define REXY_MAT_HPP
+
+#include <cstdlib> //size_t
+#include <utility> //integer_sequence
+#include <type_traits> //decay_t
+#include <cmath> //sin, cos
+#include "detail/math.hpp"
+#include "detail/matrix.hpp"
+
+namespace math{
+
+	template<class T, size_t C, size_t R>
+	class matrix : public detail::matrix_base<T,C,R>
+	{
+	private:
+		using base = detail::matrix_base<T,C,R>;
+	public:
+		using value_type = typename base::value_type;
+		using size_type = typename base::size_type;
+		using pointer = typename base::pointer;
+		using const_pointer = typename base::const_pointer;
+		using reference = typename base::reference;
+		using const_reference = typename base::const_reference;
+	public:
+		using detail::matrix_base<T,C,R>::matrix_base;
+		using detail::matrix_base<T,C,R>::operator=;
+	};
+
+	template<class T>
+	class matrix<T,3,3> : public detail::matrix_base<T,3,3>
+	{
+	private:
+		using base = detail::matrix_base<T,3,3>;
+	public:
+		using value_type = typename base::value_type;
+		using size_type = typename base::size_type;
+		using pointer = typename base::pointer;
+		using const_pointer = typename base::const_pointer;
+		using reference = typename base::reference;
+		using const_reference = typename base::const_reference;
+	public:
+		using detail::matrix_base<T,3,3>::matrix_base;
+		using detail::matrix_base<T,3,3>::operator=;
+
+		template<class U = void>
+		static constexpr matrix rotation(value_type angle){
+			value_type c = std::cos(angle);
+			value_type s = std::sin(angle);
+			return rotation(s, c);
+		}
+		template<class U = void>
+		static constexpr matrix rotation(value_type sin, value_type cos){
+			return matrix(cos, -sin, 0,
+			              sin,  cos, 0,
+			              0,  0, 1);
+		}
+		static constexpr matrix rotation(value_type angle_x, value_type angle_y, value_type angle_z){
+			//TODO
+		}
+	};
+
+	namespace detail{
+
+		template<class T>
+		struct is_matrix_helper{
+			template<class U, size_t W, size_t H>
+			static std::true_type test(matrix<U,W,H>*);
+			static std::false_type test(void*);
+
+			static constexpr bool value = std::is_same<std::true_type,decltype(test(static_cast<std::decay_t<T>*>(nullptr)))>::value;
+		};
+
+	}
+
+	template<class... Ms>
+	struct is_matrix{
+		static constexpr bool value = (detail::is_matrix_helper<Ms>::value && ...);
+	};
+
+	namespace detail{
+
+		template<class M1, class M2>
+		struct are_same_size_matrix{
+			using l = std::decay_t<M1>;
+			using r = std::decay_t<M2>;
+			static constexpr bool value = is_matrix<M1,M2>::value && l::Columns == r::Columns && l::Rows == r::Rows;
+		};
+		template<class... Ms>
+		using enable_if_matrix = std::enable_if_t<is_matrix<Ms...>::value,int>;
+
+		template<class M1, class M2>
+		using enable_if_eq_matrix = std::enable_if_t<are_same_size_matrix<M1,M2>::value,int>;
+
+	}
+
+	template<class T, class U, size_t W, size_t H>
+	constexpr bool operator==(const matrix<T,W,H>& left, const matrix<U,W,H> right){
+		for(size_t i = 0;i < left.size();++i){
+			if(left.get(i) != right.get(i))
+				return false;
+		}
+		return true;
+	}
+	template<class T, class U, size_t W, size_t H>
+	constexpr bool operator!=(const matrix<T,W,H>& left, const matrix<U,W,H> right){
+		return !(left == right);
+	}
+
+	template<class T, class U, size_t R1, size_t C1, size_t C2>
+	constexpr auto operator*(const matrix<T,C1,R1>& left, const matrix<U,C2,C1>& right){
+		using res_t = decltype(std::declval<T>() * std::declval<U>());
+		matrix<res_t,C2,R1> res(no_initialize);
+		size_t index = 0;
+		for(size_t i = 0;i < right.rows();++i){
+			for(size_t j = 0;j < left.rows();++j){
+				for(size_t k = 0;k < left.columns();++k){
+					res.get(index) += left[j][k] * right[i][k];
+				}
+				++index;
+			}
+		}
+		return res;
+	}
+	template<class T, class U, size_t C, size_t R>
+	constexpr auto operator*(const matrix<T,C,R>& left, U&& right){
+		using res_t = decltype(std::declval<T>() * std::declval<U>());
+		matrix<res_t,C,R> res(no_initialize);
+		for(size_t i = 0;i < left.size();++i){
+			res.get(i) = left.get(i) * std::forward<U>(right);
+		}
+		return res;
+	}
+	template<class T, class U, size_t C, size_t R>
+	constexpr auto operator/(const matrix<T,C,R>& left, U&& right){
+		using res_t = decltype(std::declval<T>() / std::declval<U>());
+		matrix<res_t,C,R> res(no_initialize);
+		for(size_t i = 0;i < left.size();++i){
+			res.get(i) = left.get(i) / std::forward<U>(right);
+		}
+		return res;
+	}
+	template<class T, class U, size_t C, size_t R>
+	constexpr auto operator+(const matrix<T,C,R>& left, const matrix<U,C,R>& right){
+		using res_t = decltype(std::declval<T>() + std::declval<U>());
+		matrix<res_t,C,R> res(no_initialize);
+		for(size_t i = 0;i < left.size();++i){
+			res.get(i) = left.get(i) + right.get(i);
+		}
+		return res;
+	}
+	template<class T, class U, size_t C, size_t R>
+	constexpr auto operator-(const matrix<T,C,R>& left, const matrix<U,C,R>& right){
+		using res_t = decltype(std::declval<T>() - std::declval<U>());
+		matrix<res_t,C,R> res(no_initialize);
+		for(size_t i = 0;i < left.size();++i){
+			res.get(i) = left.get(i) - right.get(i);
+		}
+		return res;
+	}
+	template<class T, class U, size_t C, size_t R>
+	constexpr auto operator-(const matrix<T,C,R>& left){
+		using res_t = decltype(std::declval<T>() - std::declval<U>());
+		matrix<res_t,C,R> res(no_initialize);
+		for(size_t i = 0;i < left.size();++i){
+			res.get(i) = -left.get(i);
+		}
+		return res;
+	}
+
+
+	template<class T, class U, size_t R1, size_t C1, size_t C2>
+	constexpr decltype(auto) operator*=(matrix<T,C1,R1>& left, const matrix<U,C2,C1>& right){
+		//have to evaluate entire expression first since matrix multiplication depends on reusing many elements
+		//cannot be expression templatized, TODO
+		return (left = (left * right));
+	}
+	template<class T, class U, size_t C, size_t R>
+	constexpr decltype(auto) operator*=(matrix<T,C,R>& left, U&& right){
+		for(size_t i = 0;i < left.size();++i){
+			left.get(i) = left.get(i) * std::forward<U>(right);
+		}
+		return left;
+	}
+	template<class T, class U, size_t C, size_t R>
+	constexpr decltype(auto) operator/=(matrix<T,C,R>& left, U&& right){
+		for(size_t i = 0;i < left.size();++i){
+			left.get(i) = left.get(i) / std::forward<U>(right);
+		}
+		return left;
+	}
+	template<class T, class U, size_t C, size_t R>
+	constexpr decltype(auto) operator+=(matrix<T,C,R>& left, const matrix<U,C,R>& right){
+		for(size_t i = 0;i < left.size();++i){
+			left.get(i) = left.get(i) + right.get(i);
+		}
+		return left;
+	}
+	template<class T, class U, size_t C, size_t R>
+	constexpr decltype(auto) operator-=(matrix<T,C,R>& left, const matrix<U,C,R>& right){
+		for(size_t i = 0;i < left.size();++i){
+			left.get(i) = left.get(i) - right.get(i);
+		}
+		return left;
+	}
+
+}
+
+#endif