Struct PathPoint

pub struct PathPoint { /* private fields */ }

Available on crate feature v4_14 only.

PathPoint is 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 PathPoint, use Path::closest_point(), Path::start_point(), Path::end_point() or PathMeasure::point().

Note that 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 PathPoint is used.

GLib type: Inline allocated boxed type with stack copy semantics.

Implementations

impl PathPoint

pub fn as_ptr(&self) -> *mut GskPathPoint

pub unsafe fn from_glib_ptr_borrow<'a>(ptr: *const GskPathPoint) -> &'a Self

Borrows the underlying C value.

pub unsafe fn from_glib_ptr_borrow_mut<'a>( ptr: *mut GskPathPoint, ) -> &'a mut Self

Borrows the underlying C value mutably.

impl PathPoint

pub fn distance(&self, measure: &PathMeasure) -> f32

Returns the distance from the beginning of the path to @self.

measure

a PathMeasure for the path

Returns

the distance of @self

pub fn position(&self, path: &Path) -> Point

Gets the position of the point.

path

the path that @self is on

Returns

position

Return location for the coordinates of the point

pub fn rotation(&self, path: &Path, direction: PathDirection) -> f32

Gets the direction of the tangent at a given point.

This is a convenience variant of tangent() that returns the angle between the tangent and the X axis. The angle can e.g. be used in gtk_snapshot_rotate().

path

the path that @self is on

direction

the direction for which to return the rotation

Returns

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

pub fn tangent(&self, path: &Path, direction: PathDirection) -> 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 @tangent is set to 0, 0.

If you want to orient something in the direction of the path, rotation() may be more convenient to use.

path

the path that @self is on

direction

the direction for which to return the tangent

Returns

tangent

Return location for the tangent at the point

impl PathPoint

pub fn curvature( &self, path: &Path, direction: PathDirection, ) -> (f32, Option<Point>)

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.

## `path` the path that @self is on ## `direction` 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

Trait Implementations

impl Clone for PathPoint

fn clone(&self) -> Self

Copies the inline boxed type by value with the type-specific copy function.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl HasParamSpec for PathPoint

type ParamSpec = ParamSpecBoxed

type SetValue = PathPoint

Preferred value to be used as setter for the associated ParamSpec.

type BuilderFn = fn(_: &str) -> ParamSpecBoxedBuilder<'_, PathPoint>

fn param_spec_builder() -> Self::BuilderFn

impl Ord for PathPoint

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for PathPoint

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for PathPoint

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl StaticType for PathPoint

fn static_type() -> Type

Returns the type identifier of Self.

impl Copy for PathPoint

impl Eq for PathPoint