private void MoveBezierPont(DraggedBezierPoint point, Point pos)
{
if (point.Type == DotType.Control1 || point.Type == DotType.Control2)
{
point.Curve.SetPoint(point.Type, pos);
return;
}
var prev = point.Curve.GetPoint(point.Type);
var diff = pos - prev;
if (point.Type == DotType.Start)
{
point.Curve.SetPoint(point.Type, pos);
var c1 = point.Curve.GetPoint(DotType.Control1);
point.Curve.SetPoint(DotType.Control1, c1 + diff);
var prevCurve = point.Curve.Previous;
if (prevCurve != null)
{
var c2 = prevCurve.GetPoint(DotType.Control2);
prevCurve.SetPoint(DotType.Control2, c2 + diff);
}
}
else if (point.Type == DotType.End)
{
point.Curve.SetPoint(point.Type, pos);
var c2 = point.Curve.GetPoint(DotType.Control2);
point.Curve.SetPoint(DotType.Control2, c2 + diff);
var nextCurve = point.Curve.Next;
if (nextCurve != null)
{
var c1 = nextCurve.GetPoint(DotType.Control1);
nextCurve.SetPoint(DotType.Control1, c1 + diff);
}
}
}
private void OnDragEnds()
{
_dragPosition = null;
_draggedBezierPoint = null;
if (_beziers.Count == 0)
{
ReDrawCanvas();
}
}
private bool TryStartDragPoint(object sender, DotType dotType)
{
if (_beziers.Count == 0)
{
return(false);
}
var ellipse = sender as Ellipse;
var curve = ellipse?.Tag as IBezierCurve;
if (curve == null)
{
return(false);
}
_draggedBezierPoint = new DraggedBezierPoint(curve, dotType);
return(true);
}
