Polyline
========

.. py:module:: rhino3dm

.. py:class:: Polyline

   .. py:method:: Polyline()

      Polyline constructor


   .. py:method:: Polyline(initialCapacity)

      Initializes a new empty polyline with an initial capacity.

      :param int initialCapacity: Number of vertices this polyline can contain without resizing.

   .. py:method:: Polyline()

      Polyline constructor


   .. py:attribute:: IsValid

      bool: Gets a value that indicates whether this polyline is valid.
      Valid polylines have at least one segment, no Invalid points and no zero length segments.Closed polylines with only two segments are also not considered valid.

   .. py:attribute:: SegmentCount

      int: Gets the number of segments for this polyline.

   .. py:attribute:: IsClosed

      bool: Test a polyline to see if it is closed.

   .. py:attribute:: Length

      float: Gets the total length of the polyline.

   .. py:method:: IsClosedWithinTolerance(tolerance)

      Test a polyline to see if it is closed.

      :param float tolerance: The tolerance.

      :return: Returns True if polyline has 4 or more points, the distance between the \
         start and end points is <= tolerance, and there is a \
         point in the polyline whose distance from the start and end \
         points is > tolerance.

      :rtype: bool

   .. py:method:: PointAt(t)

      Gets the point on the polyline at the given parameter.
      The integer part of the parameter indicates the index of the segment.

      :param float t: Polyline parameter.

      :return: The point on the polyline at t.

      :rtype: rhino3dm.Point3d

   .. py:method:: TangentAt(t)

      Gets the unit tangent vector along the polyline at the given parameter.
      The integer part of the parameter indicates the index of the segment.

      :param float t: Polyline parameter.

      :return: The tangent along the polyline at t.

      :rtype: rhino3dm.Vector3d

   .. py:method:: ClosesPoint(testPoint)

      [todo] add documentation

   .. py:method:: ClosestParameter(testPoint)

      Gets the parameter along the polyline which is closest to a test-point.

      :param rhino3dm.Point3d testPoint: Point to approximate.

      :return: The parameter along the polyline closest to testPoint.

      :rtype: float

   .. py:method:: ToNurbsCurve()

      Constructs a nurbs curve representation of this polyline.

      :return: A Nurbs curve shaped like this polyline or None on failure.

      :rtype: rhino3dm.NurbsCurve

   .. py:method:: ToPolylineCurve()

      Constructs a polyline curve representation of this polyline.

      :return: A curve shaped like this polyline or None on failure.

      :rtype: PolylineCurve

   .. py:method:: GetSegments()

      Constructs an array of line segments that make up the entire polyline.

      :return: An array of line segments or None if the polyline contains fewer than 2 points.

      :rtype: Line[]

   .. py:method:: SegmentAt(index)

      Gets the line segment at the given index.

      :param int index: Index of segment to retrieve.

      :return: Line segment at index or Line.Unset on failure.

      :rtype: Line

   .. py:staticmethod:: CreateInscribedPolygon(circle, sideCount)

      Create a regular polygon inscribed in a circle. The vertices of the polygon will be on the circle.

      :param Circle circle: The circle.
      :param int sideCount: The number of sides

      :return: A closed polyline if successful, None otherwise.

      :rtype: rhino3dm.Polyline

   .. py:staticmethod:: CreateCircumscribedPolygon(circle, sideCount)

      Create a regular polygon circumscribe about a circle. The midpoints of the polygon's edges will be tangent to the circle.

      :param Circle circle: The circle.
      :param int sideCount: The number of sides

      :return: A closed polyline if successful, None otherwise.

      :rtype: rhino3dm.Polyline

   .. py:staticmethod:: CreateStarPolygon(circle, radius, cornerCounts)

      Create a regular star polygon. The star begins at circle.PointAt(0) and the vertices
      alternate between being on circle and begin on a concentric circle of other_radius.

      :param Circle circle: The circle.
      :param float radius: The radius of other circle.
      :param int cornerCount: The number of corners on the circle. There will be 2*cornerCount sides and 2*cornerCount vertices.

      :return: A closed polyline if successful, None otherwise.

      :rtype: rhino3dm.Polyline