144 lines
3.2 KiB
C
144 lines
3.2 KiB
C

#ifndef MICROBIT_MATRIX4_H



#define MICROBIT_MATRIX4_H






/**



* Class definition for a simple matrix, that is optimised for nx4 or 4xn matrices.



*



* This class is heavily optimised for these commonly used matrices as used in 3D geometry.



* Whilst this class does support basic operations on matrices of any dimension, it is not intended as a



* general purpose matrix class as inversion operations are only provided for 4x4 matrices.



* For programmers needing more flexible Matrix support, the Matrix and MatrixMath classes from



* Ernsesto Palacios provide a good basis:



*



* https://developer.mbed.org/cookbook/MatrixClass



* https://developer.mbed.org/users/Yo_Robot/code/MatrixMath/



*/



class Matrix4



{



double *data; // Linear buffer representing the matrix.



int rows; // The number of rows in the matrix.



int cols; // The number of columns in the matrix.






public:






/**



* Constructor.



* Create a matrix of the given size.



* @param rows the number of rows in the matrix to be created.



* @param cols the number of columns in the matrix to be created.



*



* Example:



* @code



* Matrix4(10, 4); // Creates a Matrix with 10 rows and 4 columns.



* @endcode



*/



Matrix4(int rows, int cols);






/**



* Constructor.



* Create a matrix that is an identical copy of the given matrix.



* @param matrix The matrix to copy.



*



* Example:



* @code



*



* Matrix newMatrix(matrix); .



* @endcode



*/



Matrix4(const Matrix4 &matrix);






/**



* Determines the number of columns in this matrix.



*



* @return The number of columns in the matrix.



*



* Example:



* @code



* int c = matrix.width();



* @endcode



*/



int width();






/**



* Determines the number of rows in this matrix.



*



* @return The number of rows in the matrix.



*



* Example:



* @code



* int r = matrix.height();



* @endcode



*/



int height();






/**



* Reads the matrix element at the given position.



*



* @param row The row of the element to read



* @param col The column of the element to read



* @return The value of the matrix element at the given position. NAN is returned if the given index is out of range.



*



* Example:



* @code



* double v = matrix.get(1,2);



* @endcode



*/



double get(int row, int col);






/**



* Writes the matrix element at the given position.



*



* @param row The row of the element to write



* @param col The column of the element to write



* @param v The new value of the element



*



* Example:



* @code



* matrix.set(1,2,42.0);



* @endcode



*/



void set(int row, int col, double v);






/**



* Transposes this matrix.



* @return the resultant matrix.



*



* Example:



* @code



* matrix.transpose();



* @endcode



*/



Matrix4 transpose();






/**



* Multiplies this matrix with the given matrix (if possible).



* @return the resultant matrix. An empty matrix is returned if the operation canot be completed.



*



* Example:



* @code



* Matrix result = matrixA.multiply(matrixB);



* @endcode



*/



Matrix4 multiply(Matrix4 &matrix);






/**



* Performs an optimisaed inversion of a 4x4 matrix.



* Only 4x4 matrics are supported by this operation.



*



* @return the resultant matrix. An empty matrix is returned if the operation canot be completed.



*



* Example:



* @code



* Matrix result = matrixA.invert();



* @endcode



*/



Matrix4 invert();






/**



* Destructor.



*/



~Matrix4();



};






#endif
