code_points.cpp

/*
** ETIB PROJECT, 2026
** utility
** File description:
** code_points
*/
 
#include <charconv>
#include <sstream>
#include <utility/graphic/text/code_points.hpp>
 
namespace utility::graphic
{
    CodePoints::CodePoints(const std::string &content)
    {
        parse(content);
    }
 
    void CodePoints::parse(const std::string &content)
    {
        std::istringstream stream(content);
        std::string line;
        while (std::getline(stream, line)) {
            const size_t spacePos = line.find(' ');
            if (spacePos == std::string::npos) {
                continue;
            }
            // Skip a line whose code is not a 32-bit hexadecimal number, as a
            // line without a space is skipped: std::stoul threw out of the
            // constructor on it, and truncated codes above 0xFFFFFFFF.
            const char *first = line.data() + spacePos + 1;
            const char *last  = line.data() + line.size();
            while (first != last && (*first == ' ' || *first == '\t')) {
                ++first;
            }
            if (last - first > 2 && first[0] == '0'
                && (first[1] == 'x' || first[1] == 'X')) {
                first += 2;
            }
            uint32_t code = 0;
            if (std::from_chars(first, last, code, 16).ec != std::errc()) {
                continue;
            }
            _codes[line.substr(0, spacePos)] = code;
        }
    }
 
    uint32_t CodePoints::getCode(const std::string &name) const
    {
        auto it = _codes.find(name);
        if (it != _codes.end()) {
            return it->second;
        }
        return 0;
    }
 
    std::string CodePoints::toUtf8(uint32_t codePoint)
    {
        std::string result;
        if (codePoint <= 0x7F) {
            result.push_back(static_cast<char>(codePoint));
        } else if (codePoint <= 0x7FF) {
            result.push_back(
                static_cast<char>(0xC0 | ((codePoint >> 6) & 0x1F)));
            result.push_back(static_cast<char>(0x80 | (codePoint & 0x3F)));
        } else if (codePoint <= 0xFFFF) {
            result.push_back(
                static_cast<char>(0xE0 | ((codePoint >> 12) & 0x0F)));
            result.push_back(
                static_cast<char>(0x80 | ((codePoint >> 6) & 0x3F)));
            result.push_back(static_cast<char>(0x80 | (codePoint & 0x3F)));
        } else {
            result.push_back(
                static_cast<char>(0xF0 | ((codePoint >> 18) & 0x07)));
            result.push_back(
                static_cast<char>(0x80 | ((codePoint >> 12) & 0x3F)));
            result.push_back(
                static_cast<char>(0x80 | ((codePoint >> 6) & 0x3F)));
            result.push_back(static_cast<char>(0x80 | (codePoint & 0x3F)));
        }
        return result;
    }
}    // namespace utility::graphic