Class (GI Struct)

Gsk-4.0GskPathAbstractSince 4.14

Describes lines and curves that are more complex than simple rectangles.

Paths can used for rendering (filling or stroking) and for animations (e.g. as trajectories).

Gsk.Path is an immutable, opaque, reference-counted struct. After creation, you cannot change the types it represents. Instead, new Gsk.Path objects have to be created. The Gsk.PathBuilder structure is meant to help in this endeavor.

Conceptually, a path consists of zero or more contours (continuous, connected curves), each of which may or may not be closed. Contours are typically constructed from Bézier segments.

A Path

4.14

Index

Constructors

Properties

$gtype: GType<Gsk.Path>

Methods

  • Calls func for every operation of the path.

    Note that this may only approximate self, because paths can contain optimizations for various specialized contours, and depending on the flags, the path may be decomposed into simpler curves than the ones that it contained originally.

    This function serves two purposes:

    • When the flags allow everything, it provides access to the raw, unmodified data of the path.
    • When the flags disallow certain operations, it provides an approximation of the path using just the allowed operations.

    Parameters

    Returns boolean

    false if func returned false, true otherwise.

  • Computes the bounds of the given path.

    The returned bounds may be larger than necessary, because this function aims to be fast, not accurate. The bounds are guaranteed to contain the path.

    It is possible that the returned rectangle has 0 width and/or height. This can happen when the path only describes a point or an axis-aligned line.

    If the path is empty, false is returned and bounds are set to graphene_rect_zero(). This is different from the case where the path is a single point at the origin, where the bounds will also be set to the zero rectangle but true will be returned.

    Returns [boolean, Graphene.Rect]

    true if the path has bounds, false if the path is known to be empty and have no bounds

  • Computes the closest point on the path to the given point.

    If there is no point closer than the given threshold, false is returned.

    Parameters

    • point: Graphene.Point

      the point

    • threshold: number

      maximum allowed distance

    Returns [boolean, PathPoint, number]

    true if point was set to the closest point on self, false if no point is closer than threshold

  • Gets the end point of the path.

    An empty path has no points, so false is returned in this case.

    Returns [boolean, PathPoint]

    true if result was filled

  • Gets the start point of the path.

    An empty path has no points, so false is returned in this case.

    Returns [boolean, PathPoint]

    true if result was filled

  • Computes the bounds for stroking the given path with the given parameters.

    The returned bounds may be larger than necessary, because this function aims to be fast, not accurate. The bounds are guaranteed to contain the area affected by the stroke, including protrusions like miters.

    Parameters

    • stroke: Stroke

      stroke parameters

    Returns [boolean, Graphene.Rect]

    true if the path has bounds, false if the path is known to be empty and have no bounds.

  • Returns whether a point is inside the fill area of a path.

    Note that this function assumes that filling a contour implicitly closes it.

    Parameters

    Returns boolean

    true if point is inside

  • Returns if the path represents a single closed contour.

    Returns boolean

    true if the path is closed

  • Checks if the path is empty, i.e. contains no lines or curves.

    Returns boolean

    true if the path is empty

  • Appends the path to a cairo context for drawing with Cairo.

    This may cause some suboptimal conversions to be performed as Cairo does not support all features of Gsk.Path.

    This function does not clear the existing Cairo path. Call cairo_new_path() if you want this.

    Parameters

    Returns void

  • Converts the path into a human-readable string.

    You can use this function in a debugger to get a quick overview of the path.

    This is a wrapper around Gsk.Path.print, see that function for details.

    Returns string

    a new string for self

  • Decreases the reference count of a path by one.

    If the resulting reference count is zero, frees the path.

    Returns void

  • Constructs a path from a serialized form.

    The string is expected to be in (a superset of) SVG path syntax, as e.g. produced by Gsk.Path.to_string.

    A high-level summary of the syntax:

    • M x y Move to (x, y)
    • L x y Add a line from the current point to (x, y)
    • Q x1 y1 x2 y2 Add a quadratic Bézier from the current point to (x2, y2), with control point (x1, y1)
    • C x1 y1 x2 y2 x3 y3 Add a cubic Bézier from the current point to (x3, y3), with control points (x1, y1) and (x2, y2)
    • Z Close the contour by drawing a line back to the start point
    • H x Add a horizontal line from the current point to the given x value
    • V y Add a vertical line from the current point to the given y value
    • T x2 y2 Add a quadratic Bézier, using the reflection of the previous segments' control point as control point
    • S x2 y2 x3 y3 Add a cubic Bézier, using the reflection of the previous segments' second control point as first control point
    • A rx ry r l s x y Add an elliptical arc from the current point to (x, y) with radii rx and ry. See the SVG documentation for how the other parameters influence the arc.
    • O x1 y1 x2 y2 w Add a rational quadratic Bézier from the current point to (x2, y2) with control point (x1, y1) and weight w.

    All the commands have lowercase variants that interpret coordinates relative to the current point.

    The O command is an extension that is not supported in SVG.

    Parameters

    • string: string

      a string

    Returns Gsk.Path