makepad_path/
path.rs

1use crate::PathCommand;
2use makepad_geometry::{Point, Transform, Transformation};
3use makepad_internal_iter::{
4    ExtendFromInternalIterator, FromInternalIterator, InternalIterator, IntoInternalIterator,
5};
6use std::iter::Cloned;
7use std::slice::Iter;
8
9/// A sequence of commands that defines a set of contours, each of which consists of a sequence of
10/// curve segments. Each contour is either open or closed.
11#[derive(Clone, Debug, Default, PartialEq)]
12pub struct Path {
13    verbs: Vec<Verb>,
14    points: Vec<Point>,
15}
16
17impl Path {
18    /// Creates a new empty path.
19    pub fn new() -> Path {
20        Path::default()
21    }
22
23    /// Returns a slice of the points that make up `self`.
24    pub fn points(&self) -> &[Point] {
25        &self.points
26    }
27
28    /// Returns an iterator over the commands that make up `self`.
29    pub fn commands(&self) -> Commands {
30        Commands {
31            verbs: self.verbs.iter().cloned(),
32            points: self.points.iter().cloned(),
33        }
34    }
35
36    /// Returns a mutable slice of the points that make up `self`.
37    pub fn points_mut(&mut self) -> &mut [Point] {
38        &mut self.points
39    }
40
41    /// Adds a new contour, starting at the given point.
42    pub fn move_to(&mut self, p: Point) {
43        self.verbs.push(Verb::MoveTo);
44        self.points.push(p);
45    }
46
47    /// Adds a line segment to the current contour, starting at the current point.
48    pub fn line_to(&mut self, p: Point) {
49        self.verbs.push(Verb::LineTo);
50        self.points.push(p);
51    }
52
53    // Adds a quadratic Bezier curve segment to the current contour, starting at the current point.
54    pub fn quadratic_to(&mut self, p1: Point, p: Point) {
55        self.verbs.push(Verb::QuadraticTo);
56        self.points.push(p1);
57        self.points.push(p);
58    }
59
60    /// Closes the current contour.
61    pub fn close(&mut self) {
62        self.verbs.push(Verb::Close);
63    }
64
65    /// Clears `self`.
66    pub fn clear(&mut self) {
67        self.verbs.clear();
68        self.points.clear();
69    }
70}
71
72impl ExtendFromInternalIterator<PathCommand> for Path {
73    fn extend_from_internal_iter<I>(&mut self, internal_iter: I)
74    where
75        I: IntoInternalIterator<Item = PathCommand>,
76    {
77        internal_iter.into_internal_iter().for_each(&mut |command| {
78            match command {
79                PathCommand::MoveTo(p) => self.move_to(p),
80                PathCommand::LineTo(p) => self.line_to(p),
81                PathCommand::QuadraticTo(p1, p) => self.quadratic_to(p1, p),
82                PathCommand::Close => self.close(),
83            }
84            true
85        });
86    }
87}
88
89impl FromInternalIterator<PathCommand> for Path {
90    fn from_internal_iter<I>(internal_iter: I) -> Self
91    where
92        I: IntoInternalIterator<Item = PathCommand>,
93    {
94        let mut path = Path::new();
95        path.extend_from_internal_iter(internal_iter);
96        path
97    }
98}
99
100impl Transform for Path {
101    fn transform<T>(mut self, t: &T) -> Path
102    where
103        T: Transformation,
104    {
105        self.transform_mut(t);
106        self
107    }
108
109    fn transform_mut<T>(&mut self, t: &T)
110    where
111        T: Transformation,
112    {
113        for point in self.points_mut() {
114            point.transform_mut(t);
115        }
116    }
117}
118
119/// An iterator over the commands that make up a path.
120#[derive(Clone, Debug)]
121pub struct Commands<'a> {
122    verbs: Cloned<Iter<'a, Verb>>,
123    points: Cloned<Iter<'a, Point>>,
124}
125
126impl<'a> Iterator for Commands<'a> {
127    type Item = PathCommand;
128
129    fn next(&mut self) -> Option<PathCommand> {
130        self.verbs.next().map(|verb| match verb {
131            Verb::MoveTo => PathCommand::MoveTo(self.points.next().unwrap()),
132            Verb::LineTo => PathCommand::LineTo(self.points.next().unwrap()),
133            Verb::QuadraticTo => {
134                PathCommand::QuadraticTo(self.points.next().unwrap(), self.points.next().unwrap())
135            }
136            Verb::Close => PathCommand::Close,
137        })
138    }
139}
140
141#[derive(Clone, Debug, Eq, Hash, PartialEq)]
142enum Verb {
143    MoveTo,
144    LineTo,
145    QuadraticTo,
146    Close,
147}