/// <summary>
/// https://stackoverflow.com/questions/16667072/how-to-draw-arc-with-radius-and-start-and-stop-angle
/// </summary>
/// <param name="drawing"></param>
/// <param name="thisDC"></param>
/// <param name="pen"></param>
/// <param name="center"></param>
/// <param name="radius"></param>
/// <param name="startAngle"></param>
/// <param name="endAngle"></param>
/// <param name="mdoelToCanvas"></param>
protected static void DrawArc(IDrawing drawing, DrawingContext thisDC, Pen pen, CADPoint center, double radius, double startAngle, double endAngle, bool mdoelToCanvas = true)
{
CADPoint centerInCanvas = mdoelToCanvas ? drawing.ModelToCanvas(center) : center;
double radiusInCanvas = mdoelToCanvas ? drawing.ModelToCanvas(radius) : radius;
double startAngleInCanvas = MathUtils.NormalizeRadianAngle(-startAngle);
double endAngleInCanvas = MathUtils.NormalizeRadianAngle(-endAngle);
//
double angle = endAngle - startAngle;
if (endAngle < startAngle)
{
angle += Utils.PI * 2;
}
if (radiusInCanvas > 0)
{
double a0 = startAngleInCanvas < 0 ? startAngleInCanvas + 2 * Math.PI : startAngleInCanvas;
double a1 = endAngleInCanvas < 0 ? endAngleInCanvas + 2 * Math.PI : endAngleInCanvas;
if (a1 < a0)
{
a1 += Math.PI * 2;
}
SweepDirection d = SweepDirection.Counterclockwise;
bool large;
bool SmallAngle = false;
if (SmallAngle)
{
large = false;
d = (a1 - a0) > Math.PI ? SweepDirection.Counterclockwise : SweepDirection.Clockwise;
}
else
{
large = (Math.Abs(a1 - a0) < Math.PI);
}
Point p0 = centerInCanvas.AsWPF() + new Vector(Math.Cos(a0), Math.Sin(a0)) * radiusInCanvas;
Point p1 = centerInCanvas.AsWPF() + new Vector(Math.Cos(a1), Math.Sin(a1)) * radiusInCanvas;
List <PathSegment> segments = new List <PathSegment>
{
new ArcSegment(p1, new Size(radiusInCanvas, radiusInCanvas), 0.0, large, d, true)
};
List <PathFigure> figures = new List <PathFigure>
{
new PathFigure(p0, segments, true)
{
IsClosed = false
}
};
thisDC.DrawGeometry(null, pen, new PathGeometry(figures, FillRule.EvenOdd, null));
}
}
