#include "mex.h" /* Remember to include! */

/*
 When called from MATLAB, execution starts here.
 LeftHandSide = mexme(RightHandSide)
 nlhs = Number of arguments on Left-Hand Side
 plhs = Pointer to arguments on Left-Hand Side
 nrhs = Number of arguments on Right-Hand Side
 prhs = Pointer to arguments on Right-Hand Side
*/

void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[]) {

	/* Just print text. May be useful for debugging. */
	mexPrintf("Hello, world!\n"); 

	/* If we don't have exactly 1 input and 2 output */
	if (nrhs!=1 || nlhs!=2) {
		/* Throw Error message */
		mexErrMsgTxt("The number of input arguments must be 1. The number of output arguments must be 2.\n");
	}

	/* Let's extract the size of input data */
	const mwSize *dims;
 	dims = mxGetDimensions(prhs[0]); 

	/* Height */
	int h = dims[0];
	/* Width */
	int w = dims[1]; 

	mexPrintf("W: %i\nH: %i\n", w, h);

	/* Let's get the pointer to the input data (the numbers are converted to double) */
	double *data = mxGetPr(prhs[0]);

	/* Let this function output the minimum and maximum values of input 
	 data and corresponding indices.
	 It may not be clever to use mex-file to achieve this goal, because
	 there are "min" and "max"
	 functions in MATLAB.
	 But this is just an example. :)
	*/

	/* Let's create some output variables */
	
	/* First one is a 1x2 matrix of doubles (mxREAL) which stores the min and max values
	 Here 1 is the number of rows, and 2 is the number of columns.
	 */
	mxArray *mxValues = mxCreateDoubleMatrix(1, 2, mxREAL);
	/*
	 The pointer to the actual values in this matrix
	 */
	double *values = mxGetPr(mxValues);

	/* Second one is 2x2 matrix of integers(mxINT32_CLASS) which stores indices of min and max values.
	 The last argument of mxCreateNumericArray is a flag to deal with complex numbers (ignore it now).
	 */
	mxArray *mxIndices = mxCreateNumericMatrix(2, 2, mxINT32_CLASS, mxREAL);
	/*
	 Pointer to the actual values in this matrix
	 */
	int *indices = (int *)mxGetPr(mxIndices);

	/* Initialize the minimum and maximum using the first entry of the 'data' */
	values[0] = data[0];
	values[1] = data[1];
	indices[0] = 1;
	indices[1] = 1;
	indices[2] = 1;
	indices[3] = 1;

	/* So let's loop over all numbers and store the minimum and maximum values. */
	int x,y;
	for (y=0; y<h; y++)
		for (x=0; x<w; x++) {
			/* Get the value from input. Notice how MATLAB stores matrices
			 as if its elements were strung out in a long column 
			 vector. (try running "input(:)" in Matlab command window)
			*/
			double curval = data[x*h+y];
			mexPrintf("%f\n", curval);
			
			if (curval<values[0]) {
				values[0] = curval;
				indices[0] = y+1;
				indices[1] = x+1;
			}

			if (curval>values[1]) {
				values[1] = curval;
				indices[2] = y+1;
				indices[3] = x+1;
			}
		}

	
	/* Give matlab results */
	plhs[0] = mxValues;
	plhs[1] = mxIndices;
}