j3ml-fork/include/J3ML/LinearAlgebra/Matrix4x4.h

#pragma once

#include <J3ML/LinearAlgebra.h>
#include <J3ML/LinearAlgebra/Quaternion.h>

namespace LinearAlgebra {

    /// A 4-by-4 matrix for affine transformations and perspective projections of 3D geometry.
    /* This matrix can represent the most generic form of transformations for 3D objects,
     * including perspective projections, which a 4-by-3 cannot store,
     * and translations, which a 3-by-3 cannot represent.
     * The elements of this matrix are
     *  m_00, m_01, m_02, m_03
     *  m_10, m_11, m_12, m_13
     *  m_20, m_21, m_22, am_23,
     *  m_30, m_31, m_32, m_33
     *
     *  The element m_yx is the value on the row y and column x.
     *  You can access m_yx using the double-bracket notation m[y][x]
     */
    class Matrix4x4 {
    public:
        enum { Rows = 4 };
        enum { Cols = 4 };

        /// A constant matrix that has zeroes in all its entries
        static const Matrix4x4 Zero;
        /// A constant matrix that is the identity.
        static const Matrix4x4 Identity;

        /// A compile-time constant float4x4 which has NaN in each element.
        /// For this constant, each element has the value of quet NaN, or Not-A-Number.
        /// Never compare a matrix to this value. Due to how IEEE floats work, "nan == nan" returns false!
        static const Matrix4x4 NaN;

        /// Creates a new float4x4 with uninitialized member values.
        Matrix4x4() {}
        Matrix4x4(float val);
        /// Constructs this float4x4 to represent the same transformation as the given float3x3.
        /** This function expands the last row and column of this matrix with the elements from the identity matrix. */
        Matrix4x4(const Matrix3x3&);
        /// Constructs a new float4x4 by explicitly specifying all the matrix elements.
        /// The elements are specified in row-major format, i.e. the first row first followed by the second and third row.
        /// E.g. The element _10 denotes the scalar at second (index 1) row, first (index 0) column.
        Matrix4x4(float m00, float m01, float m02, float m03,
            float m10, float m11, float m12, float m13,
            float m20, float m21, float m22, float m23,
            float m30, float m31, float m32, float m33);
        /// Constructs the matrix by explicitly specifying the four column vectors.
        /** @param col0 The first column. If this matrix represents a change-of-basis transformation, this parameter is the world-space
            direction of the local X axis.
            @param col1 The second column. If this matrix represents a change-of-basis transformation, this parameter is the world-space
            direction of the local Y axis.
            @param col2 The third column. If this matrix represents a change-of-basis transformation, this parameter is the world-space
            direction of the local Z axis.
            @param col3 The fourth column. If this matrix represents a change-of-basis transformation, this parameter is the world-space
            position of the local space pivot. */
        Matrix4x4(const Vector4& r1, const Vector4& r2, const Vector4& r3, const Vector4& r4);


        explicit Matrix4x4(const Quaternion& orientation);

        /// Constructs this float4x4 from the given quaternion and translation.
        /// Logically, the translation occurs after the rotation has been performed.
        Matrix4x4(const Quaternion& orientation, const Vector3 &translation);

        Vector3 GetTranslatePart() const;
        Matrix3x3 GetRotatePart() const
        {
            return Matrix3x3 {
                At(0, 0), At(0, 1), At(0, 2),
                At(1, 0), At(1, 1), At(1, 2),
                At(2, 0), At(2, 1), At(2, 2)
            };
        }
        void SetTranslatePart(float translateX, float translateY, float translateZ);
        void SetTranslatePart(const Vector3& offset);
        void SetRotatePart(const Quaternion& q);
        void SetRotatePart(const Matrix3x3& r);


        void SetRow(int row, const Vector3& rowVector, float m_r3);
        void SetRow(int row, const Vector4& rowVector);
        void SetRow(int row, float m_r0, float m_r1, float m_r2, float m_r3);


        Vector4 GetRow(int index) const;
        Vector4 GetColumn(int index) const;
        float At(int x, int y) const;

        /// Tests if this matrix does not contain any NaNs or infs.
        /** @return Returns true if the entries of this float4x4 are all finite, and do not contain NaN or infs. */
        bool IsFinite() const;

        /// Tests if this matrix has an inverse.
        /** @return Returns true if this matrix can be inverted, up to the given epsilon. */
        bool IsInvertible(float epsilon = 1e-3f) const;

        Vector4 Diagonal() const;
        Vector4 WorldX() const;
        Vector4 WorldY() const;
        Vector4 WorldZ() const;

        /// Computes the determinant of this matrix.
        // If the determinant is nonzero, this matrix is invertible.
        float Determinant() const;

        Matrix4x4 Inverse() const;

        Matrix4x4 Transpose() const;

        Vector2 Transform(const Vector2& rhs) const;
        Vector3 Transform(const Vector3& rhs) const;
        Vector4 Transform(const Vector4& rhs) const;


        static Matrix4x4 D3DOrthoProjLH(float nearPlane, float farPlane, float hViewportSize, float vViewportSize);
        static Matrix4x4 D3DOrthoProjRH(float nearPlane, float farPlane, float hViewportSize, float vViewportSize);
        static Matrix4x4 D3DPerspProjLH(float nearPlane, float farPlane, float hViewportSize, float vViewportSize);
        static Matrix4x4 D3DPerspProjRH(float nearPlane, float farPlane, float hViewportSize, float vViewportSize);

        static Matrix4x4 OpenGLOrthoProjLH(float nearPlane, float farPlane, float hViewportSize, float vViewportSize);
        static Matrix4x4 OpenGLOrthoProjRH(float nearPlane, float farPlane, float hViewportSize, float vViewportSize);
        static Matrix4x4 OpenGLPerspProjLH(float nearPlane, float farPlane, float hViewportSize, float vViewportSize);
        static Matrix4x4 OpenGLPerspProjRH(float nearPlane, float farPlane, float hViewportSize, float vViewportSize);

        Vector3 GetTranslationComponent() const;
        Matrix3x3 GetRotationComponent() const;

        Vector4 GetRow() const;
        Vector4 GetColumn() const;

        Vector4 operator[](int row);

        Matrix4x4 operator-() const;
        Matrix4x4 operator +(const Matrix4x4& rhs) const;
        Matrix4x4 operator - (const Matrix4x4& rhs) const;

        Matrix4x4 operator *(float scalar) const;
        Matrix4x4 operator /(float scalar) const;

        Vector2 operator * (const Vector2& rhs) const { return this->Transform(rhs);}
        Vector3 operator * (const Vector3& rhs) const { return this->Transform(rhs);}
        Vector4 operator * (const Vector4& rhs) const { return this->Transform(rhs);}

        Matrix4x4 operator * (const Matrix3x3 &rhs) const;

        Matrix4x4 operator +() const;

        Matrix4x4 operator * (const Matrix4x4& rhs) const;

        Matrix4x4 &operator = (const Matrix3x3& rhs)
        {
            SetRotatePart(rhs);
            SetTranslatePart(0,0,0);
            SetRow(3, 0, 0, 0, 1);
            return *this;
        }
        Matrix4x4 &operator = (const Quaternion& rhs)
        {
            *this = rhs.ToMatrix4x4();
            return *this;
        }
        Matrix4x4 &operator = (const Matrix4x4& rhs) = default;

    protected:
        float elems[4][4];

        void SetMatrixRotatePart(Matrix4x4 &m, const Quaternion &q);
    };
}