Commit e0ed6ad9 authored by Isaak Lim's avatar Isaak Lim

- added random number generator to Core/Utils that generates a double between...

- added random number generator to Core/Utils that generates a double between 0.0 and 1.0 with garantueed precision

- use this random number generator for the McDecimater under Windows, since RAND_MAX is not large enough

git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@713 fdac6126-5c0c-442c-9429-916003d36597
parent 9478350b
/*===========================================================================*\
* *
* OpenMesh *
* Copyright (C) 2001-2011 by Computer Graphics Group, RWTH Aachen *
* www.openmesh.org *
* *
*---------------------------------------------------------------------------*
* This file is part of OpenMesh. *
* *
* OpenMesh is free software: you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License as *
* published by the Free Software Foundation, either version 3 of *
* the License, or (at your option) any later version with the *
* following exceptions: *
* *
* If other files instantiate templates or use macros *
* or inline functions from this file, or you compile this file and *
* link it with other files to produce an executable, this file does *
* not by itself cause the resulting executable to be covered by the *
* GNU Lesser General Public License. This exception does not however *
* invalidate any other reasons why the executable file might be *
* covered by the GNU Lesser General Public License. *
* *
* OpenMesh is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU LesserGeneral Public *
* License along with OpenMesh. If not, *
* see <http://www.gnu.org/licenses/>. *
* *
\*===========================================================================*/
/*===========================================================================*\
* *
* $Revision: 362 $ *
* $Date: 2011-01-26 10:21:12 +0100 (Mi, 26 Jan 2011) $ *
* *
\*===========================================================================*/
//=============================================================================
//
// Helper Functions for generating a random number between 0.0 and 1.0 with
// a garantueed resolution
//
//=============================================================================
//== INCLUDES =================================================================
#include <OpenMesh/Core/Utils/RandomNumberGenerator.hh>
//== NAMESPACES ===============================================================
namespace OpenMesh {
//== IMPLEMENTATION ===========================================================
RandomNumberGenerator::RandomNumberGenerator(const double _resolution) :
resolution_(_resolution),
iterations_(1),
maxNum_(RAND_MAX)
{
double tmp = resolution_;
while (tmp > (double(RAND_MAX) + 1) ) {
iterations_++;
tmp /= (double(RAND_MAX) + 1);
}
for ( unsigned int i = 0 ; i < iterations_ - 1; ++i ) {
maxNum_ *= (RAND_MAX + 1);
}
}
//-----------------------------------------------------------------------------
double RandomNumberGenerator::getRand() const {
double randNum = 0.0;
for ( unsigned int i = 0 ; i < iterations_; ++i ) {
randNum *= (RAND_MAX + 1);
randNum += rand();
}
return randNum / maxNum_;
}
//=============================================================================
} // namespace OpenMesh
//=============================================================================
/*===========================================================================*\
* *
* OpenMesh *
* Copyright (C) 2001-2011 by Computer Graphics Group, RWTH Aachen *
* www.openmesh.org *
* *
*---------------------------------------------------------------------------*
* This file is part of OpenMesh. *
* *
* OpenMesh is free software: you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License as *
* published by the Free Software Foundation, either version 3 of *
* the License, or (at your option) any later version with the *
* following exceptions: *
* *
* If other files instantiate templates or use macros *
* or inline functions from this file, or you compile this file and *
* link it with other files to produce an executable, this file does *
* not by itself cause the resulting executable to be covered by the *
* GNU Lesser General Public License. This exception does not however *
* invalidate any other reasons why the executable file might be *
* covered by the GNU Lesser General Public License. *
* *
* OpenMesh is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU LesserGeneral Public *
* License along with OpenMesh. If not, *
* see <http://www.gnu.org/licenses/>. *
* *
\*===========================================================================*/
/*===========================================================================*\
* *
* $Revision: 693 $ *
* $Date: 2012-09-23 16:25:16 +0200 (So, 23 Sep 2012) $ *
* *
\*===========================================================================*/
//=============================================================================
//
// Helper Functions for generating a random number between 0.0 and 1.0 with
// a garantueed resolution
//
//=============================================================================
#ifndef OPENMESH_UTILS_RANDOMNUMBERGENERATOR_HH
#define OPENMESH_UTILS_RANDOMNUMBERGENERATOR_HH
//== INCLUDES =================================================================
#include <OpenMesh/Core/System/config.h>
#include <iostream>
//== NAMESPACES ===============================================================
namespace OpenMesh {
//=============================================================================
/** Generate a random number between 0.0 and 1.0 with a garantueed resolution
*/
class OPENMESHDLLEXPORT RandomNumberGenerator
{
public:
/** \brief Constructor
*
* @param _resolution specifies the desired resolution for the random number generated
*/
RandomNumberGenerator(const double _resolution);
/// returns a random double between 0.0 and 1.0 with a garantueed resolution
double getRand() const;
private:
/// desired resolution
const double resolution_;
/// number of "blocks" of RAND_MAX that make up the desired _resolution
unsigned int iterations_;
/// maximum random number generated, which is used for normalization
double maxNum_;
};
//=============================================================================
} // namespace OpenMesh
//=============================================================================
#endif // OPENMESH_UTILS_RANDOMNUMBERGENERATOR_HH defined
//=============================================================================
......@@ -60,6 +60,9 @@
# include <cfloat>
#endif
#ifdef WIN32
# include <OpenMesh/Core/Utils/RandomNumberGenerator.hh>
#endif
//== NAMESPACE ===============================================================
......@@ -111,6 +114,10 @@ size_t McDecimaterT<Mesh>::decimate(size_t _n_collapses) {
// performed in a row
unsigned int noCollapses = 0;
#ifdef WIN32
RandomNumberGenerator randGen(mesh_.n_halfedges());
#endif
while ( n_collapses < _n_collapses) {
if (noCollapses > 20) {
......@@ -128,7 +135,11 @@ size_t McDecimaterT<Mesh>::decimate(size_t _n_collapses) {
for ( int i = 0; i < (int)randomSamples_; ++i) {
// Random halfedge handle
#ifdef WIN32
tmpHandle = typename Mesh::HalfedgeHandle(int(randGen.getRand() * (mesh_.n_halfedges() - 1)) );
#else
tmpHandle = typename Mesh::HalfedgeHandle((static_cast<double>(rand()) / RAND_MAX) * (mesh_.n_halfedges()-1) );
#endif
// if it is not deleted, we analyse it
if ( ! mesh_.status(tmpHandle).deleted() ) {
......@@ -225,6 +236,10 @@ size_t McDecimaterT<Mesh>::decimate_to_faces(size_t _nv, size_t _nf) {
// performed in a row
unsigned int noCollapses = 0;
#ifdef WIN32
RandomNumberGenerator randGen(mesh_.n_halfedges());
#endif
while ((_nv < nv) && (_nf < nf)) {
if (noCollapses > 20) {
......@@ -242,7 +257,11 @@ size_t McDecimaterT<Mesh>::decimate_to_faces(size_t _nv, size_t _nf) {
for (int i = 0; i < (int) randomSamples_; ++i) {
// Random halfedge handle
#ifdef WIN32
tmpHandle = typename Mesh::HalfedgeHandle(int(randGen.getRand() * (mesh_.n_halfedges() - 1)) );
#else
tmpHandle = typename Mesh::HalfedgeHandle((static_cast<double>(rand()) / RAND_MAX) * (mesh_.n_halfedges() - 1));
#endif
// if it is not deleted, we analyse it
if (!mesh_.status(tmpHandle).deleted()) {
......@@ -356,6 +375,10 @@ size_t McDecimaterT<Mesh>::decimate_constraints_only(float _factor) {
double energy = FLT_MAX;
double bestEnergy = FLT_MAX;
#ifdef WIN32
RandomNumberGenerator randGen(mesh_.n_halfedges());
#endif
while ((noCollapses <= 50) && (illegalCollapses <= 50) && (nv > 0) && (nf > 1)) {
// Optimal id and value will be collected during the random sampling
......@@ -363,13 +386,20 @@ size_t McDecimaterT<Mesh>::decimate_constraints_only(float _factor) {
typename Mesh::HalfedgeHandle tmpHandle(-1);
bestEnergy = FLT_MAX;
#ifndef WIN32
const double randomNormalizer = (1.0 / RAND_MAX) * (mesh_.n_halfedges() - 1);
#endif
// Generate random samples for collapses
for (int i = 0; i < (int) randomSamples_; ++i) {
// Random halfedge handle
#ifdef WIN32
tmpHandle = typename Mesh::HalfedgeHandle(int(randGen.getRand() * (mesh_.n_halfedges() - 1)) );
#else
tmpHandle = typename Mesh::HalfedgeHandle(int(rand() * randomNormalizer ) );
#endif
// if it is not deleted, we analyze it
if (!mesh_.status(mesh_.edge_handle(tmpHandle)).deleted()) {
......
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