Crate path_kit 

path-kit

基于 Skia PathKit 的 Rust 路径运算库，提供 safe 的 API 封装。 A Rust path operations library based on Skia PathKit with safe API wrappers.

功能 / Features

• 路径构建：线段、二次/三次贝塞尔、矩形、椭圆、圆、圆角矩形、RRect（四角独立半径） Path construction: lines, quadratic/cubic bezier, rect, oval, circle, round rect, RRect (per-corner radii)
• 路径布尔运算：并集、交集、差集、异或 Path boolean operations: union, intersect, difference, xor
• 路径简化、包围盒：simplify, path.tight_bounds, pathops_tight_bounds Path simplification and tight bounds computation
• 路径迭代：按动词遍历 Move/Line/Quad/Cubic/Close Path iteration over verbs and points
• 描边：将路径转为描边轮廓 Stroke: convert path to stroked outline

线程安全 / Thread safety

当前未保证 Send / Sync，请勿跨线程共享 Path、RRect、StrokeRec 等类型。 Send / Sync are not guaranteed; do not share Path, RRect, StrokeRec, etc. across threads.

类型概览 / Types

类型	说明
Path	路径
Rect	矩形
RRect	圆角矩形（支持四角独立半径）
Point	二维点
Direction	绘制方向 Cw/Ccw
RectCorner	矩形起始角
PathOp	布尔运算类型
PathVerbItem	路径迭代项
StrokeRec	描边参数

示例 / Examples

路径布尔运算 / Path boolean ops

use path_kit::{Path, Rect, Direction, RectCorner, PathOp, path_op, OpBuilder};

let mut path1 = Path::new();
path1.add_rect(&Rect::new(0.0, 0.0, 100.0, 100.0), Direction::Cw, RectCorner::UpperLeft);

let mut path2 = Path::new();
path2.add_rect(&Rect::new(50.0, 50.0, 150.0, 150.0), Direction::Cw, RectCorner::UpperLeft);

let union = path_op(&path1, &path2, PathOp::Union).unwrap();

// 批量运算 / Batch operations (use add_ref to avoid clone when reusing paths)
let result = OpBuilder::new()
    .add_ref(&path1, PathOp::Union)
    .add_ref(&path2, PathOp::Union)
    .resolve()
    .unwrap();

圆角矩形 RRect / Rounded rect with per-corner radii

use path_kit::{Path, Rect, RRect, Radii, Direction, RectCorner};

// 统一圆角 / Uniform radii
let rr = RRect::from_rect_xy(&Rect::new(0.0, 0.0, 100.0, 50.0), 10.0, 10.0);
let mut path = Path::new();
path.add_rrect(&rr, Direction::Cw);

// 四角独立半径 / Per-corner radii
let radii = [
    Radii { x: 10.0, y: 10.0 },
    Radii { x: 20.0, y: 10.0 },
    Radii { x: 10.0, y: 20.0 },
    Radii { x: 5.0, y: 5.0 },
];
let rr2 = RRect::from_rect_radii(&Rect::new(0.0, 0.0, 80.0, 60.0), &radii);
path.add_rrect(&rr2, Direction::Ccw);

路径迭代 / Path iteration

use path_kit::{Path, PathVerbItem};

let mut path = Path::new();
path.move_to(0.0, 0.0).line_to(100.0, 0.0).line_to(100.0, 100.0).close();

for item in path.iter(false) {
    match item {
        PathVerbItem::Move(p) => println!("Move to {:?}", p),
        PathVerbItem::Line(from, to) => println!("Line {:?} -> {:?}", from, to),
        PathVerbItem::Quad(c, to) => println!("Quad {:?} -> {:?}", c, to),
        PathVerbItem::Cubic(c1, c2, to) => println!("Cubic -> {:?}", to),
        PathVerbItem::Close => println!("Close"),
        _ => {}
    }
}

描边 / Stroke

use path_kit::{Path, StrokeRec};

let rec = StrokeRec::new_stroke(4.0, false);
let mut path = Path::new();
path.move_to(0.0, 0.0).line_to(100.0, 0.0);
let stroked = rec.apply_to_path(&path).unwrap();

路径简化与包围盒 / Simplify and bounds

use path_kit::{Path, simplify, pathops_tight_bounds};

let mut path = Path::new();
path.move_to(0.0, 0.0)
    .line_to(100.0, 0.0)
    .line_to(100.0, 100.0)
    .line_to(50.0, 50.0)
    .line_to(0.0, 100.0)
    .close();

let simplified = simplify(&path).unwrap();
let bounds = pathops_tight_bounds(&path).unwrap();  // or path.tight_bounds() for infallible

Structs

CornerPathEffect

圆角路径效果，将尖角变为圆角。 Corner path effect - rounds sharp corners.

DashPathEffect

虚线路径效果，将路径描边转为虚线。 Dash path effect for stroked paths (on/off intervals).

OpBuilder

路径操作构建器，用于批量执行路径布尔运算。 Path operation builder, optimized for unioning/combining many paths.

Path

路径的 safe 封装，对应 SkPath。Safe wrapper for SkPath.

PathIter

路径迭代器，按动词顺序遍历路径。Path iterator over verbs and points.

Point

二维点。A 2D point with x and y coordinates.

RRect

圆角矩形，支持四角独立半径。 Rounded rectangle with per-corner radii (each corner can have different x/y).

Radii

单角半径 (x, y)。Corner radii (x, y).

Rect

矩形，由 (left, top, right, bottom) 定义。 Rectangle defined by (left, top, right, bottom) coordinates.

StrokeRec

描边参数，描述如何将路径转为描边轮廓。 Stroke parameters - describes how to expand a path to a stroke outline.

Enums

Direction

路径绘制方向。Direction for path winding.

PathOp

并集、交集、差集、异或等路径集合运算。Union, intersect, difference, xor, reverse difference.

PathVerb

路径动词，描述路径中的每个图元。Path verb - describes each element in the path.

PathVerbItem

单步迭代结果，含动词与关联点。Single iteration result with verb and points.

RectCorner

矩形起始角，指定 add_rect 时从哪个角开始绘制。 Rectangle start corner for add_rect (which corner to begin drawing from).

StrokeStyle

描边样式。Stroke style.

Functions

path_op

对两个路径执行布尔运算。Performs boolean operation on two paths. Returns None if the operation fails.

pathops_tight_bounds

计算路径的紧密包围盒（pathops 实现）。Computes tight bounds using pathops algorithm.

simplify

简化路径，处理自相交等。Simplifies path (resolves self-intersections, etc.). Returns None if simplification fails.