Method getValueAt

gui/src/plotchannel.cpp:264–326

}

double PlotChannel::getValueAt(double pos)
{
	auto tmp = this;
	QwtSeriesData<QPointF> *curve_data = tmp->curve()->data();
	int n = curve_data->size();

	if(n == 0) {
		return -1;
	} else {
		double leftTime, rightTime, leftCustom, rightCustom;
		int rightIndex = -1;
		int leftIndex = -1;
		int left = 0;
		int right = n - 1;

		double right_s = curve_data->sample(right).x();
		double left_s = curve_data->sample(left).x();
		if(pos < std::min(right_s, left_s) || pos > std::max(right_s, left_s)) {
			return -1;
		}

		// this is used in Frequency complex mode
		bool reversed = false;
		if(right_s < left_s) {
			reversed = true;
		}

		while(left <= right) {
			int mid = (left + right) / 2;
			double xData = curve_data->sample(mid).x();

			if(xData == pos) {
				if(mid > 0) {
					leftIndex = mid - 1;
					rightIndex = mid;
				}
				break;
			} else if((xData < pos) ^ reversed) {
				left = mid + 1;
			} else {
				right = mid - 1;
			}
		}

		if((leftIndex == -1 || rightIndex == -1) && left > 0) {
			leftIndex = left - 1;
			rightIndex = left;
		}
		if(leftIndex == -1 || rightIndex == -1) {
			return -1;
		}

		leftTime = curve_data->sample(leftIndex).x();
		rightTime = curve_data->sample(rightIndex).x();

		leftCustom = curve_data->sample(leftIndex).y();
		rightCustom = curve_data->sample(rightIndex).y();