private void UpdateArcGeometry(ChartControl chartControl, ChartPanel chartPanel, ChartScale chartScale)
{
Point startPoint = StartAnchor.GetPoint(chartControl, chartPanel, chartScale);
Point endPoint = EndAnchor.GetPoint(chartControl, chartPanel, chartScale);
if (arcGeometry != null && startPoint == cachedStartPoint && endPoint == cachedEndPoint)
{
return;
}
cachedEndPoint = endPoint;
cachedStartPoint = startPoint;
if (arcGeometry != null && !arcGeometry.IsDisposed)
{
arcGeometry.Dispose();
}
Vector lineVec = endPoint - startPoint;
float width = Math.Abs((float)lineVec.X);
float height = Math.Abs((float)lineVec.Y);
SharpDX.Direct2D1.ArcSegment arcSegment = new SharpDX.Direct2D1.ArcSegment
{
ArcSize = SharpDX.Direct2D1.ArcSize.Small,
Point = new SharpDX.Vector2((float)endPoint.X, (float)endPoint.Y),
SweepDirection = SharpDX.Direct2D1.SweepDirection.CounterClockwise,
Size = new SharpDX.Size2F(width, height)
};
// Create the arc between the line two end points
arcGeometry = new SharpDX.Direct2D1.PathGeometry(Core.Globals.D2DFactory);
SharpDX.Direct2D1.GeometrySink geometrySink = arcGeometry.Open();
geometrySink.BeginFigure(new SharpDX.Vector2((float)startPoint.X, (float)startPoint.Y), SharpDX.Direct2D1.FigureBegin.Filled);
geometrySink.AddArc(arcSegment);
geometrySink.EndFigure(SharpDX.Direct2D1.FigureEnd.Open);
geometrySink.Close();
}