Class (GI Struct)

Gsk-4.0 ▶ Gsk ▶ PathPointSince 4.14

Represents a point on a path.

It can be queried for properties of the path at that point, such as its tangent or its curvature.

To obtain a Gsk.PathPoint, use Gsk.Path.get_closest_point, Gsk.Path.get_start_point, Gsk.Path.get_end_point or Gsk.PathMeasure.get_point.

Note that Gsk.PathPoint structs are meant to be stack-allocated, and don't hold a reference to the path object they are obtained from. It is the callers responsibility to keep a reference to the path as long as the Gsk.PathPoint is used.

4.14

Index

Constructors

constructor

Properties

$gtype

Methods

compare copy equal free get_curvature get_distance get_position get_rotation get_tangent

Constructors

Properties

$gtype: GType<PathPoint>

Methods

  • Returns whether point1 is before or after point2.

    Parameters

    Returns number

    -1 if point1 is before point2, 1 if point1 is after point2, 0 if they are equal

  • Returns whether the two path points refer to the same location on all paths.

    Note that the start- and endpoint of a closed contour will compare nonequal according to this definition. Use Gsk.Path.is_closed to find out if the start- and endpoint of a concrete path refer to the same location.

    Parameters

    Returns boolean

    true if point1 and point2 are equal

  • Calculates the curvature of the path at the point.

    Optionally, returns the center of the osculating circle as well. The curvature is the inverse of the radius of the osculating circle.

    Lines have a curvature of zero (indicating an osculating circle of infinite radius). In this case, the center is not modified.

    Circles with a radius of zero have INFINITY as curvature

    Note that certain points on a path may not have a single curvature, such as sharp turns. At such points, there are two curvatures — the (limit of) the curvature of the path going into the point, and the (limit of) the curvature of the path coming out of it. The direction argument lets you choose which one to get.

    Osculating circle

    Parameters

    • path: Gsk.Path

      the path that point is on

    • direction: Gsk.PathDirection

      the direction for which to return the curvature

    Returns [number, Graphene.Point]

    the curvature of the path at the given point

  • Returns the distance from the beginning of the path to the point.

    Parameters

    Returns number

    the distance of point

  • Gets the tangent of the path at the point.

    Note that certain points on a path may not have a single tangent, such as sharp turns. At such points, there are two tangents — the direction of the path going into the point, and the direction coming out of it. The direction argument lets you choose which one to get.

    If the path is just a single point (e.g. a circle with radius zero), then the tangent is set to 0, 0.

    If you want to orient something in the direction of the path, Gsk.PathPoint.get_rotation may be more convenient to use.

    Parameters

    Returns Vec2