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
);
test!(invalid_1, "M\t.", );
test!(invalid_2, "M 0 0 Z 2",
PathSegment::MoveTo { x: 0.0, y: 0.0 },
PathSegment::ClosePath
);
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 }
);
}