# DoubleBits.h

    00001 /**********************************************************************
    00002  * $Id: DoubleBits.h 1820 2006-09-06 16:54:23Z mloskot $
    00003  *
    00004  * GEOS - Geometry Engine Open Source
    00005  * http://geos.refractions.net
    00006  *
    00007  * Copyright (C) 2006 Refractions Research Inc.
    00008  *
    00009  * This is free software; you can redistribute and/or modify it under
    00010  * the terms of the GNU Lesser General Public Licence as published
    00011  * by the Free Software Foundation.
    00012  * See the COPYING file for more information.
    00013  *
    00014  **********************************************************************
    00015  *
    00016  * Last port: index/quadtree/DoubleBits.java rev. 1.7 (JTS-1.7.1)
    00017  *
    00018  **********************************************************************/
    00019
    00020 #ifndef GEOS_IDX_QUADTREE_DOUBLEBITS_H
    00021 #define GEOS_IDX_QUADTREE_DOUBLEBITS_H
    00022
    00023 #include <geos/platform.h> // for int64
    00024
    00025 #include <string>
    00026
    00027 namespace geos {
    00028 namespace index { // geos::index
    00029 namespace quadtree { // geos::index::quadtree
    00030
    00031
    00044 class DoubleBits {
    00045
    00046 public:
    00047
    00048         static const int EXPONENT_BIAS=1023;
    00049
    00050         static double powerOf2(int exp);
    00051
    00052         static int exponent(double d);
    00053
    00054         static double truncateToPowerOfTwo(double d);
    00055
    00056         static std::string toBinaryString(double d);
    00057
    00058         static double maximumCommonMantissa(double d1, double d2);
    00059
    00060         DoubleBits(double nx);
    00061
    00062         double getDouble() const;
    00063
    00065         int64 biasedExponent() const;
    00066
    00068         int getExponent() const;
    00069
    00070         void zeroLowerBits(int nBits);
    00071
    00072         int getBit(int i) const;
    00073
    00086         int numCommonMantissaBits(const DoubleBits& db) const;
    00087
    00089         std::string toString() const;
    00090
    00091 private:
    00092
    00093         double x;
    00094
    00095         int64 xBits;
    00096 };
    00097
    00098 } // namespace geos::index::quadtree
    00099 } // namespace geos::index
    00100 } // namespace geos
    00101
    00102 #endif // GEOS_IDX_QUADTREE_DOUBLEBITS_H
    00103
    00104 /**********************************************************************
    00105  * $Log$
    00106  * Revision 1.2  2006/05/23 14:29:33  strk
    00107  * * source/headers/geos/index/quadtree/DoubleBits.h, source/index/quadtree/DoubleBits.cpp: const correctness and documentation.
    00108  *
    00109  * Revision 1.1  2006/03/22 12:22:50  strk
    00110  * indexQuadtree.h split
    00111  *
    00112  **********************************************************************/
    00113