Method updateFillingRect

src/backend/worksheet/plots/cartesian/BoxPlot.cpp:1342–1393

}

void BoxPlotPrivate::updateFillingRect(int index, const QVector<QLineF>& lines) {
	const auto& unclippedLines = q->cSystem->mapLogicalToScene(lines, AbstractCoordinateSystem::MappingFlag::SuppressPageClipping);

	if (unclippedLines.isEmpty()) {
		m_fillPolygon[index] = QPolygonF();
		return;
	}

	// we have four unclipped lines for the box.
	// clip the points to the plot data rect and create a new polygon
	// out of them that will be filled out.
	QPolygonF polygon;
	const QRectF& dataRect = static_cast<CartesianPlot*>(q->parentAspect())->dataRect();
	int i = 0;
	for (const auto& line : unclippedLines) {
		// clip the first point of the line
		QPointF p1 = line.p1();
		if (p1.x() < dataRect.left())
			p1.setX(dataRect.left());
		else if (p1.x() > dataRect.right())
			p1.setX(dataRect.right());

		if (p1.y() < dataRect.top())
			p1.setY(dataRect.top());
		else if (p1.y() > dataRect.bottom())
			p1.setY(dataRect.bottom());

		// clip the second point of the line
		QPointF p2 = line.p2();
		if (p2.x() < dataRect.left())
			p2.setX(dataRect.left());
		else if (p2.x() > dataRect.right())
			p2.setX(dataRect.right());

		if (p2.y() < dataRect.top())
			p2.setY(dataRect.top());
		else if (p2.y() > dataRect.bottom())
			p2.setY(dataRect.bottom());

		if (i != unclippedLines.size() - 1)
			polygon << p1;
		else {
			// close the polygon for the last line
			polygon << p1;
			polygon << p2;
		}

		++i;
	}

	m_fillPolygon[index] = std::move(polygon);
}

/*!
 * map the outlier points from logical to scene coordinates,