Construct a polyline from a list of vertices:

stepShape =
    Polyline2d.fromVertices
        [ Point2d.meters 0 0
        , Point2d.meters 1 0
        , Point2d.meters 1 1
        , Point2d.meters 2 1
        ]

Get the vertices of a polyline.

Polyline2d.vertices stepShape
--> [ Point2d.meters 0 0
--> , Point2d.meters 1 0
--> , Point2d.meters 1 1
--> , Point2d.meters 2 1
--> ]

Get the individual segments of a polyline.

Polyline2d.segments stepShape
--> [ LineSegment2d.from
-->     (Point2d.meters 0 0)
-->     (Point2d.meters 1 0)
--> , LineSegment2d.from
-->     (Point2d.meters 1 0)
-->     (Point2d.meters 1 1)
--> , LineSegment2d.from
-->     (Point2d.meters 1 1)
-->     (Point2d.meters 2 1)
--> ]

Get the overall length of a polyline (the sum of the lengths of its segments).

Polyline2d.length stepShape
--> Length.meters 3

Get the minimal bounding box containing a given polyline. Returns Nothing if the polyline has no vertices.

Polyline2d.boundingBox stepShape
--> Just <|
-->     BoundingBox2d.fromExtrema
-->         { minX = Length.meters 0
-->         , maxX = Length.meters 2
-->         , minY = Length.meters 0
-->         , maxY = Length.meters 1
-->         }

Find the centroid (center of mass) of a polyline. This is the length-weighted average of the edges of the polyline, not the centroid of its vertices. Returns Nothing if the polyline is empty (has no vertices).

Polyline2d.centroid stepShape
--> Just (Point2d.meters 1.0 0.5)

Convert a polyline from one units type to another, by providing a conversion factor given as a rate of change of destination units with respect to source units.

Convert a polyline from one units type to another, by providing an 'inverse' conversion factor given as a rate of change of source units with respect to destination units.

Scale a polyline about a given center point by a given scale.

Rotate a polyline around the given center point counterclockwise by the given angle.

Translate a polyline by the given displacement.

Translate a polyline in a given direction by a given distance.

Mirror a polyline across the given axis.

Project (flatten) a polyline onto the given axis.

Transform each vertex of a polyline by the given function. All other transformations can be defined in terms of mapVertices; for example,

Polyline2d.mirrorAcross axis

is equivalent to

Polyline2d.mapVertices (Point2d.mirrorAcross axis)

Take a polyline defined in global coordinates, and return it expressed in local coordinates relative to a given reference frame.

Take a polyline considered to be defined in local coordinates relative to a given reference frame, and return that polyline expressed in global coordinates.