/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
 * This file is part of the LibreOffice project.
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 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * This file incorporates work covered by the following license notice:
 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
 *   with this work for additional information regarding copyright
 *   ownership. The ASF licenses this file to you under the Apache
 *   License, Version 2.0 (the "License"); you may not use this file
 *   except in compliance with the License. You may obtain a copy of
 *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
 */

#ifndef INCLUDED_SAL_QA_INC_VALUEEQUAL_HXX
#define INCLUDED_SAL_QA_INC_VALUEEQUAL_HXX

#include <sal/config.h>

#include <cmath>

#define PREC_float 1
#define PREC_double 2
#define PREC_long_double 3

template<class T>
bool is_equal(T x, T y, sal_Int16 _nPrec)
{
    if (!(std::isfinite(x) && std::isfinite(y))) {
        return x == y;
    }

    // due to the fact that this check looks only if both values are equal
    // we only need to look on one value

    // 14 digits will announce the checkPrecisionSize

    sal_Int32 nPRECISION;
    switch(_nPrec)
    {
    case PREC_float:
        nPRECISION = 6;
        break;
    case PREC_double:
        nPRECISION = 14;
        break;
    case PREC_long_double:
        nPRECISION = 20;
        break;
    default:
        nPRECISION = 2;
    }

    if (x < 0)
    {
        x = -x;
    }
    if (y < 0)
    {
        y = -y;
    }

    if (_nPrec != PREC_long_double)
    {
        printf("double equal: %.20f\n", x);
        printf("              %.20f\n", y);
    }
    //here nPrecOfN is the number after dot
    sal_Int32 nBeforeDot = sal_Int32( log10(x) );
    if ( nBeforeDot < 0)
    {
         nBeforeDot = 0;
    }
    //printf("nPRECISION is  %d\n", nPRECISION);
    sal_Int32 nPrecOfN = -nPRECISION + nBeforeDot;

    if (_nPrec != PREC_long_double)
        printf("nPrecOfN is  %" SAL_PRIdINT32 "\n", nPrecOfN);

    double nPrec = pow(0.1, -nPrecOfN);

    if (_nPrec != PREC_long_double)
        printf("        prec: %.20f\n", nPrec);

    double nDelta = fabs( x - y ) ;

    if (_nPrec != PREC_long_double)
    {
        printf("       delta: %.20f\n", nDelta);
        printf("       nPrec: %.20f\n", nPrec);
        printf("delta must be less or equal to prec\n\n");
    }

    if (nDelta > nPrec)
    {
        // values are not equal
        return false;
    }

    // values are equal
    return true;
}

bool is_float_equal(float x, float y)
{
    return is_equal<float>(x, y, PREC_float);
}
bool is_double_equal(double x, double y)
{
    return is_equal<double>(x, y, PREC_double);
}

#endif // INCLUDED_SAL_QA_INC_VALUEEQUAL_HXX

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