Struct PathMeasure 

pub struct PathMeasure { /* private fields */ }

路径测量器，用于获取路径长度、沿路径的位置和切线。 PathMeasure - measures path length and samples position/tangent along path.

支持多轮廓路径，通过 next_contour 遍历。 Supports multi-contour paths; use next_contour to iterate.

Implementations

impl PathMeasure

pub fn new() -> Self

创建空测量器。Creates empty path measure (no path).

pub fn from_path(path: &Path, force_closed: bool, res_scale: f32) -> Self

从路径创建测量器。 Creates path measure from path.

force_closed 为 true 时，开放轮廓按闭合计算长度。 res_scale 控制精度，> 1 提高精度（可能变慢）。

pub fn set_path(&mut self, path: &Path, force_closed: bool)

重置为指定路径。Resets with given path.

pub fn length(&mut self) -> f32

当前轮廓的总长度，无路径时返回 0。 Total length of current contour, or 0 if no path.

pub fn pos_tan(&mut self, distance: f32) -> Option<(Point, Point)>

在指定距离处的位置和切线。 Position and tangent at given distance along path.

距离会被限制在 [0, length] 内。 Distance is clamped to [0, length].

pub fn get_segment( &mut self, start_d: f32, stop_d: f32, dst: &mut Path, start_with_move_to: bool, ) -> bool

提取路径的 [start_d, stop_d] 段。 Extracts path segment between start_d and stop_d.

start_with_move_to 为 true 时，段以 moveTo 开始。

pub fn is_closed(&mut self) -> bool

当前轮廓是否闭合。Whether current contour is closed.

pub fn next_contour(&mut self) -> bool

移动到下一个轮廓，返回是否还有更多。 Move to next contour; returns true if more exist.

Trait Implementations

impl Default for PathMeasure

fn default() -> Self

Returns the “default value” for a type.