matrix_util.c

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#include <jwsc/config.h>

#include <stdlib.h>
#include <inttypes.h>
#include <math.h>
#include <assert.h>

#include "jwsc/matrix/matrix.h"


Error* extend_matrix_f
(
    Matrix_f**      mat_out, 
    const Matrix_f* mat_in, 
    uint32_t        row_padding,
    uint32_t        col_padding
)
{
    uint32_t num_rows, num_cols;
    uint32_t num_prows, num_pcols;
    uint32_t prow, pcol;

    Matrix_f* mat;

    num_rows = mat_in->num_rows;
    num_cols = mat_in->num_cols;

    num_prows = num_rows + 2*row_padding;
    num_pcols = num_cols + 2*col_padding;

    mat = (*mat_out == mat_in) ? NULL : *mat_out;
    create_matrix_f(&mat, num_prows, num_pcols);

    for (prow = 0; prow < (num_prows - row_padding); prow++)
    {
        if (prow < row_padding)
        {
            for (pcol = 0; pcol < col_padding; pcol++)
            {
                mat->elts[ prow ][ pcol ] 
                    = mat_in->elts[ 0 ][ 0 ];

                mat->elts[ prow ][ num_pcols-pcol-1 ] 
                    = mat_in->elts[ 0 ][ num_cols-1 ];

                mat->elts[ num_prows-prow-1 ][ pcol ] 
                    = mat_in->elts[ num_rows-1 ][ 0 ];

                mat->elts[ num_prows-prow-1 ][ num_pcols-pcol-1 ] 
                    = mat_in->elts[ num_rows-1 ][ num_cols-1 ];
            }
            for (pcol = col_padding; pcol < (num_pcols-col_padding); pcol++)
            {
                mat->elts[ prow ][ pcol ] 
                    = mat_in->elts[ 0 ][ pcol-col_padding ];
                mat->elts[ num_prows-prow-1 ][ pcol ] 
                    = mat_in->elts[ num_rows-1 ][ pcol-col_padding ];
            }
        }
        else
        {
            for (pcol = 0; pcol < col_padding; pcol++)
            {
                mat->elts[ prow ][ pcol ] 
                    = mat_in->elts[ prow-row_padding ][ 0 ];
                mat->elts[ prow ][ num_pcols-pcol-1 ] 
                    = mat_in->elts[ prow-row_padding ][ num_cols-1 ];
            }
            for (pcol = col_padding; pcol < (num_pcols-col_padding); pcol++)
            {
                mat->elts[ prow ][ pcol ] 
                    = mat_in->elts[ prow-row_padding][ pcol-col_padding ];
            }
        }
    }

    *mat_out = mat;

    return NULL;
}