Class Matrix2

samples/shared/Matrices.h:29–74

////////////////////////////////////////////////////////////////////// 2x2 matrix //////////////////////////////////////////////////////////////////////

// 2x2 matrix
///////////////////////////////////////////////////////////////////////////
class Matrix2
{
public:
    // constructors
    Matrix2();  // init with identity
    Matrix2(const float src[4]);
    Matrix2(float m0, float m1, float m2, float m3);

    void        set(const float src[4]);
    void        set(float m0, float m1, float m2, float m3);
    void        setRow(int index, const float row[2]);
    void        setRow(int index, const Vector2& v);
    void        setColumn(int index, const float col[2]);
    void        setColumn(int index, const Vector2& v);

    const float* get() const;
    float       getDeterminant();

    Matrix2&    identity();
    Matrix2&    transpose();                            // transpose itself and return reference
    Matrix2&    invert();

    // operators
    Matrix2     operator+(const Matrix2& rhs) const;    // add rhs
    Matrix2     operator-(const Matrix2& rhs) const;    // subtract rhs
    Matrix2&    operator+=(const Matrix2& rhs);         // add rhs and update this object
    Matrix2&    operator-=(const Matrix2& rhs);         // subtract rhs and update this object
    Vector2     operator*(const Vector2& rhs) const;    // multiplication: v' = M * v
    Matrix2     operator*(const Matrix2& rhs) const;    // multiplication: M3 = M1 * M2
    Matrix2&    operator*=(const Matrix2& rhs);         // multiplication: M1' = M1 * M2
    bool        operator==(const Matrix2& rhs) const;   // exact compare, no epsilon
    bool        operator!=(const Matrix2& rhs) const;   // exact compare, no epsilon
    float       operator[](int index) const;            // subscript operator v[0], v[1]
    float&      operator[](int index);                  // subscript operator v[0], v[1]

    friend Matrix2 operator-(const Matrix2& m);                     // unary operator (-)
    friend Matrix2 operator*(float scalar, const Matrix2& m);       // pre-multiplication
    friend Vector2 operator*(const Vector2& vec, const Matrix2& m); // pre-multiplication
    friend std::ostream& operator<<(std::ostream& os, const Matrix2& m);

protected:

private:
    float m[4];

};