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// mbf.cpp
// Revision 9-jul-2004
#include "mbf.h"
#include "error.h"
#include <math.h>
// For debugging:
#include <iostream>
#include <iomanip>
double mbf::mbf_s (const std::string & s)
{
if (s.size () != 4)
throw ErrFunctionCall;
unsigned char b0= s [0], b1= s [1], b2= s [2], b3= s [3];
double n= (b2 & 0x7F) | 0x80;
n= 256 * n + b1;
n= 256 * n + b0;
short e= static_cast <short> (b3 - 128 - 24);
if (e > 0)
for ( ; e > 0; --e)
n*= 2;
else
for ( ; e < 0; ++e)
n/= 2;
if (b2 & 0x80)
n= -n;
return n;
}
double mbf::mbf_d (const std::string & s)
{
if (s.size () != 8)
throw ErrFunctionCall;
unsigned char b0= s [0], b1= s [1], b2= s [2], b3= s [3],
b4= s [4], b5= s [5], b6= s [6], b7= s [7];
double n= (b6 & 0x7F) | 0x80;
n= 256 * n + b5;
n= 256 * n + b4;
n= 256 * n + b3;
n= 256 * n + b2;
n= 256 * n + b1;
n= 256 * n + b0;
short e= static_cast <short> (b7 - 128 - 56);
if (e > 0)
for ( ; e > 0; --e)
n*= 2;
else
for ( ; e < 0; ++e)
n/= 2;
if (b6 & 0x80)
n= -n;
return n;
}
namespace {
double zero= 0.0;
} // namespace
std::string mbf::to_mbf_s (double v)
{
bool negative= v < 0;
if (negative)
v= -v;
int e= static_cast <int> (log (v) / log (2) );
v/= pow (2, e - 23);
unsigned long l= static_cast <unsigned long> (v);
#if 0
std::cerr << "e= " << std::dec << e <<
" l= " << std::hex <<
std::setw (8) << std::setfill ('0') <<
l << std::endl;
#endif
unsigned char b3= static_cast <unsigned char> (e + 128 + 1);
unsigned char b2= static_cast <unsigned char> (l / (256 * 256) );
unsigned char b1= static_cast <unsigned char> ((l / 256) % 256);
unsigned char b0= static_cast <unsigned char> (l % 256);
b2&= 0x7F;
if (negative)
b2|= 0x80;
#if 0
std::cerr << std::setw (2) << int (b0) << int (b1) <<
int (b2) << int (b3) << std::endl;
#endif
return std::string (1, char (b0) ) + char (b1) + char (b2) + char (b3);
}
std::string mbf::to_mbf_d (double v)
{
bool negative= v < 0;
if (negative)
v= -v;
int e= static_cast <int> (log (v) / log (2) );
v/= pow (2, e - 55);
//unsigned long l= static_cast <unsigned long> (v);
double l;
modf (v, & l);
#if 0
std::cerr << "e= " << std::dec << e <<
" l= " << std::hex <<
std::setw (8) << std::setfill ('0') <<
l << std::endl;
#endif
unsigned char b7= static_cast <unsigned char> (e + 128 + 1);
#if 0
unsigned char b6= l / (256.0 * 256 * 256 * 256 * 256 * 256);
unsigned char b5= (l / (256.0 * 256 * 256 * 256 * 256) ) % 256.0;
unsigned char b4= (l / (256.0 * 256 * 256 * 256) ) % 256.0;
unsigned char b3= (l / (256UL * 256 * 256) ) % 256.0;
unsigned char b2= (l / (256 * 256) ) % 256.0;
unsigned char b1= (l / 256) % 256.0;
unsigned char b0= l % 256.0;
#else
double ll;
modf (l / 256, & ll);
unsigned char b0= static_cast <unsigned char> (l - 256 * ll);
l= ll;
modf (l / 256, & ll);
unsigned char b1= static_cast <unsigned char> (l - 256 * ll);
l= ll;
modf (l / 256, & ll);
unsigned char b2= static_cast <unsigned char> (l - 256 * ll);
l= ll;
modf (l / 256, & ll);
unsigned char b3= static_cast <unsigned char> (l - 256 * ll);
l= ll;
modf (l / 256, & ll);
unsigned char b4= static_cast <unsigned char> (l - 256 * ll);
l= ll;
modf (l / 256, & ll);
unsigned char b5= static_cast <unsigned char> (l - 256 * ll);
l= ll;
unsigned char b6= static_cast <unsigned char> (l);
#endif
b6&= 0x7F;
if (negative)
b6|= 0x80;
#if 0
std::cerr << std::setw (2) << int (b0) << int (b1) <<
int (b2) << int (b3) << std::endl;
#endif
return std::string (1, char (b0) ) + char (b1) + char (b2) +
char (b3) + char (b4) + char (b5) + char (b6) + char (b7);
}
// End of mbf.cpp
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