misc.cc

   1 #include "misc.hh"
   2 #include "glob.hh"
   3 #include "mtime.hh"
   4 #include <math.h>
   5
   6 int intlog2(int d) {
   7     int i=0;
   8     while (!(d&1)) {
   9         d/= 2; i++;
  10     }
  11     assert(!(d/2));
  12     return i;
  13 }
  14
  15 double log2(double x) {
  16     return log(x)  /log(2.0);
  17 }
  18
  19
  20 // golden ratio
  21
  22 const Real PHI = (1+sqrt(5))/2;
  23 const double ENGRAVERS_SPACE = PHI;
  24 const double WHOLE_SPACE = 5.0; // should be settable from input
  25
  26
  27
  28 Real
  29 duration_to_idealspace(Mtime d)
  30 {
  31     // see  Roelofs, p. 57
  32     return WHOLE_SPACE * pow(ENGRAVERS_SPACE, log2(d));
  33 }
  34
  35
  36
  37