Jim Evins
80 lines
2.8 KiB
C++
80 lines
2.8 KiB
C++
/* StrUtil.cpp
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*
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* Copyright (C) 2013 Jim Evins <evins@snaught.com>
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*
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* This file is part of gLabels-qt.
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*
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* gLabels-qt is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* gLabels-qt is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with gLabels-qt. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "StrUtil.h"
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#include <cmath>
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namespace
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{
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const double FRAC_EPSILON = 0.00005;
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const double denom[] = { 1.0, 2.0, 3.0, 4.0, 8.0, 16.0, 32.0, 0.0 };
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const char* denom_string[] = { "1", "₂", "₃", "₄", "₈", "₁₆", "₃₂", NULL };
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const char* num_string[] = { "⁰", "¹", "²", "³", "⁴", "⁵", "⁶", "⁷", "⁸", "⁹",
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"¹⁰", "¹¹", "¹²", "¹³", "¹⁴", "¹⁵", "¹⁶", "¹⁷", "¹⁸", "¹⁹",
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"²⁰", "²¹", "²²", "²³", "²⁴", "²⁵", "²⁶", "²⁷", "²⁸", "²⁹",
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"³⁰", "³¹" };
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}
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namespace libglabels
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{
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namespace StrUtil
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{
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QString &formatFraction( double x )
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{
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int i;
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double product, remainder;
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for ( i=0; denom[i] != 0.0; i++ )
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{
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product = x * denom[i];
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remainder = fabs(product - ((int)(product+0.5)));
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if ( remainder < FRAC_EPSILON ) break;
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}
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if ( denom[i] == 0.0 )
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{
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/* None of our denominators work. */
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return QString().sprintf( "%.5g", x );
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}
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if ( denom[i] == 1.0 )
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{
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/* Simple integer. */
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return QString().sprintf( "%.0f", x );
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}
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int n = (int)( x * denom[i] + 0.5 );
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int d = (int)denom[i];
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if ( n > d )
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{
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return QString().sprintf( "%d%s/%s", (n/d), num_string[n%d], denom_string[i] );
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}
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else
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{
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return QString().sprintf( "%s/%s", num_string[n%d], denom_string[i] );
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}
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}
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}
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}
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