rainynite-core/document/color.cpp

/*
 *  color.cpp - Color types
 *  Copyright (C) 2017 caryoscelus
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <core/color.h>

namespace rainynite::core {
namespace colors {

template <>
string to_hex24(RGBA<uint8_t> const& color) {
    return "#{:02x}{:02x}{:02x}"_format(color.r, color.g, color.b);
}

template <>
string to_hex32(RGBA<uint8_t> const& color) {
    return "#{:02x}{:02x}{:02x}{:02x}"_format(color.r, color.g, color.b, color.a);
}

RGBA32 parse_hex(string const& s) {
    RGBA32 color;
    color.a = 0xff;
    size_t sz = s.size()-1;
    if (s[0] != '#' || !(sz == 3 || sz == 4 || sz == 6 || sz == 8)) {
        throw std::runtime_error("Can't parse color '"+s+"'");
    }
    uint32_t c = std::stoul(s.c_str()+1, nullptr, 16);
    switch (sz) {
        case 4:
            color.a = (c & 0xf) * 1.0 * 0xff / 0xf;
            c >>= 4;
            __attribute__ ((fallthrough));
        case 3:
            color.b = (c & 0xf) * 1.0 * 0xff / 0xf;
            c >>= 4;
            color.g = (c & 0xf) * 1.0 * 0xff / 0xf;
            c >>= 4;
            color.r = (c & 0xf) * 1.0 * 0xff / 0xf;
            break;
        case 8:
            color.a = c & 0xff;
            c >>= 8;
            __attribute__ ((fallthrough));
        case 6:
            color.b = c & 0xff;
            c >>= 8;
            color.g = c & 0xff;
            c >>= 8;
            color.r = c & 0xff;
            break;
    }
    return color;
}

std::ostream& operator<<(std::ostream& stream, Color c) {
    return stream << to_hex32(c);
}

} // namespace color
} // namespace rainynite::core