Path

Added in version 4.14.

class Path(*args, **kwargs)

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).

GskPath is an immutable, opaque, reference-counted struct. After creation, you cannot change the types it represents. Instead, new GskPath objects have to be created. The 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.

Methods

class Path

equal(path2: Path) → bool

Returns whether two paths have identical structure.

Note that it is possible to construct paths that render identical even though they don’t have the same structure.

Added in version 4.22.

Parameters:

path2 – another path

foreach(flags: PathForeachFlags, func: Callable[[PathOperation, list[Point], float, Any], bool], user_data: Any = None) → bool

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.

Added in version 4.14.

Parameters:

• flags – flags to pass to the foreach function

• func – the function to call for operations

• user_data – user data passed to func

foreach_intersection(path2: Path | None, func: Callable[[Path, PathPoint, Path, PathPoint, PathIntersection, Any], bool], user_data: Any = None) → bool

Finds intersections between two paths.

This function finds intersections between path1 and path2, and calls func for each of them, in increasing order for path1.

If path2 is not provided or equal to path1, the function finds non-trivial self-intersections of path1.

When segments of the paths coincide, the callback is called once for the start of the segment, with GSK_PATH_INTERSECTION_START, and once for the end of the segment, with GSK_PATH_INTERSECTION_END. Note that other intersections may occur between the start and end of such a segment.

If func returns FALSE, the iteration is stopped.

Added in version 4.20.

Parameters:

• path2 – the second path

• func – the function to call for intersections

• user_data – user data passed to func

get_bounds() → tuple[bool, Rect]

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. For accurate bounds, use get_tight_bounds.

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 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.

Added in version 4.14.

get_closest_point(point: Point, threshold: float) → tuple[bool, PathPoint, float]

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

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

Added in version 4.14.

Parameters:

• point – the point

• threshold – maximum allowed distance

get_end_point() → tuple[bool, PathPoint]

Gets the end point of the path.

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

Added in version 4.14.

get_next(point: PathPoint) → tuple[bool, PathPoint]

Moves point to the next vertex.

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

Added in version 4.22.

Parameters:

point – the current point

get_previous(point: PathPoint) → tuple[bool, PathPoint]

Moves point to the previous vertex.

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

Added in version 4.22.

Parameters:

point – the current point

get_start_point() → tuple[bool, PathPoint]

Gets the start point of the path.

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

Added in version 4.14.

get_stroke_bounds(stroke: Stroke) → tuple[bool, Rect]

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.

Added in version 4.14.

Parameters:

stroke – stroke parameters

get_tight_bounds() → tuple[bool, Rect]

Computes the tight bounds of the given path.

This function works harder than get_bounds to produce the smallest possible bounds.

Added in version 4.22.

in_fill(point: Point, fill_rule: FillRule) → bool

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

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

Added in version 4.14.

Parameters:

• point – the point to test

• fill_rule – the fill rule to follow

is_closed() → bool

Returns if the path represents a single closed contour.

Added in version 4.14.

is_empty() → bool

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

Added in version 4.14.

classmethod parse() → Path | None

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 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.

Added in version 4.14.

print_(string: String) → None

Parameters:

string

to_cairo(cr: Context) → None

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 GskPath.

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

Added in version 4.14.

Parameters:

cr – a cairo context

to_string() → str

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 print, see that function for details.

Added in version 4.14.