Method paint_envelope

DSView/pv/view/mathtrace.cpp:313–358

}

void MathTrace::paint_envelope(QPainter &p,
    int zeroY, int left, const int64_t start, const int64_t end,
    const double pixels_offset, const double samples_per_pixel)
{
	using namespace Qt;

    data::MathStack::EnvelopeSection e;
    _math_stack->get_math_envelope_section(e, start, end, samples_per_pixel);

	if (e.length < 2)
		return;

    p.setPen(QPen(NoPen));
    QColor envelope_colour = _colour;
    envelope_colour.setAlpha(View::ForeAlpha);
    p.setBrush(envelope_colour);

	QRectF *const rects = new QRectF[e.length];
	QRectF *rect = rects;
    double top = get_view_rect().top();
    double bottom = get_view_rect().bottom();

    for(uint64_t sample = 0; sample < e.length-1; sample++) {
		const float x = ((e.scale * sample + e.start) /
            samples_per_pixel - pixels_offset) + left + _view->trig_hoff()/samples_per_pixel;
        const data::MathStack::EnvelopeSample *const s =
			e.samples + sample;

		// We overlap this sample with the next so that vertical
		// gaps do not appear during steep rising or falling edges
        const float b = min(max(top, zeroY - max(s->max, (s+1)->min) * _scale), bottom);
        const float t = min(max(top, zeroY - min(s->min, (s+1)->max) * _scale), bottom);

		float h = b - t;
		if(h >= 0.0f && h <= 1.0f)
			h = 1.0f;
		if(h <= 0.0f && h >= -1.0f)
			h = -1.0f;

		*rect++ = QRectF(x, t, 1.0f, h);
	}

	p.drawRects(rects, e.length);

	delete[] rects;
}

void MathTrace::paint_type_options(QPainter &p, int right, const QPoint pt, QColor fore)
{