/usr/include/geos/index/quadtree/DoubleBits.h is in libgeos-dev 3.2.2-3ubuntu1.
This file is owned by root:root, with mode 0o644.
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* $Id: DoubleBits.h 2556 2009-06-06 22:22:28Z strk $
*
* GEOS - Geometry Engine Open Source
* http://geos.refractions.net
*
* Copyright (C) 2006 Refractions Research Inc.
*
* This is free software; you can redistribute and/or modify it under
* the terms of the GNU Lesser General Public Licence as published
* by the Free Software Foundation.
* See the COPYING file for more information.
*
**********************************************************************
*
* Last port: index/quadtree/DoubleBits.java rev. 1.7 (JTS-1.10)
*
**********************************************************************/
#ifndef GEOS_IDX_QUADTREE_DOUBLEBITS_H
#define GEOS_IDX_QUADTREE_DOUBLEBITS_H
#include <geos/export.h>
#include <geos/platform.h> // for int64
#include <string>
namespace geos {
namespace index { // geos::index
namespace quadtree { // geos::index::quadtree
/** \brief
* DoubleBits manipulates Double numbers
* by using bit manipulation and bit-field extraction.
*
* For some operations (such as determining the exponent)
* this is more accurate than using mathematical operations
* (which suffer from round-off error).
*
* The algorithms and constants in this class
* apply only to IEEE-754 double-precision floating point format.
*
*/
class GEOS_DLL DoubleBits {
public:
static const int EXPONENT_BIAS=1023;
static double powerOf2(int exp);
static int exponent(double d);
static double truncateToPowerOfTwo(double d);
static std::string toBinaryString(double d);
static double maximumCommonMantissa(double d1, double d2);
DoubleBits(double nx);
double getDouble() const;
/// Determines the exponent for the number
int64 biasedExponent() const;
/// Determines the exponent for the number
int getExponent() const;
void zeroLowerBits(int nBits);
int getBit(int i) const;
/** \brief
* This computes the number of common most-significant bits in
* the mantissa.
*
* It does not count the hidden bit, which is always 1.
* It does not determine whether the numbers have the same exponent;
* if they do not, the value computed by this function is meaningless.
*
* @param db
*
* @return the number of common most-significant mantissa bits
*/
int numCommonMantissaBits(const DoubleBits& db) const;
/// A representation of the Double bits formatted for easy readability
std::string toString() const;
private:
double x;
int64 xBits;
};
} // namespace geos::index::quadtree
} // namespace geos::index
} // namespace geos
#endif // GEOS_IDX_QUADTREE_DOUBLEBITS_H
/**********************************************************************
* $Log$
* Revision 1.2 2006/05/23 14:29:33 strk
* * source/headers/geos/index/quadtree/DoubleBits.h, source/index/quadtree/DoubleBits.cpp: const correctness and documentation.
*
* Revision 1.1 2006/03/22 12:22:50 strk
* indexQuadtree.h split
*
**********************************************************************/
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