Add Path2D (#35783)

Signed-off-by: Lukas Lihotzki <lukas@lihotzki.de>
This commit is contained in:
Lukas Lihotzki 2025-03-26 13:12:44 +01:00 committed by GitHub
parent f0ea3c6150
commit 251eeb2c2d
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
53 changed files with 1566 additions and 262 deletions

View file

@ -0,0 +1,13 @@
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
mod number;
mod path;
mod stream;
#[derive(Debug, Default, Eq, PartialEq)]
pub struct Error;
pub(crate) use path::PathParser;
pub(crate) use stream::Stream;

View file

@ -0,0 +1,198 @@
// Copyright 2018 the SVG Types Authors
// Copyright 2025 the Servo Authors
// SPDX-License-Identifier: Apache-2.0 OR MIT
use std::str::FromStr;
use crate::svgpath::{Error, Stream};
/// An [SVG number](https://www.w3.org/TR/SVG2/types.html#InterfaceSVGNumber).
#[derive(Clone, Copy, Debug, PartialEq)]
pub struct Number(pub f32);
impl std::str::FromStr for Number {
type Err = Error;
fn from_str(text: &str) -> Result<Self, Self::Err> {
let mut s = Stream::from(text);
let n = s.parse_number()?;
s.skip_spaces();
if !s.at_end() {
return Err(Error);
}
Ok(Self(n))
}
}
impl Stream<'_> {
/// Parses number from the stream.
///
/// This method will detect a number length and then
/// will pass a substring to the `f64::from_str` method.
///
/// <https://www.w3.org/TR/SVG2/types.html#InterfaceSVGNumber>
pub fn parse_number(&mut self) -> Result<f32, Error> {
// Strip off leading whitespaces.
self.skip_spaces();
if self.at_end() {
return Err(Error);
}
self.parse_number_impl().map_err(|_| Error)
}
fn parse_number_impl(&mut self) -> Result<f32, Error> {
let start = self.pos();
let mut c = self.curr_byte()?;
// Consume sign.
if matches!(c, b'+' | b'-') {
self.advance(1);
c = self.curr_byte()?;
}
// Consume integer.
match c {
b'0'..=b'9' => self.skip_digits(),
b'.' => {},
_ => return Err(Error),
}
// Consume fraction.
if let Ok(b'.') = self.curr_byte() {
self.advance(1);
self.skip_digits();
}
if let Ok(c) = self.curr_byte() {
if matches!(c, b'e' | b'E') {
let c2 = self.next_byte()?;
// Check for `em`/`ex`.
if c2 != b'm' && c2 != b'x' {
self.advance(1);
match self.curr_byte()? {
b'+' | b'-' => {
self.advance(1);
self.skip_digits();
},
b'0'..=b'9' => self.skip_digits(),
_ => {
return Err(Error);
},
}
}
}
}
let s = self.slice_back(start);
// Use the default f32 parser now.
if let Ok(n) = f32::from_str(s) {
// inf, nan, etc. are an error.
if n.is_finite() {
return Ok(n);
}
}
Err(Error)
}
/// Parses number from a list of numbers.
pub fn parse_list_number(&mut self) -> Result<f32, Error> {
if self.at_end() {
return Err(Error);
}
let n = self.parse_number()?;
self.skip_spaces();
self.parse_list_separator();
Ok(n)
}
}
/// A pull-based [`<list-of-numbers>`] parser.
///
/// # Examples
///
/// ```
/// use svgtypes::NumberListParser;
///
/// let mut p = NumberListParser::from("10, 20 -50");
/// assert_eq!(p.next().unwrap().unwrap(), 10.0);
/// assert_eq!(p.next().unwrap().unwrap(), 20.0);
/// assert_eq!(p.next().unwrap().unwrap(), -50.0);
/// assert_eq!(p.next().is_none(), true);
/// ```
///
/// [`<list-of-numbers>`]: https://www.w3.org/TR/SVG2/types.html#InterfaceSVGNumberList
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub struct NumberListParser<'a>(Stream<'a>);
impl<'a> From<&'a str> for NumberListParser<'a> {
#[inline]
fn from(v: &'a str) -> Self {
NumberListParser(Stream::from(v))
}
}
impl Iterator for NumberListParser<'_> {
type Item = Result<f32, Error>;
fn next(&mut self) -> Option<Self::Item> {
if self.0.at_end() {
None
} else {
let v = self.0.parse_list_number();
if v.is_err() {
self.0.jump_to_end();
}
Some(v)
}
}
}
#[rustfmt::skip]
#[cfg(test)]
mod tests {
use crate::svgpath::Stream;
macro_rules! test_p {
($name:ident, $text:expr, $result:expr) => (
#[test]
fn $name() {
let mut s = Stream::from($text);
assert_eq!(s.parse_number().unwrap(), $result);
}
)
}
test_p!(parse_1, "0", 0.0);
test_p!(parse_2, "1", 1.0);
test_p!(parse_3, "-1", -1.0);
test_p!(parse_4, " -1 ", -1.0);
test_p!(parse_5, " 1 ", 1.0);
test_p!(parse_6, ".4", 0.4);
test_p!(parse_7, "-.4", -0.4);
test_p!(parse_8, "-.4text", -0.4);
test_p!(parse_9, "-.01 text", -0.01);
test_p!(parse_10, "-.01 4", -0.01);
test_p!(parse_11, ".0000000000008", 0.0000000000008);
test_p!(parse_12, "1000000000000", 1000000000000.0);
test_p!(parse_13, "123456.123456", 123456.123456);
test_p!(parse_14, "+10", 10.0);
test_p!(parse_15, "1e2", 100.0);
test_p!(parse_16, "1e+2", 100.0);
test_p!(parse_17, "1E2", 100.0);
test_p!(parse_18, "1e-2", 0.01);
test_p!(parse_19, "1ex", 1.0);
test_p!(parse_20, "1em", 1.0);
test_p!(parse_21, "12345678901234567890", 12345678901234567000.0);
test_p!(parse_22, "0.", 0.0);
test_p!(parse_23, "1.3e-2", 0.013);
// test_number!(parse_24, "1e", 1.0); // TODO: this
}

View file

@ -0,0 +1,393 @@
// Copyright 2021 the SVG Types Authors
// Copyright 2025 the Servo Authors
// SPDX-License-Identifier: Apache-2.0 OR MIT
use canvas_traits::canvas::PathSegment;
use crate::svgpath::{Error, Stream};
pub struct PathParser<'a> {
stream: Stream<'a>,
state: State,
last_cmd: u8,
}
impl<'a> PathParser<'a> {
pub fn new(string: &'a str) -> Self {
Self {
stream: Stream::from(string),
state: State::default(),
last_cmd: b' ',
}
}
}
impl Iterator for PathParser<'_> {
type Item = Result<PathSegment, Error>;
fn next(&mut self) -> Option<Self::Item> {
self.stream.skip_spaces();
let Ok(curr_byte) = self.stream.curr_byte() else {
return None;
};
let cmd = if self.last_cmd == b' ' {
if let move_to @ (b'm' | b'M') = curr_byte {
self.stream.advance(1);
move_to
} else {
return Some(Err(Error));
}
} else if curr_byte.is_ascii_alphabetic() {
self.stream.advance(1);
curr_byte
} else {
match self.last_cmd {
b'm' => b'l',
b'M' => b'L',
b'z' | b'Z' => return Some(Err(Error)),
cmd => cmd,
}
};
self.last_cmd = cmd;
Some(to_point(&mut self.stream, cmd, &mut self.state))
}
}
#[derive(Default)]
pub struct State {
start: (f32, f32),
pos: (f32, f32),
quad: (f32, f32),
cubic: (f32, f32),
}
pub fn to_point(s: &mut Stream<'_>, cmd: u8, state: &mut State) -> Result<PathSegment, Error> {
let abs = cmd.is_ascii_uppercase();
let cmd = cmd.to_ascii_lowercase();
let (dx, dy) = if abs { (0., 0.) } else { state.pos };
let seg = match cmd {
b'm' => PathSegment::MoveTo {
x: s.parse_list_number()? + dx,
y: s.parse_list_number()? + dy,
},
b'l' => PathSegment::LineTo {
x: s.parse_list_number()? + dx,
y: s.parse_list_number()? + dy,
},
b'h' => PathSegment::LineTo {
x: s.parse_list_number()? + dx,
y: state.pos.1,
},
b'v' => PathSegment::LineTo {
x: state.pos.0,
y: s.parse_list_number()? + dy,
},
b'c' => PathSegment::Bezier {
cp1x: s.parse_list_number()? + dx,
cp1y: s.parse_list_number()? + dy,
cp2x: s.parse_list_number()? + dx,
cp2y: s.parse_list_number()? + dy,
x: s.parse_list_number()? + dx,
y: s.parse_list_number()? + dy,
},
b's' => PathSegment::Bezier {
cp1x: state.cubic.0,
cp1y: state.cubic.1,
cp2x: s.parse_list_number()? + dx,
cp2y: s.parse_list_number()? + dy,
x: s.parse_list_number()? + dx,
y: s.parse_list_number()? + dy,
},
b'q' => PathSegment::Quadratic {
cpx: s.parse_list_number()? + dx,
cpy: s.parse_list_number()? + dy,
x: s.parse_list_number()? + dx,
y: s.parse_list_number()? + dy,
},
b't' => PathSegment::Quadratic {
cpx: state.quad.0,
cpy: state.quad.1,
x: s.parse_list_number()? + dx,
y: s.parse_list_number()? + dy,
},
b'a' => PathSegment::SvgArc {
radius_x: s.parse_list_number()?,
radius_y: s.parse_list_number()?,
rotation: s.parse_list_number()?,
large_arc: s.parse_flag()?,
sweep: s.parse_flag()?,
x: s.parse_list_number()? + dx,
y: s.parse_list_number()? + dy,
},
b'z' => PathSegment::ClosePath,
_ => return Err(crate::svgpath::Error),
};
match seg {
PathSegment::MoveTo { x, y } => {
state.start = (x, y);
state.pos = (x, y);
state.quad = (x, y);
state.cubic = (x, y);
},
PathSegment::LineTo { x, y } | PathSegment::SvgArc { x, y, .. } => {
state.pos = (x, y);
state.quad = (x, y);
state.cubic = (x, y);
},
PathSegment::Bezier {
cp2x, cp2y, x, y, ..
} => {
state.pos = (x, y);
state.quad = (x, y);
state.cubic = (x * 2.0 - cp2x, y * 2.0 - cp2y);
},
PathSegment::Quadratic { cpx, cpy, x, y, .. } => {
state.pos = (x, y);
state.quad = (x * 2.0 - cpx, y * 2.0 - cpy);
state.cubic = (x, y);
},
PathSegment::ClosePath => {
state.pos = state.start;
state.quad = state.start;
state.cubic = state.start;
},
_ => {},
}
Ok(seg)
}
#[rustfmt::skip]
#[cfg(test)]
mod tests {
use super::*;
macro_rules! test {
($name:ident, $text:expr, $( $seg:expr ),*) => (
#[test]
fn $name() {
let mut s = PathParser::new($text);
$(
assert_eq!(s.next().unwrap().unwrap(), $seg);
)*
if let Some(res) = s.next() {
assert!(res.is_err());
}
}
)
}
test!(null, "", );
test!(not_a_path, "q", );
test!(not_a_move_to, "L 20 30", );
test!(stop_on_err_1, "M 10 20 L 30 40 L 50",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 30.0, y: 40.0 }
);
test!(move_to_1, "M 10 20", PathSegment::MoveTo { x: 10.0, y: 20.0 });
test!(move_to_2, "m 10 20", PathSegment::MoveTo { x: 10.0, y: 20.0 });
test!(move_to_3, "M 10 20 30 40 50 60",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 30.0, y: 40.0 },
PathSegment::LineTo { x: 50.0, y: 60.0 }
);
test!(move_to_4, "M 10 20 30 40 50 60 M 70 80 90 100 110 120",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 30.0, y: 40.0 },
PathSegment::LineTo { x: 50.0, y: 60.0 },
PathSegment::MoveTo { x: 70.0, y: 80.0 },
PathSegment::LineTo { x: 90.0, y: 100.0 },
PathSegment::LineTo { x: 110.0, y: 120.0 }
);
test!(arc_to_1, "M 10 20 A 5 5 30 1 1 20 20",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::SvgArc {
radius_x: 5.0, radius_y: 5.0,
rotation: 30.0,
large_arc: true, sweep: true,
x: 20.0, y: 20.0
}
);
test!(arc_to_2, "M 10 20 a 5 5 30 0 0 20 20",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::SvgArc {
radius_x: 5.0, radius_y: 5.0,
rotation: 30.0,
large_arc: false, sweep: false,
x: 30.0, y: 40.0
}
);
test!(arc_to_10, "M10-20A5.5.3-4 010-.1",
PathSegment::MoveTo { x: 10.0, y: -20.0 },
PathSegment::SvgArc {
radius_x: 5.5, radius_y: 0.3,
rotation: -4.0,
large_arc: false, sweep: true,
x: 0.0, y: -0.1
}
);
test!(separator_1, "M 10 20 L 5 15 C 10 20 30 40 50 60",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 5.0, y: 15.0 },
PathSegment::Bezier {
cp1x: 10.0, cp1y: 20.0,
cp2x: 30.0, cp2y: 40.0,
x: 50.0, y: 60.0,
}
);
test!(separator_2, "M 10, 20 L 5, 15 C 10, 20 30, 40 50, 60",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 5.0, y: 15.0 },
PathSegment::Bezier {
cp1x: 10.0, cp1y: 20.0,
cp2x: 30.0, cp2y: 40.0,
x: 50.0, y: 60.0,
}
);
test!(separator_3, "M 10,20 L 5,15 C 10,20 30,40 50,60",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 5.0, y: 15.0 },
PathSegment::Bezier {
cp1x: 10.0, cp1y: 20.0,
cp2x: 30.0, cp2y: 40.0,
x: 50.0, y: 60.0,
}
);
test!(separator_4, "M10, 20 L5, 15 C10, 20 30 40 50 60",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 5.0, y: 15.0 },
PathSegment::Bezier {
cp1x: 10.0, cp1y: 20.0,
cp2x: 30.0, cp2y: 40.0,
x: 50.0, y: 60.0,
}
);
test!(separator_5, "M10 20V30H40V50H60Z",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 10.0, y: 30.0 },
PathSegment::LineTo { x: 40.0, y: 30.0 },
PathSegment::LineTo { x: 40.0, y: 50.0 },
PathSegment::LineTo { x: 60.0, y: 50.0 },
PathSegment::ClosePath
);
test!(all_segments_1, "M 10 20 L 30 40 H 50 V 60 C 70 80 90 100 110 120 S 130 140 150 160
Q 170 180 190 200 T 210 220 A 50 50 30 1 1 230 240 Z",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 30.0, y: 40.0 },
PathSegment::LineTo { x: 50.0, y: 40.0 },
PathSegment::LineTo { x: 50.0, y: 60.0 },
PathSegment::Bezier {
cp1x: 70.0, cp1y: 80.0,
cp2x: 90.0, cp2y: 100.0,
x: 110.0, y: 120.0,
},
PathSegment::Bezier {
cp1x: 130.0, cp1y: 140.0,
cp2x: 130.0, cp2y: 140.0,
x: 150.0, y: 160.0,
},
PathSegment::Quadratic {
cpx: 170.0, cpy: 180.0,
x: 190.0, y: 200.0,
},
PathSegment::Quadratic {
cpx: 210.0, cpy: 220.0,
x: 210.0, y: 220.0,
},
PathSegment::SvgArc {
radius_x: 50.0, radius_y: 50.0,
rotation: 30.0,
large_arc: true, sweep: true,
x: 230.0, y: 240.0
},
PathSegment::ClosePath
);
test!(all_segments_2, "m 10 20 l 30 40 h 50 v 60 c 70 80 90 100 110 120 s 130 140 150 160
q 170 180 190 200 t 210 220 a 50 50 30 1 1 230 240 z",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 40.0, y: 60.0 },
PathSegment::LineTo { x: 90.0, y: 60.0 },
PathSegment::LineTo { x: 90.0, y: 120.0 },
PathSegment::Bezier {
cp1x: 160.0, cp1y: 200.0,
cp2x: 180.0, cp2y: 220.0,
x: 200.0, y: 240.0,
},
PathSegment::Bezier {
cp1x: 220.0, cp1y: 260.0, //?
cp2x: 330.0, cp2y: 380.0,
x: 350.0, y: 400.0,
},
PathSegment::Quadratic {
cpx: 520.0, cpy: 580.0,
x: 540.0, y: 600.0,
},
PathSegment::Quadratic {
cpx: 560.0, cpy: 620.0, //?
x: 750.0, y: 820.0
},
PathSegment::SvgArc {
radius_x: 50.0, radius_y: 50.0,
rotation: 30.0,
large_arc: true, sweep: true,
x: 980.0, y: 1060.0
},
PathSegment::ClosePath
);
test!(close_path_1, "M10 20 L 30 40 ZM 100 200 L 300 400",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 30.0, y: 40.0 },
PathSegment::ClosePath,
PathSegment::MoveTo { x: 100.0, y: 200.0 },
PathSegment::LineTo { x: 300.0, y: 400.0 }
);
test!(close_path_2, "M10 20 L 30 40 zM 100 200 L 300 400",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 30.0, y: 40.0 },
PathSegment::ClosePath,
PathSegment::MoveTo { x: 100.0, y: 200.0 },
PathSegment::LineTo { x: 300.0, y: 400.0 }
);
test!(close_path_3, "M10 20 L 30 40 Z Z Z",
PathSegment::MoveTo { x: 10.0, y: 20.0 },
PathSegment::LineTo { x: 30.0, y: 40.0 },
PathSegment::ClosePath,
PathSegment::ClosePath,
PathSegment::ClosePath
);
// first token should be EndOfStream
test!(invalid_1, "M\t.", );
// ClosePath can't be followed by a number
test!(invalid_2, "M 0 0 Z 2",
PathSegment::MoveTo { x: 0.0, y: 0.0 },
PathSegment::ClosePath
);
// ClosePath can be followed by any command
test!(invalid_3, "M 0 0 Z H 10",
PathSegment::MoveTo { x: 0.0, y: 0.0 },
PathSegment::ClosePath,
PathSegment::LineTo { x: 10.0, y: 0.0 }
);
}

View file

@ -0,0 +1,162 @@
// Copyright 2018 the SVG Types Authors
// Copyright 2025 the Servo Authors
// SPDX-License-Identifier: Apache-2.0 OR MIT
use crate::svgpath::Error;
/// A streaming text parsing interface.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub struct Stream<'a> {
text: &'a str,
pos: usize,
}
impl<'a> From<&'a str> for Stream<'a> {
#[inline]
fn from(text: &'a str) -> Self {
Stream { text, pos: 0 }
}
}
impl<'a> Stream<'a> {
/// Returns the current position in bytes.
#[inline]
pub fn pos(&self) -> usize {
self.pos
}
/// Sets current position equal to the end.
///
/// Used to indicate end of parsing on error.
#[inline]
pub fn jump_to_end(&mut self) {
self.pos = self.text.len();
}
/// Checks if the stream is reached the end.
///
/// Any [`pos()`] value larger than original text length indicates stream end.
///
/// Accessing stream after reaching end via safe methods will produce
/// an error.
///
/// Accessing stream after reaching end via *_unchecked methods will produce
/// a Rust's bound checking error.
///
/// [`pos()`]: #method.pos
#[inline]
pub fn at_end(&self) -> bool {
self.pos >= self.text.len()
}
/// Returns a byte from a current stream position.
#[inline]
pub fn curr_byte(&self) -> Result<u8, Error> {
if self.at_end() {
return Err(Error);
}
Ok(self.curr_byte_unchecked())
}
/// Returns a byte from a current stream position.
///
/// # Panics
///
/// - if the current position is after the end of the data
#[inline]
pub fn curr_byte_unchecked(&self) -> u8 {
self.text.as_bytes()[self.pos]
}
/// Checks that current byte is equal to provided.
///
/// Returns `false` if no bytes left.
#[inline]
pub fn is_curr_byte_eq(&self, c: u8) -> bool {
if !self.at_end() {
self.curr_byte_unchecked() == c
} else {
false
}
}
/// Returns a next byte from a current stream position.
#[inline]
pub fn next_byte(&self) -> Result<u8, Error> {
if self.pos + 1 >= self.text.len() {
return Err(Error);
}
Ok(self.text.as_bytes()[self.pos + 1])
}
/// Advances by `n` bytes.
#[inline]
pub fn advance(&mut self, n: usize) {
debug_assert!(self.pos + n <= self.text.len());
self.pos += n;
}
/// Skips whitespaces.
///
/// Accepted values: `' ' \n \r \t`.
pub fn skip_spaces(&mut self) {
while !self.at_end() && matches!(self.curr_byte_unchecked(), b' ' | b'\t' | b'\n' | b'\r') {
self.advance(1);
}
}
/// Consumes bytes by the predicate.
pub fn skip_bytes<F>(&mut self, f: F)
where
F: Fn(&Stream<'_>, u8) -> bool,
{
while !self.at_end() {
let c = self.curr_byte_unchecked();
if f(self, c) {
self.advance(1);
} else {
break;
}
}
}
/// Slices data from `pos` to the current position.
#[inline]
pub fn slice_back(&self, pos: usize) -> &'a str {
&self.text[pos..self.pos]
}
/// Skips digits.
pub fn skip_digits(&mut self) {
self.skip_bytes(|_, c| c.is_ascii_digit());
}
#[inline]
pub(crate) fn parse_list_separator(&mut self) {
if self.is_curr_byte_eq(b',') {
self.advance(1);
}
}
// By the SVG spec 'large-arc' and 'sweep' must contain only one char
// and can be written without any separators, e.g.: 10 20 30 01 10 20.
pub(crate) fn parse_flag(&mut self) -> Result<bool, Error> {
self.skip_spaces();
let c = self.curr_byte()?;
match c {
b'0' | b'1' => {
self.advance(1);
if self.is_curr_byte_eq(b',') {
self.advance(1);
}
self.skip_spaces();
Ok(c == b'1')
},
_ => Err(Error),
}
}
}