本文整理汇总了C++中QwtPlotCurve::sample方法的典型用法代码示例。如果您正苦于以下问题：C++ QwtPlotCurve::sample方法的具体用法？C++ QwtPlotCurve::sample怎么用？C++ QwtPlotCurve::sample使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类QwtPlotCurve的用法示例。
在下文中一共展示了QwtPlotCurve::sample方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: closestCurvePoint
//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
QPointF RiuSummaryQwtPlot::closestCurvePoint(const QPoint& cursorPosition, QString* valueString, QString* timeString, int* yAxis) const
{
QPointF samplePoint;
QwtPlotCurve* closestCurve = nullptr;
double distMin = DBL_MAX;
int closestPointSampleIndex = -1;
const QwtPlotItemList& itmList = itemList();
for (QwtPlotItemIterator it = itmList.begin(); it != itmList.end(); it++)
{
if ((*it)->rtti() == QwtPlotItem::Rtti_PlotCurve)
{
QwtPlotCurve* candidateCurve = static_cast<QwtPlotCurve*>(*it);
double dist = DBL_MAX;
int candidateSampleIndex = candidateCurve->closestPoint(cursorPosition, &dist);
if (dist < distMin)
{
closestCurve = candidateCurve;
distMin = dist;
closestPointSampleIndex = candidateSampleIndex;
}
}
}
if (closestCurve && distMin < 50)
{
samplePoint = closestCurve->sample(closestPointSampleIndex);
if (yAxis) *yAxis = closestCurve->yAxis();
}
if (timeString)
{
const QwtScaleDraw* timeAxisScaleDraw = axisScaleDraw(QwtPlot::xBottom);
if (timeAxisScaleDraw)
{
*timeString = timeAxisScaleDraw->label(samplePoint.x()).text();
}
}
if (valueString && closestCurve)
{
const QwtScaleDraw* yAxisScaleDraw = axisScaleDraw(closestCurve->yAxis());
if (yAxisScaleDraw)
{
*valueString = yAxisScaleDraw->label(samplePoint.y()).text();
}
}
return samplePoint;
}