Convert C# double to Delphi Real48

Question

I\'ve found the following question Convert Delphi Real48 to C# double but I want to go the other way, C# to Delphi.

Does anyone know how this can be done? I\'ve trie

Answer 1

In C/C++

typedef struct {
   unsigned char exponent;  // 8 bites;
   unsigned long mantisaLo; // 32 of 39 bites
   unsigned char mantisaHi : 7, sign : 1;  // 7 of 39 bites
} T_Real48;

typedef struct {
   unsigned long mantisaLo; // 32 of 52 bites
   unsigned long mantisaHi:20, exponent: 11, sign : 1; // 20 of 52 bites
} T_Double64;

double doubleToReal48(double val)
{
  T_Real48 real48;
  T_Double64 *double64 = (T_Double64*) &val;

  real48.mantisaHi = double64->mantisaHi >> 13;
  real48.mantisaLo =(double64->mantisaLo >> 13) + ((double64->mantisaHi & 0x1FFF) << 19);
  real48.exponent  = double64->exponent - 894;
  real48.sign      = double64->sign;

  if (real48.exponent == 0) {
      real48.mantisaHi = 0;
      real48.mantisaLo = 0;
  }

  return *(double *)&real48;
}

double real48ToDouble(double val)
{
  T_Real48 *real48 = (T_Real48*) &val;
  T_Double64 double64;

  double64.mantisaHi = (real48->mantisaHi << 13) + (real48->mantisaLo >> 19);
  double64.mantisaLo = real48->mantisaLo << 13;
  double64.exponent  = real48->exponent + 894;
  double64.sign      = real48->sign;

  return *(double *)&double64;
}