/// <summary>
/// Returns the index of a scatter point that is nearest to the location <c>hitpoint</c>
/// </summary>
/// <param name="layer">The layer in which this plot item is drawn into.</param>
/// <param name="hitpoint">The point where the mouse is pressed.</param>
/// <returns>The information about the point that is nearest to the location, or null if it can not be determined.</returns>
public XYScatterPointInformation GetNearestPlotPoint(IPlotArea layer, PointD2D hitpoint)
{
Processed2DPlotData pdata;
if (null != (pdata = _cachedPlotDataUsedForPainting))
{
PlotRangeList rangeList = pdata.RangeList;
PointF[] ptArray = pdata.PlotPointsInAbsoluteLayerCoordinates;
double mindistance = double.MaxValue;
int minindex = -1;
for (int i = 1; i < ptArray.Length; i++)
{
double distance = Math2D.SquareDistanceLineToPoint(hitpoint, ptArray[i - 1], ptArray[i]);
if (distance < mindistance)
{
mindistance = distance;
minindex = Math2D.Distance(ptArray[i - 1], hitpoint) < Math2D.Distance(ptArray[i], hitpoint) ? i - 1 : i;
}
}
// ok, minindex is the point we are looking for
// so we have a look in the rangeList, what row it belongs to
int rowindex = rangeList.GetRowIndexForPlotIndex(minindex);
return(new XYScatterPointInformation(ptArray[minindex], rowindex, minindex));
}
return(null);
}
/// <summary>
/// Returns the index of a scatter point that is closest to the location <c>hitpoint</c>
/// </summary>
/// <param name="layer">The layer in which this plot item is drawn into.</param>
/// <param name="hitpoint">The point where the mouse is pressed.</param>
/// <returns>The information about the point that is nearest to the location, or null if it can not be determined.</returns>
public XYZScatterPointInformation GetNearestPlotPoint(IPlotArea layer, HitTestPointData hitpoint)
{
Processed3DPlotData pdata;
if (null != (pdata = _cachedPlotDataUsedForPainting))
{
PlotRangeList rangeList = pdata.RangeList;
var ptArray = pdata.PlotPointsInAbsoluteLayerCoordinates;
double mindistance = double.MaxValue;
int minindex = -1;
var hitTransformation = hitpoint.HitTransformation;
var lineStart = hitTransformation.Transform(ptArray[0]).PointD2DWithoutZ;
for (int i = 1; i < ptArray.Length; i++)
{
var lineEnd = hitTransformation.Transform(ptArray[i]).PointD2DWithoutZ;
double distance = Math2D.SquareDistanceLineToPoint(PointD2D.Empty, lineStart, lineEnd);
if (distance < mindistance)
{
mindistance = distance;
minindex = Math2D.Distance(lineStart, PointD2D.Empty) < Math2D.Distance(lineEnd, PointD2D.Empty) ? i - 1 : i;
}
lineStart = lineEnd;
}
// ok, minindex is the point we are looking for
// so we have a look in the rangeList, what row it belongs to
int rowindex = rangeList.GetRowIndexForPlotIndex(minindex);
return(new XYZScatterPointInformation(ptArray[minindex], rowindex, minindex));
}
return(null);
}