mat2.h

/*
**  UICore
**  Copyright (c) 1997-2015 The UICore Team
**
**  This software is provided 'as-is', without any express or implied
**  warranty.  In no event will the authors be held liable for any damages
**  arising from the use of this software.
**
**  Permission is granted to anyone to use this software for any purpose,
**  including commercial applications, and to alter it and redistribute it
**  freely, subject to the following restrictions:
**
**  1. The origin of this software must not be misrepresented; you must not
**     claim that you wrote the original software. If you use this software
**     in a product, an acknowledgment in the product documentation would be
**     appreciated but is not required.
**  2. Altered source versions must be plainly marked as such, and must not be
**     misrepresented as being the original software.
**  3. This notice may not be removed or altered from any source distribution.
**
**  Note: Some of the libraries UICore may link to may have additional
**  requirements or restrictions.
**
**  File Author(s):
**
**    Magnus Norddahl
**    Mark Page
**    Harry Storbacka
*/

#pragma once

#include <cstdint>
#include "mat3.h"
#include "mat4.h"
#include "vec2.h"

namespace uicore
{
    template<typename Type>
    class Mat2;

    template<typename Type>
    class Mat3;

    template<typename Type>
    class Mat4;

    template<typename Type>
    class Mat2
    {
    public:
        Mat2()
        {
            for (auto & elem : matrix)
                elem = 0;
        }
        Mat2(const Mat2<Type> &copy)
        {
            for (int i = 0; i < 4; i++)
                matrix[i] = copy.matrix[i];
        }

        explicit Mat2(const Mat3<Type> &copy);

        explicit Mat2(const Mat4<Type> &copy);

        explicit Mat2(const float *init_matrix)
        {
            for (int i = 0; i < 4; i++)
                matrix[i] = (Type)init_matrix[i];
        }

        explicit Mat2(Type m00, Type m01, Type m10, Type m11)
        {
            matrix[0 * 2 + 0] = m00; matrix[0 * 2 + 1] = m01;
            matrix[1 * 2 + 0] = m10; matrix[1 * 2 + 1] = m11;
        }

        explicit Mat2(const double *init_matrix)
        {
            for (int i = 0; i < 4; i++)
                matrix[i] = (Type)init_matrix[i];
        }

        explicit Mat2(const int64_t *init_matrix)
        {
            for (int i = 0; i < 4; i++)
                matrix[i] = (Type)init_matrix[i];
        }

        explicit Mat2(const int32_t *init_matrix)
        {
            for (int i = 0; i < 4; i++)
                matrix[i] = (Type)init_matrix[i];
        }

        explicit Mat2(const int16_t *init_matrix)
        {
            for (int i = 0; i < 4; i++)
                matrix[i] = (Type)init_matrix[i];
        }

        explicit Mat2(const int8_t *init_matrix)
        {
            for (int i = 0; i < 4; i++)
                matrix[i] = (Type)init_matrix[i];
        }

        static Mat2<Type> null();

        static Mat2<Type> identity();

        static Mat2<Type> multiply(const Mat2<Type> &matrix_1, const Mat2<Type> &matrix_2);

        static Mat2<Type> add(const Mat2<Type> &matrix_1, const Mat2<Type> &matrix_2);

        static Mat2<Type> subtract(const Mat2<Type> &matrix_1, const Mat2<Type> &matrix_2);

        static bool is_equal(const Mat2<Type> &first, const Mat2<Type> &second, Type epsilon)
        {
            for (int i = 0; i < 4; i++)
            {
                Type diff = second.matrix[i] - first.matrix[i];
                if (diff < -epsilon || diff > epsilon) return false;
            }
            return true;
        }

        Type matrix[4];

        bool is_equal(const Mat2<Type> &other, Type epsilon) const { return Mat2<Type>::is_equal(*this, other, epsilon); }

        operator Type const*() const { return matrix; }

        operator Type *() { return matrix; }

        Type &operator[](int i) { return matrix[i]; }

        const Type &operator[](int i) const { return matrix[i]; }

        Type &operator[](unsigned int i) { return matrix[i]; }

        const Type &operator[](unsigned int i) const { return matrix[i]; }

        Mat2<Type> &operator =(const Mat2<Type> &copy) { memcpy(matrix, copy.matrix, sizeof(matrix)); return *this; }

        Mat2<Type> &operator =(const Mat4<Type> &copy);

        Mat2<Type> &operator =(const Mat3<Type> &copy);

        Mat2<Type> operator *(const Mat2<Type> &mult) const;

        Mat2<Type> operator +(const Mat2<Type> &add_matrix) const;

        Mat2<Type> operator -(const Mat2<Type> &subtract_matrix) const;

        bool operator==(const Mat2<Type> &other) const
        {
            for (int i = 0; i < 4; i++)
                if (matrix[i] != other.matrix[i]) return false;
            return true;
        }

        bool operator!=(const Mat2<Type> &other) const { return !((*this) == other); }
    };

    typedef Mat2<int> Mat2i;
    typedef Mat2<float> Mat2f;
    typedef Mat2<double> Mat2d;
}