Implement Matrix3x3 missing members and documentation

include/J3ML/LinearAlgebra/Matrix3x3.h

@@ -228,31 +228,63 @@ namespace J3ML::LinearAlgebra {
         Vector3 Column(int index) const;
         Vector3 Col(int index) const;
         /// This method also allows assignment to the retrieved column.
-        Vector3& Col(int index);
+        //Vector3& Col(int index);
 
         /// Returns only the first three elements of the given column.
         Vector3 GetColumn3(int index) const;
         Vector3 Column3(int index) const;
         Vector3 Col3(int index) const;
         /// This method also allows assignment to the retrieved column.
-        Vector3& Col3(int index);
+        //Vector3& Col3(int index);
+
+        /// Sets the value of a given row.
+        /** @param row The index of the row to a set, in the range [0-2].
+            @param data A pointer to an array of 3 floats that contain the new x, y, and z values for the row.*/
+        void SetRow(int row, const float* data);
+        void SetRow(int row, const Vector3 & data);
+        void SetRow(int row, float x, float y, float z);
+
+        /// Sets the value of a given column.
+        /** @param column The index of the column to set, in the range [0-2]
+            @param data A pointer ot an array of 3 floats that contain the new x, y, and z values for the column.*/
+        void SetColumn(int column, const float* data);
+        void SetColumn(int column, const Vector3 & data);
+        void SetColumn(int column, float x, float y, float z);
 
 
-
-        void SetRow(int i, const Vector3 &vector3);
-        void SetColumn(int i, const Vector3& vector);
+        /// Sets a single element of this matrix
+        /** @param row The row index (y-coordinate) of the element to set, in the range [0-2].
+            @param col The col index (x-coordinate) of the element to set, in the range [0-2].
+            @param value The new value to set to the cell [row][col]. */
         void SetAt(int x, int y, float value);
 
+
+        /// Sets this matrix to equal the identity.
+        void SetIdentity();
+
+
+        void SwapColumns(int col1, int col2);
+
+        void SwapRows(int row1, int row2);
+
         float &At(int row, int col);
         float At(int x, int y) const;
 
-        void Set(const Matrix3x3 &x3);
-
+        /// Sets this to be a copy of the matrix rhs.
+        void Set(const Matrix3x3 &rhs);
+        /// Sets all values of this matrix/
+        void Set(float _00, float _01, float _02,
+                 float _10, float _11, float _12,
+                 float _20, float _21, float _22);
+        /// Sets all values of this matrix.
+        /// @param valuesThe values in this array will be copied over to this matrix. The source must contain 9 floats in row-major order
+        /// (the same order as the Set() function aove has its input parameters in).
+        void Set(const float *values);
 
+        /// Orthonormalizes the basis formed by the column vectors of this matrix.
         void Orthonormalize(int c0, int c1, int c2);
 
 
-
         /// Convers this rotation matrix to a quaternion.
         /// This function assumes that the matrix is orthonormal (no shear or scaling) and does not perform any mirroring (determinant > 0)
         Quaternion ToQuat() const;
@@ -261,11 +293,8 @@ namespace J3ML::LinearAlgebra {
         bool TryConvertToQuat(Quaternion& q) const;
 
 
-
-
-
-
         /// Returns the main diagonal.
+        /// The main diagonal consists of the elements at m[0][0], m[1][1], m[2][2]
         Vector3 Diagonal() const;
         /// Returns the local +X/+Y/+Z axis in world space.
         /// This is the same as transforming the vector{1,0,0} by this matrix.
@@ -286,16 +315,78 @@ namespace J3ML::LinearAlgebra {
         // @note This function computes 9 LOADs, 9 MULs and 5 ADDs. */
         float Determinant() const;
 
-        // Returns an inverted copy of this matrix. This
-        Matrix3x3 Inverse() const;
+        /// Computes the determinant of a symmetric matrix.
+        /** This function can be used to compute the determinant of a matrix in the case the matrix is known beforehand
+            to be symmetric. This function is slightly faster than Determinant().
+         * @return
+         */
+        float DeterminantSymmetric() const;
+
+        // Returns an inverted copy of this matrix.
+        Matrix3x3 Inverted() const;
 
         // Returns a transposed copy of this matrix.
-        Matrix3x3 Transpose() const;
+        Matrix3x3 Transposed() const;
+
+        /// Returns the inverse transpose of this matrix.
+        Matrix3x3 InverseTransposed() const;
+
+        /// Inverts this matrix using numerically stable Gaussian elimination.
+        /// @return Returns true on success, false otherwise;
+        bool Inverse(float epsilon = 1e-6f);
+
+        /// Inverts this matrix using Cramer's rule.
+        /// @return Returns true on success, false otherwise.
+        bool InverseFast(float epsilon = 1e-6f);
+
+
+        /// Solves the linear equation Ax=b.
+        /** The matrix A in the equations is this matrix. */
+        bool SolveAxb(Vector3 b, Vector3& x) const;
+
+        /// Inverts a column-orthogonal matrix.
+        /** If a matrix is of form M=R*S, where
+            R is a rotation matrix and S is a diagonal matrix with non-zero but potentially non-uniform scaling
+            factors (possibly mirroring), then the matrix M is column-orthogonal and this function can be used to compute the inverse.
+            Calling this function is faster than calling the generic matrix Inverse() function.\
+            Returns true on success. On failure, the matrix is not modified. This function fails if any of the
+            elements of this vector are not finite, or if the matrix contains a zero scaling factor on X, Y, or Z.
+            @note The returned matrix will be row-orthogonal, but not column-orthogonal in general.
+            The returned matrix will be column-orthogonal if the original matrix M was row-orthogonal as well.
+            (in which case S had uniform scale, InverseOrthogonalUniformScale() could have been used instead)*/
+        bool InverseColOrthogonal();
+
+        /// Inverts a rotation matrix.
+        /** If a matrix is of form M=R*S, where R is a rotation matrix and S is either identity or a mirroring matrix, then
+            the matrix M is orthonormal and this function can be used to compute the inverse.
+            This function is faster than calling InverseOrthogonalUniformScale(), InverseColOrthogonal(), or the generic
+            Inverse().
+            This function may not be called if this matrix contains any scaling or shearing, but it may contain mirroring.*/
+        bool InverseOrthogonalUniformScale();
+
+        void InverseOrthonormal();
+
+        bool InverseSymmetric();
+
+        void Transpose();
+
+        bool InverseTranspose();
+
+        void RemoveScale();
+
+
 
         // Transforms the given vectors by this matrix M, i.e. returns M * (x,y,z)
         Vector2 Transform(const Vector2& rhs) const;
         Vector3 Transform(const Vector3& rhs) const;
 
+        /// Performs a batch transformation of the given array.
+        void BatchTransform(Vector3 *pointArray, int numPoints) const;
+        void BatchTransform(Vector3 *pointArray, int numPoints, int stride) const;
+
+        /// Returns the sum of the diagonal elements of this matrix.
+        float Trace() const;
+
 
         Matrix3x3 ScaleBy(const Vector3& rhs);
         Vector3 GetScale() const;