src/external/tng_io/include/compression/fixpoint.h

   1 /* This code is part of the tng compression routines.
   2  *
   3  * Written by Daniel Spangberg
   4  * Copyright (c) 2010, 2013, The GROMACS development team.
   5  *
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the Revised BSD License.
   9  */
  10
  11 #ifndef FIXPOINT_H
  12 #define FIXPOINT_H
  13
  14 #include "../compression/my64bit.h"
  15
  16 /* There are at least 32 bits available in a long. */
  17 typedef unsigned long fix_t;
  18
  19 /* Positive double to 32 bit fixed point value */
  20 fix_t Ptngc_ud_to_fix_t(double d, const double max);
  21
  22 /* double to signed 32 bit fixed point value */
  23 fix_t Ptngc_d_to_fix_t(double d, const double max);
  24
  25 /* 32 bit fixed point value to positive double */
  26 double Ptngc_fix_t_to_ud(fix_t f, const double max);
  27
  28 /* signed 32 bit fixed point value to double */
  29 double Ptngc_fix_t_to_d(fix_t f, const double max);
  30
  31 /* Convert a floating point variable to two 32 bit integers with range
  32    -2.1e9 to 2.1e9 and precision to somewhere around 1e-9. */
  33 void Ptngc_d_to_i32x2(double d, fix_t *hi, fix_t *lo);
  34
  35 /* Convert two 32 bit integers to a floating point variable
  36    -2.1e9 to 2.1e9 and precision to somewhere around 1e-9. */
  37 double Ptngc_i32x2_to_d(fix_t hi, fix_t lo);
  38
  39 #endif