Field Points on a Line using von Koch

void line(
    ct::plot::cairo::plot_2d& plot,
    ct::vector_spice::field_vector& field,
    glm::vec2 p0,
    glm::vec2 p1,
    ct::plot::cairo::pixel color,
    unsigned long n
) {
    glm::vec2 dif = p1 - p0;

    float normal_base = 1.f / (n - 1);

    //plot.line(p0, p1, color);

    for (unsigned long i = 0; i < n; ++i)
    {
        float normal = normal_base * i;

        glm::vec2 pn0 = p0 + dif * normal;

        //plot.circle_filled(pn0, .05, color);

        field.push_back({ { pn0, 0 }, -1 });
    }
}


void koch(
    ct::plot::cairo::plot_2d& plot,
    ct::vector_spice::field_vector& field,
    unsigned long ri,
    unsigned long rn,
    glm::vec2 p0,
    glm::vec2 p1,
    unsigned long n
) {
    if (ri >= rn) return;


    glm::vec2 dif = p1 - p0;
    glm::vec2 dif_perp = { -dif.y, dif.x };
    glm::vec2 dif_mid = p0 + dif * 1.f / 2.f;

    float scale = 1.f / 3.f;

    glm::vec2 k0 = p0;
    glm::vec2 k1 = k0 + dif * scale;
    glm::vec2 k2 = dif_mid + dif_perp * scale;
    glm::vec2 k3 = p1 - dif * scale;
    glm::vec2 k4 = p1;


    /*
    plot.line(k0, k1, CT_RGBF(1, 0, 0));
    plot.line(k1, k2, CT_RGBF(0, 1, 0));
    plot.line(k2, k3, CT_RGBF(0, 0, 1));
    plot.line(k3, k4, CT_RGBF(0, 1, 1));
    */

    unsigned long line_n = 5;

    line(plot, field, k0, k1, CT_RGBF(1, 0, 0), line_n);
    line(plot, field, k1, k2, CT_RGBF(0, 1, 0), line_n);
    line(plot, field, k2, k3, CT_RGBF(0, 0, 1), line_n);
    line(plot, field, k3, k4, CT_RGBF(0, 1, 1), line_n);


    koch(plot, field, ri + 1, rn, k0, k1, n);
    koch(plot, field, ri + 1, rn, k1, k2, n);
    koch(plot, field, ri + 1, rn, k2, k3, n);
    koch(plot, field, ri + 1, rn, k3, k4, n);


}