/***************************************************************************** * * This file is part of Mapnik (c++ mapping toolkit) * * Copyright (C) 2014 Artem Pavlenko * * This library 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 2.1 of the License, or (at your option) any later version. * * This library 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 Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * *****************************************************************************/ #ifndef MAPNIK_NUMERIC_2_STRING_HPP #define MAPNIK_NUMERIC_2_STRING_HPP #include <mapnik/global.hpp> #include <string> #include <sstream> #include <memory> #include <algorithm> static inline std::string numeric2string(const char* buf) { std::int16_t ndigits = int2net(buf); std::int16_t weight = int2net(buf+2); std::int16_t sign = int2net(buf+4); std::int16_t dscale = int2net(buf+6); std::unique_ptr<std::int16_t[]> digits(new std::int16_t[ndigits]); for (int n=0; n < ndigits ;++n) { digits[n] = int2net(buf+8+n*2); } std::ostringstream ss; if (sign == 0x4000) ss << "-"; int i = std::max(weight,std::int16_t(0)); int d = 0; // Each numeric "digit" is actually a value between 0000 and 9999 stored in a 16 bit field. // For example, the number 1234567809990001 is stored as four digits: [1234] [5678] [999] [1]. // Note that the last two digits show that the leading 0's are lost when the number is split. // We must be careful to re-insert these 0's when building the string. while ( i >= 0) { if (i <= weight && d < ndigits) { // All digits after the first must be padded to make the field 4 characters long if (d != 0) { #ifdef _WINDOWS int dig = digits[d]; if (dig < 10) { ss << "000"; // 0000 - 0009 } else if (dig < 100) { ss << "00"; // 0010 - 0099 } else { ss << "0"; // 0100 - 0999; } #else switch(digits[d]) { case 0 ... 9: ss << "000"; // 0000 - 0009 break; case 10 ... 99: ss << "00"; // 0010 - 0099 break; case 100 ... 999: ss << "0"; // 0100 - 0999 break; } #endif } ss << digits[d++]; } else { if (d == 0) ss << "0"; else ss << "0000"; } i--; } if (dscale > 0) { ss << '.'; // dscale counts the number of decimal digits following the point, not the numeric digits while (dscale > 0) { int value; if (i <= weight && d < ndigits) value = digits[d++]; else value = 0; // Output up to 4 decimal digits for this value if (dscale > 0) { ss << (value / 1000); value %= 1000; dscale--; } if (dscale > 0) { ss << (value / 100); value %= 100; dscale--; } if (dscale > 0) { ss << (value / 10); value %= 10; dscale--; } if (dscale > 0) { ss << value; dscale--; } i--; } } return ss.str(); } #endif