/// <summary>
/// Gets the nearest point but allows for normalising the x and y
/// by different distances, which is required if you scale the x
/// and y seperately, but want to get the visually closest point.
/// </summary>
/// <param name="points"></param>
/// <param name="point"></param>
/// <param name="inverseNormalisation"></param>
/// <param name="nearestDistanceSquared"></param>
/// <returns></returns>
public static PointAndPrimitive GetEllipseScaledNearestPoint(IEnumerable <PointAndPrimitive> points, Point point, Vector ratio, out double nearestDistanceSquared)
{
Point inverseNormalisation = new Point(1 / ratio.X, 1 / ratio.Y);
nearestDistanceSquared = 0;
PointAndPrimitive nearestPoint = new PointAndPrimitive(point, null);
try {
// Just pick off the first point to initialize stuff
foreach (PointAndPrimitive testPoint in points)
{
nearestDistanceSquared = new Vector((testPoint.X - point.X) * inverseNormalisation.X, (testPoint.Y - point.Y) * inverseNormalisation.Y).LengthSquared;
nearestPoint = testPoint;
break;
}
// Loop through all points to find the closest
foreach (PointAndPrimitive testPoint in points)
{
double distanceSquared = new Vector((testPoint.X - point.X) * inverseNormalisation.X, (testPoint.Y - point.Y) * inverseNormalisation.Y).LengthSquared;
if (distanceSquared < nearestDistanceSquared)
{
nearestDistanceSquared = distanceSquared;
nearestPoint = testPoint;
}
}
} catch (Exception) {
}
return(nearestPoint);
}
/// <summary>
/// Handles when the mouse moves in a way that that it can execute on a thread that isn't
/// the GUI thread.
/// </summary>
/// <param name="mousePos"></param>
/// <param name="minimumBounds"></param>
/// <returns></returns>
public Point MouseMoved(Point mousePos, Rect minimumBounds)
{
bool newLocked = false;
PointAndPrimitive newPoint = new PointAndPrimitive(mousePos, null);
lock (_points) {
if (_points.Count > 0)
{
double nearestDistanceSquared;
newPoint = GetEllipseScaledNearestPoint(_points, mousePos, (Vector)(minimumBounds.Size), out nearestDistanceSquared);
newLocked = nearestDistanceSquared <= 1;
}
}
bool lockedChanged = newLocked != _locked;
bool pointChanged = newPoint.Point != _closestPoint.Point;
if (_closestPoint.Primitive != null && _closestPoint.Primitive.LegendLabel != null)
{
_closestPoint.Primitive.LegendLabel.IsHighlighted = false;
}
_locked = newLocked;
_closestPoint = newPoint;
Action updateGui = () => {
if (_closestPoint.Primitive != null)
{
ChartPrimitive primitive = _closestPoint.Primitive;
if (primitive.LegendColor != Colors.Transparent && primitive.LegendLabel != null && _locked)
{
primitive.LegendLabel.IsHighlighted = true;
}
}
if ((pointChanged && _locked) || lockedChanged)
{
OnClosestPointChanged();
}
};
if (_dispatcher.Thread != Thread.CurrentThread)
{
_dispatcher.Invoke(updateGui);
}
else
{
updateGui();
}
return(_locked ? _closestPoint.Point : mousePos);
}
/// <summary>
/// Gets the nearest point but allows for normalising the x and y
/// by different distances, which is required if you scale the x
/// and y seperately, but want to get the visually closest point.
/// </summary>
/// <param name="points"></param>
/// <param name="point"></param>
/// <param name="inverseNormalisation"></param>
/// <param name="nearestDistanceSquared"></param>
/// <returns></returns>
public static PointAndPrimitive GetEllipseScaledNearestPoint(IEnumerable<PointAndPrimitive> points, Point point, Vector ratio, out double nearestDistanceSquared) {
Point inverseNormalisation = new Point(1 / ratio.X, 1 / ratio.Y);
nearestDistanceSquared = 0;
PointAndPrimitive nearestPoint = new PointAndPrimitive(point, null);
// Just pick off the first point to initialize stuff
foreach(PointAndPrimitive testPoint in points) {
nearestDistanceSquared = new Vector((testPoint.X - point.X) * inverseNormalisation.X, (testPoint.Y - point.Y) * inverseNormalisation.Y).LengthSquared;
nearestPoint = testPoint;
break;
}
// Loop through all points to find the closest
foreach(PointAndPrimitive testPoint in points) {
double distanceSquared = new Vector((testPoint.X - point.X) * inverseNormalisation.X, (testPoint.Y - point.Y) * inverseNormalisation.Y).LengthSquared;
if(distanceSquared < nearestDistanceSquared) {
nearestDistanceSquared = distanceSquared;
nearestPoint = testPoint;
}
}
return nearestPoint;
}
/// <summary>
/// Handles when the mouse moves in a way that that it can execute on a thread that isn't
/// the GUI thread.
/// </summary>
/// <param name="mousePos"></param>
/// <param name="minimumBounds"></param>
/// <returns></returns>
public Point MouseMoved(Point mousePos, Rect minimumBounds) {
bool newLocked = false;
PointAndPrimitive newPoint = new PointAndPrimitive(mousePos, null);
if(_points.Count > 0) {
double nearestDistanceSquared;
newPoint = GetEllipseScaledNearestPoint(_points, mousePos, (Vector)(minimumBounds.Size), out nearestDistanceSquared);
newLocked = nearestDistanceSquared <= 1;
}
bool lockedChanged = newLocked != _locked;
bool pointChanged = newPoint.Point != _closestPoint.Point;
if(_closestPoint.Primitive != null && _closestPoint.Primitive.LegendLabel != null) {
_closestPoint.Primitive.LegendLabel.IsHighlighted = false;
}
_locked = newLocked;
_closestPoint = newPoint;
Action updateGui = () => {
if(_closestPoint.Primitive != null) {
ChartPrimitive primitive = _closestPoint.Primitive;
if(primitive.LegendColor != Colors.Transparent && primitive.LegendLabel != null && _locked) {
primitive.LegendLabel.IsHighlighted = true;
}
}
if((pointChanged && _locked) || lockedChanged) {
OnClosestPointChanged();
}
};
if(_dispatcher.Thread != Thread.CurrentThread) {
_dispatcher.Invoke(updateGui);
} else {
updateGui();
}
return _locked ? _closestPoint.Point : mousePos;
}