131 lines
3.9 KiB
C++
131 lines
3.9 KiB
C++
/*****************************************************************************
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*
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* This file is part of Mapnik (c++ mapping toolkit)
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*
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* Copyright (C) 2017 Artem Pavlenko
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* This library 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 GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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*****************************************************************************/
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// mapnik
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#include <mapnik/color.hpp>
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#include <mapnik/color_factory.hpp>
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#include <mapnik/config_error.hpp>
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#pragma GCC diagnostic push
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#include <mapnik/warning_ignore.hpp>
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#include <boost/spirit/include/karma.hpp>
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#pragma GCC diagnostic pop
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namespace mapnik {
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color::color(std::string const& str, bool premultiplied)
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{
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*this = parse_color(str);
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premultiplied_ = premultiplied;
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}
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std::string color::to_string() const
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{
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namespace karma = boost::spirit::karma;
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boost::spirit::karma::eps_type eps;
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boost::spirit::karma::double_type double_;
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boost::spirit::karma::uint_generator<uint8_t,10> color_;
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std::string str;
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std::back_insert_iterator<std::string> sink(str);
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karma::generate(sink, eps(alpha() < 255)
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// begin grammar
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<< "rgba("
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<< color_(red()) << ','
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<< color_(green()) << ','
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<< color_(blue()) << ','
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<< double_(alpha()/255.0) << ')'
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"rgb("
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<< color_(red()) << ','
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<< color_(green()) << ','
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<< color_(blue()) << ')'
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// end grammar
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);
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return str;
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}
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std::string color::to_hex_string() const
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{
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namespace karma = boost::spirit::karma;
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boost::spirit::karma::hex_type hex;
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boost::spirit::karma::eps_type eps;
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boost::spirit::karma::right_align_type right_align;
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std::string str;
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std::back_insert_iterator<std::string> sink(str);
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karma::generate(sink,
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// begin grammar
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'#'
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<< right_align(2,'0')[hex(red())]
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<< right_align(2,'0')[hex(green())]
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<< right_align(2,'0')[hex(blue())]
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<< eps(alpha() < 255) << right_align(2,'0')[hex(alpha())]
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// end grammar
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);
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return str;
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}
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namespace {
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static std::uint8_t multiply(std::uint8_t c, std::uint8_t a)
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{
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std::uint32_t t = c * a + 128;
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return std::uint8_t(((t >> 8) + t) >> 8);
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}
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}
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bool color::premultiply()
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{
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if (premultiplied_) return false;
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if (alpha_ != 255)
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{
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red_ = multiply(red_, alpha_);
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green_ = multiply(green_, alpha_);
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blue_ = multiply(blue_, alpha_);
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}
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premultiplied_ = true;
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return true;
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}
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bool color::demultiply()
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{
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if (!premultiplied_) return false;
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if (alpha_ < 255)
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{
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if (alpha_ == 0)
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{
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red_ = green_ = blue_ = 0;
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}
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else
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{
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std::uint32_t r = (std::uint32_t(red_) * 255) / alpha_;
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std::uint32_t g = (std::uint32_t(green_) * 255) / alpha_;
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std::uint32_t b = (std::uint32_t(blue_) * 255) / alpha_;
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red_ = (r > 255) ? 255 : r;
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green_ = (g > 255) ? 255 : g;
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blue_ = (b > 255) ? 255 : b;
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}
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}
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premultiplied_ = false;
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return true;
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}
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}
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