/* ---------------------------------------------------------------

   File Name:    fpbin.c
   Author:       James E. Stine
                 Dept. of EECS
		 Lehigh University 
   Last Revised: 6/13/97 
   Purpose:      This file contains support for display a double-precision
                 number in matlab in Hex, Binary, and Decimal 
                 (up to 64 digits)

  Copyright: Lehigh University 1997, 1998, 1999

  Use without express written consent is strictly forbidden.  Violators
  shall be persecuted at the highest extent of the law.
 
 -------------------------------------------------------------------*/

#include "mex.h"
#include "matrix.h"
#include "round.h"
#include <math.h>
#include <stdio.h>
#include <stdlib.h>

#define INPUT_ARRAY  prhs[0]

/* Function Prototype */
void disp_binary(double, int, int);
void disp_dp_counter(int);


/* Global Declarations */
double dp_approx;
union {
  unsigned short x[4];
  double v;
} dp_number;


/* 

   Function:      disp_dp_counter
   Description:   This function displays the Double-Precision counter and
                  legend associated with the double type.
   Argument List: int bits
   Return value:  none

*/
void disp_dp_counter(int bits) {

  int i;
  int j;

  /* Write whether position is s, e, or m */
  j = 1;
  mexPrintf("s");
  for(i=0;i<11;i++) {
    mexPrintf("e");
    j++;
  }
  for(i=0;i<52;i++) {
    if (j%16 == 0)
      mexPrintf(" ");
    mexPrintf("m");
    j++;    
  }
  
  /* Line break */
  mexPrintf("\n");

  /* Write counter on next line */
  for(i=0; i<bits; i++) {
    if (i%16 == 0 && i != 0)
      mexPrintf(" ");    
    mexPrintf("%d",i%10);    

  }

  /* Line break */  
  mexPrintf("\n");

  /* Write Separator */
  for(i=0; i<bits; i++) {
    if (i%16 == 0 && i != 0)
      mexPrintf(" ");
    mexPrintf("-");
  }
   
  /* Line break */
  mexPrintf("\n");


}


/* 

   Function:      disp_binary
   Description:   This function displays a Double-Precision number into
                  four 16 bit integers using the global union variable 
		  dp_number
   Argument List: double x            The value to be converted
                  int bits_to_left    Number of bits left of radix point
		  int bits_to_right   Number of bits right of radix point
   Return value:  none

*/
void disp_binary(double x, int bits_to_left, int bits_to_right) {
  int i; 
  double diff;

  if (fabs(x) <  pow(2.0, ((double) -bits_to_right)) ) {
    for (i = -bits_to_left + 1; i <= bits_to_right; i++) {
      mexPrintf("0");
    }
    if (i == bits_to_right+1) 
      mexPrintf(" ");
    
    return;
  }

  if (x < 0.0) 
    x = pow(2.0, ((double) bits_to_left)) + x;

  for (i = -bits_to_left + 1; i <= bits_to_right; i++) {
    diff = pow(2.0, ((double) -i) );
    if (x < diff) 
      mexPrintf("0");
    else {
      mexPrintf("1");
      x -= diff;
    }
    if (i == 0) 
      mexPrintf(" ");
    
  }

}


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

  mxArray    *char_array;
  double     value;
  const char *array_name;

  if(nrhs!=1) {
    mexErrMsgTxt("Usage : fpbin(array)\n");
  }
  
  value = mxGetScalar(INPUT_ARRAY);

  /* initialize the union */
  dp_number.v = value;

  disp_dp_counter(64);

  /* print union out */
  disp_binary(dp_number.x[0],16,0);
  disp_binary(dp_number.x[1],16,0);
  disp_binary(dp_number.x[2],16,0);
  disp_binary(dp_number.x[3],16,0);


  mexPrintf("\n\n");
  mexPrintf("Hex Values\n");
  mexPrintf("0x%x 0x%x 0x%x 0x%x\n\n", dp_number.x[0], dp_number.x[1], 
	    dp_number.x[2], dp_number.x[3]);

  mexPrintf("%1.53lg\n",value);
  

  

    
}