/// <overloads>
/// Draws the specified <see cref="RegularPolygon"/> or <see cref="PolygonGrid"/> to the
/// specified <see cref="StreamGeometry"/>.</overloads>
/// <summary>
/// Draws the specified <see cref="RegularPolygon"/> to the specified <see
/// cref="StreamGeometry"/>.</summary>
/// <param name="polygon">
/// The <see cref="RegularPolygon"/> to draw.</param>
/// <param name="context">
/// The <see cref="StreamGeometryContext"/> that receives <paramref name="polygon"/>.
/// </param>
/// <param name="offset">
/// The offset by which to shift <paramref name="polygon"/>.</param>
/// <param name="isFilled">
/// <c>true</c> to use the area covered by <paramref name="polygon"/> for hit-testing,
/// rendering, and clipping; otherwise, <c>false</c>.</param>
/// <exception cref="ArgumentNullException">
/// <paramref name="polygon"/> or <paramref name="context"/> is a null reference.
/// </exception>
/// <remarks>
/// <b>Draw</b> issues one <see cref="StreamGeometryContext.BeginFigure"/> call with the
/// specified <paramref name="isFilled"/> parameter for the first <see
/// cref="RegularPolygon.Vertices"/> element of the specified <paramref name="polygon"/>,
/// and then one <see cref="StreamGeometryContext.LineTo"/> call for each remaining element.
/// All coordinates are shifted by the specified <paramref name="offset"/>.</remarks>
public static void Draw(this RegularPolygon polygon,
StreamGeometryContext context, PointD offset, bool isFilled)
{
PointD[] vertices = polygon.Vertices;
PointD start = vertices[0] + offset;
context.BeginFigure(start.ToWpfPoint(), isFilled, true);
for (int i = 1; i < vertices.Length; i++)
{
PointD next = vertices[i] + offset;
context.LineTo(next.ToWpfPoint(), true, true);
}
}
/// <overloads>
/// Converts the specified <see cref="RegularPolygon"/> to a closed <see
/// cref="PathFigure"/>.</overloads>
/// <summary>
/// Converts the specified <see cref="RegularPolygon"/> to a closed <see
/// cref="PathFigure"/>.</summary>
/// <param name="polygon">
/// The <see cref="RegularPolygon"/> to convert.</param>
/// <returns>
/// A closed and frozen <see cref="PathFigure"/> containing all <see
/// cref="RegularPolygon.Vertices"/> of the specified <paramref name="polygon"/>.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="polygon"/> is a null reference.</exception>
public static PathFigure ToFigure(this RegularPolygon polygon)
{
PointD[] vertices = polygon.Vertices;
PathFigure figure = new PathFigure();
figure.StartPoint = vertices[0].ToWpfPoint();
for (int i = 1; i < vertices.Length; i++)
{
figure.Segments.Add(new LineSegment(vertices[i].ToWpfPoint(), true));
}
figure.IsClosed = true;
figure.Freeze();
return(figure);
}
