Developer Documentation
RandomNumberGenerator.cc
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41 
42 //=============================================================================
43 //
44 // Helper Functions for generating a random number between 0.0 and 1.0 with
45 // a garantueed resolution
46 //
47 //=============================================================================
48 
49 
50 //== INCLUDES =================================================================
51 
52 
53 #include <OpenMesh/Core/Utils/RandomNumberGenerator.hh>
54 
55 
56 //== NAMESPACES ===============================================================
57 
58 
59 namespace OpenMesh {
60 
61 
62 //== IMPLEMENTATION ===========================================================
63 
65  resolution_(_resolution),
66  iterations_(1),
67  maxNum_(RAND_MAX + 1.0)
68 {
69  double tmp = double(resolution_);
70  while (tmp > (double(RAND_MAX) + 1.0) ) {
71  iterations_++;
72  tmp /= (double(RAND_MAX) + 1.0);
73  }
74 
75  for ( unsigned int i = 0 ; i < iterations_ - 1; ++i ) {
76  maxNum_ *= (RAND_MAX + 1.0);
77  }
78 }
79 
80 //-----------------------------------------------------------------------------
81 
83  double randNum = 0.0;
84  for ( unsigned int i = 0 ; i < iterations_; ++i ) {
85  randNum *= (RAND_MAX + 1.0);
86  randNum += rand();
87  }
88 
89  return randNum / maxNum_;
90 }
91 
92 double RandomNumberGenerator::resolution() const {
93  return maxNum_;
94 }
95 
96 //=============================================================================
97 } // namespace OpenMesh
98 //=============================================================================
double maxNum_
maximum random number generated, which is used for normalization
RandomNumberGenerator(const size_t _resolution)
Constructor.
const size_t resolution_
desired resolution
size_t iterations_
number of "blocks" of RAND_MAX that make up the desired _resolution
double getRand() const
returns a random double between 0.0 and 1.0 with a guaranteed resolution