src/library/range.cpp

   1 #include "range.hpp"
   2 #include "minmax.hpp"
   3
   4 range range::make_b(uint32_t l, uint32_t h)
   5 {
   6         return range(l, h);
   7 }
   8
   9 range::range(uint32_t l, uint32_t h)
  10 {
  11         _low = l;
  12         _high = h;
  13 }
  14
  15 range& range::operator+=(uint32_t o) throw()
  16 {
  17         _low += o;
  18         _high += o;
  19
  20         return *this;
  21 }
  22
  23 range& range::operator&=(const range& b) throw()
  24 {
  25         //Offset ranges down.
  26         uint32_t offset = _low;
  27         uint32_t L = _high - _low;
  28         uint32_t A = b._low - _low;
  29         uint32_t B = b._high - _low;
  30
  31         bool asl = (A < L);     //There is initial overlap between ranges.
  32         bool asb = (A <= B);    //Range 2 does not warp around.
  33
  34         //If there is initial overlap, the range bottom is A+offset, otherwise 0+offset.
  35         _low = offset + (asl ? A : 0);
  36         //If asl EQU asb, then range top is min(L, B). Otherwise if asl, it is L, otherwise 0.
  37         _high = offset + ((asl == asb) ? min(L, B) : (asl ? L : 0));
  38
  39         return *this;
  40 }
  41
  42 bool range::in(uint32_t x) const throw()
  43 {
  44         return ((x - _low) < (_high - _low));
  45 }