Method paintEvent

src/gui/ClientGateLevelView.cpp:77–217

}

void ClientGateLevelView::paintEvent(QPaintEvent*)
{
    QPainter p(this);
    p.setRenderHint(QPainter::Antialiasing, true);

    const QRectF full = rect();
    p.fillRect(full, kBgColor());

    // Plot region: inset the left gutter for dB labels and the right
    // strip for the peak bar.
    const QRectF plot(full.left() + kGutterPx, full.top() + 4,
                      full.width() - kGutterPx - kPeakBarPx - 4,
                      full.height() - 8);

    // Frame the plot.
    p.setPen(QPen(kFrameColor(), 1.0));
    p.drawRect(plot);

    // Horizontal grid + labels.
    QFont f = p.font();
    f.setPixelSize(9);
    p.setFont(f);
    for (float db : kTicks) {
        const float y = dbToY(db);
        p.setPen(QPen(kGridColor(), 1.0));
        p.drawLine(QPointF(plot.left(), y), QPointF(plot.right(), y));
        p.setPen(kAxisLabel());
        QString s = (db > 0.0f ? "+" : "") + QString::number(static_cast<int>(db));
        p.drawText(QPointF(full.left() + 2.0f, y + 3.0f), s);
    }

    // History plot — newest sample at the right edge, older scrolling
    // left.  Draw order (bottom to top visually so later strokes
    // paint over earlier ones cleanly):
    //   1. Audible band — from plot.bottom up to (input + grDb),
    //      filled amber.  Represents the portion of the signal that
    //      actually makes it through the gate.
    //   2. Gated band — from (input + grDb) up to input level,
    //      filled dark gray.  Represents the gain being "taken away"
    //      from the input.
    //   3. Input top-edge outline in bright white so the original
    //      signal envelope stays legible on top of the fills.
    p.save();
    p.setClipRect(plot);

    const float colW = plot.width() / float(kHistoryCount);

    // ── Audible band (amber) ───────────────────────────────────
    QPainterPath audiblePath;
    for (int i = 0; i < kHistoryCount; ++i) {
        const int idx = (m_writeIdx + i) % kHistoryCount;
        const Sample& s = m_history[idx];
        const float x = plot.right() - (kHistoryCount - 1 - i) * colW;
        // When gate is fully open, grDb = 0 → yGr = yIn; the amber
        // band touches the input outline.  When the gate closes,
        // grDb is negative and yGr sits lower → amber band shrinks,
        // revealing the gray gated band above it.
        const float yGr = dbToY(s.inputDb + s.grDb);