Gsk.PathPoint¶

Fields¶

None

Methods¶

	`compare` (point2)
	`copy` ()
	`equal` (point2)
	`free` ()
	`get_curvature` (path, direction)
	`get_distance` (measure)
	`get_position` (path)
	`get_rotation` (path, direction)
	`get_tangent` (path, direction)

Details¶

class Gsk.PathPoint¶

An opaque type representing 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 GskPathPoint, use [method`Gsk`.Path.get_closest_point], [method`Gsk`.Path.get_start_point], [method`Gsk`.Path.get_end_point] or [method`Gsk`.PathMeasure.get_point].

Note that GskPathPoint 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 GskPathPoint is used.

New in version 4.14.

compare(point2)¶

Parameters:: point2 (Gsk.PathPoint) – another path point
Returns:: -1 if self is before point2, 1 if self is after point2, 0 if they are equal
Return type:: int

Returns whether self is before or after point2.

New in version 4.14.

copy()¶

Returns:: the copied point
Return type:: Gsk.PathPoint

Copies a path point.

New in version 4.14.

equal(point2)¶

Parameters:: point2 (Gsk.PathPoint) – another path point
Returns:: true if self and point2 are equal
Return type:: bool

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 [method`Gsk`.Path.is_closed] to find out if the start- and endpoint of a concrete path refer to the same location.

New in version 4.14.

free()¶: Frees a path point copied by [method`Gsk`.PathPoint.copy].

New in version 4.14.

get_curvature(path, direction)¶

Parameters:

path (Gsk.Path) – the path that self is on
direction (Gsk.PathDirection) – the direction for which to return the curvature

Returns:

the curvature of the path at the given point

center:: return location for the center of the osculating circle

Return type:

(float, center: Graphene.Point or None)

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.

New in version 4.14.

get_distance(measure)¶

Parameters:: measure (Gsk.PathMeasure) – a path measure for the path
Returns:: the distance of self
Return type:: float

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

New in version 4.14.

get_position(path)¶

Parameters:: path (Gsk.Path) – the path that self is on
Returns:: Return location for the coordinates of the point
Return type:: position: Graphene.Point

Gets the position of the point.

New in version 4.14.

get_rotation(path, direction)¶

Parameters:

path (Gsk.Path) – the path that self is on
direction (Gsk.PathDirection) – the direction for which to return the rotation

Returns:

the angle between the tangent and the X axis, in degrees

Return type:

float

Gets the direction of the tangent at a given point.

This is a convenience variant of [method`Gsk`.PathPoint.get_tangent] that returns the angle between the tangent and the X axis. The angle can e.g. be used in gtk_snapshot_rotate().

New in version 4.14.

get_tangent(path, direction)¶

Parameters:

path (Gsk.Path) – the path that self is on
direction (Gsk.PathDirection) – the direction for which to return the tangent

Returns:

Return location for the tangent at the point

Return type:

tangent: Graphene.Vec2

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, [method`Gsk`.PathPoint.get_rotation] may be more convenient to use.

New in version 4.14.