matlab_fake.cpp

#include "mat.h"     // from MATLAB
#include "matrix.h"  // from MATLAB
#include "matio.h"   // https://github.com/tbeu/matio
#include "string.h"
#include "stdlib.h"

/* 
 * Open a MAT-file "filename" using mode "mode".  Return
 * a pointer to a MATFile for use with other MAT API functions.
 *
 * Current valid entries for "mode" are
 * "r"    == read only.
 * "w"    == write only (deletes any existing file with name <filename>).
 * "w4"   == as "w", but create a MATLAB 4.0 MAT-file.
 * "w7.3" == as "w", but create a MATLAB 7.3 MAT-file.
 * "u"    == update.  Read and write allowed, existing file is not deleted.
 * 
 * Return NULL if an error occurs.
 */
MATFile* matOpen(const char *filename, const char * mode)
{
	int imode = 0;

	if(strcmp(mode, "r") == 0)
	{
		imode |= MAT_ACC_RDONLY;
		imode |= MAT_FT_UNDEFINED;
	}
	if(strcmp(mode, "w") == 0 || strcmp(mode, "u") == 0)
	{
		imode |= MAT_ACC_RDWR;
		imode |= MAT_FT_UNDEFINED;
	}
	if(strcmp(mode, "w4") == 0)
	{
		imode |= MAT_ACC_RDWR;
		imode |= MAT_FT_MAT4;
	}
	if(strcmp(mode, "w7.3") == 0)
	{
		printf("fatal: %s is not supported\n", filename);
		abort();
	}

	return reinterpret_cast<MATFile*>(
	    Mat_Open(filename, imode)
	);
}


/*
 * Close a MAT-file opened with matOpen.
 * The pointer-to-MATfile argument is invalid, once matClose returns.
 * Return zero for success, EOF on error.
 */
matError matClose(MATFile *pMF)
{
	return Mat_Close(
	    reinterpret_cast<mat_t*>(pMF)
	);
}


/*
 * Read the array value for the specified variable name from a MAT-file.
 *
 * Return NULL if an error occurs.
 */
mxArray * matGetVariable(MATFile * pMF, const char * name)
{
	mat_t* mf = reinterpret_cast<mat_t*>(pMF);
	matvar_t* content = Mat_VarRead(mf, name);
	if(content == 0)
	{
		return 0;
	}
	//Mat_VarPrint(content, 1);

	return reinterpret_cast<mxArray*>(content);
}


/// fake libmx funcs

int      mxGetM(const mxArray* arr)
{
	const matvar_t* content = reinterpret_cast<const matvar_t*>(arr);
	return content->rank >= 1 ? content->dims[0] : 0;
}

int      mxGetN(const mxArray* arr)
{
	const matvar_t* content = reinterpret_cast<const matvar_t*>(arr);
	if(content->rank < 2)
	{
		return 0;
	}

	int ret = 1;
	for(int i = 1; i < content-> rank; ++i)
	{
		ret *= content->dims[i];
	}
	return ret;
}

mxArray* mxGetCell(const mxArray* arr, int idx)
{
	const matvar_t* content = reinterpret_cast<const matvar_t*>(arr);
	matvar_t* cell = Mat_VarGetCell(const_cast<matvar_t*>(content), idx);

	return reinterpret_cast<mxArray*>(cell);
}

mxArray* mxGetField(const mxArray* arr, int idx, const char* name)
{
	const matvar_t* content = reinterpret_cast<const matvar_t*>(arr);
	matvar_t* field = Mat_VarGetStructFieldByName(const_cast<matvar_t*>(content), name, idx);

	return reinterpret_cast<mxArray*>(field);
}

void*    mxGetData(const mxArray* arr)
{
	// Just works on this single line!!
	return reinterpret_cast<const matvar_t*>(arr)->data;
}

void     mxDestroyArray(mxArray* arr)
{
	Mat_VarFree(
	    reinterpret_cast<matvar_t*>(arr)
	);
}