source: downloads/openal-0.0.8/src/al_matrix.c @ 17

#include "al_siteconfig.h"

#include <AL/al.h>
#include <math.h>
#include <stdlib.h>

#include "al_debug.h"
#include "al_types.h"
#include "al_main.h"
#include "al_matrix.h"

/*
 * _alMatrixMul( ALmatrix *result, ALmatrix *m1, ALmatrix *m2 )
 *
 * Multiplies m1 by m2, populating result.
 *
 *  FIXME: please check my math
 */
void _alMatrixMul( ALmatrix *result, ALmatrix *m1, ALmatrix *m2 ) {
        int m2cols = m2->cols;
        int m1rows = m1->rows;
        int m1cols = m1->cols;
        int i;
        int j;
        int k;

        ALfloat sum;

        for(i = 0; i < m2cols; i++) {
                for(j = 0; j < m1rows; j++) {
                        sum = 0.0f;

                        for(k = 0; k < m1cols; k++) {
                                sum += m1->data[j][k] * m2->data[k][i];
                        }

                        result->data[j][i] = sum;
                }
        }

        return;
}

/*
 * _alMatrixAlloc( int rows, int cols )
 *
 * Allocates, initializes, and returns a matrix with the dimensions matching
 * the passed arguments, or NULL on error.
 */
ALmatrix *_alMatrixAlloc(int rows, int cols) {
        ALmatrix *retval;
        int i;

        retval = malloc(sizeof *retval);
        if(retval == NULL) {
                return NULL;
        }

        retval->data = malloc(rows * sizeof *retval->data);
        if(retval->data == NULL) {
                return NULL;
        }

        for(i = 0; i < rows; i++) {
                /* FIXME: clean return on error */
                retval->data[i] = malloc(cols * sizeof *retval->data[i]);
        }

        retval->rows = rows;
        retval->cols = cols;

        return retval;
}

/*
 * _alMatrixFree( ALmatrix *m )
 *
 * Frees a matrix allocated with _alMatrixAlloc.
 */
void _alMatrixFree(ALmatrix *m) {
        int i;

        if(m == NULL) {
                return;
        }

        for(i = 0; i < m->rows; i++) {
                free( m->data[i] );
        }

        free(m->data);
        free(m);

        return;
}