Method paint_envelope

DSView/pv/view/analogsignal.cpp:525–599

}

void AnalogSignal::paint_envelope(QPainter &p,
    const pv::data::AnalogSnapshot *snapshot,
    int zeroY, const int start_pixel,
    const uint64_t start_index, const int64_t sample_count,
    const double samples_per_pixel, const int order,
    const float top, const float bottom, const int width)
{
    using namespace Qt;
    using pv::data::AnalogSnapshot;
    pv::data::AnalogSnapshot *pshot = const_cast<pv::data::AnalogSnapshot*>(snapshot);

    AnalogSnapshot::EnvelopeSection e;
    pshot->get_envelope_section(e, start_index, sample_count,
                                   samples_per_pixel, order);
    if (e.samples_num == 0)
        return;

    p.setPen(QPen(NoPen));
    p.setBrush(_colour);

    if (!_rects)
        _rects = new QRectF[width+10];
    
    QRectF *rect = _rects;
    int px = -1, pre_px;
    float y_min = zeroY, y_max = zeroY, pre_y_min = zeroY, pre_y_max = zeroY;
    int pcnt = 0;
    const double scale_pixels_per_samples = e.scale / samples_per_pixel;
    int64_t end_v = pshot->get_ring_end();
    const uint64_t ring_end = max((int64_t)0, end_v / e.scale - 1);
    const int hw_offset = get_hw_offset();

    float x = start_pixel;
    for(uint64_t sample = 0; sample < e.length; sample++) {
        const uint64_t ring_index = (e.start + sample) % (_view->session().cur_samplelimits() / e.scale);
        if (sample != 0 && ring_index == ring_end)
            break;

        const AnalogSnapshot::EnvelopeSample *const ev =
            e.samples + ((e.start + sample) % e.samples_num);

        const float b = min(max((float)(zeroY + (ev->max - hw_offset) * _scale + 0.5), top), bottom);
        const float t = min(max((float)(zeroY + (ev->min - hw_offset) * _scale + 0.5), top), bottom);

        pre_px = px;
        if(px != floor(x)) {
            if (pre_px != -1) {
                // We overlap this sample with the previous so that vertical
                // gaps do not appear during steep rising or falling edges
                if (pre_y_min > y_max)
                    *rect++ = QRectF(pre_px, y_min, 1.0f, pre_y_min-y_min+1);
                else if (pre_y_max < y_min)
                    *rect++ = QRectF(pre_px, pre_y_max, 1.0f, y_max-pre_y_max+1);
                else
                    *rect++ = QRectF(pre_px, y_min, 1.0f, y_max-y_min+1);
                pre_y_min = y_min;
                pre_y_max = y_max;
                pcnt++;