our_dick/include/mat.tpp

/**
	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_TPP
#define REXY_MAT_TPP

#include <cstdlib> //size_t
#include <cmath> //sin, cos
#include <type_traits> //decay_t, declval

namespace math{

	template<typename T>
	matrix<T,3,3> matrix<T,3,3>::rotation(value_type angle){
		value_type c = std::cos(angle);
		value_type s = std::sin(angle);
		return rotation(s, c);
	}
	template<typename T>
	constexpr matrix<T,3,3> matrix<T,3,3>::rotation(value_type sin, value_type cos){
		return matrix(cos, -sin, 0,
		              sin,  cos, 0,
		              0,  0, 1);
	}
	template<typename T>
	constexpr matrix<T,3,3> matrix<T,3,3>::rotation(value_type angle_x, value_type angle_y, value_type angle_z){
		//TODO
	}

	template<typename T, typename 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<typename T, typename 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<typename T, typename 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<typename T, typename 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<typename T, typename 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<typename T, typename 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<typename T, typename 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<typename T, typename 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<typename T, typename 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<typename T, typename 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<typename T, typename 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<typename T, typename 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<typename T, typename 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