Method draw_logic_tick_mark

DSView/pv/view/ruler.cpp:425–559

}

void Ruler::draw_logic_tick_mark(QPainter &p)
{
    using namespace Qt;

    if (_view.session().get_device()->have_instance() == false){
        return;
    }

    const double SpacingIncrement = 32.0;
    const double MinValueSpacing = 16.0;
    const int ValueMargin = 5;
    const double abs_min_period = 10.0 / _view.session().cur_snap_samplerate();

    double min_width = SpacingIncrement;
    double typical_width;
    double tick_period = 0;
    double scale = _view.scale();
    int64_t offset = _view.offset();

    const uint64_t cur_period_scale = ceil((scale * min_width) / abs_min_period);

    // Find tick spacing, and number formatting that does not cause
    // value to collide.
    _min_period = cur_period_scale * abs_min_period;

    const int order = (int)floorf(log10f(scale * _view.get_view_width()));
    //const double order_decimal = pow(10, order);
    const unsigned int prefix = (order - FirstSIPrefixPower) / 3;
    _cur_prefix = prefix;
    assert(prefix < countof(SIPrefixes));
    typical_width = p.boundingRect(0, 0, INT_MAX, INT_MAX,
        AlignLeft | AlignTop, format_time(offset * scale,
        prefix)).width() + MinValueSpacing;
    do
    {
        tick_period += _min_period;

    } while(typical_width > tick_period / scale);

    const int text_height = p.boundingRect(0, 0, INT_MAX, INT_MAX,
        AlignLeft | AlignTop, "8").height();

    // Draw the tick marks
    QColor fore(QWidget::palette().color(QWidget::foregroundRole()));
    fore.setAlpha(View::ForeAlpha);
    p.setPen(fore);

    const double minor_tick_period = tick_period / MinPeriodScale;
    const int minor_order = (int)floorf(log10f(minor_tick_period));
    //const double minor_order_decimal = pow(10, minor_order);
    const unsigned int minor_prefix = (minor_order - FirstSIPrefixPower) / 3;
    assert(minor_prefix < countof(SIPrefixes));

    const double first_major_division =
        floor(offset * scale / tick_period);
    const double first_minor_division =
        floor(offset * scale / minor_tick_period + 1);
    const double t0 = first_major_division * tick_period;