Method data_string

source/matplot/axes_objects/contours.cpp:736–1192

    }

    std::string contours::data_string() {
        // If there is a jump from a border to the other, we need to complete
        // the curve from one point to another to avoid filled curves that don't
        // make sense.
        double _xmax = xmax();
        double _xmin = xmin();
        double _ymax = ymax();
        double _ymin = ymin();
        auto is_border_jump = [&](double x1, double y1, double x2, double y2) {
            constexpr uint8_t NONE = 0;
            constexpr uint8_t NORTH = 1;
            constexpr uint8_t SOUTH = 2;
            constexpr uint8_t WEST = 3;
            constexpr uint8_t EAST = 4;
            uint8_t xy1_border = NONE;
            if (x1 <= _xmin) {
                xy1_border = WEST;
            } else if (x1 >= _xmax) {
                xy1_border = EAST;
            } else if (y1 <= _ymin) {
                xy1_border = SOUTH;
            } else if (y1 >= _ymax) {
                xy1_border = NORTH;
            }
            if (xy1_border != NONE) {
                uint8_t xy2_border = NONE;
                if (x2 <= _xmin) {
                    xy2_border = WEST;
                } else if (x2 >= _xmax) {
                    xy2_border = EAST;
                } else if (y2 <= _ymin) {
                    xy2_border = SOUTH;
                } else if (y2 >= _ymax) {
                    xy2_border = NORTH;
                }
                if (xy2_border != NONE && xy2_border != xy1_border) {
                    return true;
                }
            }
            return false;
        };

        auto [lower_levels, upper_levels] = get_lowers_and_uppers();

        std::stringstream ss;
        ss.precision(10);
        ss << std::fixed;
        if (filled_) {
            // Plot the line segments
            // Create one filled curve for each segment of a contour.

            bool plot_background = _levels[0] < zmin_;
            if (plot_background) {
                // find background polygon level
                auto &largest_segment_with_children = line_segments_[0];
                auto &largest_segment =
                    std::get<0>(largest_segment_with_children);
                size_t line_index = std::get<0>(largest_segment);